OBJECTIVE: To construct a schistosomiasis transmission risk assessment system in Wuhan City and preliminary evaluate its application effect, so as to promote the rational allocation of schistosomiasis control resources and accelerate the progress towards schistosomiasis elimination. METHODS: The schistosomiasis risk assessment indicators were collected through referring schistosomiasis surveillance data of Wuhan City from 2014 to 2020, literature review and expert interviews. Indicators within each criterion and sub-criterion were screened using the Delphi method, and a hierarchical structure model was created based on analytic hierarchy process. Quantitative assignment of each indicator was conducted according to relative importance, and the weight and combination weight of each criterion were calculated in each analytic hierarchy framework to create a schistosomiasis transmission risk assessment system, which was used for the schistosomiasis transmission risk assessment in 12 national schistosomiasis surveillance sites in Wuhan City. RESULTS: A three-level schistosomiasis transmission risk assessment system was preliminarily constructed, which included a target layer, 5 criterion layers and 21 sub-criterion layers. Of all indicators in the criterion layer, transmission route had the highest weight (0.433), followed by source of Schistosoma japonicum infection (0.294); and among all indicators in the sub-criterion layer, S. japonicum infection in Oncomelania hupensis and sentinel mice had the highest combination weight (0.125), followed by prevalence of S. japonicum infection in humans (0.091) and bovines (0.053), snail control by chemical treatment (0.049), positive rate of inquiry examinations (0.048), allocation of schistosomiasis control professionals (0.045), and areas of submerged snail-infested settings (0.041). Of the 12 national schistosomiasis surveillance sites in Wuhan City, there were 5 sites with weights of > 0.8, 4 sites with weights of 0.6 to 0.8, and 3 sites with weights of < 0.6 in 2020. CONCLUSIONS A schistosomiasis transmission risk assessment system has been constructed based on analytic hierarchy process in Wuhan City, which may provide a evidence-based basis for health resource allocation and decision-making for schistosomiasis control.
Animals ; Humans ; Cattle ; Mice ; Analytic Hierarchy Process ; Schistosomiasis/prevention & control* ; Schistosomiasis japonica/epidemiology* ; Snails ; Risk Assessment

OBJECTIVE: To investigate the dynamic changes of macrophage numbers and apoptosis during Schistosoma japonicum infection, and to investigate the possible mechanisms of macrophage apoptosis induced by S. japonicum soluble egg antigen (SEA). METHODS: C57BL/6 mice at ages of 6~8 weeks were randomly divided into 4 groups, including three experimental groups and a normal control group. Each mouse in the experimental groups was infected with (12 ± 1) cercariae of S. japonicum via the abdominal skin, and all mice in an experimental group were sacrificed 3, 5, 8 weeks post-infection, respectively, while mice in the control group were not infected with S. japonicum cercariae and sacrificed on the day of S. japonicum infection in the experimental group. Mouse liver specimens and peritoneal exudation cells were sampled in each group, and the dynamic changes of macrophage numbers and apoptosis were detected. Mouse peritoneal macrophages were isolated, purified and treated with S. japonicum SEA, PBS and ovalbumin (OVA) in vitro, and the macrophage apoptosis was detected using flow cytometry. The mRNA and protein expression of BCL-2 protein family members were determined in macrophages using real-time quantitative PCR (qP-CR) and Western blotting assays, and the activation of caspase 3 was determined using flow cytometry and Western blotting. In addition, macrophages were in vitro treated with S. japonicum SEA in presence of a caspase inhibitor, H₂O₂ or N-acetyl-L-cysteine, and the apoptosis of macrophages was detected using flow cytometry. RESULTS: The total macrophage numbers continued to increase in mouse liver [(0.873 ± 0.106) × 106, (2.737 ± 0.460) × 10⁶ and (3.107 ± 0.367) × 10⁶ cells, respectively; F = 81.900, P < 0.01] and peritoneal specimens [(5.282 ± 1.136) × 105, (7.500 ± 1.200) × 10⁵ and (12.800 ± 0.800) × 10⁵ cells, respectively; F = 55.720, P < 0.01] 3, 5 and 8 weeks post-infection with S. japonicum, and the numbers of apoptotic macrophages also continued to increase in mouse liver [(0.092 ± 0.018) × 10⁶, (0.186 ± 0.025) × 10⁶ and (0.173 ± 0.0270) × 10⁶ cells; F = 57.780, P < 0.01] and peritoneal specimens [(0.335 ± 0.022) × 10⁵, (0.771 ± 0.099) × 10⁵ and (1.094 ± 0.051) × 10⁵ cells; F = 49.460, P < 0.01] 3, 5 and 8 weeks post-infection with S. japonicum. The apoptotic rate of SEA-treated macrophages [(24.330 ± 0.784)%] was significantly higher than that of PBS-[(18.500 ± 1.077)%] and OVA-treated macrophages [(18.900 ± 1.350)%] (both P values < 0.01). There were no significant differences in the mRNA or protein expression of Bcl-2 [Bcl - 2 mRNA expression: (1.662 ± 0.943) vs. (1.000 ± 0.000), t = 1.215, P > 0.05; BCL protein expression: (0.068 ± 0.004) vs. (0.070 ± 0.005), t = 0.699, P > 0.05], Bax [Bax mRNA expression: (0.711 ± 0.200) vs. (1.000 ± 0.000), t = 2.507, P > 0.05; BAX protein expression: (0.089 ± 0.005) vs. (0.097 ± 0.003), t = 2.232, P > 0.05] and Bak [Bak mRNA expression: (1.255 ± 0.049) vs. (1.00 ± 0.00), t = 0.897, P > 0.05; BAK protein expression: (0.439 ± 0.048) vs. (0.571 ± 0.091), t = 2.231, P > 0.05] between in SEA- and PBS-treated macrophages. S. japonicum SEA induced macrophage apoptosis in the presence of a caspase inhibitor (F = 0.411, P > 0.05); however, SEA failed to induce macrophage apoptosis in the presence of H₂O₂ or NAC (F = 11.880 and 9.897, both P values < 0.05). CONCLUSIONS S. japonicum SEA may induce macrophage apoptosis through promoting reactive oxygen species expression during S. japonicum infections in mice.
Animals ; Apoptosis ; Caspases ; Hydrogen Peroxide ; Macrophages ; Mice ; Mice, Inbred C57BL ; RNA, Messenger ; Schistosoma japonicum ; Schistosomiasis japonica ; bcl-2-Associated X Protein

OBJECTIVE: To evaluate the diagnostic efficacy of indirect haemagglutination assay (IHA) for detection of Schistosoma japonicum infections among boatmen and fishermen in Dongting Lake region, so as to provide insights into improving the schistosomiasis surveillance program among boatmen and fishermen. METHODS: The boatmen and fishermen were detected for S. japonicum infections using IHA and Kato-Katz technique or miracidium hatching test nylon gauze simultaneously at schistosomiasis testing sites in the anchor sites for boatmen and fishermen in the Dongting Lake region during the period from 2014 to 2016, and using IHA for serological screening followed by parasitological testing of seropositives during the period from 2017 to 2019. The sensitivity and specificity of IHA were evaluated for detection of S. japonicum infections among boatmen and fishermen, with the 2014-2016 parasitological testing results as a gold standard. In addition, the seroprevalence of S. japonicum infections was compared among boatmen and fishermen with different characteristics and among years. RESULTS: A total of 306 schistosomiasis testing sites were assigned for boatmen and fishermen, and a total of 143 360 person-time boatmen and fishermen were tested for S. japonicum infections in the Dongting Lake region from 2014 to 2019. The sensitivity and specificity of IHA were 69.9%, 97.3% and 96.1% (χ² = 74.6, P < 0.05), and 70.9%, 74.5% and 71.9% for detection of S. japonicum infections from 2014 to 2016 (χ² = 29.4, P < 0.05), respectively. The seroprevalence of S. japonicum infections reduced from 30.3% in 2014 to 1.8% in 2019 among boatmen and fishermen, appearing an overall tendency towards a decline (Z = 1 552.4, P < 0.05). In addition, male, individuals at ages of 45 to 60 years, full-time boatmen and fishermen were more likely to be seropositive for S. japonicum infections (all P values < 0.05). CONCLUSIONS The seroprevalence of S. japonicum infections appeared a tendency towards a decline among boatmen and fishermen in the Dongting Lake region year by year from 2014 to 2019. IHA presented a high efficacy for screening of S. japonicum infections among boatmen and fishermen in the Dongting Lake region.
Animals ; China/epidemiology* ; Hemagglutination ; Humans ; Lakes ; Male ; Middle Aged ; Prevalence ; Schistosoma japonicum ; Schistosomiasis/epidemiology* ; Schistosomiasis japonica/prevention & control* ; Seroepidemiologic Studies

China still has more than 30,000 patients of advanced schistosomiasis while new cases being reported consistently. D-dimer is a fibrin degradation product. As ascites being the dominating symptom in advanced schistosomiasis, the present study aimed to explore a prediction model of ascites with D-dimer and other clinical easy-achievable indicators. A case-control study nested in a prospective cohort was conducted in schistosomiasis-endemic area of southern China. A total of 291 patients of advanced schistosomiasis were first investigated in 2013 and further followed in 2014. Information on clinical history, physical examination, and abdominal ultrasonography, including the symptom of ascites was repeatedly collected. Result showed 44 patients having ascites. Most of the patients' ascites were confined in the kidney area with median area of 20 mm². The level of plasma D-dimer and pertinent liver function indicators were measured at the initial investigation in 2013. Compared with those without ascites, cases with ascites had significantly higher levels of D-dimer (0.71±2.44 μg/L vs 0.48±2.12 μg/L, P=0.005), as well ALB (44.5 vs 46.2, g/L) and Type IV collagen (50.04 vs 44.50 μg/L). Receiver operating characteristic curve analyses indicated a moderate predictive value of D-dimer by its own area under curve (AUC) of 0.64 (95% CI: 0.54–0.73) and the cutoff value as 0.81 μg/L. Dichotomized by the cutoff level, D-dimer along with other categorical variables generated a prediction model with AUC of 0.76 (95% CI: 0.68–0.89). Risks of patients with specific characteristics in the prediction model were summarized. Our study suggests that the plasma D-dimer level is a reliable predictor for incident ascites in advanced schistosomiasis japonica patients.
Area Under Curve ; Ascites* ; Case-Control Studies ; China ; Cohort Studies ; Collagen Type IV ; Fibrin ; Humans ; Kidney ; Liver ; Physical Examination ; Plasma* ; Prospective Studies* ; ROC Curve ; Schistosoma japonicum ; Schistosomiasis japonica* ; Schistosomiasis* ; Ultrasonography

OBJECTIVETo observe the dynamic changes of immune responses of splenocytes in mice immunized with recombinant vaccine Bifidobacterium bifidum (pGEX-Sj32) of Schistosoma japonicum and investigate the immunological mechanism of the vaccine.

METHODSEighty-eight BALB/c mice were randomized for immunization with 10⁶ CFU recombinant vaccine orally or with 10⁵ CFU recombinant vaccine intranasally. Four mice were selected from each group every two weeks to test the responses of the splenocytes to stimulations with SjAWA or ConA. MTT assay and flow cytometry were used to assess splenocyte proliferation and the distribution of CD4⁺ and CD8⁺ T cells, respectively; the levels of interleukin-10 (IL-10), IL-12 and tumor necrosis factor-α (TNF-α) in the cell culture supernatant were detected by ELISA.

RESULTSRegardless of the stimulations, the splencytes showed significantly enhanced proliferation in weeks 2-16 in oral administration group and in weeks 2-18 in intranasal group (P<0.01). CD4⁺ subsets in both two groups increased obviously in weeks 2-12 (P<0.01) but CD8⁺ subsets remained stable. In oral administration group, the levels of TNF-α, IL-10 and IL-12 increased in weeks 2-14, 2-18 and 2-14, and peaked at week 8, 10 and 6, respectively; in intranasal group, the cytokines increased in weeks 2-14, 2-18 and 2-18, and peaked at week 8, 10 and 8, respectively.

CONCLUSIONThe recombinant vaccine rBb (pGEX-Sj32) can induce effective immune responses in mice.

Animals ; Antigens, Helminth ; immunology ; Bifidobacterium ; CD4-Positive T-Lymphocytes ; immunology ; CD8-Positive T-Lymphocytes ; immunology ; Interleukin-10 ; immunology ; Interleukin-12 ; immunology ; Mice ; Mice, Inbred BALB C ; Schistosoma japonicum ; Schistosomiasis japonica ; prevention & control ; Spleen ; cytology ; immunology ; Tumor Necrosis Factor-alpha ; immunology ; Vaccination ; Vaccines, Synthetic ; immunology

To identify SJCHGC01743 gene of Schistosoma japonicum and evaluate the potential of the recombinant protein as a new vaccine candidate for schistosomiasis, polymerase chain reaction (PCR) technique was used to amplify the cDNA of the gene and real-time RT-PCR was used to analyze the transcription profiles of SJCHGC01743 at different development stages. Recombinant plasmid was successfully constructed and transformed into competent Escherichia coli BL21 (DE3). Then the recombinant protein was expressed, purified and emulsified with ISA206 adjuvant to immunize BALB/c mice for three times. The immunogenicity was confirmed by Western blotting and tissue localization was detected by indirect immunofluorescent assay. The specific antibody level was detected by ELISA. The immunoprotection of rSjOST48 was evaluated by the reduction in worm and egg counts in mice. A cDNA with 1 248 nucleotides was isolated from 28-day-old schistosomes cDNAs by PCR. Sequence analysis revealed that SJCHGC01743 was a 48-kDa subunit of the oligosaccharyltransferase complex (OST48) and named as SjOST48. Real-time PCR analysis indicated that this gene was expressed in all investigated stages and had the highest expression level in 28 d worms, the level of gene transcription in female worms was significantly higher than that of male worms. Then recombinant plasmid pET28a(+)-SjOST48 was successfully constructed and expressed in E. coli BL21 (DE3). Western blotting analysis showed that rSjOST48 had good immunogenicity. Indirect immunofluorescent analysis revealed that SjOST48 was mainly distributed on the tegument of the worms. The result of ELISA indicated that the rSjOST48 vaccinated group could induce a significant increase in the level of specific IgG, IgG1 and IgG2a. An immunoprotection experiment showed that the vaccination of rSjOST48 in mice induced 32.62% (P < 0.05) reduction in the numbers of worms and 57.61% (P < 0.01) in eggs in liver, compared with that of the control group. This study provides the foundation for proceeding further research on the biological function of SjOST48 and screening new vaccine candidates for schistosomiasis.
Animals ; Antibodies, Helminth ; blood ; Cloning, Molecular ; DNA, Complementary ; Escherichia coli ; Female ; Genes, Helminth ; Helminth Proteins ; genetics ; immunology ; Immunoglobulin G ; blood ; Male ; Mice ; Mice, Inbred BALB C ; Real-Time Polymerase Chain Reaction ; Recombinant Proteins ; immunology ; Schistosoma japonicum ; genetics ; Schistosomiasis japonica ; prevention & control ; Vaccination

OBJECTIVETo study the dynamics of the reinfection of Schistosoma japonicum and related risk factors among the people in schistosomiasis endemic areas in China.

METHODSLiterature retrieval was conducted by using databases of PubMed, CNKI,VIP and Wanfang to collected all the data about the human re-infection of Schistosoma japonicum and related risk factors in the endemic areas in China. And a Mata-analysis was conducted on the literatures met the inclusion standards.

RESULTSEighteen studies involving 12 604 people for infection survey and 3 128 people for re-infection survey were included in the analysis. The overall infection rate was 20.8%, and the overall re-infection rate was 21.0% . The difference had no statistical significance (Z = 1.12, P = 0.26). The re-infection related factors included baseline infection intensity (OR = 3.58, 95% CI: 1.56-8.22); the index of contaminated water OR = 2.37, 95% CI: 1.08-5.22); distance from house to river-side (OR = 1.72, 95% CI: 0.41-7.30) and age (OR = 0.48, 95% CI: 0.19-1.23).

CONCLUSIONThe baseline infection intensity, the index of contaminated water and distance from house to river-side were the risk factors related to the re-infection of Schistosoma japonicum and age was a protective factor.

Animals ; Asian Continental Ancestry Group ; China ; Humans ; Risk Factors ; Schistosoma japonicum ; Schistosomiasis japonica ; epidemiology ; parasitology

OBJECTIVETo examine the expression profile and immunofluorescence localization of the major egg antigen p40 of Schistosoma japonicum (Sjp40) during granuloma formation in the liver of infected New Zealand white rabbits.

METHODSNew Zealand white rabbits were infected with S. japonicum cercariae, and the livers were harvested at 29 and 45 days post-infection (dpi). The total RNA of the liver tissues was extracted for expression profiling of Sjp40 by quantitative reverse transcription-PCR (qRT-PCR) with GAPDH of S. japonicum as the endogenous reference gene. The expression of Sjp40 in the liver were detected by Western blotting using anti-Sjp40 monoclonal antibody (mAb) 9G7 or anti-Toxoplasma gondii tSAG1 mAb Y3A8 (control) as the primary antibody. Paraffin sections of the liver were prepared for observing egg granuloma formation using HE staining and for indirect immunofluorescence assay of Sjp40 location in the trapped eggs and egg granulomas.

RESULTSThe level of Sjp40 mRNA in the eggs trapped in rabbit livers was significantly higher at 45 dpi than that at 29 dpi (P<0.05), and Western blotting confirmed the presence of Sjp40 protein in the rabbit livers at both 29 and 45 dpi. Immunofluorescence assay demonstrated localized expression of Sjp40 in the immature eggs in the rabbit liver at 29 dpi, but at 45 dpi fluorescence was detected in clusters of mature eggs containing miracidium and in the surrounding egg granulomas.

CONCLUSIONSThe transcriptional levels of Sjp40 significantly increased with the maturation of eggs trapped in the rabbit livers. Sjp40 protein spread from the eggs to the surrounding egg granuloma at 45 dpi when acute liver granulomatous lesions occur, suggesting that Sjp40 plays a key role in egg granulomas formation in the livers of infected New Zealand white rabbits.

Animals ; Antibodies, Monoclonal ; Antigens, Helminth ; metabolism ; Fluorescent Antibody Technique ; Gene Expression Profiling ; Granuloma ; parasitology ; Helminth Proteins ; metabolism ; Liver ; parasitology ; RNA, Messenger ; Rabbits ; Schistosoma japonicum ; Schistosomiasis japonica

OBJECTIVETo analyze the impact of water transfer project from the Yangtze River to the Huaihe River on schistosomiasis transmission, and to evaluate the risk of the disease input to the potential endemic area in Anhui Province, namely the Chaohu Lake region.

METHODSFrom 2008 to 2012, 1 fixed and 3 mobile surveillance sites in the Chaohu Lake area were selected, and the schistosomiasis infection situation of 615 local residents in the fix surveillance site was investigated in autumn of 2008 and 2012, while the schistosomiasis infection situation of 1603 mobile population in the 3 mobile surveillance sites were investigated in autumn of 2008 to 2012. All people were screened by indirect hemagglutination assay (IHA), and the positive ones were then examined by sedimentation method. 303 local livestock and livestock from schistosomiasis endemic areas were examined by stool hatching method in autumn of 2008 to 2012. From 2008 to 2012, the distribution of Oncomelania snails was investigated in risk areas and suspicious areas, and the snail spreading pattern was conducted through salvaging floaters in rivers connected with the Yangtze River. In addition, the Oncomelania snails were raised in the cages on the beaches of the Chaohu Lake, a control area, from 2007 to 2010, and their survival and reproduction capacity was observed.

RESULTSIn 2008 and 2012, 301 and 314 local residents were detected by IHA, but there were no positive found. From 2008 to 2012, a total of 1603 mobile population were examined by IHA, and the positive rate of antibody was 3.1% (49/1603); 75 individuals were examined by sedimentation method, and the positive rate was 36.00% (27/75). A total of 303 livestock were examined by stool hatching method, but no one showed positive. A total of 1630 km(2) in risk areas and 3551 km(2) in suspicious areas were surveyed, but there were no Oncomelania snails found. A total of 457.6 kg floating debris were investigated, and 11 Oncomelania snails were found. From 2007 to 2010, the survival rate of Oncomelania snails in two trail areas in the Chaohu Lake and in the control area was 88% (86/98), 51% (45/89), 30% (25/71), 24% (20/84) and 92% (85/92), 54% (50/92), 23% (12/52), 17% (13/79) and 96% (85/89), 52% (44/85), 26% (18/69), 18% (14/76), respectively, there were no statistical significance between the trial areas and the control area (χ1(2) = 3.78, P > 0.01; χ2(2) = 0.27, P > 0.01; χ3(2) = 2.51, P > 0.01; χ4(2) = 1.50, P > 0.01), and filial generation snails were found in each observation area from 2008 to 2010, the number was 156-312.

CONCLUSIONThe imported infectious sources of schistosomiasis have been found in the Chaohu Lake region, the possibility of imported exogenous Oncomelania snails spreading into the Lake and surviving and reproducing there is high. The risk of schistosomiasis input to the potential endemic area in Anhui Province is predicted to be high.

Animals ; Cross-Sectional Studies ; Environmental Monitoring ; Humans ; Lakes ; parasitology ; Risk Assessment ; Rivers ; parasitology ; Schistosomiasis japonica ; epidemiology ; prevention & control ; transmission ; Snails ; parasitology

Animals ; Female ; Gastrectomy ; Humans ; Lymphoma, B-Cell, Marginal Zone ; parasitology ; pathology ; surgery ; Middle Aged ; Schistosoma japonicum ; Schistosomiasis japonica ; complications ; Stomach Neoplasms ; parasitology ; pathology ; surgery