Table of Content

20 December 2023, Volume 35 Issue 6

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Schistosomiasis control in Sichuan Province since the 12th Five⁃Year Plan period: progress and prospects

SHANG Jingye, ZHANG Yu, PU Chen, WAN Jiajia, CHEN Lin, WU Zisong, LIU Yang

2023, 35(6):  539-544,556. 

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An ambitious goal has been set for elimination of schistosomiasis in all endemic counties (districts) in Sichuan Province by 2023. To achieve this goal, and to continue to consolidate the control achievements, it is necessary to understand the current endemic status of schistosomiasis, identify the challenges and analyze the experiences and lessons from the schistosomiasis control program, and develop targeted control strategies and interventions in the province. This paper reviews the progress of schistosomiasis control in Sichuan Province since the 12th Five⁃Year Plan period, analyzes the challenges in the schistosomiasis elimination program, and proposes recommendations for future directions and priorities.

Construction of an evaluation index system for the capability of comprehensive control of mountain⁃type zoonotic visceral leishmaniasis based on the One Health concept

LIU Jingshu, ZHOU Zhengbin, ZHANG Xiaoxi, HUANG Lulu, LUO Zhuowei, CHEN Shenglin, ZHANG Yi, LI Shizhu

2023, 35(6):  545-556. 

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Objective　To construct an evaluation index system for the capability of comprehensive control of mountain⁃type zoonotic visceral leishmaniasis based on the One Health concept, so as to provide insights into the control and elimination of mountain⁃type zoonotic visceral leishmaniasis using the One Health approach. Methods　A preliminary evaluation index system was constructed based on literature review, panel discussions and field surveys. Thirty⁃three experts were selected from 7 provincial disease control and prevention centers in Beijing Municipality, Hebei Province, Shanxi Province, Henan Province, Sichuan Province, Shaanxi Province and Gansu Province where mountain⁃type zoonotic visceral leishmaniasis was endemic, and two rounds of expert consultations were conducted to screen the indicators. The positive coefficient, degree of concentration, degree of coordination, and authority of the experts were calculated, and the normalized weights of each index were calculated with the analytic hierarchy process. Results　The response rates of questionnaires during two rounds of expert consultation were both 100.00% (33/33), and the authority coefficients of the experts were 0.86 and 0.88, respectively. The coefficients of coordination among experts on the rationality, importance, and operability of the indicators were 0.392, 0.437, 0.258, and 0.364, 0.335, 0.263, respectively (all P values < 0.05). Following screening, the final evaluation index system included 3 primary indicators, 17 secondary indicators, and 50 tertiary indicators. The normalized weights of primary indicators “external environment”, “internal support” and “comprehensive control” were 16.98%, 38.73% and 44.29%, respectively. Among the secondary indicators of the primary indicator “external environment”, the highest weight was seen for natural environment (66.67%), and among the secondary indicators of the primary indicator “internal support”, the lowest weight was seen for the scientific research for visceral leishmaniasis control (8.26%), while other indicators had weights of 12.42% to 13.38%. Among the secondary indicators of the primary indicator “comprehensive control”, the weight was 16.67% for each indicator. Conclusions　An evaluation index system has been constructed for the capability of comprehensive control of mountain⁃type zoonotic visceral leishmaniasis based on the One Health concept. In addition to assessment of the effect of conventional mountain⁃type zoonotic visceral leishmaniasis control measures, this index system integrates the importance of top⁃level design, organizational management, and implementation of control measures, and includes indicators related to multi⁃sectoral cooperation.

Single⁃nucleotide polymorphisms of artemisinin resistance⁃related Pfubp1 and Pfap2mu genes in Bioko Island, Equatorial Guinea from 2018 to 2020

ZHANG Taichan, LIANG Xueyan, WEI Huagui, LIN Min, CHEN Jiangtao

2023, 35(6):  557-564,572. 

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Objective　To investigate the prevalence of single nucleotide polymorphisms (SNPs) of artemisinin resistance⁃related Pfubp1 and Pfap2mu genes in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea, so as to to provide baseline data for the formulation of malaria control strategies in Bioko Island. Methods　A total of 184 clinical blood samples were collected from patients with P. falciparum malaria in Bioko Island, Equatorial Guinea from 2018 to 2020, and genomic DNA was extracted. The Pfubp1 and Pfap2mu gene SNPs of P. falciparum were determined using a nested PCR assay and Sanger sequencing, and the gene sequences were aligned. Results　There were 159 wild⁃type P. falciparum isolates (88.83%) from Bioko Island, Equatorial Guinea, and 6 SNPs were identified in 20 Pfubp1⁃mutant P. falciparum isolates (11.17%), in which 4 non⁃synonymous mutations were detected, including E1516G, K1520E, D1525E, E1528D. There was only one Pfubp1gene mutation site in 19 Pfubp1⁃mutant P. falciparum isolates (95.00%), in which non⁃synonymous mutations accounted for 68.42% (13/19). D1525E and E1528D were identified as major known epidemic mutation sites in the Pfubp1 gene associated with resistance to artemisinin⁃based combination therapies (ACTs). At amino acid position 1525, there were 178 wild⁃type P. falciparum isolates (99.44%) and 1 mutant isolate (0.56%), with such a mutation site identified in blood samples in 2018, and at amino acid position 1528, there were 167 wild⁃type P. falciparum isolates (93.30%) and 12 mutant isolates (6.70%). The proportions of wild⁃type P. falciparum isolates were 95.72% (134/140), 79.25% (126/159) and 95.83% (161/168) in the target amplification fragments of the three regions in the Pfap2mu gene (Pfap2mu⁃inner1, Pfap2mu⁃inner2, Pfap2mu⁃inner3), respectively. There were 16 different SNPs identified in all successfully sequenced P. falciparum isolates), in which 7 non⁃synonymous mutations were detected, including S160N, K199T, A475V, S508G, I511M, L595F, and Y603H. There were 7 out of 43 Pfap2mu⁃mutant P. falciparum isolates (16.28%) that harbored only one gene mutation site, in which non⁃synonymous mutations accounted for 28.57% (2/7). For the known delayed clearance locus S160N associated with ACTs, there were 143 wild⁃type (89.94%) and 16 Pfap2mu⁃mutant P. falciparum isolates (10.06%). Conclusions　Both Pfubp1 and Pfap2mu gene mutations were detected in P. falciparum isolates from Bioko Island, Equatorial Guinea from 2018 to 2020, with a low prevalence rate of Pfubp1 gene mutation and a high prevalence rate of Pfap2mu gene mutation. In addition, new mutation sites were identified in the Pfubp1 (E1504E and K1520E) and Pfap2mu genes (A475V and S508G).

Species and population density of malaria vector Anopheles in Sichuan Province from 2011 to 2021

GONG Xi, WU Xiaohong, HUO Fang, YU Tao, GE Li, LIU Yang, LI Li

2023, 35(6):  565-572. 

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Objective　To investigate the distribution of malaria vector Anopheles in Sichuan Province from 2011 to 2021, so as to provide the scientific evidence for improving the surveillance of malaria vector Anopheles and preventing re⁃establishment of imported malaria in Sichuan Province. Methods　The density and species of Anopheles mosquitoes were investigated using human⁃bait trapping and light trapping techniques in malaria vector surveillance sites of Sichuan Province from 2011 to 2021. The number, population and density of captured Anopheles mosquitoes were collected and descriptively analyzed, and the geographical distribution map of malaria vectors was plotted using the software ArcGIS 10.7 in Sichuan Province. Results　A total of 152 243 Anopheles mosquitoes were captured in malaria vector surveillance sites of Sichuan Province from 2011 to 2021, including 150 987 An. sinensis (99.18%) and 1 256 An. anthropophagus (0.82%) ([χ2] = 5 938.92, P < 0.01), and no other Anopheles species were captured. The annual densities of An. sinensis and An. anthropophagus were 0.64 to 1.27 mosquitoes/(person⁃hour) and 0 to 0.07 mosquitoes/(person⁃hour) by the human⁃bait trapping technique, and 6.46 to 26.50 mosquitoes/(light⁃night) and 0 to 0.82 mosquitoes/(light⁃night) by the light trapping technique in malaria vector surveillance sites of Sichuan Province from 2011 to 2021. A relatively higher density of An. anthropophagus was seen in Renshou County, Jianyang City, Weiyuan County and Mabian Yi Autonomous County ［> 0.40 mosquitoes/(person⁃hour)］ by the human⁃bait trapping technique, and in Cuiping District and Gaoxian County in Yibin City ［> 1.00 mosquito/(light⁃night)］ by the light trapping technique in Sichuan Province from 2011 to 2018, with no An. anthropophagus captured from 2019 to 2021, and a relatively higher density of An. sinensis was detected in Emeishan City, Lushan County, Luojiang District, Tongchuan District and Zhaohua District ［> 4.00 mosquitoes/(person⁃hour)］ by the human⁃bait trapping technique, and in Huili County, Yuexi County, Dechang County, Langzhong City, Pingchang County and Xuanhan County ［> 40.00 mosquitoes/(light⁃night)］ by the light trapping technique in Sichuan Province from 2011 to 2021. Conclusions　Malaria vectors were still widespread in Sichuan Province from 2011 to 2021, and An. sinensis was the dominant species of malaria vectors. There is still a risk of local re⁃establishment of imported malaria in Sichuan Province, and it is needed to continue to improve the surveillance of imported malaria cases and malaria vectors.

Comparison of the efficiency of different etiological assays for detection of Schistosoma japonicum infections in wild mice

XU Xiaojuan, CHEN Xuefeng, WU Fan, WU Chenyang, LIU Ting, DAI Bo, WANG Tianping, ZHANG Shiqing

2023, 35(6):  573-582,589. 

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Objective　To compare the efficiency of multiple etiological techniques for detection of Schistosoma japonicum infections in wild mice, so as to provide technical supports to assessment of schistosomiasis transmission risk. Methods　Wild mice were captured with baited traps at night in Oncomelania hupensis snail⁃infested settings in schistosomiasis⁃endemic foci of Anhui Province from October to November, 2022. S. japonicum infections were detected in wild mice using microscopy of mouse liver tissues, microscopy of mouse mesenteric tissues, microscopy of mouse liver tissue homogenates, miracidial hatching test of mouse liver tissue homogenates, Kato⁃Katz technique and miracidial hatching test of mouse stool samples alone and in combinations. Identification of S. japonicum eggs or miracidia by any of these six assays was defined as an infection. The sensitivity of six assays alone or in combinations was compared for detection of S. japonicum infections in wild mice. Results　A total of 1 703 wild mice were captured, with 366 wild mice detected positive for S. japonicum (21.49%). There were significant differences in the prevalence of S. japonicum infections in wild mice by six assays (Q = 529.33, P < 0.001) and in the sensitivity of six assays for detection of S. japonicum infections in wild mice ([χ2] = 527.78, P < 0.001). In addition, the combination of microscopy of mouse liver tissues and mesenteric tissues, combination of microscopy of mouse liver tissues and liver tissue homogenates and combination of microscopy of mouse liver tissues, microscopy of mesenteric tissues, microscopy of liver tissue homogenates and Kato⁃Katz technique showed 86.61%, 87.16% and 97.27% sensitivities for detection of S. japonicum infections in wild mice, respectively. Conclusions　Diverse etiological assays show various efficiencies for detection of S. japonicum infections in wild mice. Combination of microscopy of mouse liver tissues and microscopy of mesenteric tissues, and combination of microscopy of mouse liver tissues and microscopy of liver tissue homogenates are potential approaches for field detection of S. japonicum infections in wild mice.

Molecular epidemiological characteristics of newly diagnosed HIV⁃1 cases in Fujian Province in 2020

XIE Meirong, LIN Liying, WANG Zhenghua, QIU Yuefeng, LU Xiaoli, ZHANG Chunyang, WU Shouli

2023, 35(6):  583-589. 

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Objective　To investigate the HIV⁃1 genotype and distribution of newly diagnosed HIV⁃1 cases in Fujian Province in 2020, so as to provide insights into formulation of the precise AIDS control strategy in the province. Methods　Newly diagnosed HIV⁃1 cases without antiretroviral therapy (excluding AIDS patients) were randomly sampled from each city of Fujian Province in 2020 at a proportion of 50% of the mean number of HIV⁃infected cases reported across 9 cities of Fujian Province during the past three years. Subjects’ demographic and epidemiological data were collected and blood samples were collected. The HIV⁃1 pol gene was amplified using nested reverse⁃transcription PCR assay, and the gene sequences were used for HIV⁃1 genotyping and phylogenetic analysis. The gene sequences were uploaded to the HIV Drug Resistance Database (http://hivdb.stanford.edu) for genotypic drug resistance assays, and the scores and level of HIV drug resistance were estimated using the HIVDB Algorithm version 9.5. Results　A total of 1 043 newly diagnosed HIV⁃1 cases were reported in Fujian Province in 2020, and 936 gene sequences were successfully obtained following sequencing of blood samples. There were 9 HIV⁃1 genotypes characterized in blood samples from 936 newly diagnosed HIV⁃1 cases, with CRF07_BC (52.1%) and CRF01_AE (30.4%) as predominant subtypes, followed by CRF08_BC (4.9%), CRF55_01B (3.0%), subtype C (2.5%), subtype B (2.1%), CRF85_BC (1.7%), CRF59_01B (0.3%) and CRF65_CPX (0.1%), and unidentified subtypes were found in 26 blood samples. HIV⁃1 drug resistance was detected in 43 out of the 936 newly diagnosed HIV⁃1 cases, with 4.6% prevalence of HIV⁃1 drug resistance prior to therapy, and the highest drug resistance was found in the HIV CRF59_01B subtype, followed by in CRF08_BC, B, C, CRF01_AE, CRF07_BC and other subtypes, with a significant difference in the genotype⁃specific prevalence of HIV⁃1 drug resistance ([χ2] = 45.002, P < 0.05). Conclusions　There was a HIV⁃1 genotype diversity in Fujian Province in 2020, and emerging recombinant and drug⁃resistant HIV⁃1 strains were detected and spread across patients and regions. Monitoring of HIV⁃1 genotypes is recommended to be reinforced for timely understanding of the transmission and spread of novel recombinant and drug⁃resistant HIV⁃1 strains.

Preliminary study on the effect of Echinococcus multilocaris on phenotypic transformations of glucose metabolism and polarization types in macrophages

SHEN Yinhong, ZHANG Tao, YANG Zi⁃han, ZHANG Yaogang, HUANG Dengliang, HOU Jing, TIAN Meiyuan, MA Yanyan

2023, 35(6):  590-603,613. 

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Objective　To investigate the effects of Echinococcus multilocularis on the phenotypic transformations of glucose metabolism, polarization types and inflammatory responses in macrophages, so as to provide insights into elucidation of echinococcosis pathogenesis. Methods　Bone marrow cells were isolated from C57BL/6J mice at ages of 6 to 8 weeks, and induced into bone marrow⁃derived macrophages (BMDMs) with mouse macrophage colony⁃stimulating factor (M⁃CSF), which served as controls (BMDMs⁃M0). BMDMs⁃M0 induced M2 macrophages by interleukin⁃4 for 24 hours served as the IL⁃4 induction group, and BMDMs⁃M0 co⁃cultured with 2.4 ng/mL E. multilocularis cystic fluid (CF) served as the BMDM⁃CF co⁃culture group, while BMDMs⁃M0 co⁃cultured with E. multilocularis protoscolex (PSC) at a ratio of 500∶1 served as the BMDM⁃PSC co⁃culture group. The types of polarization of BMDMs co⁃cultured with E. multilocularis CF and PSC were analyzed using flow cytometry, and the expression of macrophage markers, inflammatory factors, and glucose metabolism⁃related enzymes was quantified using fluorescent quantitative real⁃time PCR (qPCR) and Western blotting assays. Results　There were significant differences among the four groups in terms of Arginase⁃1 (Arg1) (F = 1 457.00, P < 0.000 1), macrophages⁃derived C⁃C motif chemokine 22 (Ccl22) (F = 22 203.00, P < 0.000 1), resistin⁃like α (Retnla) (F = 151.90, P < 0.000 1), inducible nitric oxide synthase (iNOS) (F = 107.80, P < 0.001), hexokinase (HK) (F = 9 389.00, P < 0.000 1), pyruvate kinase (PK) (F = 641.40, P < 0.001), phosphofructokinase 1 (PFK1) (F = 43.97, P < 0.01), glucokinase (GK) (F = 432.50, P < 0.000 1), pyruvate dehydrogenase kinases1 (PDK1) (F = 737.30, P < 0.000 1), lactic dehydrogenase (LDH) (F = 3 632.00, P < 0.000 1), glucose transporter 1 (GLUT1) (F = 532.40, P < 0.000 1), glyceraldehyde⁃3⁃phosphate dehydrogenase (GAPDH) (F = 460.00, P < 0.000 1), citrate synthase (CS) (F = 5 642.00, P < 0.01), glycogen synthase1 (GYS1) (F = 273.30, P < 0.000 1), IL⁃6 (F = 1 823.00, P < 0.000 1), IL⁃10 (F = 291.70, P < 0.000 1), IL⁃1β (F = 986.60, P < 0.000 1), and tumor necrosis factor (TNF)⁃α (F = 334.80, P < 0.000 1) and transforming growth factor (TGF)⁃β mRNA expression (F = 163.30, P < 0.001). The proportion of M2 macrophages was significantly higher than that of M1 macrophages in the BMDM⁃PSC co⁃culture group [(22.87% ± 1.48%) vs. (1.70% ± 0.17%); t = 24.61, P < 0.001], and the proportion of M2 macrophages was significantly higher than that of M1 macrophages in the BMDM⁃CF co⁃culture group [(20.07% ± 0.64%) vs. (1.93% ± 0.25%); t = 45.73, P < 0.001]. The mRNA expression of M2 macrophages markers Arg1, Ccl22 and Retnla was significantly higher in the BMDM⁃CF and BMDM⁃PSC co⁃culture groups than in the control group (all P values < 0.01), and no significant difference was seen in the mRNA expression of the M1 macrophage marker iNOS among the three groups (P > 0.05), while qPCR assay quantified higher mRNA expression of key glycolytic enzymes HK, PK and PFK, as well as inflammatory factors IL⁃10, IL⁃1β, TNF⁃α and TGF⁃β in the BMDM⁃CF and BMDM⁃PSC co⁃culture groups than in the control group (all P values < 0.01). Western blotting assay determined higher HK, PK and PFK protein expression in the BMDM⁃PSC co⁃culture group than in the control group (all P values < 0.05), and qPCR quantified higher GLUT1, GAPDH and IL⁃6 mRNA expression in the BMDM⁃CF co⁃culture group than in the control group (all P values < 0.05), while higher HK, PK and PFK protein and mRNA expression (all P values < 0.01), as well as lower IL⁃6 and TNF⁃α and higher TGF⁃β mRNA expression (both P values < 0.05) was detected in the IL⁃4 induction group than in the control group. Glycolytic stress test showed no significant difference in the extracellular acidification rate (ECAR) of mouse BMDM among the control group, IL⁃4 induction group and BMDM⁃PSC co⁃culture group (F = 124.4, P < 0.05), and a higher ECAR was seen in the BMDM⁃PSC co⁃culture group and a lower ECAR was found in the IL⁃4 induction group than in the control group (both P values < 0.05). Conclusions Treatment of E. multilocularis CF or PSC mainly causes polarization of BMDM into M2 macrophages, and phenotypic transformation of glucose metabolism into high⁃energy and high⁃glycolytic metabolism, and affects inflammatory responses in BMDM.

Quantitative analysis of risk assessment indicators for re⁃introduction of imported malaria in China

CHAI Liying, CAO Yuanyuan, ZHAO Li, LIU Kaixuan, CHONG Zeyin, LU Yan, ZHU Guoding, CAO Jun, LU Guangyu

2023, 35(6):  604-613. 

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Objective　To quantitatively analyze the risk indicators of re⁃introduction of imported malaria in China and their weighting coefficients, so as to investigate the difference in the contribution of risk indicators included in the current risk assessment framework for re⁃introduction of imported malaria in China to the risk assessment of re⁃introduction of imported malaria. Methods　Publications pertaining to the risk assessment framework for re⁃introduction of imported malaria in China that reported the risk indicators and their weighting coefficients were retrieved in PubMed, Web of Science, CNKI, Wanfang Data, and VIP with terms of “malaria”, “re⁃introduction/re⁃transmission/re⁃establishment”, “risk assessment/risk evaluation/risk prediction” from the inception of the database through 3 August 2023, and literature search was performed in Google Scholar to ensure the comprehensiveness of the retrieval. Basic characteristics of included studies were extracted using pre⁃designed information extraction forms by two investigators, and data pertaining to risk indicators of re⁃introduction of imported malaria were cross⁃checked by these two investigators. The risk indicators included in the risk assessment framework for re⁃introduction of imported malaria in China and their weighting coefficients were visualized with the Nightingale’s rose diagrams using the software R 4.2.1, and the importance of risk indictors was evaluated with the frequency of risk indicators included in the risk assessment framework and the ranking of weighting coefficients of risk indicators. In addition, the capability of risk indicators screened by different weighting methods was compared by calculating the ratio of the maximum to the minimum of the weighting coefficients of the risk indicators screened by different weighting methods. Results　A total of 2 138 publications were retrieved, and following removal of duplications and screening, a total of 8 publications were included in the final analysis. In these 8 studies, 8 risk assessment frameworks for re⁃introduction of imported malaria in China and 52 risk indicators of re⁃introduction of imported malaria were reported, in which number of imported malaria cases (n = 8) and species of malaria vectors were more frequently included in the risk assessment frameworks (n = 8), followed by species of imported malaria parasites (n = 6) and population density of local malaria vectors (n = 6), and species of local malaria vectors (n = 6), number of imported malaria cases (n = 5) and species of imported malaria parasites had the three highest weighting coefficients (n = 4). The weighting methods included expert scoring method, combination of expert scoring method and analytic hierarchy process, and combination of expert scoring method and entropy weight method in these 8 studies, and the ratios of the maximum to the minimum of the weighting coefficients of the risk indicators screened by the expert scoring method were 1.143 to 2.241, while the ratios of the maximum to the minimum of the weighting coefficients of the risk indicators screened by combination of the expert scoring method and analytic hierarchy process were 34.970 to 162.000. Conclusions　Number of imported malaria cases, species of imported malaria parasites, species of local malaria vectors and population density of local malaria vectors are core indicators in the current risk assessment framework for re⁃introduction of imported malaria in China. Combination of the expert scoring method and analytic hierarchy process is superior to the expert scoring method alone for weighting the risk indicators.

Effectiveness of comprehensive echinococcosis control measures with emphasis on management of infectious source in Sichuan Province from 2010 to 2022

HE Wei, YU Wenjie, HUANG Yan, LIAO Sha, ZHANG Guangjia, WANG Qi, LI Ruirui, YANG Liu, YAO Renxin, ZHANG Zhongshuang, ZHONG Bo, LIU Yang, WANG Qian

2023, 35(6):  614-620. 

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Objective　To evaluate the effectiveness of comprehensive echinococcosis control measures with emphasis on management of infectious source in Sichuan Province from 2010 to 2022, so as to provide insights into formulation of future control interventions. Methods　Data pertaining to comprehensive echinococcosis control measures with emphasis on management of infectious source and echinococcosis surveillance in Sichuan Province from 2010 to 2022 were collected. The effectiveness of comprehensive echinococcosis control measures with emphasis on management of infectious source was evaluated with prevalence of human echinococcosis, detection of newly diagnosed echinococcosis patients, prevalence of Echinococcus infection in domestic dogs, prevalence of cystic echinococcosis in livestock, prevalence of alveolar echinococcosis in small mammals and awareness of echinococcosis control knowledge, and Spearman’s rank correlation analysis. Results　The prevalence of human echinococcosis reduced from 1.08% in 2010 to 0.40% in 2022 in Sichuan Province ([χ2] = 1 482.97, P < 0.05), with a reduction from 0.30% to 0.02% in the detection of newly diagnosed echinococcosis cases ([χ2] = 2 776.41, P < 0.05), a reduction from 15.87% to 0.46% in the prevalence of Echinococcus infection in domestic dogs ([χ2] = 20 823.96, P < 0.05), a reduction from 8.05% to 1.07% in the prevalence of cystic echinococcosis in livestock ([χ2] = 1 296.02, P < 0.05), and the awareness of echinococcosis control knowledge increased from 50.65% to 95.24% ([χ2] = 34 938.63, P < 0.05); in addition, there was a year⁃specific prevalence rate of alveolar echinococcosis in small mammals ([χ2] = 164.07，P < 0.05). Spearman’s rank correlation analysis revealed that the detection of newly diagnosed echinococcosis cases correlated positively with the prevalence of Echinococcus infections in domestic dogs (rs = 0.823, P < 0.05) and the prevalence of cystic echinococcosis in livestock (rs = 0.795, P < 0.05), and correlated negatively with the awareness of echinococcosis control knowledge (rs = − 0.918, P < 0.05), and the prevalence of Echinococcus infection in domestic dogs correlated positively with the prevalence of cystic echinococcosis in livestock (rs = 0.753, P < 0.05) and negatively with the awareness of echinococcosis control knowledge (rs = −0.747, P < 0.05); however, there was no correlation between the prevalence of Echinococcus infections in domestic dogs and the prevalence of alveolar echinococcosis in small mammals (rs = −0.750, P > 0.05). Conclusions　The comprehensive echinococcosis control measures with emphasis on management of infectious source had achieved remarkable effectiveness in Sichuan Province; however, the transmission chain of echinococcosis has not been interrupted. Reinforced comprehensive echinococcosis control measures with emphasis on management of infectious source and sustained tracking evaluation of the effectiveness are recommended in Sichuan Province.

Epidemiological and clinical features of newly reported advanced schistosomiasis cases in Sichuan Province from 2011 to 2022

ZHANG Yu, LIU Yang, GU Xiaoqin, WANG Nannan, WAN Jiajia, ZHANG Yi, CHEN Lin

2023, 35(6):  621-625,632. 

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Objective　To analyze the epidemiological characteristics of newly reported advanced schistosomiasis cases in Sichuan Province, so as to provide the evidence for analyzing the causes and formulating targeted control measures of newly reported advanced schistosomiasis cases. Methods　Individual case investigation forms for advanced schistosomiasis cases were collected from the Sichuan Provincial Epidemic Annual Report System from 2011 to 2022, and patients’ demographics, previous medical history and liver parenchymal grading were retrieved. All advanced schistosomiasis cases’ medical records were reviewed, and the subtypes of schistosomiasis⁃endemic villages where the cases’ household registration were, floating population, survival and death and time of death were collected. Results　A total of 321 newly reported advanced schistosomiasis cases were found in Sichuan Province from 2011 to 2022, with a male to female ratio of 0.99 to 1. There were 274 cases at ages of over 50 years (85.4%), with the highest proportion seen at ages of 60 to 69 years (87 cases, 27.1%), and splenomegaly was the most common type (180 cases, 56.1%), with no dwarfism type detected. The highest number of cases was reported in 2011 (78 cases), followed by in 2022 (74 cases), and the highest number of cases were reported in Meishan City (199 cases, 62.0%), Dongpo District (131 cases, 40.8%), and hilly subtype areas (136 cases, 42.4%). As of the end of 2022, there were 111 deaths due to advanced schistosomiasis, with the highest number of deaths seen in 2018 (25 deaths), and the highest mortality was seen among patients with the ascites type (41.2%). There were 47 (37.3%), 40 (59.5%) and 4 (23.5%) cases with grade Ⅲ liver parenchyma among patients with splenomegaly, ascites, and colonic proliferation types, respectively, and there was a significant difference in the grading of Ⅲ liver parenchyma among three types of patients (H = 12.092, P < 0.05), with more severe liver parenchyma injuries seen among patients with the ascites type than among those with splenomegaly and colonic proliferation type (Z = 24.262 and 44.738, both Padjusted values < 0.05). Conclusions　There have been newly reported advanced schistosomiasis cases in Sichuan Province during recent years, and patients with the ascites type should be given a high priority among advanced schistosomiasis cases in Sichuan Province. Intensified clue surveys are needed for early identification and treatment of advanced schistosomiasis cases, so as to increase the survival rate and improve the quality of life.

Effectiveness of the central government⁃funded echinococcosis control programme in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022

LI Yuhua, ZHANG Peng, SUN Chenqing, XIAO Ning, YANG Yuancheng, ZHONG Baolin, FANG Chun, KUI Guoxiang, LIU Zijing, LI Fan, YANG Shijie, FENG Yu

2023, 35(6):  626-632. 

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Objective　To evaluate the effectiveness of the central government⁃funded echinococcosis control programme in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, so as to provide insights into echinococcosis control. Methods　Administrative villages were sampled using a multi⁃stage cluster random sampling method from Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, and all residents at ages of 12 years and older in the sampled villages were screened for echinococcosis, and schools were sampled using a cluster sampling method, and all children at ages of 12 years and older in the sampled schools were screened for echinococcosis. Domestic dogs were sampled using a systematic random sampling method, and one domestic dog stool sample was collected from each household. Stray dog stool samples were collected outside the villages, and Echinococcus coproantigens were detected using enzyme⁃linked immunosorbent assay in domestic and stray dogs. In addition, echinococcosis was screened in sheep and cattle in designated slaughterhouses in Tianzhu Tibetan Autonomous County. The trends in the prevalence of echinococcosis in humans and livestock and the positive rate of Echinococcus coproantigens in dogs were examined with the Cochran⁃Armitage trend test. In addition, individuals screened for echinococcosis were randomly sampled from 2007 to 2022 for survey on the awareness of echinococcosis control knowledge. Results　A total of 290 356 person⁃times were screened for echinococcosis among residents at ages of 12 years and older in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, with 1 094 residents detected with cystic echinococcosis, and the detection of echinococcosis appeared a tendency towards a gradual decline over years ([χ2] = 358.602, P < 0.001). A total of 32 931 person⁃times were screened for echinococcosis among children at ages of 12 years and older in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, with 296 children detected with echinococcosis, and the detection of echinococcosis appeared a tendency towards a gradual decline over years ([χ2] = 267.673, P < 0.001). A total of 33 230 domestic dog stool samples were tested for Echinococcus coproantigens in Tianzhu Tibetan Autonomous County, Gansu Province from 2007 to 2022, with 1 777 Echinococcus coproantigens⁃positive samples tested, and the positive rate of Echinococcus coproantigens appeared a tendency towards a decline in domestic dogs over years ([χ2] = 2 210.428, P < 0.001), while the positive rate of Echinococcus coproantigens showed a tendency towards a rise in domestic animals from 2016 to 2022 ([χ2] = 37.745, P < 0.001). The positive rate of Echinococcus coproantigens remained relatively stable in stray dogs in Tianzhu Tibetan Autonomous County, Gansu Province from 2019 to 2022 ([χ2] = 0.315, P = 0.575). A total of 10 973 sheep were screened for echinococcosis in Tianzhu Tibetan Autonomous County from 2007 to 2022, with 334 sheep detected with echinococcosis, and the detection of echinococcosis appeared a tendency towards a decline in sheep over years ([χ2] = 53.579, P < 0.001); however, there was no significant change in the detection of echinococcosis during the period from 2015 through 2022 ([χ2] = 1.520, P = 0.218). A total of 2 400 cattle were screened for echinococcosis in Tianzhu Tibetan Autonomous County from 2017 to 2022, with 231 cattle detected with echinococcosis, and the detection of echinococcosis showed a tendency towards a decline over years ([χ2] = 5.579, P < 0.05). The awareness of echinococcosis control knowledge increased from 44.37% in 2007 to 94.00% in 2022 among residents at ages of 12 years and older and from 52.50% in 2007 to 92.50% in 2022 among children at ages of 12 years and older in Tianzhu Tibetan Autonomous County, respectively. Conclusions 　There has been a reduction in the detection of echinococcosis in humans and domestic animals and the positive rate of Echinococcus coproantigens in dogs and a rise in the awareness of the echinococcosis control knowledge following the implementation of the central government⁃funded echinococcosis control programme in Tianzhu Tibetan Autonomous County, Gansu Province; however, integrated echinococcosis control measures are still required for further control of the prevalence of echinococcosis.

Prevalence of taeniasis and sero⁃prevalence of anti⁃cysticercus antibody among residents in Tibetan agricultural areas of Sichuan Province

CHEN Xingwang, HUANG Lin, YU Wenjie, HE Wei, LI Tiaoying, LIU Yang

2023, 35(6):  633-637,645. 

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Objective　To investigate the prevalence and epidemiological characteristics of taeniasis and cysticercosis among residents in Tibetan agricultural areas of Sichuan province, so as to provide insights for the prevention and control of taeniasis and cysticercosis. Methods　From 2016 to 2022, Kangding City, Daocheng County, Derong County, Ruoergai County and Muli Tibetan Autonomous County were sampled from Tibetan agricultural areas of Ganzi Tibetan Autonomous Prefecture, Aba Tibetan and Qiang Autonomous Prefecture and Liangshan Yi Autonomous Prefecture in Sichuan Province, and 1 to 6 townships were sampled from each county (district), followed by 4 to 7 villages sampled from each township. Primary school children were sampled using a cluster sampling method, and permanent residents at ages of over 16 years were randomly sampled from each village. Participants’ demographics, history of tapeworm excretion during the past year and clinical symptoms and signs of cysticercosis were collected through questionnaire surveys, and participants’ stool and venous blood samples were collected. Taenia eggs were detected in stool samples using the direct smear method, and deworming was performed among taeniasis patients with areca nut⁃squash seeds. The tapeworm species were identified using a multiplex PCR assay, and serum specific IgG antibody against cysticercus was detected using enzyme⁃linked immunosorbent assay (ELISA). Results　A total of 5 249 respondents participated in the questionnaire survey, including 603 respondents (11.5%) with a self⁃reported history of proglottids secretion during the past year. A total of 3 976 residents were subjected to stool examinations, and the detection of Taenia eggs was 6.5%. Of 258 participants undergoing deworming, there were 403 cases (94.2%) with excretions of Taenia worms or proglottids. The mean prevalence of taeniasis was 10.9% (439/4 043), and there were gender⁃, age⁃ and region⁃specific prevalence rates of taeniasis ([χ2] = 36.73, 126.31 and 163.41, all P values < 0.05). Multiplex PCR assays detected 41 cases with T. solium infections (12.5%), 197 cases with T. saginata infections (59.9%) and 91 cases with T. asiatica infections (27.6%) among 329 patients undergoing deworming, and there were region⁃specific prevalence rates of T. solium, T. saginata and T. asiatica infections ([χ2] = 45.39, P < 0.05). In addition, the sero⁃prevalence of anti⁃cysticercus IgG antibody was 7.0% (345/4 933), and there were age⁃ and region⁃specific sero⁃prevalence rates of anti⁃cysticercus IgG antibody ([χ2] = 13.49 and 51.76, both P values < 0.05). Conclusion　Multiple Taenia species are prevalent in Tibetan agricultural areas of Sichuan Province and the sero⁃prevalence of anti⁃cysticercus antibody is high among residents. Monitoring and control of taeniasis and cysticercosis should be strengthened.

Tracking evaluation on the implementation of Survey of oncomelanid snails (WS/T 563—2017) in Sichuan and Anhui provinces

WAN Jiajia, YU Chenghang, WANG Nannan, PU Chen, ZHANG Yu, LIU Daohua, CAO Zhiguo, ZHENG Bin, LIU Yang

2023, 35(6):  638-640,650. 

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To evaluate the implementation of Survey of oncomelanid snails (WS/T 563—2017) in schistosomiasis⁃endemic foci, two schistosomiasis⁃endemic counties were selected from two provinces of Sichuan and Anhui. Professional staff working in province⁃, city⁃, county⁃ and township⁃level disease control and prevention institutions, parasitic disease control institutions or medical institutions were recruited, and the understanding, use and implementation of Survey of oncomelanid snails (WS/T 563—2017) were investigated using questionnaires and interviews. The awareness, use, proportion of propagation and implementation and correct rate of answering questions pertaining to Survey of oncomelanid snails (WS/T 563—2017) were analyzed. A total of 270 questionnaires were allocated, and 269 were recovered, including 254 valid questionnaires. The overall awareness of Survey of oncomelanid snails (WS/T 563—2017) was 84.64% (215/254), and propagation and implementation of Survey of oncomelanid snails (WS/T 563—2017) was not performed in 23.28% (17/73) of the survey institutions following implementation of Survey of oncomelanid snails (WS/T 563—2017), with meeting training and allocation of propagation materials as the main type of propagation and implementation. Among 254 respondents, 77.16% (196/254) were familiar with the standard, 66.14% (168/254) understood the conditions for use of the standard during snail surveys, and 96.85% (246/254) had the approach for identifying snails. In addition, there were 41.73% (106/254), 50.78% (129/254) and 7.48% (19/254) of respondents that considered the operability of Survey of oncomelanid snails (WS/T 563—2017) was very good, good and general, respectively. The findings demonstrate that the issue and implementation of Survey of oncomelanid snails (WS/T 563—2017) has filled the gap for the standardization of snail control techniques, and which plays an importang guiding role in the national schistosomiasis control program.

Practice and development of schistosomiasis control culture in China: A case of Jiangxi Province

WU Changming, GE Jun, LIN Dandan

2023, 35(6):  641-645. 

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Schistosomiasis control is not only a disease control programme, but also a great social practice activity in China. During the evolution of national schistosomiasis control programmes, the special schistosomiasis control culture has been cultivated and developed, which contains the spiritual connotation of government⁃led, people⁃oriented, respect for science and integration of all efforts. The publication of Chairman Mao Zedong’s two poems entitled “Farewell to the God of Plague” and the postscript in 1958 was a sign for the formation and development of Chinese schistosomiasis control culture, which always lead the orientation of development and practice of schistosomiasis control culture building. The schistosomiasis control culture provide powerful spiritual motivation and supports to schistosomiasis control programmes in China, and improving the building of schistosomiasis control culture is of great significance to strengthen our belief in achieving the goal of schistosomiasis elimination, mobilize all social resources, accelerate the progress towards elimination of schistosomiasis and facilitate the high⁃quality development of healthcare services. Chinese schistosomiasis control spirit is the refinement from the cultural connotation of the long⁃term schistosomiasis control programmes in China, and is the most essential and concentrated embodiment of the schistosomiasis control culture. This article describes the great significance of two poems entitled “Farewell to the God of Plague”, summarizes the connotation and role of schistosomiasis control spirit, and introduces the practice, development and innovation of schistosomiasis control culture building in Jiangxi Province.

Current prevalence and control strategies of visceral leishmaniasis in Sichuan Province: A review

ZHENG Lujie, WU Xiaohong, LIU Yang

2023, 35(6):  646-650. 

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Visceral leishmaniasis is a parasitic disease transmitted by Phlebotomus chinensis that poses a great threat to human health. Historically, visceral leishmaniasis was predominantly prevalent in northwestern regions of Sichuan Province. Following the founding of the People’s Republic of China, large⁃scale integrated interventions had been implemented in visceral leishmaniasis⁃endemic areas of Sichuan Province, including identification and treatment of visceral leishmaniasis patients, elimination of infected dogs, Ph. chinensis control and health education. This review summarizes the prevalence of visceral leishmaniasis, discusses the control strategy of visceral leishmaniasis and analyzes the challenges of elimination of visceral leishmaniasis based on the One Health concept in Sichuan Province, so as to provide insights into elimination of visceral leishmaniasis in the province.