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  • Tropical Skin Diseases Research Column
    ZHANG Shu, ZHOU Mengshi, LI Rui, GENG Yuanyuan, ZHAO Fei, HE Lihua, GONG Jie
    China Tropical Medicine. 2023, 23(8): 783-789. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.01

    Objective To screen out a more universally applicable culture medium for the isolation and culturing of pathogenic fungi through comparing the performance of various universal fungal culture media, to optimize the fungal culturomics technique, and to better apply it to the culturomics research of pathogenic fungi. Methods Multiple common fungal culture media Sabouraud dextrose agar (SDA), potato dextrose agar (PDA), modified Dixon (mDixon), modified Leeming-Notman agar (MLNA), etc., and a new pan-fungal medium (PF) were used to culture 40 strains of common pathogenic fungi to to determine the growth states of strains under different conditions. Based on that, PF, SDA, PDA, mDixon and MLNA, a total of 5 culture media, were used to isolate and culture a simulated sample (suspension of Candida albicans and Aspergillus fumigatus), 10 human samples (4 fecal samples and 6 vaginal secretion samples) and 3 environmental samples. Results The positive growth rates of 40 strains of pathogenic fungi in the 7 media were as follows: PDA 95.0% (38/40), SDA 95.0% (38/40), BHI 95.0% (38/40), YPD 90.0% (36/40), mDixon 95.0% (38/40), MLNA 87.5% (35/40), PF 100.0% (40/40). For the simulated samples, PF could effectively promote the self-limited growth of filamentous fungi, performing better in isolation and culture. For the human samples and environmental samples, PF showed the same versatility as SDA and PDA. Conclusions In the isolation and culturing of pathogenic fungi, PF medium can effectively isolate and culture most fungal species. Meanwhile, PF can make the fast-growing fungi show self-limited growth and clear edges, and not easy to cross-contamination, which indicates it is conducive to the isolation and identification of single colonies. PF medium outperforms other common media in isolating strains from unknown samples in culturomics, which illustrates PF medium can be effectively used for the study of fungal culturomics.

  • Articles
    LIANG Shuang, JIANG Yiwen, YANG Guiling, ZHANG Qi, TANG Shimiao, CAO Hongwei, QI Wei
    China Tropical Medicine. 2023, 23(9): 906-910. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.03

    Objective To evaluate the application of TB laboratory detection technology in Liaoning Province from 2016 to 2022, and to provide scientific basis for further improving the detection rate of Mycobacterium tuberculosis in the province. Methods The medical records of registered tuberculosis patients in Liaoning Province from 2016 to 2022 were collected from the "Tuberculosis Information Management System" in the "China Disease Prevention and Control Information System" subsystem. Statistical analysis was performed for sputum coating, sputum culture, and molecular biology testing. Results From 2016 to 2022, a total of 152 778 patients with pulmonary tuberculosis were registered in Liaoning Province. The detection rate of sputum smear microscopy was 98.03% (149 775/152 778), the detection rate of sputum culture was 20.72% (31 661/152 778), and the detection rate of molecular biology testing was 20.21% (30 737/152 778). From 2018 to 2022, the rate of molecular biological detection showed an increasing trend (χ2trend=7 104.466, P<0.01), while from 2016 to 2021, the detection rate of sputum culture showed an increasing trend, with statistical significance (χ2trend=3,068.701, P<0.01). The sputum smear detection rate showed a downward trend(χ2trend=689.913, P<0.01).. There were significant differences in the results of sputum smear microscopy, sputum culture, and molecular biology testing, as confirmed by the McNemar test (P<0.01). The positive rate of pathogenic academics increased from 26.27% in 2016 to 51.55% in 2022, showing a yearly upward trend (χ2trend=5 262.863, P<0.01), with significant differences between each year (χ2=5 686.935, P<0.01). Among pulmonary tuberculosis patients with positive pathogenic microorganisms, the proportion of sputum smear-positive cases decreased from 94.32% to 52.36%, showing a downward trend (χ2trend=5 010.104, P<0.01). The proportion of culture-positive cases increased from 5.68% in 2016 to 12.83% in 2022, showing an upward trend (χ2trend=122.501, P<0.01). In Liaoning Province, molecular biology testing has been carried out since 2018, and the proportion of molecular biology-positive cases increased from 11.51% to 34.81%, showing an increasing trend (χ2trend=1 969.326, P<0.01). The number of positive patients in molecular biological tests in municipal hospitals accounted for 18.69% (8 386/44 778) of etiological positive patients, while the number of positive patients in county-level hospitals accounted for 13.61% (2 439/17 924) of etiological positive patients, with significant differences (χ2=231.594, P<0.01). Conclusions The implementation of molecular biology testing for tuberculosis in Liaoning Province is one of the main measures to improve the positive rate of etiology, and it helps to diagnose tuberculosis patients timely and accurately

  • Research Reports
    ZHAO Yahong, ZHANG Shana, LI Yi, XU Junyue
    China Tropical Medicine. 2023, 23(9): 1007-1010. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.21

    Objective To report a case of suppurative knee arthritis caused by Pasteurella multocida and review relevant literature to improve the awareness of the clinical physicians regarding this bacterium and provide reference for clinical diagnosis and treatment. Methods A case of right knee suppurative arthritis caused by Pasteurella multocida was retrospectively reported and relevant literatures were reviewed in this article. Results The infected person was a 76-year-old female patient with a 5-year history of intermittent pain in his right knee and suffered from joint swelling, aggravation pain, and limited flexion and extension activities after intraarticular injection of sodium hyaluronate. After admission and completing all necessary tests, the patient was later confirmed to have been infected with Pasteurella multocida. The patient's right knee was promptly examined and cleared under arthroscopic surgery, synovium and meniscus were excised, a drainage tube was inserted, and continuous joint cavity irrigation was performed after the surgery, and then ceftriaxone was injected and amoxicillin/clavulanate potassium was taken orally for anti-infection and the patient's condition improved significantly after 26 days. Conclusions Pasteurella multocida infection cases are relatively rare, but the consequences in high-risk groups are relatively serious. Therefore, awareness of Pasteurella multocida and infection caused by it should be improved and high-risk groups should try to avoid contact with infectious sources as well as strengthen the management of pets so as to avoid infection.

  • Articles
    WEI Ling, SHAO Lingli, CHEN Ting, REN Juan, LIU Qingjun
    China Tropical Medicine. 2023, 23(9): 941-946. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.09

    Objective To investigate the impact of SARS-CoV-2 virus infection on the risk of thrombosis in COVID-19 outpatient patients with mild and regular symptoms. Methods Outpatient patients during the SARS-CoV-2 large-scale infection period after the policy adjustment for COVID-19 in Beijing in 2022 were selected as the observation group, and the dynamic zero-clearing period before the policy adjustment and outpatient patients during the 2022/2021/2020 period were taken as the three control groups. The patients with physiological factors that may increase the risk of coagulation, such as thrombotic diseases, malignant tumors, female pregnancy and other physiological factors, were excluded. Pediatric patients under 14 years old were also excluded. Age was expressed as median (interquartile). The changes in blood routine, fibrin/fibrinogen degradation products, and D-Dimer in Beijing outpatient patients were studied with statistical method and data analysis techniques. Results Compared with the control groups, the observation group showed a statistically significant decrease in red blood cells (RBC), hemoglobin (Hb), and hematocrit (HCT) levels, and an increase in monocytes (MONO) and platelet (PLT) counts, all showed statistically significant differences (P<0.0001). The proportion of fibrinogen degradation product (FDP) and D-Dimer of observation group exceeding the range increased significantly. Compared with the three control groups, the number of outpatient fibrinogen degradation products (FDP) in the observation group of patients aged 50 years and or older increased by 171%-793%, and the number of patients aged below 50 years increased by 791%-2 068%. The monthly average number of patients under 50 years old in the observation group with D-Dimer exceeding the threshold increased by more than 48.98%, and the monthly average number of patients with D-Dimer exceeding the threshold in patients aged 50 or older increased by 346%-998%. Conclusions The results of this study suggest that outpatient patients with mild or regular SARS-CoV-2 infection are also at risk for thrombotic events, and monitoring blood coagulation indicators such as D-dimer is recommended to avoid the sudden onset of thrombosis-related fatal complications.

  • Articles
    WANG Jieying, CHEN Zhuolin, XU Yuni, YU Chunchun, KONG Fanrong, CHEN Qiong, ZHONG Yeteng
    China Tropical Medicine. 2023, 23(9): 947-953. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.10

    Objective To identify the species of Mycobacteroides abscessus complex (MABC) in patients with pulmonary infection from the Second Affiliated Hospital of Hainan Medical University, and to investigate the species types, drug sensitivity and population distribution of MABC in pulmonary infection in Hainan. Methods Respiratory tract specimens were collected from suspected tuberculosis patients who visited the Second Affiliated Hospital of Hainan Medical University from January 2014 to December 2021 and cultured for Mycobacterium isolation. Non-tuberculous mycobacteria (NTM) strains were preliminarily identified by p-nitrobenzoic acid/thiophen-2-carbohydrazide (PNB/TCH) medium and DNA microarray chip, and then MABC and its subspecies were identified by hsp65 and rpoB gene sequencing. In vitro antimicrobial susceptibility test was performed by broth microdilution method. Results A total of 3 025 respiratory specimens from suspected pulmonary tuberculosis patients were collected during the study period. Among the 123 patients with identified MABC isolates, 124 MABC strains were isolated and identified, including 74 strains of Mycobacteroides abscessus subsp. abscessus, 38 strains of Mycobacteroides abscessus subsp. massiliense and 12 strains of Mycobacteroides abscessus subsp. bolletii. Among them, 118 patients had single MABC subspecies infection, one patient had mixed infection with two MABC subspecies, two patients had mixed infection with MABC and other NTM, and two cases had mixed infection with MABC and M.tuberculosis. There were more female patients than male patients with a ratio of 1:0.64, and those aged 50 and above amounted to 76.42% (94/123, 95%CI: 67.93%-83.61%). There was no significant difference in age distribution between male and female patients (Z=-0.944, P=0.347). The drug susceptibility results showed that all MABC strains were sensitive to Tigecycline (TGC), with a resistance rate of 0.81% (1/124) to Amikacin (AK), and resistance rates of 6.45% (8/124), 32.26% (40/124), and 74.19% (92/124) to Cefoxitin (FOX), Linezolid (LZD), and Imipenem (IPM), respectively. For Clarithromycin (CLR), MABC showed induced resistance, and there was a statistically significant difference in the CLR (14D) resistance rates among the three subspecies (χ2=66.335, P<0.001). The resistance rates to Tobramycin (TOB), Doxycycline (DOX), Moxifloxacin (MFX), Ciprofoxacin (CIP), Trimethoprim/Sulfamethoxazole (TMP-SMX), and Amoxicillin/Clavulanic acid (AMC) were high, all >80%. Conclusion In Hainan Province, pulmonary infections with MABC are mainly caused by Mycobacteroides abscessus subsp. Abscessus, which show high rates of inducible resistance to CLR. Timely and accurate identification of MABC to subspecies and drug susceptibility testing are of significant important for clinical decision-making.

  • Articles
    ZHOU Yaowu, SUN Weijiang, TIAN Guangqiang, XU Jianwei, YANG Shiman, DING Chunli, DUAN Kaixia, TIAN Peng, SUN Xiaodong, LIN Zurui
    China Tropical Medicine. 2023, 23(9): 897-901. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.01

    Objective To compare the screening effects of RDT, microscopy and PCR for malaria among residents in low malaria areas and elimination areas, and to investigate the presence of malaria in residents of border Villages in Cangyuan Va County and asymptomatic infections in surrounding areas, providing a basis for preventing re-introduction of malaria after elimination. Methods From August 2020 to March 2021, the fingertip blood of the investigated subjects was collected from three survey sites in the border area between China and Myanmar, namely Banlao Township in Cangyuan Va Autonomous County of Lincang City, Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar, Yongmo and Dayan Township, Nandeng Special Zone, the Second Special Zone of Shan State, Myanmar. The malaria parasite antigen detection test kit, malaria parasite microscopic examination, fluorescent quantitative PCR and nested PCR were used to detect the asymptomatic infection of malaria parasites. Results A total of 1 040 blood samples were collected, including 606 from China and 434 from Myanmar, with 506 males and 534 females. Among them,, there were 51 individuals aged 0 to <5 years, 283 aged 5 to < years, 187 aged 15 to < years, 232 aged 30 to <45 years, 205 aged 45 to < years, and 82 aged ≥60 years. All 1 040 people tested negative for plasmodium antigen detection kit. One case of Plasmodium vivax detected by plasmodium microscopic etiology, with a detection rate of 0.10%. One case of P. vivax was also detected by fluorescent quantitative PCR and nested PCR, with a detection rate of 0.10%. Among them, one case of P. vivax was detected in Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar, with a detection rate of 0.35%. The detection rates of malaria parasites in Banlao Township in Cangyuan Va Autonomous County of Lincang City, Yunnan Province and Yongmo Township and Dayan Township, Nandeng Special District, the Second Special Zone of Shan State, Myanmar were both 0. The difference in the detection rate of malaria parasites among the three survey sites was not statistically significant (χ2=2.682, P>0.05). The asymptomatic P. vivax infection was detected in a 6-year-old girl from Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar. Conclusions RDT is not suitable for malaria screening in low malaria area and elimination area. Microscopic examination and PCR can be used for malaria screening, but PCR operation is complex and costly. In surrounding areas outside of China, malaria is still prevalent, while there is no source of malaria infection in border villages of Cangyuan Va County. However, there is a risk of importation, and timely and effective measures should be taken to prevent re-introduction and transmission.

  • Articles
    LIANG Dejuan, AN Liping, LI Yao, ZHAO Peizhen, GUAN Qingfeng, ZHAO Jianguo
    China Tropical Medicine. 2023, 23(9): 930-935. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.07

    Objective To understand the morphological characteristics and ultrastructure of the dominant species of Rhipicephalus sanguineus in Hainan at different developmental stages, and provide theoretical basis for the identification of the lineage and control of Rhipicephalus sanguineus. Methods The external morphology of different developmental stages of the dominant species of Rhipicephalus sanguineus, including larva, nymph and adult tick in Hainan were observed by scanning electron microscope. Results The division between each segment of larva pedipalps was not obvious, and setae was serrated; dental formula type 2 | 2; 3 pairs of podomere; a pair of setae on the anal valve; none of anal groove, spiracular plate, porous area and genital aperture. There was a clear boundary at the beginning of each segment of nymph pedipalps; dental formula type 2 | 2; 4 pairs of podomere; 3 pairs of setae on the anal valve; anal groove; none of porous area and genital aperture. The male adult tick's trichotheca are covered by the pedipalps, and the whole bristles are conical; dental formula type 3 | 3; 4 pairs of podomere; anal groove and paraprocts; 7 setae on the anal valve; genital aperture was oval. The female of adult tick can be distinguished by dental formula 3 | 3; pairs of podomere; porous areas with 3 short setae; anal groove; 4 pairs of setae and 2 pores on the anal valve; genital pore was broadly U-shaped. In addition, the male adult's scutum occupies almost the entire dorsal surface, the basis capituli of larva, nymph and adult tick all were hexagonal, and the existence of Haller's organ was found on the first pair of legs. Conclusions Scanning electron microscopy observation of the different developmental stages of R.sanguineus revealed clear morphological features, preliminarily suggesting that R.sanguineus in Hainan Province may belong to the tropical lineage, which provide a certain experimental basis for the identification of the tick and the comprehensive prevention and control of local tick-borne diseases.

  • Articles
    WANG Ting, WANG Jieying, WANG Yanshuang, CHEN Xiaojuan, CHEN Lin, CHEN Shaowen, LIAO Yan, LIN Chong
    China Tropical Medicine. 2023, 23(9): 922-929. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.06

    Objective To analyze the characteristics and corresponding drug resistance of pathogenic bacterial spectrum in eight major infection sites of hospitalized patients, and to provide epidemiological data for the rational selection of antibiotics in clinical practice. Methods A total of 396 bacterial strains isolated from clinical specimens of hospitalized patients in member institutions of the Hainan Provincial Bacterial Resistance Monitoring Network from September 1, 2020, to September 30, 2022, were included in this study. Data were screened and filtered from the database of MH120 Microbial Identification and Drug Sensitivity Analysis System based on the technical scheme of the National Bacterial Drug Resistance Surveillance Network and Science and Technology Basic Resources Investigation Project research plan in 2020. The testing data were integrated, summarized, and analyzed using EXCEL and WHONET 5.6 software, and statistical analysis was conducted using SPSS 26.0 software. Results Among of 396 strains of bacteria, 78 (19.7%) were isolated from respiratory tract specimens, 74 (18.7%) from urinary tract specimens, 72 (18.2%) from blood specimens, 54 (13.6%) from abdominal cavity specimens, 48 (12.1%) from skin and soft tissue specimens 48 strains (12.1%), 30 (7.6%) from reproductive tract specimens, 22 (5.6%) from central nervous system specimens, 18 (4.5%) from digestive tract specimens. Gram-negative bacteria accounted for 69.4% of the isolates, while gram-positive bacteria accounted for 30.6%. The top five gram-negative bacteria isolated were Klebsiella pneumoniae (14.9%), Escherichia coli (14.4%), Pseudomonas aeruginosa (10.4%), Acinetobacter baumannii (5.3%), and Salmonella species (4.5%). The top five gram-positive bacteria were Staphylococcus aureus (11.1%), Streptococcus agalactis (7.8%), Enterococcus faecalis (3.0%), Enterococcus faecium (2.8%), and Streptococcus suis (1.8%). Respiratory failure and bloodstream infection were independent influencing factors of treatment response (P<0.01). The resistance rate of Escherichia coli to ampicillin was 81.4%, and the resistance rate of Staphylococcus aureus to gentamicin and levofloxacin were both below 7%. Conclusions The pathogen spectra vary with different infection sites of patients, and rational selection of antibiotics based on drug susceptibility testing is crucial to shorten the treatment time of patients and avoid the unnecessary emergence of drug-resistant strains caused by drug abuse.

  • Tropical Skin Diseases Research Column
    LIU Fuming, HUANG Yaxin, DENG Yongqiong, XIONG Xia, OUYANG Yongliang
    China Tropical Medicine. 2023, 23(8): 801-806. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.04

    Objective To analyze and compare the differences in serum lipid metabolomics between patients with moderate to severe acne and healthy controls to understand the characteristics of serum lipid metabolism in acne patients.Methods Serum samples were collected from 30 patients with moderate to severe acne and 30 healthy controls matched for age, gender and body mass index in the Department of Dermatology, the Affiliated Hospital of Southwest Medical University from May 2019 to Apr. 2020. Serum lipid metabolomics was analyzed by liquid chromatography-tandem mass spectrometry. Partial least squares discriminant analysis (PLS-DA) was used for multivariate statistical analysis of differentially expressed lipid metabolites. The metabolic pathways with significant differences between the two groups were screened by Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Using Mann-Whitney U test to calculate differential metabolites. Spearman correlation analysis was used to analyze the correlation between serum PC (18:2e/20:2) concentration and acne severity. Results The PLS-DA results showed that the composition of serum lipid metabolites in acne patients was significantly separated from that in healthy controls. Of the top 30 lipid metabolites with the most significant differences, four kinds of triglycerides (TG), two kinds of diglycerides (DG), six kinds of phosphatidylcholine (PC), one kind of MePC, two kinds of sphingomyelin (SM), two kinds of phosphatidylinositol (PI), two kinds of ceramide (monohexosyl ceramide, Hex1Cer; dihexosyl ceramide, Hex2Cer), two cardiolipin (CL) were found to be increased in the acne group (P<0.05). The levels of one kind of DG, two kinds of lysophosphatidyl ethanolamines (LPE), one kind of dimethylphosphatidyl ethanolamine (dMePE), one kind of bismethyl phosphatidic acid (BisMePA), three kinds of phosphatidyl ethanolamine (PE) and one kind of ceramide were found to be decreased in the acne group (P<0.05), and most of them belonged to phospholipid metabolites. Spearman correlation analysis showed that serum PC (18:2e/20:2) concentration was positively correlated with acne severity (r=0.456, P=0.004). KEGG enrichment function analysis revealed that the differential lipid metabolites were primarily enriched in metabolic pathways such as sphingolipid signaling pathway, cholesterol metabolism, insulin resistance, glycerophospholipid metabolism, among which the sphingolipid signaling pathway may play an important role. Conclusion There are significant differences in serum lipid metabolism between acne patients and healthy controls. Lipid metabolism disorders may be related to the pathogenesis of acne, but it’s molecular mechanism still needs further experimental exploration.

  • Articles
    SHEN Jin, SUN Shaojun, MA Jun, YANG Qianyun, LIU Qingyang, WANG Qiubo
    China Tropical Medicine. 2023, 23(9): 988-993. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.17

    Objective To investigate the molecular characteristics and drug resistance of Staphylococcus aureus (SA) isolated from wounds of paatients with orthopedic trauma, and analyze the molecular subtyping, virulence genes and drug resistance of SA in wounds of patients, so as to provide reference for the prevention and treatment of wound SA infection in patients. Methods From January 2020 to June 2022, a total of 128 SA isolates were collected from wound specimens of orthopedic trauma patients at Wuxi 9th People's Hospital Affiliated to Soochow University. Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) were differentiated using PCR. Multilocus Sequence Typing (MLST), staphylococcal protein A (spa), staphylococcal chromatoidal cassette mec (SCCmec), and accessory gene regulator (agr) typing were performed to determine the molecular typing and presence of virulence genes and drug resistance profiles. Results Among the 128 SA isolates, 76 (59.38%) were MRSA and 52 (40.62%) were MSSA. MRSA typing showed that, MLST was dominated by ST59 (46 strains, 60.53%), spa was dominated by t437 (52.63%), SCCmec was dominated by Ⅰ (42.11%) and Ⅳ (39.47%). MSSA typing showed that, MLST was dominated by ST188 (30.77%), spa was dominated by t189 (61.54%), agr was dominated by Ⅰ (53.85%). In MLST typing, ST59 of MRSA was higher than that of MSSA, and ST188 and ST6 of MRSA were lower than those of MSSA (χ2=36.207, 20.227, 9.984, P<0.05). In spa typing, the t437 of MRSA was higher than that of MSSA, and the t189 of MRSA was lower than that of MSSA (χ2=18.276, 32.781, P<0.05). The virulence genes showed that, the detection rates of hlb and seb in MRSA were higher than those in MSSA (χ2=47.838, 10.261, P<0.05), and the detection rates of cna and ebpS in MRSA were lower than those in MSSA (χ2=26.176, 8.305, P<0.05). Drug susceptibility test showed that, and the drug resistance rates of MRSA and MSSA to vancomycin (VAN) and linezolid (LNZ) were 0. The drug resistance rates of MRSA to oxacillin (OXA), ERY and CLI were 86.84%, 68.42% and 76.32%, which were higher than corresponding 7.69%, 42.31% and 46.15% of MSSA (χ2=78.055, 8.623, 12.200, P<0.05). The analysis of multi-drug resistant strains (MDR) showed that 76 MRSA strains were MDR strains, and 12 of 52 MSSA strains (23.08%) were MDR strains. Conclusions The molecular characteristics of SA isolated from orthopedic trauma patients' wounds were predominantly associated with MRSA strains of ST59-t437-SCCmec Ⅰ/Ⅳ-MRSA and ST188/ST6-t189-agr Ⅰ. These strains showed higher resistance to oxacillin, erythromycin, clindamycin, and higher susceptibility to vancomycin and linezolid. Such characteristics were closely related to the carriage of virulence genes. Clinicians should pay attention to the presence of MDR MSSA and develop appropriate antimicrobial strategies based on SA's molecular characteristics and antimicrobial resistance.

  • Articles
    QI Xiaoqi, OU Jianming, CHEN Wu, CAI Shaojian, XIE Zhonghang, WU Shenggen, ZHENG Kuicheng
    China Tropical Medicine. 2023, 23(9): 902-905. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.02

    Objective To analyze the epidemiological characteristics of viral hepatitis E in Fujian Province from 2012-2021, and to provide scientific evidence for the prevention and control of hepatitis E in the future. Methods Descriptive epidemiological method was used to analyze hepatitis E cases in Fujian Province from 2012 to 2021. Results From 2012 to 2021, a total of 8 877 cases of hepatitis E were reported in Fujian Province from 2012-2021. The overall incidence rate showed a decreasing trend (χ2trend =458.14, P<0.001), with the lowest incidence rate of 1.32/100 000 in 2020 and an annual average incidence rate of 2.29/100 000 per year. The incidence was higher in winter and spring, with the months of March and April having the highest number of reported cases (2 146, 24.17%) and the fewest cases were reported in September (571, 6.43%). The difference in reported incidence rates between cities was statistically significant (χ2=1 877.75, P<0.01). The comprehensive experimental zone of Pingtan had the highest average reported incidence rate of 6.03/100 000, while Zhangzhou had the lowest at 0.94/100 000. The number of male cases was higher than the number of female cases, with a male to female ratio of 2.04∶1. The disease was most prevalent among middle-aged and elderly individuals, with the age group of 40-<65 years having the highest number of reported cases, accounting for 57.44% (5 099/8 877) of all cases. The age group of 50-<55 years had the highest reported incidence, with the number of reported cases increasing with age below 50 years, but decreasing with age over 50 years. As for occupational distribution, peasants had the highest proportion of the disease, accounting for 34.49% (3 062 cases) of the total cases. Conclusions The reported incidence rate of hepatitis E in Fujian showed a downward from 2012 to 2021. Due to the impact of COVID-19, incidence of the lowest was 2020, but it did not reflect the true situation of the disease, which may have affected trend of hepatitis E. In order to control and reduce the incidence of hepatitis E, efforts should be made to increase publicity and education on health knowledge and vaccination among key areas and populations, strengthen monitoring and diagnostic capability, and implement comprehensive prevention and control measures.

  • Research Reports
    WANG Mengbin, QI Yunxia
    China Tropical Medicine. 2023, 23(9): 1002-1006. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.20

    Bartter syndrome (BS) is a kind of inherited metabolic disease characterized by electrolyte and endocrine disorder, resulting from genetic gene mutation or deletion. Clinically, it manifests as vomiting, constipation, feeding difficulties, weight loss, growth retardation. The laboratory examination shows hypokalemia, metabolic alkalosis, hyperreninemia, aldosteronism, etc. As an autosomal recessive genetic disease, BS has an extremely low incidence rate, making diagnosis and treatment quite challenging. In recent years, with the progress of gene detection and other technologies, China has made great progress in the study of BS, more and more BS has been diagnosed accurately. According to known gene mutation types, it can be divided into type 1, type 2, type 3, type 4, type 5 and Gitelman syndrome, a total of 6 types, with type 4 further divided into type 4a and type 4b. At present, the most common type of children with BS in clinical practice is type 3, which is the classic type of BS. This paper reports a case of Bartter syndrome type 4b (BS4b). After two rounds of three-generation family gene sequencing, it was discovered that the infant had a combined mutation of both the CLCNKA and CLCNKB alleles, in addition to Alport syndrome, and both parents were carriers of this type of gene defect. The child was finally diagnosed as BS4b and Alport syndrome. This report, combined with the patient's clinical features, diagnosis and treatment process, as well as related literature analysis, aims to provide experience for understanding and diagnosis and treatment of this disease.

  • Articles
    LI Xionghui, LI Daijun, ZHOU Wenwu, LIU Jun, HE Qi
    China Tropical Medicine. 2023, 23(9): 983-987. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.16

    Objective To analyze the correlation between the thromboelastography (TEG) indexes and the indexes related to liver injury in patients with heat stroke, and explore the diagnostic value of TEG indexes for liver injury in patients with heat stroke. Methods A total of 95 patients with exertional heat stroke (EHS) admitted to 924 Hospital of the Joint Service Support Force of the People's Liberation Army of China from August 2020 to July 22 were selected, and divided into a non-liver injury group (55 cases) and a liver injury group (40 cases) according to whether there was liver injury. TEG instrument was used for the detection of thromboelastography to record the TEG parameters, including reaction time (R), agglutination time (K), α angle, maximum amplitude (MA value), and coagulation complex index (CI). The levels of glutamic transaminase (AST), alanine aminotransferase (ALT), total bilirubin (TBil), albumin (ALB) were detected by automatic biochemical analyzer. Pearson's method was applied to analyze the correlation between thromboelastography indexes R, K, α angle, CI and liver function indexes AST, ALT, TBil, ALB in patients with heat stroke after liver injury. Receiver operating characteristic curve (ROC) was applied to analyze the predictive value of thromboelastography indexes R, K, α angle, CI and combined detection for liver injury in patients with heat stroke. Results Compared with the non-liver injury group, the AST, ALT and TBil levels in patients with heat stroke in the liver injury group were higher (t=26.174, 16.923, 18.414, P<0.05), while the ALB level was lower (t=24.596, P<0.05); compared with the non-liver injury group, the R and K of patients with heat stroke in the liver injury group were higher (t=58.014, 52.862, P<0.05), and the α angle and CI were lower (t=46.853, 60.717, P<0.05); R was positively correlated with AST and ALT (r=0.532, 0.610, P<0.001), and negatively correlated with ALB (r=-0.551, P<0.001) in patients with heat stroke complicated with liver injury; K was positively correlated with AST, ALT and TBil (r=0.661, 0.531, 0.504, P<0.001); α angle was negatively correlated with AST and ALT (r=-0.473, -0.448, P<0.01), and positively correlated with ALB (r=0.539, P<0.001); CI was negatively correlated with AST, ALT and TBil (r=-0.458, -0.505, -0.549, P<0.001); the area under the curve (AUC) of thromboelastography indexes R, K, α angle and CI in predicting liver injury in patients with heat stroke was 0.807 (sensitivity of 70.0%, specificity of 81.6%), 0.831 (sensitivity of 77.5%, specificity of 85.5%), 0.747 (sensitivity of 67.5%, specificity of 74.5%), and 0.788 (sensitivity of 77.5%, specificity of 83.6%), respectively. The AUC of combined detection to predict liver injury in patients with heat stroke was 0.967 (sensitivity of 92.5%, specificity of 91.9%). Conclusions The thromboelastography indexes are correlated with the indexes related to liver injury in patients with heat stroke, and the thromboelastography indexes are helpful to diagnose liver injury in patients with heat stroke.

  • Articles
    ZHENG Gezhi, DU Juan, WEN Juan, ZHANG Liang, HE Yingli
    China Tropical Medicine. 2023, 23(9): 954-960. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.11

    Objective To determine the rate of nasal carriage Staphylococcus aureus among healthcare workers in Department of Infectious Diseases department of the First Affiliated Hospital of Xi'an Jiaotong University Hospital, and to perform characterization on isolated strains. Methods A cross-sectional study was performed on 86 healthcare workers from February 2022 to June. Nasal swabs were collected from the healthcare workers, and S. aureus were identified after incubation. Antibiotic susceptibility, including chlorhexidine and mupirocin, was assessed by disk diffusion and minimal inhibitory concentration method. The PCR technique was used to detect the biocide resistance genes (qacAB, smr, lmrS mepA, and sepA), virulence genes (pvl, fnbA/fnbB, sea, seb, sec, sed, tst, eta, etb) and mecA gene. SCCmec typing and multilocus sequence typing was performed. For mupirocin-resistant strains, PCR amplification and sequencing were used to identify whether the strains had ileS gene mutations or carried resistant genes (mupA and mupB). Results S. aureus was isolated from 37 of the 86 healthcare workers (43.02%), including 13 methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains showed low resistance rates to levofloxacin (2.70%, 1/37), chloramphenicol (8.11%, 3/37), tetracycline (8.11%, 3/37), gentamicin (10.81%, 4/37), and ciprofloxacin (10.81%, 4/37). A total of 17 strains were identified as multidrug-resistant strains. Four SCCmec types were identified in MRSA strains, with the type II being the most frequent (53.85%, 7/13), followed by type IV (30.77%, 4/13). ST59 (46.15%, 6/13) was the most frequent among MRSA strains, while ST5 (41.67%, 10/24) was the most frequent among methicillin-susceptible S. aureus (MSSA) strains. sea was the most frequent virulence gene (56.76%, 21/37). sepA and mepA were detected in all 37 isolates. One Staphylococcus aureus strain was not sensitive to chlorhexidine, two strains had the missense mutation V588F (G1762T) and showed low level resistance to mupirocin, and one strain carrying mupA gene was highly resistant to mupirocin. Conclusion The nasal colonization rate of Staphylococcus aureus among healthcare worker in the investigated hospital was high, indicating a risk for nosocomial infections. Strengthened monitoring and decolonization treatment should be carried out to reduce these risks.

  • Articles
    LIANG Tong, LIU Ying, LI Youxia, CAI Shuijiang, HUANG Huang, LIU Yongjin, DU Shuhua, LAI Wenjiao, DENG Xilong
    China Tropical Medicine. 2023, 23(9): 961-965. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.12

    Objective To investigate the clinical features and risk factors for severe tsutsugamushi disease, so as to provide reference for diagnosis and differentiation of severe tsutsugamushi disease as soon as possible. Methods The clinical data of 178 cases of inpatients with tsutsugamushi disease admitted to the Guangzhou Eighth People's Hospital, Guangzhou Medical University from January 2016 to September 2021 were collected and analyzed according to their gender, age, underlying diseases, clinical characteristics at admission, laboratory examination results within 24 hours of admission and epidemiological history. The patients were divided into the severe group and the non-severe group according to the diagnostic criteria. The data of clinical characteristics, laboratory examination and prognosis of the two groups were compared. Multivariate logistic regression analysis was performed on the variables with statistical significance and the receiver operating characteristic curve (ROC) was drawn. Results A total of 178 patients were included in this study, with 37 in the severe group and 141 in the non-severe group. Compared with the non-severe group, the age of the severe group was older, the underlying diseases were more, the incidence of dyspnea and the levels of white blood cell, total bilirubin, aspartate aminotransferase, lactate dehydrogenase, cystatin C, uric acid and serum creatinine were significantly increased, the levels of platelet and albumin were significantly decreased (all P<0.05). The dyspnea [odds ratio (OR value)=8.93, 95% confidence interval (CI): 1.200-66.424; P=0.032], total bilirubin (OR=1.091, 95%CI: 1.028-1.159; P=0.004) and serum creatinine (OR=1.052, 95%CI: 1.004-1.102; P=0.033) were independent risk factors for severe tsutsugamushi disease. The area under ROC curve of total bilirubin and serum creatinine were 0.777 and 0.764, respectively (both P<0.01), indicating high predictive value for severe tsutsugamushi disease. The optimal cut-off value for total bilirubin was 23.01 µmol/L, with a sensitivity of 54.10% and a specificity of 90.60%; the optimal cut-off value for creatinine was 126.45 µmol/L, with a sensitivity of 43.20% and a specificity of 100.00%. The case fatality rate of severe tsutsugamushi disease was 2.70%. Conclusions The patients with severe tsutsugamushi disease are older, and have more underlying diseases. Dyspnea, increased total bilirubin and elevated serum creatinine are independent risk factors for severe tsutsugamushi disease, which can help in the early identification of severe tsutsugamushi disease early.

  • Case Report
    WENG Shenghui, SONG You, LIU Xiaojing, HU Hui, DU Rong
    China Tropical Medicine. 2023, 23(8): 893-896. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.20

    To report on two patients with Coronavirus Disease 2019 (COVID-19) combined with diffuse connective tissue disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection followed for nearly 3 years, in order to understand the long-term effects on the patients' immune system. Both patients were male, aged 81-82 years, and were hospitalized with fever on January 29, 2020 and February 10, 2020, respectively. Both were diagnosed with COVID-19 after positive SARS-CoV-2 polymerase chain reaction (PCR) tests. After receiving anti-infection treatment, cough suppressants, expectorants, and symptomatic supportive treatment, their body temperature returned to normal and two consecutive PCR tests were negative for SARS-CoV-2, and they were discharged from hospital. However, due to recurring fevers and varying degrees of rheumatic disease-related symptoms, both patients were readmitted to the hospital, indicating the presence of positive autoantibodies and organ involvement. One patient recovered from COVID-19 with recurrent fever, joint pain, muscle aches and subcutaneous nodules, and was subsequently diagnosed with undifferentiated connective tissue disease. The other patient developed recurrent fever, mouth ulcers and rash after recovery from COVID-19 and was subsequently diagnosed with anti neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV). The patient was treated with glucocorticoids and immunosuppressive drugs and the symptoms resolved rapidly and subsequent laboratory and imaging examinations showed stable condition. However, due to self-termination of medication, their symptoms quickly relapsed, and further treatment with glucocorticoids and immunosuppressive agents resulted in sustained stability of their condition. The erythrocyte sedimentation rate and hypersensitive C-reactive protein remained within normal limits, and lung CT scans showed stable lesions with partial absorption. SARS-CoV-2 infection may have long-term effects on patients' immune systems, leading to abnormal immune responses and diffuse connective tissue disease. This suggests that regular follow-up observation of immune system-related diseases may be necessary for elderly patients with COVID-19.

  • Articles
    LIN Yongtong, MAI Shikang, HUANG Long, LI Yonghua, WANG Guanyu, CHEN Licui
    China Tropical Medicine. 2023, 23(7): 748-753. https://doi.org/10.13604/j.cnki.46-1064/r.2023.07.13

    Objective To analyze the accuracy and feasibility of GeneXpert MTB/RIF (GeneXpert) detection in the detection of Mycobacterium tuberculosis and the characteristics of rifampicin-resistant rpoB gene mutations. Methods A total of 4 234 sputum samples from suspected tuberculosis patients diagnosed in Sanya tuberculosis designated hospitals from 2015 to 2021 were selected and subjected to sputum smear, solid culture, drug sensitivity test by solid proportion method and GeneXpert detection. Results The positive detection rates of sputum smear, solid culture and GeneXpert of 4 234 sputum samples were 29.24% (1 238/4 234), 32.17% (1 362/4 234) and 35.40% (1 499/4 234), respectively. The positive detection rate of GeneXpert was higher than that of sputum smear, and the difference was statistically significant (χ2=36.775, P<0.01). It was slightly higher than solid culture, and the difference was not statistically significant (χ2=9.908, P=0.02). Taking solid culture results as the gold standard, the sensitivity and specificity of GeneXpert for detecting MTB were 91.04% (1 240/1 362) and 90.98% (2 613/2 872), respectively. According to the proportional drug susceptibility test results as the gold standard, the sensitivity and specificity of GeneXpert in detecting rifampicin resistance were 96.96% (96/99) and 98.86% (1 128/1 141), respectively, with the consensus rate of 98.71%. The accuracy of rifampicin resistance in GeneXpert group without probe mutation was significantly lower than that in group with probe mutation. There was a statistical difference in probe mutation frequency between newly treated and retreated cases. The analysis of rpoB gene mutation frequency characteristics showed: Probe E (50.00%) > Probe A (22.12%) > Probe D (14.42%) > Probe B (6.73%) > combined probe (5.77%) > Probe C (0.96%). Conclusions GeneXpert detection can quickly and effectively diagnose rifampicin-resistant tuberculosis, which is helpful for early clinical diagnosis and treatment. In this region, the rpoB gene mutation probes of rifampicin-resistant tuberculosis mainly occurr in Probe E and Probe A, with the least mutations in Probe C.

  • Articles
    HUANG Jinping, LI Yanjun, LI Xiangqing, LU Xiaoyan, LIU Shuaifeng, QIAO Shan, DONG Wenyi, SHEN Zhiyong
    China Tropical Medicine. 2023, 23(9): 911-915. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.04

    Objective To explore the dynamic characteristics of stigmatization in HIV/AIDS patients and provide scientific evidence for psychological care. Methods HIV/AIDS patients receiving antiretroviral therapy (ART) treatment in Nanning Fourth People's Hospital were randomly selected for baseline and 1 year follow-up questionnaire survey including internalized HIV stigma, anticipated HIV stigma, exposure to HIV stigma. The differences between the two groups at different time points were dynamically compared to analyze the changing characteristics of stigma in HIV/AIDS patients. Results After one year of ART treatment, among the eight items of internalizing stigma, five items including the proportion of feeling ashamed of being infected with HIV/AIDS, feeling unclean because of being infected with HIV/AIDS, feeling inferior to others because of having HIV/AIDS, feeling guilty because of having HIV/AIDS, and having a poorer self-perception due to how others view HIV/AIDS decreased significantly from 34.0% to 43.5% at the baseline to 19.5% to 29.5%, showing significant improvement with statistical significance (χ2=18.586, 14.277, 10.473, 12.219, 9.934, P<0.05); among the nine items of anticipated stigma, four items including the proportion of community/community workers not taking my needs seriously, discriminating against me, refusing to provide services for me, and healthcare workers avoiding contact with me decreased significantly from 16.0% to 27.5% at the baseline to 7.0% to 15.5%, respectively, showing significant improvement with statistical significance (χ2=13.690, 15.787, 12.034, 12.593, P<0.05); among the 16 items of exposure to HIV stigma, six items including the proportion of experiencing physical attacks, psychological pressure from spouses/partners, being refused sexual relationships, losing jobs or other economic sources, being rejected or losing a job opportunity due to HIV/AIDS, changing job nature due to HIV/AIDS, or being refused medical services decreased significantly from 2.5% to 15.0% at the baseline to 1.0% to 8.0%, respectively, showing significant improvement with statistical significance (χ2=8.619, 15.558, 6.061, 9.049, 5.432, 8.156, P<0.05). Physical assaults on people with HIV/AIDS increased by 5.5 percent(χ2=5.368, P<0.05). Conclusions Through 1-year dynamic monitoring, 48.48% of the three dimensions of stigma of HIV/AIDS patients were alleviated. Treatment intervention, self-acceptance and the creation of a good non-discriminatory social environment have an important impact on the stigma of HIV/AIDS patients and deserve the attention of society as a whole.

  • Articles
    LONG Yongyan, LONG Hui, FAN Guoyin, XUE Lin, SHUAI Shufen, WANG Wei, WU Kui
    China Tropical Medicine. 2023, 23(9): 936-940. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.08

    Objective To understand the contamination status, drug resistance, virulence gene carrying status, and molecular typing characteristics of Vibrio parahaemolyticus (VP) in aquatic products sold in Nanchang City. Methods A total of 170 commercial crayfishes, freshwater fish frogs and related smears samples were collected from various farmers' markets in Nanchang from March to September 2021. The strains of V. parahaemolyticus were detected and isolated from the samples. Antibiotic resistance test, virulence gene test, and pulsed-field gel electrophoresis (PFGE) molecular typing analysis were carried out. Results Among the collected samples, V.parahaemolyticus was only isolated from crayfish and crayfish smear samples, with a total of 35 strains of VP isolated. No V.parahaemolyticus strain was isolated from other freshwater fish, frogs, and their smear samples. Among the 17 common antibiotics tested, only two trains showed resistance to ampicillin, and one strain to streptomycin,, and all were sensitive to other antibiotics; all 35 strains of V. parahaemolyticus carried the gene, but only one strain carried the heat-resistant related hemolysin gene trh, and no direct heat-resistant hemolysin gene tdh positive strain was found; PFGE pattern clustering showed that there was no strain with the same PFGE pattern, and there was no obvious dominant cluster among these strains, and their genetic relationship was relatively distant. Conclusions The contamination of V. parahaemolyticus in small and medium-sized crayfish sold in the market in Nanchang City is relatively serious. The V. parahaemolyticus isolates in these polluted crayfish generally do not carry key virulence genes such as tdh, are sensitive to common antibiotics, and only have low-level resistance to ampicillin and streptomycin. PFGE pattern clustering showed that V. parahaemolyticus does not have no obvious dominant cluster, and these strains have rich genetic diversity, indicating that they may have different sources.

  • Articles
    HU Mengjiao, CHEN Meilin, LIU Dong, ZHANG Bihong, DUAN Liu, WANG Jun, WANG Xuewei, ZHANG Yingbo
    China Tropical Medicine. 2023, 23(10): 1109-1113. https://doi.org/10.13604/j.cnki.46-1064/r.2023.10.17

    Objective To observe the curative effect of thread-hanging combined with cotton plug on stage Ⅲ paronychia. Methods Sixty-one patients with stage Ⅲ paronychia were selected and randomly divided into a treatment group and a control group. The treatment group (n=31) was treated with thread-hanging and tampon under local infiltration anesthesia, and changed dressing and tampon every day after operation. After the wound healed, the patient soaked his feet in warm water every day and changed the tampon himself until the symptoms subsided, and the knot did not receive special treatment, and the nail plate would naturally shed as it outgrew the paronychia. The control group (n=30) was treated with thread-hanging and nail groove reconstruction under nerve block anesthesia, and the dressing was changed every day after operation. After thread removal, the patients soaked their feet in warm water every day until the symptoms subsided, and the knot was not specially treated, and it naturally fell off with the growth of the deck beyond the nail groove. The postoperative Visual Analog Scale (VAS) pain score, pain duration, wound healing time, cure rate, effective rate and recurrence rate of paronychia, and patients' satisfaction with the operation were compared between the two groups. Results Compared with the control group, the treatment group had lower VAS pain scores on the first and third postoperative days (2.1±0.3) and (0.2±0.1) vs. (6.3±0.1) and (3.2±0.2), respectively, shorter duration of pain and wound healing time (3.3±0.3) days and (10.1±0.5) days vs. (5.2±0.3) days and (15.2±0.3) days, respectively, higher cure rate (87.1% vs. 66.7%), lower failure rate (12.9% vs. 33.3%), lower recurrence rate (7.4% vs. 20.0%), and higher patient satisfaction (97.0% vs.75.3%). The treatment group showed significant superiority over the control group in all outcomes. Conclusion For patients with stage Ⅲ paronychia, thread-hanging combined with cotton tampon without nail groove reconstruction is advantageous as it avoids additional skin trauma, and does not affect the nail appearance and normal periungual barrier after healing,, reduces patient discomfort, and shortens the time off work, resulting in a higher cure rate. This treatment approach is therefore worth promoting in clinical practice.

  • Articles
    LI Sheng, JIN Juan, HE Jian, XIN Youquan, BAI Jixiang, ZHANG Qi, ZHAO Haihong, ZHANG Xiaolu, YANG Xiaoyan, DAI Ruixia
    China Tropical Medicine. 2023, 23(9): 916-921. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.05

    Objective To understand the phenotypic and genetic characteristics of Yersinia pestis strains isolated from Himalayan marmot natural focus area and domestic rat plague focus area in southern China, and provide reference for mastering the pathogenic characteristics of Yersinia pestis of two plague foci. Methods A total of 412 of Yersinia pestis strains isolated from Himalayan marmot plague focus and domestic rat plague focus of southern China were subjected to to sorbitol fermentation assays, virulence factor, different region (DFR) typing, and clustered regularly interspaced palindromic repeats (CRISPR) typing. Results The biochemical types of Y. pestis from the two plague foci showed distinct regional distribution features. Five biochemical phenotypes were identified in Yersinia pestis isolated from Himalayan marmot natural focus area, while only one biochemical phenotype was identified in strains isolated from the domestic rat plague focus of Southern China. Most of the Yersinia pestis isolated from the two plague foci were capable of producing the virulence factors of Fl and PstI. Among the strains from Himalayan marmot focus, 70.53% (201/285) were VW-positive, 75.09% (214/285) were Pgm-positive, 20.00% (57/285) of the strains were Pgm-negative, and 5.26% (15/285) were Pgm mixed-type strains. Among strains from domestic rat plague focus of southern China, 37.80% (48/127) were VW-positive, 29.13% (37/127) were Pgm-positive, 58.27% (74/127) were Pgm-negative, and 12.60% (16/127) were Pgm mixed-type strains. DFR typing revealed 22 genotypes of Y. pestis from the Himalayan marmot plague focus, with the main genotypes being type 5, 7, 8, 10, 19, 32 and 49. All strains from domestic rat plague focus area in southern China belonged to type 9. CRISPR typing revealed that all strains from the Himalayan marmot natural focus were classified into 7 CRISPR gene clusters and 14 CRISPR genotypes, with the main genotypes being G7, G22, G26-a1'and G22-A1'. All strains from domestic rat plague focus area in southern China belonged to CRISPR genotype G30, with the gene cluster being Ca8. Conclusions The phenotypes and genotypes of the Yersinia pestis of Himalayan marmot plague focus are diverse, with an obvious characteristics of geographical distribution. The phenotype and genotype of the Yersinia pestis of domestic rat plague focus of Southern China are single. DFR and CRISPR genotyping methods with phenotypic characteristics can effectively identify the Yersinia pestis isolated from the two plague foci, thereby meeting the needs of identification and traceability research.

  • Tropical Skin Diseases Research Column
    CHEN Zunyi, YU Huiyuan, CHEN Yao, CAO Yongyan, DONG Bilin, ZENG Zhiliang, YANG jing
    China Tropical Medicine. 2023, 23(8): 811-814. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.06

    Objective To investigate the clinical types of children's tinea capitis and the distribution of fungal pathogens in Wuhan from 2011 to 2020, and to provide scientific basis for the prevention, diagnosis and treatment of children's tinea capitis. Methods Laboratory data of children with tinea capitis in outpatient and inpatient department of dermatology in Wuhan No.1 Hospital from January 2011 to December 2020 were collected. A total of 542 cases of pediatric tinea capitis were included, with 239 male cases and 303 female cases. Microscopic examination of fungi and culture identification were performed on the affected skin lesions of the children. Chi-square test was used to analyze the differences in pathogen spectrum of children with different age groups and clinical type. Results Among the pediatric tinea capitis patients, the age group with the highest prevalence was preschool children (3 to <7 years old), accounting for 48.52% (263/542). The top three pathogenic fungi were Trichophytes violaceum (49.26%, 267/542), Microsporum canis(31.55%, 171/542) and Trichophyton mentagrophytes (9.96%, 54/542). Trichophyton violaceum was the main pathogen in all ages, followed by Microsporum canis. The infection rate of Microsporum canis in children over 7 years old was lower than that in children under 7 years old, and the infection rate of Trichophyton rubrum in infants was higher than that in other ages.The distribution of Trichophytes violaceum, Trichophyton mentagrophytes, Nannizzia gypseum and Microsporum ferrugineum was uniform in all age groups. Trichophytes violaceum and Trichophyton tousurans mainly caused black-dot ringworm, Microsporum canis mainly caused tinea alba, Trichophyton mentagrophytes,Nannizzia gypseum and Trichophytonrubrum mainly caused kerion. Except for Microsporum ferrugineum, the composition ratios of other fungi species showed statistically significant differences among different clinical types of tinea capitis (P<0.05). Conclusions Preschool children are the most commonly affected age group by pediatric tinea capitis, and black-dot ringworm caused by Trichophytes violaceum is the main clinical type. Analysis of the high-riskage group, pathogenic fungi and clinical types of tinea capitis in children can enhance the understanding of its epidemiological characteristics, which is helpful for early diagnosis and targeted standardized treatment of pediatric tinea capitis.

  • Articles
    HU Yuanyuan, LIU Ya, HE Jiao, YANG Xuejiao, LIU Zhenzhen
    China Tropical Medicine. 2023, 23(9): 971-976. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.14

    Objective To establish a risk prediction model for nosocomial infection in preterm very low birth weight infants, and conduct internal validation. Methods A total of 206 cases of very low birth weight premature infants hospitalized in the Department of Neonatology of Union Hospital Affiliated to Tongji Medical College from January 2018 to June 2020 were included in this study, factors that may affect the nosocomial infection of children were collected, and the infants were divided into two groups according to whether there is nosocomial infection. The influencing factors were compared between the two groups, and multivariate Logistic regression analysis was performed after screening variables with LASSO regression. According to the results of multi factor analysis, the nomogram model was constructed and verified internally. Results A total of 29 of 206 children had nosocomial infection (14.08%), and 33 pathogenic bacteria were detected, including 23 Gram-negative bacteria, 9 Gram-positive bacteria and 1 fungus. The results of multivariate logistic regression analysis based on LASSO regression showed that the risk factors for nosocomial infection of VLBW premature infants were 28-31+6 weeks of gestation, amniotic fluid pollution, mechanical ventilation, indwelling gastric tube, unreasonable use of antibiotics, and hospitalization time ≥ 7 days. The protective factors were Apgar score ≥ 7 points at 1 min and breast feeding accounting for 50% or more (P<0.05). The Area Under Curve (AUC) of ROC curve of nomogram model was 0.946 [95%CI(0.923, 1.000)]. The calibration curve showed that the probability of hospital infection predicted by the model was basically consistent with the actual probability. The decision curve showed that when the probability threshold of nomogram model to predict the risk of nosocomial infection of very low birth weight premature infants was 0-0.85, the net rate of return was greater than 0. Conclusion Preterm infants with extremely low birth weight are at high risk of nosocomial infection, mainly affected by factors such as gestational weeks, hospitalization time, amniotic fluid pollution, etc. The nomogram model constructed by the above factors has high accuracy and discrimination for predicting nosocomial infection in such children.

  • Articles
    HUANG Jingjing, HOU Ping, ZENG Xiangjie, KE Qianyu, LUO Xingxiong
    China Tropical Medicine. 2023, 23(9): 977-982. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.15

    Objective In order to understand and master the prevalence of different genotypes and the rate of different drug-resistant Mycobacterium tuberculosis genotypes in Hainan Province, 136 drug-resistant Mycobacterium tuberculosis strains collected in Hainan province in 2022 were genotyped, and to provide scientific basis for tuberculosis prevention and control strategy in Hainan Province. Methods A total of 136 drug-resistant Mycobacterium tuberculosis strains were collected in Hainan Province. The clinical isolates were genotyped using the Spoligotyping technique, and the drug resistance rates of different genotypes of Mycobacterium tuberculosis were statistically analyzed. Results Among the 136 strains of drug-resistant Mycobacterium tuberculosis, 54.41% (74/136) belonged to the Beijing types, 27.94% (38/136) to non-Beijing types and newly identified genotypes accounted for 17.65% (24/136). The Beijing type included two genotypes, SIT1 and SIT269 genotypes, accounting for 52.94% (72/136) and 1.47% (2/136) respectively. Among the non-Beijing genotypes, the T type (T1, T2, T3) accounted for 21.32% (29/136), the U type accounted for 6.62% (9/136). Clustering analysis of genotyping results revealed two major clusters, Beijing type and non-Beijing type, as well as several scattered novel genotypes. Clustering analysis of Spoligotyping results classified the 136 drug-resistant strains into 3 clusters, with a clustering rate of 75.74% (103/136). The rates of mono-resistance (MR), poly-resistance (PR), multi-drug resistance (MDR), and other types of drug resistance in Beijing type and non-Beijing type were 41.89% (31/74), 13.51% (10/74), 24.33% (18/74), 20.27% (15/74) and 36.84% (14/38), 15.79% (6/38), 26.32% (10/38), 21.05% (8/38) respectively. Chi-square test results showed no statistically significant differences in drug resistance rates between the Beijing and non-Beijing types (P>0.05). Conclusion The genotype of Mycobacterium tuberculosis in Hainan Province showed genetic polymorphism, with the main epidemic genotype being SIT1 in the Beijing type. Monitoring of Mycobacterium tuberculosis in this genotype should be strengthened.

  • Articles
    LIU Su, ZHANG Yun, LI Ting, WU Tuo, ,CAO Yanlin, LI Kechao, MENG Xiaolong
    China Tropical Medicine. 2023, 23(8): 857-862. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.14

    Objective To investigate the morphological features of the Pneumocystis jirovecii, in order to facilitate early detection and rapid diagnosis of this rare pathogen from a morphology point of view by laboratory technicians. By analyzing the laboratory features and application value of different pathogen detection methods in the diagnosis of Pneumocystis jirovecii pneumonia, we aim to provide the most reliable diagnostic basis for rapid diagnosis of Pneumocystis jirovecii pneumonia. Methods A retrospective analysis was conducted on the test results of bronchoalveolar lavage fluid samples from a comprehensive hospital in Zhangqiu District, Jinan City, Shandong Province, and a hospital in Changde City from April 2022 to October 2022. Five confirmed cases of Pneumocystis jirovecii pneumonia were detected. Its clinical manifestations, laboratory results, and morphological characteristics of pathogens under different stains were analyzed to discuss the advantages and disadvantages of different detection methods. Results Cytological examination of bronchoalveolar lavage fluid found the trophozoites and cysts of Pneumocystis jirovecii by Wright's-Giemsa staining in 4 cases (80%), and the cysts of Pneumocystis jirovecii by Silver hexamine staining in 4 cases (80%), while the metagenomic next-generation sequencing confirmed all the 5 positive results. All 5 patients had different degrees of reduction in the absolute count of peripheral blood lymphocytes, and the serum lactic dehydrogenase and (1-3)-β-D-Glucan were increased. Among the 5 patients in this study, 4 were treated with sulfamethoxazole combined with caspofungin, and 1 was treated with sulfamethoxazole. Three patients were cured and discharged from hospital after treatment, but two died. Conclusions The method of Wright's-Giemsa staining for the cytological examination of bronchoalveolar lavage fluid to find Pneumocystis jirovecii has the unique and irreplaceable advantages as silver staining. Metagenomic next-generation sequencing can further increase the positive detection rate of Pneumocystis jirovecii. The combination of cytological examination of bronchoalveolar lavage fluid with metagenomic next-generation sequencing is a powerful diagnostic method for rapid diagnosis of Pneumocystis jirovecii pneumonia, which can diagnose accurately and reduce missed diagnosis.

  • Research Reports
    JIA Xishuai, ZHOU Shuimao, LUO Huatang, YANG Yan
    China Tropical Medicine. 2023, 23(9): 998-1001. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.19

    Objective To investigate the prevalence of C580Y mutation of kelch13 gene in the imported P. falciparum cases in Wuhan City, China, and to provide a reference basis for the prevention and treatment of imported falciparum malaria. Methods From 2009 to 2015, blood samples were collected from returnees who infected with P. falciparum in endemic areas of Africa and Southeast Asia in Wuhan City. The P. falciparum DNA was extracted from the blood samples, and kelch13 gene was amplified by loop-mediated isothermal amplification (LAMP), and the distribution of C580Y mutation was analyzed. Results C580Y mutation was detected in 16 of the 208 cases tested by LAMP. No mutations were detected in 69 cases of imported falciparum malaria from Africa during 2009-2012, while 13 cases of the C580Y mutation were detected in 114 cases from 2013 to 2015, with a mutation rate of 11.4%. The mutation rate in South Africa, West Africa, and Central Africa was 12.5%, 9.6%, and 19.0%, respectively, with no mutations detected in cases from North Africa and East Africa. Among the 25 cases of falciparum malaria from Southeast Asia between 2009 and 2013, three cases were positive for the C580Y mutation, all from Myanmar, with a mutation rate of 14.3% (3/21) in Myanmar and 12.0% (3/25) in Southeast Asia. There was no significant difference in the mutation rate between Africa and Southeast Asia after 2013 (P>0.05). Conclusions Our findings highlight the varying degrees of C580Y mutations of kelch13 gene in imported P. falciparum cases in Wuhan and suggest the need for enhanced monitoring and evaluation of related resistance genes.

  • Research Reports
    WANG Zhuo, HUANG Guanpeng, WU Qiong, HUANG Xiaoyang, MA Youxin, MAO Enrong, LI Bing, WU Yimin
    China Tropical Medicine. 2023, 23(9): 994-997. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.18

    Objective To explore the prevalence and bacterial strains of Francisella tularensis (F. tularensis) in wild rodents in Changbai Mountain area of China, and to further understand the epidemiological characteristics of F. tularensis infections in this area. Methods Wild rodents were captured from forest and forest-edge farmland from Kuandian County and Jianshi Forest District in the Changbai Mountain area, 2012-2014. DNA was extracted from the spleen tissues of the rodents, and the fopA gene of F. tularensis in wild rodents was detected using nested PCR. The infection rates were calculated for different areas and rat species. The bacterial subspecies of positive samples were identified using type-specific primers (C1/C4), and sequencing and comparative analysis were performed. Results A total of 133 wild rodents belonging to 6 rat species were captured. Among them, eight samples from three rat species (Apodemus agrarius, Apodemus peninsulae, Tscherskia triton ) were detected positive, with the overall positive rate of 6.01%. The positive rates of F. tularensis of Ji'an and Kuandian were 7.46% and 4.54%, respectively, and there was no difference in positive rates for different regions (χ2=0.117, P=0.732) and different rat species (χ2=0.641, P=0.986). The subspecies analysis showed that the detected 8 trains of F.tularensisall belonged to F.tularensis type B (F.subspecies subsp. holarctica). Genetic evolution analysis was performed on the fopA gene sequences of three positive samples (JA56, JA33, and JA38), which clustered together with Russia strains(CP009694.1, CP044004.1) and China strains (HM371344.1, HM371343.1) F.tularensis type B, with sequence similarities ranging from 99.21% to 99.47%. Conclusions Infection of F.tularensis subsp. holarctica existed in wild rodents in Changbai Mountain area of China, which suggests the existence of F.tularensis infection risks in this area.

  • Articles
    WU Xia, YANG Yuanli, LI Aifang, ZHENG Huiqiang, TAN Xiaowen, CUI Xiaoli, KANG Lei, ZHOU Yong, YANG Han, LEI Jing
    China Tropical Medicine. 2023, 23(8): 846-851. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.12

    Objective To compare the diagnostic efficacy of the upgraded version of the GeneXpert automated fluorescent quantitative PCR system (GeneXpert MTB/RIF Ultra, GeneXpert Ultra) and the original version of the GeneXpert system (GeneXpert MTB/RIF, Xpert), real-time fluorescent quantitative nucleic acid detection (FQ-PCR), real-time fluorescent thermostatic amplification of Mycobacterium tuberculosis RNA (SAT-RNA), real-time fluorescent thermostatic amplification detection of DNA (thermostatic amplification method) and traditional BACTEC MGIT 960 liquid culture (culture method) for special specimens of tuberculosis, in order to analyze its application value in clinical detection. Methods Using prospective research methods, a total of 170 special specimens (including 47 pleural and ascites effusion samples, and 34 24-hour urinary sediment specimens, 49 tissue specimens and 40 fester specimens) were collected i'an Chest Hospital from January to September 2021. GeneXpert Ultra, Xpert, FQ-PCR, SAT-RNA, isothermal amplification, and traditional culture were used for detection. Clinical diagnosis was used as the standard, and sensitivity, specificity, positive predictive value, negative predictive value, coincidence rate, and Kappa value were compared among the methods. Results The sensitivities of GeneXpert Ultra, Xpert, FQ-PCR, SAT-RNA, isothermal amplification, and traditional culture were 65.18% (73/112), 49.11% (55/112), 37.50% (42/112), 19.64% (22/112), 8.04% (9/112), and 22.32% (25/112), respectively. The sensitivity of GeneXpert Ultra was higher than that of the other five methods, and the differences were statistically significant (χ2=66.25, 42.10, 28.89, 13.09, 4.92, 15.18, all P<0.05). GeneXpert Ultra result analysis showed that: 5.48%(4/73) cases had trace, that is, trace Mycobacterium tuberculosis load, 79.45% (58/73) cases were extremely low, 10.96% (8/73) cases were low, 2.74% (2/73) were medium,, and 1.36% (1/73) were high load. In 4 trace samples, the Xpert detection was negative for all. Of the 73 GeneXpert Ultra positive reports, 63 were rifampicin-sensitive, 6 were rifampicin-resistant, and 4 were rifampicin-resistant but of unclear resistance. Of the 55 Xpert positive reports, 45 were rifampicin-sensitive, 2 were rifampicin-resistant, and 8 were rifampicin-resistant but of unclear resistance.. Conclusions The new generation of GeneXpert MTB/RIF Ultra has high sensitivity, specificity and drug resistance detection rate, and its advantage is even more apparent in the pathogenic diagnosis of special specimens of tuberculosis. It can be used as one of the preferred methods in samples with low bacterial load.

  • Review
    LIU Zhihong, QIN Yaqin, SU Minghua
    China Tropical Medicine. 2023, 23(12): 1358-1364. https://doi.org/10.13604/j.cnki.46-1064/r.2023.12.21

    Sepsis is an inflammatory disorder syndrome caused by the infection of pathogenic microorganisms, which organ dysfunction due to the dysregulated response of the body to the infection. Sepsis is a dangerous disease with a high fatality rate. The liver, an important organ involved in human biological transformation, energy metabolism, and cytokine production. Its role in sepsis is like a "double-edged sword" because the liver acts as not only an important defense line of the body against microorganisms but also a common target of inflammatory disorders and damage, making it one of the most vulnerable organs in sepsis. The liver contributes to pathogen clearance through immune responses, but the resulting inflammatory reactions can also lead to tissue and organ damage. Sepsis liver injury is an independent risk factor for poor prognosis in sepsis patients, and preventing its occurrence and promoting early recovery can partially inhibit disease progression and reduce mortality rates. However, the pathogenesis of sepsis liver injury is not yet fully understood, and there is a lack of early and effective means of diagnosis and treatment. In-depth research on its pathogenesis will provide a better understanding of its occurrence and development, further supporting the theoretical basis for the treatment of sepsis liver injury and identifying some new targets for sepsis treatment, ultimately reducing the mortality of sepsis.

  • Case Report
    ZHU Hong, QIU Feiqin, GUO Jialiang, ZHANG Hua
    China Tropical Medicine. 2023, 23(11): 1237-1240. https://doi.org/10.13604/j.cnki.46-1064/r.2023.11.20

    Objective To investigate the clinical manifestations, diagnosis, treatment and prognosis of COVID-19-associated multisystem inflammatory syndrome in children (MIS-C) with multisystem organ failure, and to analyze the differences between the syndrome resembling Kawasaki disease and Kawasaki disease. Methods We report a case of child diagnosed with SARS-CoV-2 infection who developed MIS-C with multi-organ failure. Literature was reviewed to further discuss clinical symptoms, diagnosis, treatment, and prognosis of MIS-C. Results The patient 's condition progressed rapidly and was severe, with acute kidney injury at admission, presenting with urine output of 0 mL in 8 hours, serum creatinine of 675.1 μmol/L, urea nitrogen of 38.2 mmol/L, creatine kinase 4 932 U/L, along with continuously elevated serum amylase, peaking at 5 809.7 U/L, aspartate aminotransferase of 995 U/L, alanine aminotransferase of 240 U/L, and frequent vomiting. The patient was categorized as critically ill. The confirmed patient with MIS-C was managed in pediatric intensive care units (PICU), received early continuous blood purification, jejunal tube feeding, and combined treatment with intravenous methylprednisolone pulse and human immunoglobulin for intravenous injection (IVIG), resulting in complete recovery and discharge. Through literature review, it can be analyzed that MIS-C is systemic inflammatory response characterized by multi-organ dysfunction from a cytokine storm, which differentiates it from Kawasaki disease characterized by acute systemic vasculitis triggered by infectious factors, ultimately leading to cardiovascular accidents as the main cause of death. Conclusions When fever (≥38 ℃) persists for at least 24 hours, accompanied by high inflammatory symptoms and dysfunction in two or more systems, requiring intensive care treatment, and there is evidence of SARS-CoV-2 infection, MIS-C should be diagnosed early, and intervention and treatment should be initiated promptly to achieve favorable outcomes.

  • Articles
    JIA Huihua, CHEN Qinyan, JIANG Zhihua, WANG Xueyan, ZHANG Wenjia, TIM J Harrison, J BROOKS Jackson, LI Wu, FANG Zhongliao
    China Tropical Medicine. 2023, 23(8): 822-827. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.08

    Objective To clarify the long-term evolution of hepatitis B virus (HBV) quasi-species in HBsAg asymptomatic carriers in Long'an county, Guangxi. Methods ELISA was used to detect serological markers of HBV. Viral loads were measured by real time PCR. HBV DNA was extracted from serum by kits. The whole HBV genome was amplified using nested PCR and amplicons were sequenced by next-generation sequencing (NGS). These sequences from NGS were analyzed by the software like Mega. Results Serum samples were collected from 9 HBsAg asymptomatic carriers in Longan County, Guangxi at 4 different time points in 2004, 2007, 2013, 2019 or 2020. A total of 23 serum samples and 309 full-length gene quasi-species sequences were obtained, with an average amount of (0.18±0.07) G sequencing data for each sample. Genotype of 55.54%(5/9) the studied subjects underwent genotype conversion during the long-term evolution process of HBV quasi-species, and the genotyping results of the phylogenetic tree in the PreS/S region are in perfect agreement with the results of the whole genome analysis; recombinant B/C, I/C were found; the Sn ranged from 0 to 0.37 and the genetic diversity ranged from 0 to 0.11, respectively. A total of 21 special single nucleotide/amino acid mutations (7 in the S region, 2 in the X region, 3 in the PreC region and 9 in the BCP region) and 6 deletion mutations were detected, multiple mutations were found and no drug resistant mutations were found; 77.8%(7/9) of the HBV strains carried by the subjects in 2004 had double mutations at nt1 762(A→T) and 1 764(G→A) and a stop mutation at nt1 896(G→A); HBV mutations can be restored from the mutant type to the wild type and (or) vice versa without antiviral drug pressure, and The evolution rate of HBV genome was 2.03×10-5~3.50×10-3. Conclusion HBV genotype, recombinants, genetic complexity and diversity of HBV quasi-species can change over time during in natural infection. The transformation between HBV mutation type and wild type reduces the value of predicting clinical outcomes by genetic types and related mutations to some extent. The HBV genome evolution rate of asymptomatic carriers of HBsAg in Long'an County is very high.

  • Articles
    ZHAO Bennan, LIU Dafeng, BAO Lei, GUO Lihua, JIANG Xiaoman, MAO Yi
    China Tropical Medicine. 2023, 23(11): 1169-1172. https://doi.org/10.13604/j.cnki.46-1064/r.2023.11.08

    Objective To summarize the clinical characteristics of 35 patients with human monkeypox in Chengdu City, in order to provide theoretical basis for prevention and control of monkeypox epidemic in China. Methods A total of 35 patients diagnosed with monkeypox infection by Chengdu CDC from July 1 to July 23, 2023 were included in our study. The results of general clinical data, blood laboratory tests, lymph node ultrasound and chest CT results were collected in order to analyze the clinical features of human monkeypox patients in Chengdu City. Results All 35 monkeypox patients were young adult males, and there were no serious or fatal cases. Among them, 32 cases (91.4%) were men who have sex with men (MSM), and 30 cases had engaged in male-to-male sexual behavior within 21 days prior to the onset of the disease, of which 13 cases had taken protective measures. Fever symptoms were observed in 26 cases (74.3%) of the patients, with 19 cases experiencing fever within 1-6 days after the appearance of rash. The initial rash commonly occurred in the male external genitalia. Color ultrasound examinations indicated that all patients had swollen inguinal lymph nodes. C-reactive protein was elevated in 26 cases (74.3%) of patients, and 19 cases showed CD3+CD4+T/CD3+CD8+T< 1.0. 15 cases (42.8%) of the patients were infected with both monkeypox virus and HIV, 28.5% (10/35) of patients had concomitant skin infections and anorectal proctitis,respectively. The mean time from rash onset to the shedding of rash scabs was 14.8 days. Conclusions The MSM population in sexually active age group is the main infection object of human monkeypox virus. In monkeypox patients in Chengdu City, the rash starting at genital areas and rash occurring before systemic symptoms were common. Swollen inguinal lymph nodes are especially common in monkeypox patients. Skin infection and anorectal proctitis are the most common complications in monkeypox patients in Chengdu City. The abnormal cellular immune function in monkeypox patients is mainly reflected in the inverted ratio of CD3+CD4+T/CD3+CD8+T. Currently, there is no evidence to suggest that protective measures during male-to-male sexual behavior can reduce the risk of human monkeypox infection.

  • Prevention and Control of Major Infectious Diseases
    GAO Qi
    China Tropical Medicine. 2024, 24(1): 1-5. https://doi.org/10.13604/j.cnki.46-1064/r.2024.01.01

    Malaria used to be one of the most prevalent infectious diseases in China. With the unremitting efforts of several generations, China has achieved remarkable achievements from malaria control to elimination. In particular, after 10 years of national malaria elimination action, local transmission has been successfully interrupted, and the indigenous cases reduced from 30 million to zero. Despite the successful malaria elimination in China, the global malaria epidemic is still serious and Anopheles mosquitos are still existing in the original malaria-endemic areas in China. With the risks of thousands of imported cases every year and cross-border positive Anopheles mosquitoes give rise to new challenges. Preventing malaria re-establishment will be a long-term task after the elimination of malaria in China. This paper summarizes the five pillars and the new case-based "1-3-7" strategy for malaria elimination in China, analyzes the global malaria situation, and the new characteristics of the risk of re-establishment after malaria elimination in China. It is suggested that continuously political support, timely adjustment the risk stratification of re-establishment, strengthening the diagnosis and treatment capacity of imported malaria in hospitals/clinicals, and the monitoring and early warning/emergency response capacity in CDCs, attaching importance to innovative research and the production/supply of special antimalarial products will be important in the preventing re-establishment setting in China.

  • Articles
    WANG Zheng, REN Li, YANG Fu-rong, SHEN Yu-min, HU Cai-qin, HAO Yan-ling, ZHU Biao, LI Dan, SHAO Yi-ming
    China Tropical Medicine. 2023, 23(6): 590-595. https://doi.org/10.13604/j.cnki.46-1064/r.2023.06.06

    Objective To construct SARS-CoV-2 receptor binding domain molecular probe for monoclonal memory B cell sorting and obtain RBD specific neutralizing antibodies from peripheral blood mononuclear cells (PBMCs) of COVID-19 convalescents by single-cell sorting. Methods The SARS-CoV-2 RBD sequence was downloaded from GenBank, and the Avi tag and 6-histidine tags were added at the C-terminal. After codon optimization, it was chemically synthesized, cloned into the pDRVI1.0 vector, expressed after transfection of 293F cells, and biotinylated consequently. RBD-specific B cells were sorted out with this probe1 from the PBMCs of convalescents recovered from COVID-19. After B cells were lysed, the variable regions of heavy chain and light chain were amplified, cloned into the antibody expression vector, and transfected into 293F cells to express the antibody. Then the antibody was purified from the supernatant using protein A column and SARS-CoV-2 pseudovirus was used to test their neutralizing activity. Results RBD-Avi probe was produced and successfully biotinylated sequentially with an efficiency of 30%-50%. Western blot analysis revealed that the biotinylated probe was recognized by the antibodies purified from COVID-19 convalescent plasma. Using this probe, 7 and 16 RBD-specific memory B cells were successfully isolated from the PBMCs of two convalescent individuals, accounting for 0.24% and 0.17% of the total cell population, respectively. After amplifying the variable regions of antibody heavy and light chains from the lysed B cells, 7 and 12 pairs of antibody heavy-light chains were obtained. A total of 16 antibodies were expressed in the convalescent individuals, and most of the purified antibodies showed neutralizing activity against the pseudovirus, with IC50 values of 6 antibodies below 1 μg/mL. The IC50 values of XJ-A9 and SCF-F1 against the wild-type pseudovirus were 0.07 μg/mL and 0.35 μg/mL, respectively. Conclusion The SARS-CoV-2 RBD molecular probe constructed in this study has good antigenicity, and the isolated antibodies present neutralizing activity against wild-type SARS-CoV-2 pseudovirus.

  • Articles
    YUAN Huicheng, WAN Xuena, XU Shaohua, ZHAO Liangcun, YANG Kai
    China Tropical Medicine. 2023, 23(8): 863-869. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.15

    Objective To elucidate the potential mechanism of Jindanjiangan Capsule in the treatment of liver fibrosis by network pharmacology and molecular docking. Methods Active ingredients and targets of Jindanjiangan Capsules were searched by Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and HERB databases, and the disease targets were screened by DisGeNET and Therapeutic Target Database (TTD) databases. The targets of the active ingredients of Jindanjiangan Capsule were matched with the disease targets, and the common targets were imported into the String database platform to construct a protein-protein interaction network (PPI) network. CytoNCA tool of Cytoscape 3.9.1 software was used for topological analysis to screen key targets. Traditional Chinese Medicine-Key Active Ingredients-Key Target Network was constructed by Cytoscape 3.9.1 Software. KEGG enrichment analysis of key targets was performed through the DAVID platform. The molecular docking of active ingredients and targets was performed to verify the above results using LeDock software. Results By screening, 180 potential active ingredients and 1 340 targets of Jindanjiangan Capsule and 1 060 targets of liver fibrosis, and 273 common targets were obtained. 29 key targets related to liver fibrosis were screened out by PPI network interaction, and verified by KEGG analysis and molecular docking. Jindanjiangan capsule acts on key targets such as EGFR, MMP9, PTGS2, ESR1, PIK3CA, F2, PPARG, and PTPN11 through active components such as isovitexin, quercetin 7-O-β-D-glucoside, (3S, 6S) -3- (benzyl) -6- (4-hydroxybenzyl) piperazine-2,5-quinone, 6-O-syringoyl-8-O-acetylshanzhiside methyl ester, tanshinone II, nortanshinone, capillaris chromone, and etanone. The specific mechanism may be related to HIF-1 signaling pathway, C-type lectin receptor signaling pathway, Toll-like receptor signaling pathway, tumor necrosis factor signaling pathway, relaxin signaling pathway, FoxO signaling pathway and so on. Conclusion Jindanjiangan capsule can effectively treat hepatic fibrosis through multi-component, multi-target and multi-pathway.

  • Articles
    ZOU Fanlu, SHI Yiyi, YU Zhijian, PAN Weiguang, WANG Hongyan, CHENG Hang, DENG Xiangbin, XIONG Yanpeng
    China Tropical Medicine. 2023, 23(9): 966-970. https://doi.org/10.13604/j.cnki.46-1064/r.2023.09.13

    Objective To investigate the antimicrobial activity of omadacycline (OMC) against clinical Streptococcus agalactiae (GBS) isolates, as well as its relationship with biofilm formation, resistance genes and virulence genes. Methods A total of 136 strains of Streptococcus agalactiae isolated from Shenzhen Nanshan People's Hospital between 2015 to 2020. The minimum inhibitory concentration (MIC) of OMC against Streptococcus agalactiae was determined by broth microdilution. Crystal violet staining was used to detect the biofilm formation ability of GBS. Resistance genes (tetM, tetO, tetK, ermB, OptrA) and virulence genes (cpsⅢ, bca, fbsA, cpsA, scpB) were investigated by polymerase chain reaction (PCR). Results Among the 136 clinical isolates of GBS, 20 strains (14.7%) were resistant to OMC, 64 (47.1%) were intermediate, and 52 (38.2%) were sensitive. Fifty-seven strains (41.9%) were biofilm-positive, 20 of which (35.1%) were sensitive to OMC. Seventy-nine strains (58.1%) were biofilm-negative, 32 of which (40.5%) were susceptible to OMC. There was a statistically significant difference in the sensitivity rates between the two groups of strains (χ2=63.062, P<0.001), but there was no significant difference in the sensitivity of OMC among the biofilm-positive strains (Fisher's exact test, P=0.824). The resistance rates of tetM, tetO, ermB and OptrA positive strains were higher than those of negative strains, while tetK was opposite. The presence of tetM (Z=0.815, P=0.415), tetO (Z=0.151, P=0.88), tetK (Z=0.567, P=0.571), ermB (Z=1.198, P=0.231) resistance genes in Streptococcus agalactiae had no significant impact on the sensitivity of OMC. However, the presence of the OptrA resistance gene showed a statistically significant effect on the sensitivity of OMC (Z=2.913, P=0.004). The virulence factors cpsⅢ, bca, fbsA, cpsA and scpB were all detected at a rate higher than 50%. The presence of the virulence genes cpsⅢ (Z=0.222, P=0.824), bca (Z=0.141, P=0.888), fbsA (Z=0.813, P=0.416), and cpsA (Z=1.615, P=0.106) in Streptococcus agalactiae had no significant impact on the sensitivity of OMC. However, there was a significant inter-group difference in the scpB virulence gene (Z=2.844, P=0.004), but the rank mean values and resistance rates of scpB-positive strains were lower than those of the negative strains. Conclusions The formation of biofilm in Streptococcus agalactiae reduces its sensitivity to OMC, but there was no significant difference in the sensitivity to OMC among the biofilm-positive strains. The presence of resistance genes tetM, tetO, tetK, ermB, and virulence genes cpsⅢ, bca, fbsA, cpsA, scpB in Streptococcus agalactiae is not associated with OMC resistance, but the presence of the resistance gene OptrA is correlated with OMC resistance..

  • Articles
    WANG Xingbin, JIANG Mingxia, ZHAO Changming, MA Yongcheng, ZHANG Zuhao, HUANG Qiuli, WANG Ling, LIU Kuangyi, ZHANG Yaxin, WANG Zhaofen
    China Tropical Medicine. 2023, 23(8): 815-821. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.07

    Objective To analyze the resistance and spatial distribution of Mycobacterium tuberculosis (MTB) to six commonly used anti-tuberculosis drugs in Qinghai Province from 2016 to 2019, so as to provide a reference for tuberculosis treatment and drug-resistant tuberculosis control. Methods A total of 1 182 identified strains of Mycobacterium tuberculosis in Qinghai Province from 2016 to 2019 were collected, and 6 anti-tuberculosis drugs were subjected to drug susceptibility tests and strain confirmed by the proportional method. By means of ArcMap10.7 and SaTScan10.1 software, map visualization, spatial autocorrelation analysis and spatial scanning of MTB drug resistance were performed to identify MTB drug resistance clusters in Qinghai Province. Results From 2016 to 2019, the total drug resistance (TDR) rate of 1 182 Mycobacterium tuberculosis strains in Qinghai Province was 23.77% (281/1 182), with a mono-resistance (MR) rate of 11.08% (131/1 182), a poly-resistance (PDR) rate of 3.89% (46/1 182), a multi-drug resistance (MDR) rate of 8.80% (104/1 182), and an extensive drug resistance (XDR) rate of 0.85% (10/1 182). The rates of MDR, XDR and TDR all showed a decreasing trend year by year (P<0.01). The drug resistance spectrum displayed 21 combinations. The TDR rate and MDR rate in the retreatment patients were higher than those of the initial treated patients, and the difference was statistically significant (χ2TDR=22.784, χ2MDR=45.082, P<0.01). In terms of demographic characteristics, the TDR rate in males was higher than that in females, and the middle-aged group was higher than other age groups, and the differences were statistically significant (χ2=7.541, 10.825, P<0.05). The results of global spatial autocorrelation analysis showed that there was no statistical significance in the autocorrelation and obvious spatial clustering of MTB drug resistance in Qinghai Province from 2016 to 2019 (P>0.05), which indicated a random distribution. The results of spatiotemporal scanning showed that there was a kind of clustering area, but the clustering effect was not significant (P>0.05), indicating a random distribution. Conclusions The TDR of MTB in Qinghai Province from 2016 to 2019 showed a downward trend year by year. In comparison with the national average, the rate of multi-drug resistance and extensive drug resistance was still high, and most of the multi-drug resistance resulted from rifampicin and isoniazid. The drug-resistant population mainly consisted of retreatment, males, and young and middle-aged populations. Drug-resistant strains had no significant spatial clustering and showed a random distribution within the study area.

  • Case Reports
    FU Gaojia, LIN Daojiong
    China Tropical Medicine. 2023, 23(7): 773-777. https://doi.org/10.13604/j.cnki.46-1064/r.2023.07.17

    By report a case in which the main symptom was cholestasis in an infant and the diagnosis of Alagille syndrome (ALGS) was made after a tortuous treatment process, so as to provide clinicians with experience in diagnosing this type of patient. The patient was a 1-year and 11-month-old male who was admitted to the hospital with "abnormal liver function found for more than 1 year". Physical examination showed a wide forehead, sunken eye sockets, wide eye spacing, a sharp chin, and a grade II systolic murmur in the pulmonary valve region. Biochemical findings showed abnormal liver function accompanied by significant elevation of total bile acids and γ-glutamyl transpeptidase. CT scan of the thoracic vertebrae showed sagittal vertebral fractures in the thoracic 3-7 vertebrae, and pulmonary arteriography showed pulmonary stenosis and genetic testing indicated a JAG1 mutation. Combining the patient's specific facial features, heart defects, spinal deformities, and bile stasis clinical symptoms, along with the genetic analysis results, the final diagnosis was confirmed as Alagille syndrome. Alagille syndrome is the most common cause of chronic cholestasis with phenotypic features and is a dominant inherited disease involving multiple systems. Most patients present with bile stasis as the main symptom within the first three months after birth. Alagille syndrome needs to be distinguished from various forms of cholestasis in infancy, and since biliary atresia requires early surgical treatment, most children with cholestasis as the main clinical manifestation are considered to have biliary atresia at an early stage and undergo a caesarean section. If Alagille syndrome is misdiagnosed as biliary atresia, and surgery may worsen the prognosis. Therefore, the biggest challenge in the early diagnosis of Alagille syndrome is how to distinguish it from biliary atresia. Therefore, physicians need to improve their knowledge of rare cholestatic liver disease in clinical practice to accurately identify rare cholestatic liver disease in the early stages of the disease, and improve improve their diagnosis and treatment levels.

  • Case Reports
    LIANG Yueyi, WEN Hainan, CHEN Dongke, LIU Yanchao, SUN Lihong, ZHANG Pan, XIE Shoujun
    China Tropical Medicine. 2023, 23(7): 778-782. https://doi.org/10.13604/j.cnki.46-1064/r.2023.07.18

    To report a case of Aspergillus salwaensis-induced spinal infection and its laboratory detection. The inflammatory granulation and necrotic tissue samples of a patient with spinal infection were collected from, the Affiliated Hospital of Chengde Medical College on June 17, 2020 for direct smear microscopy and culture, and the isolated strain was identified by microscopy by smear staining, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF-MS), molecular identification and in vitro antifungal susceptibility test. The patient was 62 years old female and presented with recurrent chest and back pain with no obvious cause. The initial diagnosis was spinal infection, after 7 days of treatment with levofloxacin, the effect was not good. Surgery was then performed remove the lesion via posterior thoracic debridement, and fungal hypha was observed under microscope in tissue specimens. The isolated strains had no typical structure, MALDI-TOF-MS was used for identification for many times, but there was no identification result. After 7 days of fluconazole treatment, the patient's condition improved, and her chest and back pain were alleviated compared to before surgery. The patient was discharged and followed up in the outpatient department, the fungus was later identified as Aspergillus salwaensis by sequence analysis of the internal transcribed spacer (ITS) gene sequencing, and the patient's antifungal medication was changed to voriconazole after with the attending physician. The patient consciously recovered well with no pain in the operative area and normal spinal activity at 1 year follow-up. The possibility of spinal fungal infection should be considered in patients with back pain without a clear cause and poor response to routine antibiotic treatment. Direct smear report of microscopic results are very important for guiding clinical antibiotic selection for rare filament fungi with atypical colony and microscopic morphology and unsuccessful MALDI-TOF-MS identification, molecular biological methods such as ITS sequence analysis can be helpful for early identification of the fungal species, improving identification speed.

  • Tropical Skin Diseases Research Column
    YUAN Shujuan, CHEN Huan
    China Tropical Medicine. 2023, 23(8): 796-800. https://doi.org/10.13604/j.cnki.46-1064/r.2023.08.03

    Objective To investigate the detection methods of newly discovered leprosy cases in Hunan Province in 2013-2022, and analyze the trend of changes, and provide scientific basis for the prevention and treatment of leprosy. Methods The detailed information of newly diagnosed leprosy cases in Hunan Province from 2013 to 2022 was collected through the Leprosy Management Information System (LEPMIS), and the descriptive epidemiological method was used to analyze the detection methods of newly discovered leprosy cases. Results From 2013 to 2022, a total of 250 newly diagnosed leprosy cases were detected in Hunan Province, including 143 cases (57.20%) were found in outpatient clinics, 33 cases (13.20%) were found in clue investigations, 27 cases (10.80%) were notifiable-reported, 23 cases (9.20%) were self-reported, 11 cases (4.40%) were found in other ways (e.g., group survey), 9 cases (3.60%) were found in contact examinations, 2 cases (0.80%) were found in census, and 2 cases (0.80%) were found in epidemic point inspection. From 2013 to 2022, the number of cases detected in outpatient clinics showed an upward trend (rs=0.515), while the cases detected in clue investigation (rs=-0.873), notifiable-reported (rs=-0.127), self-reported (rs=-0.301), contact examination (rs=-0.363), census (rs=-0.701) and epidemic point inspection (rs=-0.701) showed a downward trend. The majority of leprosy cases with different demography characteristics and clinical characteristics were found through outpatient clinics, except that the majority of leprosy cases in children were found by contact examination (66.76%). Of 165 male cases, 92 cases (55.76%) were found in outpatient clinics and 51 out of 85 female cases (60.00%) were found in outpatient clinics. Among age groups, 113 out of 187 cases aged 15 to 60 (60.43%) and 30 out of 60 cases aged over 60 (50.00%) were found in outpatient clinics. Among patients with different occupations, 112 out of 208 cases of farmers (53.85%) and 31 out of 42 cases of other occupations (73.81%) were found in outpatient clinics. Among cases with different types of leprosy, 111 out of 185 cases of multibacillary leprosy (60.00%) and 32 out of 65 cases of paucibacillary leprosy (49.23%) were found in outpatient clinics. Among cases with different numbers of skin lesions, 4 out of 8 cases of skin lesion-free leprosy (50.00%), 3 out of 9 cases of single skin lesion leprosy (33.33%), and 136 out of 233 cases of multiple skin lesions leprosy (58.37%) were found in outpatient clinics. Of 72 cases without nerve damage, 48 cases (66.67%) were found in outpatient clinics. Of 27 cases with single nerve damage, 17 cases (62.96%) were found in outpatient clinics. Of 151 cases with multiple nerve damage, 78 cases (51.66%) were found in outpatient clinics. Among patients with different levels of malformation, 58 out of 102 cases with no malformation (56.86%), 28 out of 45 cases with GradeⅠ malformation (62.22%), 35 out of 68 cases with Grade Ⅱmalformation (51.47%), and 22 out of 35 cases with other types of malformation (62.86%) were found in outpatient clinics. Conclusions Outpatient clinics is the main way to detect newly diagnosed leprosy cases under the low prevalence of leprosy in Hunan Province, and it is an important strategy to move the early detection of leprosy cases to comprehensive medical institutions in the future.