Table of Content

25 August 2025, Volume 37 Issue 4

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Epidemiology and management of echinococcosis in China and Mongolia and the risk of cross⁃border transmission

LIU Jing, DANZENG Quzhen, MO Xiaojin, MIAO Yurun, SU Xuan, HU Wei, ZHANG Ting

2025, 37(4):  337-343. 

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Currently, echinococcosis is highly prevalent in both China and Mongolia, and the risk of cross⁃border echinococcosis transmission raises growing concerns. This article describes the epidemiology of echinococcosis in China and Mongolia, compares echinococcosis control measures between the countries, and discusses the potential risk of cross⁃border echinococcosis transmission due to human and animal mobility, transboundary movement of animal hosts, and disparities in control capacity between the two countries. In addition, the article proposes the promising cooperation areas for joint prevention and control of echinococcosis between the two countries, including the joint development of guidelines and standards, technical and financial assistance, and cross⁃border pathogen monitoring and tracing, so as to provide insights into cross⁃boundary health cooperation between China and Mongolia, effective management of echinococcosis transmission, and improvements in the regional public health security. 

Skin flora, odor and malaria transmission

SONG Xiumei, WANG Jingwen

2025, 37(4):  344-345, 379. 

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Malaria, which is transmitted primarily by bites of female Anopheles mosquitoes, is a mosquito⁃borne infectious disease that poses a serious threat to human health. Host body odor is a key factor to attract Anopheles mosquitoes. Upon Plasmodium infection, host body odors change, leading to increased attractiveness to female Anopheles mosquitoes; however, the underlying mechanisms remain clear. A recent study reported remarkable changes of skin flora and volatile substances in mice following Plasmodium infections, and ethylbenzene was found to increase host attractiveness to mosquitoes, which provides new insights into development of novel malaria control strategies.

Diagnostic value of the inquiry examination method for taeniasis based on the receiver operating characteristic curve 

LIU Jianfeng, WANG Wenya, ZHANG Mizhen, ZHOU Changhai, LIU Liu, ZHAO Luyuan, LI Keron, ZHANG Dongqi, LIU Yuhua, LIU Hongkun, CHEN Shaorong, QIAN Menbao, LI Shizhu

2025, 37(4):  346-354. 

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Objective　To evaluate the value of inquiry examinations for diagnosis of taeniasis in field investigations, so as to provide insights into improving the efficiency and accuracy of taeniasis control programmes.  Methods　Four taeniasis⁃endemic villages were sampled in Dali Bai Autonomous Prefecture, Yunnan Province in October 2023 as survey sites, and at least 305 permanent residents at ages of over 3 years were randomly sampled from each site. Face⁃to⁃face inquiries were performed with structured questionnaires to investigate participants' history and frequency of proglottids release during the past year, consumption of raw or undercooked meat products or pork liver during the past six months, history and time of deworming. Participants' stool samples were collected, and Taenia eggs were detected in stool samples using Kato⁃Katz technique (two slides of one stool sample). Egg⁃positive individuals or participants with a history of proglottids release during the past year were given diagnostic deworming with areca nuts and pumpkin seeds. The detection of Taenia eggs using Kato⁃Katz technique and release of Taenia worms or proglottids following diagnostic deworming served as a gold standard to evaluate the diagnostic efficiency of inquiry examinations for taeniasis. The receiver operating characteristic (ROC) curves of inquiry examinations for diagnosis of taeniasis were plotted, and the area under the curve (AUC) was calculated. In addition, Taenia worms or proglottids released following diagnostic deworming were subjected to multiplex PCR assay and Sanger sequencing for species identification.  Results　A total of 1 842 participants were included, and 1 842 valid questionnaires were recovered. A total of 1 533 stool samples were collected, among which 25 egg⁃positives were identified. Questionnaire surveys showed that 1 305 respondents had consumed raw or undercooked meat products during the past six months, and 42 respondents had a history of proglottids release during the past year. Diagnostic deworming was given to on the aforementioned 25 egg⁃positive individuals and 42 participants who self⁃reported a history of proglottids release during the past year, and 33 participants had a release of complete worms. Following exclusion of records of individuals receiving deworming during the past 3 months, during the past year, and all participants with a history of deworming, the AUCs were 0.767 (Z = 4.71, P < 0.001), 0.762 (Z = 4.51, P < 0.001), and 0.762 (Z = 4.52, P < 0.001) for diagnosis of Taenia infections with "self⁃reported history of proglottids release during the past year", respectively, and pairwise comparisons showed no statistically significant differences (D values, -0.005 to 0.328; all P values > 0.05). Following exclusion of records of individuals receiving deworming during the past 3 months, during the past year, and all participants with a history of deworming, the AUCs were 0.797 (Z = 4.71, P < 0.001), 0.835 (Z = 4.17, P < 0.001), and 0.847 (Z = 3.98, P < 0.001) for diagnosis of Taenia infections with "self⁃reported history of twice proglottids releases", respectively, and pairwise comparisons showed no statistically significant differences (D values, -0.43 to -0.10; all P values > 0.05). Following exclusion of records of all individuals receiving deworming, the diagnostic sensitivity and specificity of "self⁃reported history of twice proglottids releases" were 87.50% and 81.82%, respectively. Following exclusion of records of individuals receiving deworming at different intervals, the AUCs were 0.529 to 0.532 for diagnosis of Taenia infections with "self⁃reported consumption of raw or undercooked meat products or pork liver during the past 6 months" (all P values > 0.05). Among 33 individuals with releases of complete Taenia worms, 31 individuals were identified with T. asiatica infections (93.94%), with a mean worm burden of (1.39 ± 0.72) worms/person, and 2 were identified with T. saginata infections (6.06%), with one worm in each participant. Conclusions　A history of Taenia proglottids release during the past year as revealed by inquiry examinations exhibit a diagnostic value for taeniasis and may serve as an initial screening tool for field taeniasis screening. Increasing the frequency of Taenia proglottids release during inquiry examinations and exclusion of records of individuals receiving deworming during the analysis may improve the value for diagnosis of taeniasis. 

Establishment and preliminary evaluation of recombinase⁃aided isothermal nucleic acid amplification combined with nanopore sequencing for identification of Plasmodium species

LIN Wen'ai, CHEN Liying, ZHANG Cheng, WEI Huagui, TANG Caiqun, WANG Rong, LIN Liyun, LIN Min

2025, 37(4):  355-361. 

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Objective　To develop a novel assay based on recombinase⁃aided isothermal nucleic acid amplification (RAA) and nanopore sequencing for species identification of Plasmodium vivax, P. ovale, P. malariae and P. falciparum, and to preliminarily assess its detection performance. Methods　Dried blood spot samples were collected from 89 malaria patients. Genomic DNA of Plasmodium was extracted from dried blood spots using the Chelex⁃100 method, and the species of Plasmodium was identified using TaqMan real⁃time fluorescence quantitative reverse transcription PCR, real⁃time quantitative reverse transcriptoin PCR(RT⁃qPCR) and nested PCR (nPCR) assays. Then, 8 sets of specific RAA primers were designed targeting the 18S ribosomal RNA (18S rRNA) genes of P. vivax, P. ovale, P. malariae and P. falciparum. The optimal primer combination was selected for amplification of the extracted Plasmodium DNA samples, and the 49 samples with the best amplification effect were selected for nanopore sequencing. The species identification of 49 dried blood spot samples from malaria patients was compared by RT⁃qPCR assay, nPCR assay and RAA⁃nanopore sequencing, and the sensitivity, specificity and accuracy of RT⁃qPCR assay and RAA⁃nanopore sequencing were evaluated with nPCR identification as the gold standard.  Results　RAA amplification showed that among the 8 primer combinations, only the F1R2 combination produced a single fragment, and the band of the amplification product was the brightest; therefore, this primer combination was selected for RAA amplification of 89 Plasmodium genomic DNA samples. RAA⁃nanopore sequencing successfully amplified the 18S rRNA gene of 4 Plasmodium species in dried blood spot samples from malaria patients. Among the blood spot samples positive for RAA amplification, 49 samples with a single, clear and bright target band were selected for nanopore sequencing. Of these 49 samples, nPCR identified P. falciparum infection in 22 samples, P. malariae infection in 6 samples, P. vivax infection in 6 samples, P. ovale infection in 14 samples and P. falciparum⁃P. malariae mixed infection in one sample, and RT⁃qPCR detected P. falciparum infection in 25 samples, P. malariae infection in 5 samples, P. vivax infection in 6 samples and P. ovale infection in 14 samples, while RAA⁃nanopore sequencing identified P. falciparum infection in 23 samples, P. malariae infection in 6 samples, P. vivax infection in 6 samples, P. ovale infection in 13 samples and P. falciparum⁃P. malariae mixed infection in one sample. If nPCR assay served as the gold standard, the sensitivity, specificity and accuracy of RAA⁃nanopore sequencing were 92.00%, 97.33% and 96.00% for species identification of malaria parasites, which were higher than those (88.24%, 97.32%, and 95.00%) of the RT⁃qPCR assay. Conclusions　The RAA⁃nanopore sequencing established in this study is sensitive, specific and accurate for identifying Plasmodium species, which may serve as a supplementary approach to conventional techniques for detection of malaria parasites.

Changes in murine skin odors following Plasmodium infections and their impact on mosquito attraction

LI Jianyong, LI Meilin, HE Biao, LIU Taiping, ZHU Feng, ZHANG Jian, XU Wenyue

2025, 37(4):  362-370. 

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Objective　To investigate the alterations in skin volatile odors in mice following Plasmodium infections and their effect on  mosquito attraction, and to analyze the changes in murine skin microbiota, so as to provide the scientific evidence for unraveling pathogen⁃host⁃vector interactions and management of vector⁃borne diseases. Methods　Twenty 6⁃week⁃old female mice of the C57BL/6 strain were randomly divided into the infection and control groups, of 10 mice in each group. Mice in the infection group were each injected with 1 × 106 Plasmodium yoelii via the tail vein, and mice in the control group received an equivalent volume of phosphate⁃buffered saline (PBS). Blood samples were collected from mouse tail vein daily on days 1 to 6 post⁃infection for preparation of blood smears for microscopic observation to dynamically monitor changes in parasitaemias. A triple⁃cage olfactometer was deployed to compare the numbers of Anopheles stephensi attraction to mice between the two groups. Mouse cutaneous volatile odors were collected with adsorbents and analyzed by gas⁃chromatography⁃mass⁃spectrometry (GC⁃MS) to identify odorous molecules, and the amounts of odorous molecules on mouse skin were compared between groups. In addition, mouse skin microbiota was collected with cottonswabs for 16S rRNA gene amplicon sequencing to compare the relative abundance of bacteria in mouse skin microbiota between the two groups. Results　The parasitaemias were  0, (2.30 ± 0.87)%, (8.00 ± 4.34)%, (31.30 ± 3.51)%, (42.00 ± 2.65)% and (51.00 ± 3.61)% in mice in the infection group on days 1 to 6 post⁃infection with Plasmodium (F = 165.60, P < 0.001), and the gametocytaemias were 0, (0.14 ± 0.06)%, (0.39 ± 0.10)%, (0.63 ± 0.15)%, (1.10 ± 0.10)% and (1.53 ± 0.31)%, respectively (F = 44.58, P < 0.001). Pairwise comparisons showed the highest parasitaemias and gametocytaemias in mice 6 days post⁃infection (both P values < 0.05), and linear regression analysis revealed that both the parasitaemias (b = 11.36, t = 14.43, P < 0.001) and gametocytaemias (b = 0.31, t = 12.80, P < 0.001) appeared a tendency towards a rise over days. The proportions of mosquito attraction to mice were 50.45% (106/210), 49.55% (119/240), 49.18% (112/227), 55.87% (132/236), 66.84% (159/237), 61.32% (138/226) and 54.65% (126/230) in the infection group on the day of infection and on days 1 to 6 post⁃infection, which appeared a tendency towards a rise over days ([χ2] = 9.536, P < 0.05). A total of 24 odors were identified in mouse skin surface, and Plasmodium⁃infected mice exhibited significantly higher enrichment of p⁃cresol (134 954.86 ± 40 485.75 vs. 34 700.13 ± 4 774.68; t = 4.260, P = 0.013), ethylbenzene (1 214 980.59 ± 111 546.49 vs. 355 445.01 ± 53 369.70; t = 12.04, P = 0.00) and nonanal (62 215.11 ± 11 348.82 vs 24 040.15 ± 8 557.10; t = 4.35, P = 0.02), and lower contents of toluene (61 833.23 ± 2 755.23 vs. 152 906.21 ± 10 199.69; t = 14.93, P = 0.00), benzaldehyde (583 921.81 ± 39 764.63 vs. 1 071 368.84 ± 254 069.28; t = 3.28, P = 0.00) and indole (10 991.89 ± 582.76 vs. 27 275.57 ± 3 995.59; t = 6.99, P = 0.00) relative to controls. In addition, higher relative abundance  of Streptococcus (0.29 ± 0.12 vs. 0.12 ± 0.09; t = 2.54, P = 0.03) and Rothia (0.16 ± 0.05 vs. 0.04 ± 0.06; t = 3.52, P = 0.01) and lower abundance  of Lactococcus (0.02 ± 0.04 vs. 0.27 ± 0.20; t = 2.73, P = 0.03) were found on mouse skin surface in the infection group than in the control group. Conclusion　 Upon infection with Plasmodium, the volatile odor profile emitted from the skin of mice undergoes alterations, resulting in increased attractiveness to mosquitoes. This phenomenon may be attributed to parasite⁃induced changes in the skin microbiota.

Epidemiological characteristics of severe fever with thrombocytopenia syndrome in China from 2010 to 2023

DU Shanshan, SHI Yue, CHEN Xi, LIU Huihui, ZHANG Lijie, HUANG Xiaoxia

2025, 37(4):  371-379. 

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Objective　To investigate the epidemiological characteristics of severe fever with thrombocytopenia syndrome (SFTS) and to identify factors affecting deaths among SFTS patients in China from 2010 to 2023, so as to provide insights into scientific prevention and control of SFTS. Methods　Demographic and epidemiological characteristics of reported, definitively diagnosed SFTS cases in China from 2010 to 2023 were captured from National Notifiable Infectious Disease Reporting System of China Information System for Disease Control and Prevention, including current residence address, age, gender, occupation, time of incidence and date of death, and the temporal, spatial and population distributions of SFTS cases were analyzed. The county⁃level incidence of reported SFTS cases in China from 2010 to 2023 was subjected to spatial autocorrelation analysis, and the global Moran's I index was calculated. The high⁃incidence clusters for SFTS were identified using space⁃time scan analysis based on a Poisson distribution model, and the relative risk (RR) and log⁃likelihood ratio (LLR) were estimated. In addition, factors affecting the death and their risk levels were identified among SFTS cases using chi⁃square test and logistic regression models, and the risk of death was evaluated with odds ratio (OR).  Results　A total of 27 457 SFTS cases were reported in China from 2010 to 2023, and the number of SFTS cases increased from 71 in 2010 to 5 062 in 2023, appearing a tendency towards a rise (b = 5.567, t = 51.35, P < 0.05). A total of 1 326 deaths occurred during the 14⁃year study period, with a case fatality rate of 4.82%, and the annual incidence and fatality of SFTS were 0.005/105 to 0.359/105, and 2.70% to 12.70%. SFTS cases were reported across 27 provinces in China, which were predominantly reported in 7 provinces of Shandong (7 890 cases, 28.74%), Henan (6 286 cases, 22.89%), Anhui (5 718 cases, 20.83%), Hubei (3 938 cases, 14.34%), Liaoning (1 418 cases, 5.16%), Zhejiang (990 cases, 3.61%), and Jiangsu (957 cases, 3.49%), accounting for 99.05% (27 197/27 457) of totally reported cases in China. The time of SFTS incidence appeared a seasonal distribution, and the incidence of SFTS peaked during the period from May to July, with a significant difference in the time of SFTS incidence among provinces (P < 0.01). Among all SFTS cases, there were 12 894 men (46.96%) and 14 563 women (53.04%), and there were 61.27% (16 823/27 457) of SFTS cases at ages of 61 years and older, with farmers as the predominant occupation (84.74%, 23 266/27 457). The annual Moran's I index for SFTS incidence ranged from 0.326 2 to 0.607 5 from 2010 to 2023, and there were significant differences in the Moran's I index for SFTS incidence each year from 2011 to 2023 (z = 10.207 to 18.101, all P values < 0.001), presenting spatial clusters. Local spatial autocorrelation analysis identified "high⁃high", "low⁃high", "high⁃low", and "low⁃low" clusters of reported SFTS cases in China, with "high⁃high" clusters predominantly distributed in 5 provinces of Shandong, Anhui, Hubei, Henan, and Liaoning, covering 63 counties (cities, districts) in 2011 to 134 counties (cities, districts) in 2023. Monthly space⁃time scans identified three high⁃incidence clusters for SFTS in 4 provinces of Henan, Shandong, Jiangsu and Anhui. Univariate analysis revealed the risk of death of reported SFTS cases was associated with province ([χ2] = 605.48, P < 0.01), gender ([χ2] = 23.421, P < 0.01), age ([χ2] = 254.18, P < 0.01), duration from disease onset to diagnosis ([χ2] = 49.895, P < 0.01), and occupation ([χ2] = 30.685, P < 0.01), and multivariate logistic regression analysis revealed a higher risk of death among SFTS cases reported in three provinces of Shandong [OR = 3.081, 95% confidence interval (CI): (2.605, 3.643)], Zhejiang [OR = 4.280, 95% CI: (3.367, 5.441)], and Jiangsu [OR = 2.733, 95% CI: (2.059, 3.628)]; among SFTS cases at ages of 70 years and older [> 70 to 80 years: OR = 4.511, 95% CI: (1.626, 12.511); > 80 years and older: OR = 3.632, 95% CI: (1.241, 10.631)]; among male SFTS cases males than among female cases [OR = 1.243, 95% CI: (1.114, 1.387)]; and among SFTS cases 31 days and longer duration from disease onset to diagnosis [OR = 1.660, 95% CI: (1.254, 2.197)]. Conclusions　The number of reported SFTS cases has remarkably risen in China in recent years, with expanded geographic distributions, seasonal distribution and spatial clusters. Targeted preventive and control measures for SFTS are urgently needed.

Characterization and phylogenetic evolution of tick⁃derived Rickettsiales and emerging viruses in northern Jiangsu Province

CHEN Guoqing, MEI Wei, JIANG Shangde, TAO Luqiu, JI Yuxi, CUI Qian, ZHANG Hongjun, AN Ran, XU Bing, WANG Wei

2025, 37(4):  380-386, 414. 

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Objective　To investigate the tick species, and tick⁃derived Rickettsiales bacteria and recently emerging tick⁃derived viruses in hilly and costal mudflat wetland settings in northern Jiangsu Province, so as to provide insights into management of tick⁃borne tropical diseases in northern Jiangsu Province.  Methods　Ticks were sampled from hilly settings in Yuyi County, Huai'an City and coastal mudflat wetland settings in Jiangsu Yancheng Wetlands & Rare Birds National Nature Reserve in Tinghu District, Yancheng City on April, 2025. Following characterization of tick species, nucleic acid was isolated from ticks under a sterile condition, and tick⁃derived pathogens were detected using nested and semi⁃nested real⁃time PCR assays, including Rickettsia, Ehrlichia, Anaplasma, Yezo virus, Alongshan virus, Songling virus, Beiji nairovirus and Wetland virus. The PCR amplification products were sequenced for analysis of phylogenetic evolution and genetic characteristics.  Results　A total of 154 ticks were captured, including 114 from Huai'an City and 40 from Yancheng City, and 153 ticks were characterized as Haemaphysalis longicornis and one as H. flava. A total of 5 ticks were tested positive for Rickettsiales bacteria and viruses by semi⁃nested real⁃time PCR assay (3.25%), including 4 ticks from hilly settings in Xuyi County, Huai'an City, tested positive for Anaplasma, and one tick from coastal mudflat wetland settings in Tinghu District, Yancheng City, tested positive for Rickettsia; however, ticks were tested negative for Ehrlichia, or recently emerging Yezo virus, Alongshan virus, Songling virus, Beiji nairovirus or Wetland virus. Sequence alignment using BLASTn and phylogenetic analysis revealed that genetic differentiation occurred in four A. bovis isolates in one species of A. bovis, with two genetic clades generated, and one R. japonica variant was identified, with its nucleotide sequences highly homologous to Shandong isolates of R. japonica. Conclusions　Ticks are widely distributed in hilly and costal mudflat wetland settings in northern Jiangsu Province, and tick⁃derived pathogens have a genetic diversity. Tick⁃borne Anaplasma and Rickettsia pose a zoonotic potential.  

Cloning and bioinformatics analysis of surface antigen⁃related sequence protein SRS67 and SRS20A genes in Toxoplasma gondii

CHEN Xiaoxiao, YIN Deqi, MA Wenyu, YI Tingting, LI Hongwei, LIU Lijun, LIU Zhijun, DU Mengze, ZHOU Shuanghai, LI Qiuming

2025, 37(4):  387-397. 

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Objective　To predict the structures and immunogenicity of surface antigen⁃related sequence protein SRS67 and SRS20A in Toxoplasma gondii using bioinformatics methods, and to generate prokaryotic expression vectors for protein expression, so as to identify the functions of recombinant SRS67 and SRS20A proteins and their potential as vaccine candidates against T. gondii. Methods　T. gondii SRS67 and SRS20A gene and amino acid sequences were downloaded from the ToxoDB database. The open reading frames (ORFs) of SRS67 and SRS20A genes were analyzed in the ORF Finder website. The relative molecular mass, isoelectric point, amino acid composition and lipophilicit index of SRS67 and SRS20A proteins were predicted using the ProtParam software. The protein hydrophilicity/hydrophobicity of was predicted using the ProtScale tool, the transmembrane regions were predicted using the TMHMM software, the signal peptides were predicted in the SignalP⁃4.1 website, the secondary and tertiary structures of the proteins were predicted in the NPS@SPOMA and SWISS⁃MODEL websites. The phosphorylation sites of the proteins were predicted using the NetPhos⁃3.1 program, the antigenic epitopes of proteins were predicted using the Immuonmedicine Group program. B⁃cell epitopes, helper T⁃cell (Th) epitopes, and cytotoxic T lymphocyte (CTL) epitopes were predicted using the IEDB and SYFPEITHI websites, and the antigenicity scores of epitopes were evaluated using the software VaxiJen 2.0 to select the dominant epitopes. Primer sequences were synthesized based on the SRS67 and SRS20A protein⁃coding gene sequences from the ToxoDB database, and SRS67 and SRS20A genes were amplified using PCR reactions with T. gondii cDNA as a template. The amplification products were subjected to double restriction⁃enzyme digestion, and the target fragments were recovered and ligated into DH5α competent cells with T4 ligase. Positive single colonies were selected and cultured, and the pET⁃32a⁃SRS67 and pET⁃32a⁃SRS20A recombinant plasmids were extracted, transformed into competent cells for induction of recombinant protein expression. The expression of recombinant proteins was determined using sodium dodecyl sulfate⁃polyacrylamide gel electrophoresis (SDS⁃PAGE) and Western blotting. Results　Bioinformatics analysis predicted that SRS67 and SRS20A genes were 633 bp and 987 bp in length, contained 7 and 15 ORFs, and encoded 210 and 328 amino acids, respectively. The SRS67 protein had a relative molecular mass of 23 135.65, a signal peptide (D = 0.590) and no transmembrane regions, contained 22 phosphorylation sites and 8 antigenic determinants, and was a hydrophilic protein. The SRS20A protein had a relative molecular mass of 34 944.91, a signal peptide (D = 0.697) and transmembrane regions, contained 39 phosphorylation sites and 15 antigenic determinants, and was a hydrophilic protein. The SRS67 and SRS20A proteins shared similar secondary structures, both containing α⁃helices, β⁃sheets, and random coils, and their tertiary structure models exhibited typical globular characteristics, with Global Model Quality Estimation scores of 0.74 and 0.77, respectively. The average antigenic propensity score was 1.046 4 for the SRS67 protein and 1.037 4 for the SRS20A protein, respectively. SRS67 and SRS20A proteins had 7 and 8 dominant B⁃cell epitopes, 10 and 20 dominant Th⁃cell epitopes, and 2 and 3 dominant CTL epitopes, respectively. As expected, the PCR amplification products of SRS67 and SRS20A genes were approximately 633 bp and 987 bp in size. The SRS67 recombinant protein exhibited the highest expression in the precipitate following induction with 0.1 mmol/L IPTG for 16 h, and the SRS20A recombinant protein showed the highest expression following induction with 0.5 mmol/L IPTG for 16 h. SDS⁃PAGE and Western blotting confirmed successful expression of the recombinant proteins. Conclusions　The SRS67 and SRS20A proteins possess multiple cellular epitopes and exhibit favorable immunogenicity. The recombinant SRS67 and SRS20A proteins have been successfully expressed, which provides the theoretical evidence for deciphering protein functions and screening effective vaccine antigens against toxoplasmosis.

Effectiveness of integrated soil⁃borne nematodiasis and clonorchiasis control programmesin Guizhou Province from 2019 to 2023

LI Yang, ZHU Aiya, LI Anmei, XIANG Hong, DAI Jiarui, YUAN Maoyang, GENG Yan

2025, 37(4):  398-402. 

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Objective　To evaluate the effectiveness of the integrated soil⁃borne nematodiasis and clonorchiasis control programmesin Guizhou Province from 2019 to 2023, so as to provide insights into formulation of appropriate parasitic disease control strategies in the province.  Methods　From 2019 to 2023, Shiqian County in Tongren City and Zhenfeng County in Qianxi'nan Buyi and Miao Autonomous Prefecture were selected as pilot counties in Guizhou Province for soil⁃borne nematodiasis prevention and control programmes, and Rongjiang County in Qiandongnan Miao and Dong Autonomous Prefecture was selected as a pilot county for clonorchiasis control programmes. Integrated control measures were implemented in these 3 pilot counties, including surveys on human parasitic infections, deworming, health education and improved water and sanitation. At least 1 000 individuals were sampled from each of three pilot counties using a stratified multi⁃stage random sampling method from 2019 to 2023 for detection of soil⁃borne nematodes and Clonorchis sinensis human infections, and the awareness of soil⁃borne nematodiasis and clonorchiasis control knowledge was investigated among residents in pilot counties using questionnaire surveys. In addition, the implementation of deworming and coverage of sanitary toilets and safe drinking water were collected in three pilot counties. Results　   The prevalence of soil⁃borne nematode human infections reduced from 7.78% (79/1 016), 2.80% (28/1 001) and 14.40% (144/1 000) in 2019 to 1.18% (12/1 014), 1.38% (14/1 001) and 2.73% (28/1 024) in 2023 in Shiqian County, Zhenfeng County, and Rongjiang County, respectively ([χ2] = 51.51, 4.91 and 88.54, all P values < 0.05). No C. sinensis human infections were detected Shiqian County or Zhenfeng County from 2019 to 2023, and the prevalence of C. sinensis human infections reduced from 1.80% (18/1 000) in 2019 to 0.29% (3/1 024) in 2023 in Rongjiang County ([χ2] = 11.19, P < 0.05). Free deworming was provided to 574 cases with soil⁃borne nematode infections and 47 cases with C. sinensis infections detected in three pilot counties from 2019 to 2023. The coverage of health education was 100% in both Zhenfeng County and Shiqian County during the period from 2019 to 2023, and the awareness of soil⁃borne nematodiasis control knowledge increased from 93.60% (234/250) in Zhenfeng County and 70.97% (577/813) in Shiqian County in 2019 to 99.20% (248/250) and 98.40% (492/500) in 2023, respectively. The coverage of health education increased from 60.07% (161/268) in 2019 to 100% (250/250) in 2023 in Rongjiang County, and the awareness of clonorchiasis control knowledge increased from 80.67% (121/150) in 2019 to 99.20% (248/250) in 2023. The coverage of sanitary toilets increased from 48.89% (61 078/124 935), 34.20% (40 381/118 085) and 70.55% (60 604/85 920) in 2019 to 65.87% (77 649/117 878), 56.00% (63 252/112 948) and 89.15% (72 737/81 590) in 2023 in Shiqian County, Zhenfeng County and Rongjiang County, respectively, and the coverage of safe drinking water was all 100% in both Shiqian County and Rongjiang County during the 5⁃year study period, and increased from 85.33% (100 765/118 085) in 2019 to 100% (112 948/112 948) in 2023 in Zhenfeng County. Conclusions　There were remarkable reductions in the prevalence of soil⁃borne nematodes human infections in Shiqian County, Zhenfeng County, and Rongjiang County and in the prevalence of C. sinensis human infections in Rongjiang County, Guizhou Province following the 5⁃year integrated control programmes from 2019 to 2023. The widespread application of the health education⁃led and human parasitic diseases examination and treatment⁃based integrated soil⁃borne nematodiasis and clonorchiasis control programmes seems justified. 

Epidemiological characteristics of imported malaria cases in Chengdu City from 2016 to 2023

FENG Lan, WANG Leyuan, JIANG Xiaojuan, TAN Kaike, LI Peng

2025, 37(4):  403-408. 

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Objective　To investigate the epidemiological characteristics of imported malaria cases in Chengdu City, Sichuan Province from 2016 to 2023, so to provide insights into formulation of the malaria control strategy in the city. ‌Methods　All data pertaining to imported malaria cases reported in Chengdu City during the period from 2016 to 2023 were retrieved from the China Disease Prevention and Control Information System, and the epidemiological characteristics and diagnosis and treatment of imported malaria cases were analyzed. ‌ Results　A total of 463 imported malaria cases were reported in Chengdu City from 2016 to 2023, with Plasmodium falciparum malaria as the predominant type (71.27%, 330/463). Imported malaria cases returned from Africa (94.17%, 436/463), Asia (5.61%, 26/463), and South America (0.22%, 1/463), and were predominantly reported in May, June and December each year. Geographically, imported malaria cases were distributed across 20 counties (districts) in Chengdu City, with most cases (64.15%, 297/463) reported in Jinjiang District, and the male to female ratio of imported malaria cases was 21.05∶1, with most cases diagnosed among migrant labors at ages of 20 to 50 years. There were 35.85% (166/463) of imported malaria cases seeking healthcare services on the day of disease onset, and cases with over 3 days of healthcare⁃seeking following disease onset were primarily farmers and labors at ages of 30 to 50 years. There were 456 imported malaria cases seeking healthcare services for the first time in domestic medical institutions following disease onset, and there were 341 cases with definitive diagnosis at the initial diagnosis (74.78%, 341/456). The domestic institutions with the highest proportion of correct malaria diagnosis at the initial diagnosis were county⁃level medical and health institutions (91.43%, 128/140), followed by city⁃level medical and health institutions (82.45%, 155/188), provincial⁃level medical and health institutions (80.00%, 44/55), and a low proportion of correct malaria diagnosis was seen in township healthcare centers (11.11%, 3/27), village healthcare clinics (0, 0/4) and individual doctors (0, 0/28).  Conclusions　Imported malaria cases in Chengdu City were primarily originated from Africa from 2016 to 2023, with P. falciparum malaria as the predominant type, and the malaria diagnostic capacity was low in grassroots healthcare institutions in the city. Intensified health education for malaria prevention and control targeting labors going to work in Africa and continuous improvements in the malaria diagnostic and treatment capability in healthcare institutions are recommended, in order to reduce the risk of re⁃establishment from imported malaria in Chengdu City.

Epidemiological characteristics of reported echinococcosis cases in Shaanxi Province from 2016 to 2023

NING Shaoqi, LIU Chenyue, NIAN Yunpeng, HU Danni, LI Xinxin, WANG Guan, ZHANG Luqian

2025, 37(4):  409-414. 

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Objective　To investigate the epidemiological characteristics of reported echinococcosis cases and their trends in Shaanxi Province from 2016 to 2023, so as to provide insights into optimization of echinococcosis control and surveillance strategies in the province. Methods　All data pertaining to echinococcosis cases in Shaanxi Province from 2016 to 2023 were captured from China's National Notifiable Disease Reporting System. All echinococcosis cases were subjected to duplicate checking and individual epidemiological surveys, and the temporal, population, and spatial distributions of reported echinococcosis cases were descriptively analyzed.  Results　A total of 94 echinococcosis cases were reported in Shaanxi Province from 2016 to 2023, and all cases were diagnosed with cystic echinococcosis, including 38 cases (40.43%) with definitive diagnosis of echinococcosis and 56 cases (59.57%) with clinically diagnosed echinococcosis, and 26 cases (27.66%) from echinococcosis⁃endemic foci, 33 imported cases (35.11%), and 35 suspected locally acquired cases (37.23%). Male cases were predominantly at ages of > 40 to 70 years (66.67%), and female cases were mainly at ages of > 55 to 70 years (43.24%). Farmer was the predominant occupation (68.09%), and junior high school was the predominant educational level (29.79%). Reported echinococcosis cases from endemic foci were mainly concentrated in Dingbian County (23 cases, 88.46%), and imported echinococcosis cases were primarily distributed in Xi'an City and Xianyang City in the central Guanzhong region (19 cases, 57.58%), while suspected locally acquired cases were mainly distributed in Tongchuan City, Xi'an City, and Weinan City in the central and eastern Guanzhong region (22 cases, 62.86%). Among the 33 imported echinococcosis cases, 31 cases (93.94%) had a history of long⁃term residence in, travel to, or visiting relatives or friends in endemic areas, and 11 (33.33%) had a history of contacts with dogs or foxes in endemic areas. Of the 35 suspected locally acquired echinococcosis cases, 18 cases (51.43%) had a history of breeding dogs or exposure to neighbors' dogs, and no history of other relevant exposure. Conclusions　The prevalence of echinococcosis was low in Shaanxi Province from 2016 to 2023; however, there was a risk of continuous importation of echinococcosis cases in the province. Intensified echinococcosis control measures are recommended among high⁃risk populations with adaptations to local circumstances. 

Effectiveness of an artificial intelligence⁃enabled microscopic imaging recognition system for detection of Schistosoma japonicum eggs

CHEN Lu, LUO Hongwei, WU Chunjiang, WAN Junfang, WU Jiali, LIU Haobing, LI Bin, YANG Shunyi

2025, 37(4):  415-419. 

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Objective　To evaluate the effectiveness of an artificial intelligence (AI)⁃enabled microscopic imaging recognition system integrated in the modified Kato⁃Katz thick smear technique for detection of Schistosoma japonicum eggs, so as to provide insights into precise control and elimination of schistosomiasis. Methods　In October 2023, 20 fecal samples were collected from healthy residents negative for S. japonicum infection in Wuhan City, and each fecal sample was prepared into 4 Kato⁃Katz test slides, with 3 slides added S. japonicum egg suspensions with concentrations of approximately 25, 10, and 5 eggs per 10 μL, respectively, and one untreated. A total of 80 Kato⁃Katz test slides were prepared, and were divided into mild, moderate, and severe infection groups, and a negative control group, according to the number of eggs per gram of feces on each slide, with 20 slides in each group. S. japonicum eggs were detected on 80 Kato⁃Katz test slides with the AI⁃enabled microscopic imaging recognition system and manual microscopy, and the differences were compared between the two methods in terms of average detection time, accurate rate of qualitative detection, accurate rate of quantitative detection, percentage of missed detection, and percentage of false detection. Results　The average detection time of the imaging recognition system was longer than manual microscopy for detection of S. japonicum eggs on Kato⁃Katz test slides in all groups [(16.70 ± 0.01) min vs. (15.78 ± 2.11) min; t = 3.90, P < 0.05]. The detection time of the imaging recognition system was shorter than manual microscopy for detection of S. japonicum eggs on Kato⁃Katz test slides in the severe infection group (t = -3.91, P < 0.05), but was longer than manual microscopy in the the mild infection group (t = 5.03, P < 0.05) and the negative control group (t = 8.37, P < 0.05), while there was no significant difference in the detection time between the two methods in the moderate infection group (t = -0.09, P > 0.05). In addition, the imaging recognition system [97.50% (78/80) and 91.67% (55/60)] had higher accurate rates of both qualitative and quantitative detections than manual microscopy [81.25% (65/80) and 31.67% (19/60)] ([χ2] = 11.08 and 34.11, both P values < 0.05), and the imaging recognition system had a lower percentage of missed detection in the infection groups [3.33% (2/60)] and a lower percentage of false detection in the negative control group (0) than manual microscopy [13.33% (8/60) and 35.00% (7/20)] ([χ2] = 6.07, 5.14, both P values < 0.05). Conclusions　The AI⁃enabled microscopic imaging recognition system is effective to improve the accuracy for detection of S. japonicum eggs with the Kato⁃Katz technique, and is accurate to quantify and simple to perform, which may provide technical support for diagnosis of schistosomiasis and other parasitic diseases.

Global research hotspots and trends of wildlife⁃associated zoonoses from 1990 to 2024

ZHANG Zhifang, DENG Yanqin, WU Shenggen

2025, 37(4):  420-427. 

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Objective　To investigate the global hotspot issues and future directions of wildlife⁃associated zoonoses, so as to provide insights into identification of future research proprieties of wildlife⁃associated zoonoses.  Methods　Research and review articles pertaining to wildlife⁃associated zoonoses were retrieved from the Web of Science Core Collection from 1990 to 2024, and the annual publication trends and visualization maps for research collaborations among authors, institutions and countries were analyzed using the software CiteSpace 6.3.R3. In addition, the keyword co⁃occurrence, burst and clustering maps and co⁃citation clustering maps were created to identify the research hotspots and frontier landscapes of wildlife⁃associated zoonoses.  Results　A total of 2 479 English publications were included in this bibliometric analysis. The annual publication output started to increase since 2001, and peaked in 2021 (336 publications). There were 12 authors with more than 10 publications from 1990 to 2024. The top 10 most productive institutions included 8 colleges or universities, with University of California, Davis ranking first (114 publications). The United States of America played a significant mediating role in international collaborations (betweenness centrality = 0.31) and produced the largest number of publications (1 004), and the collaboration network maps among authors, institutions, and countries all appeared localized clustering with overall fragmentation. Keyword co⁃occurrence analysis identified high⁃frequency terms including infection (489 occurrences), prevalence (398 occurrences), transmission (351 occurrences), wildlife (330 occurrences) and epidemiology (231 occurrences), and keyword burst analysis revealed the research focus of wildlife⁃associated zoonoses shifting from specific zoonotic diseases such as trichinellosis and tuberculosis to interdisciplinary domains including wildlife trade, virulence, One Health, and antimicrobial resistance. Keyword clustering analysis identified antimicrobial resistance and One Health as current research hotspots, and co⁃citation clustering analysis showed human health, agricultural intensification, and first case reports as theoretical basis for wildlife⁃associated zoonoses. Conclusions　The wildlife⁃associated zoonoses research has expanded exponentially across the world. Advocating for One health concept is an important task for management of emerging and re⁃emerging zoonoses currently and in future.

Application of eco⁃immunology in parasitology and parasitic diseases research: a review

WANG Xu, YIN Jianhai, LIU Hua, HAN Shuai, HU Yuan, SHEN Yujuan, CAO Jianping

2025, 37(4):  428-433, 446. 

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As an emerging interdisciplinary field bridging ecology and immunology, eco⁃immunology focuses on the co⁃evolutionary dynamics between hosts and parasites within natural environments, and aims to unravel the ecological mechanisms underlying the formation of host immune strategies, so as to provide new insights into parasitology and parasitic diseases research. Based on case studies of diverse host⁃parasite systems, including insects⁃protozoans, fish⁃cestodes, amphibians⁃nematodes, reptiles⁃arthropods, birds⁃ectoparasites, and mammals⁃helminths, this review summarizes critical eco⁃immunological principles, including host tolerance trade⁃offs under resource constraints, transgenerational epigenetic adaptation, nutrition⁃immunity interactions, and immune conflicts triggered by multiparasite co⁃infections. In addition, the article discusses the feasibility and practical pathways of ecological management and interventions to achieve biodiversity conservation and disease control based on the eco⁃immunological theory, so as to provide innovative insights into responses to address ecological conservation and public health challenges in the context of global changes.


Metagenomic next⁃generation sequencing technology and its application in diagnosis of Pneumocystis jirovecii infection: a review

XUE Ting, DU Weiqin, ZHAO Yujing, XU Jia

2025, 37(4):  434-446. 

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Pneumocystis jirovecii is an opportunistic fungal pathogen causing fatal Pneumocystis jirovecii pneumonia (PJP) among immunocompromised patients. Conventional pathogen detection methods have limitations, which hinders early diagnosis and treatment of PJP, resulting in misdiagnosis and underdiagnosis, and high mortality rates. Metagenomic next⁃generation sequencing (mNGS), which is high in sensitivity and specificity for pathogen detection, enables accurate detection of P. jirovecii and P. jirovecii co⁃infection with other pathogens, which facilitates timely diagnosis and treatment of PJP. This review summarizes the advances in mNGS technology and its application in diagnosis of PJP, highlighting its critical clinical value in improving diagnostic effectiveness, guiding clinical therapy, and preventing nosocomial transmission of PJP.

Balamuthia mandrillaris amebic encephalitis in children: a case report

CHEN Tianyu, JIN Danqun, YE Huan

2025, 37(4):  447-450. 

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Balamuthia mandrillaris amebic encephalitis is a rare but highly fatal parasitic disease in the central nervous system caused by amebae infections. This disease is characterized by complex, diverse and non⁃specific clinical manifestations and high difficulty in diagnosis, resulting in a high likelihood of missing diagnosis and misdiagnosis. This article presents the diagnosis and treatment of a child with definitive diagnosis B. mandrillaris amebic encephalitis as revealed by metagenomic next⁃generation sequencing of cerebrospinal fluids, so as to provide insights into clinical diagnosis and treatment of B. mandrillaris amebic encephalitis.