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 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

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 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

Radiation sensitive protein 23 (RAD23) is a nucleotide excision repair (NER) protein that plays an important role in Ubiquitin-proteasome pathway (UPP). Schistosoma japonicum radiation sensitive protein23 (SjRAD23) cDNA sequences were amplified by PCR and cloned into pET28a (+) vector to construct recombinant expression plasmid pET28a(+)-SjRAD23. The recombinant protein was expressed as both inclusion bodies and the supernatant in Escherichia coli BL21 (DE3) cell. Immunofluorescence observation shows that SjRAD23 was mainly distributed on the tegument surface of the worms. ELISA assay reveals that specific IgG, IgG1 and IgG2a antibodies could be detected in the sera of rSjRAD23 immunized mice. Western blotting analysis shows that the recombinant SjRAD23 could be recognized by serum specific to soluble adult worm antigen of S. japonicum. BALB/c mice vaccinated with rSjRAD23 combined with 206 adjuvant revealed 35.94% worm reduction and 40.59% liver egg reduction when compared with that of the adjuvant control
Animals ; Antibodies, Helminth ; blood ; Blotting, Western ; Cloning, Molecular ; DNA Repair Enzymes ; genetics ; metabolism ; DNA, Complementary ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; Genetic Vectors ; Helminth Proteins ; genetics ; immunology ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; genetics ; immunology ; Schistosoma japonicum ; genetics ; metabolism ; Schistosomiasis japonica ; prevention & control ; Vaccines ; immunology

Schistosomiasis japonica is an endemic, zoonotic disease of major public health importance in China. Vaccination is needed as a complementary approach to the ongoing control programs. In the present study, we determined if the efficacies of DNA vaccine encoding the SjGST and Sj32 asparaginyl endopeptidase protein could be enhanced by boosting with SjGST-32 protein vaccines. Mice were inoculated with a VR1012-SjGST-32 DNA vaccine followed by boosting with rSjGST-32 at 0, 14 and 28 d. Two weeks after the final boost, mice were challenged percutaneously with cercariae. On day 45 following the challenge, all mice were sacrificed and the numbers of recovered worms and hepatic eggs were counted. Moreover, we analyzed the immune response among various vaccination groups. The results showed that DNA vaccine efficacy was enhanced when mice were boosted with protein vaccine. Adult worm and liver egg burdens were reduced 42.3% and 59.6%, respectively. We further found that DNA vaccine followed by boosting with protein significantly increased the IgG titer and T cell proliferation over those seen in mice vaccinated solely with DNA vaccines. Furthermore, the higher level of IFN-gamma expression in the splenetic CD4+ T cell showed that DNA prime-Protein boosting vaccine induced CD4+ Th1-type responses. Thus, DNA vaccine efficacy was significantly enhanced via boosting protein vaccine which might provide a basis for rational application of the Schistosoma vaccine.
Animals ; Antigens, Helminth ; immunology ; Female ; Glutathione Transferase ; administration & dosage ; immunology ; Helminth Proteins ; immunology ; Immunization, Secondary ; methods ; Mice ; Mice, Inbred C57BL ; Recombinant Fusion Proteins ; administration & dosage ; immunology ; Schistosoma japonicum ; Schistosomiasis japonica ; prevention & control ; Vaccination ; methods ; Vaccines, DNA ; administration & dosage ; immunology

OBJECTIVE: To determine the immune-protective effect of Japan Schistosoma (Chinese mainland strain) 23 kD membrane protein-heat shock protein (SjC23-Hsp70) DNA vaccine plus adjuvantinduced interleukin-12 (IL-12) plasmid DNA on Schistosoma japonicum infection in water buffalos. METHODS: Forty-five health water buffalos (8-10 months old) in non-endemic area of schistosomiasis were randomly assigned into group A (SjC23-Hsp70+IL-12, 300 μg), group B (SjC23+IL-12, 300 μg) and group C (pVAX+IL-12, 300 μg), 15 in each group. Each buffalo was immuned by shoulder intramuscular injection for 3 times, at an interval of 28 days. Twenty-eight days after the last immunization, each buffalo was infected with 1000 Japan cercariae of Schistosoma. Fecal examinations were conducted 2 days and 1 day before the perfusion, and on the day of perfusion. The number of hatching miracidia and eggs per gram feces was recorded. Fifty-six days after the infection, the buffalos were sacrificed and perfused via the descending aorta. The recovered adult worms and eggs in the liver tissue were counted. RESULTS: We compared group A and B with group C: the estrogen reduction rate was 45.7% and 26.61%; bug reduction rate was 44.51% and 25.84%; the fecal egg reduction rate was 41.1% and 31.63%; the miracidium reduction rate was 48.11% and 38.07%; and the liver egg reduction rate was 43.39% and 31.95%. The above rates in group A were higher than those in group B (P<0.05). CONCLUSION SjC23-Hsp70 DNA vaccine combined with IL-12 may have a significant immunoprotective effect on buffalos.
Animals ; Antigens, Helminth ; immunology ; Buffaloes ; Cattle ; HSP70 Heat-Shock Proteins ; genetics ; immunology ; Helminth Proteins ; immunology ; Immunization ; methods ; Interleukin-12 ; genetics ; immunology ; Membrane Proteins ; immunology ; Schistosomiasis japonica ; immunology ; prevention & control ; veterinary ; Vaccines, DNA ; administration & dosage ; immunology ; Vaccines, Synthetic ; immunology

Schistosomiasis is a kind of common disease around the riverside or lakeside areas, especially popular in rural areas, and causes huge economic loss. Based on existing schistosomiasis dynamic models and data, a new method of working out coefficients, and an improved model were provided in our study. The improved model can be applied to the study of the characteristics of transmission of schistosomiasis, and the effect of new control methods for schistosomiasis was evaluated.
Animals ; Cattle ; China ; Computer Simulation ; Humans ; Models, Theoretical ; Numerical Analysis, Computer-Assisted ; Schistosoma japonicum ; isolation & purification ; Schistosomiasis japonica ; epidemiology ; prevention & control ; transmission ; Snails ; parasitology

The present study was intend to clone and express the cDNA encoding Cyclophilin B (CyPB) of Schistosoma japonicum, its preliminary biological function and further immunoprotective effect against schistosome infection in mice. RT-PCR technique was applied to amplify a full-length cDNA encoding protein Cyclophilin B (Sj CyPB) from schistosomula cDNA. The expression profiles of Sj CyPB were determined by Real-time PCR using the template cDNAs isolated from 7, 13, 18, 23, 32 and 42 days parasites. The cDNA containing the Open Reading Frame of CyPB was then subcloned into a pGEX-6P-1 vector and transformed into competent Escherichia coli BL21 for expressing. The recombinant protein was renaturated, purified and its antigenicity were detected by Western blotting, and the immunoprotective effect induced by recombinant Sj CyPB was evaluated in Balb/C mice. The cDNA containing the ORF of Sj CyPB was cloned with the length of 672 base pairs, encoding 223 amino acids. Real-time PCR analysis revealed that the gene had the highest expression in 18-day schistosomula, suggesting that Sj CyPB was schistosomula differentially expressed gene. The recombinant protein showed a good antigenicity detected by Western blotting. Animal experiment indicated that the vaccination of recombinant CyPB protein in mice led to 31.5% worm and 41.01% liver egg burden reduction, respectively, compared with those of the control. A full-length cDNA differentially expressed in schistosomula was obtained. The recombinant Sj CyPB protein could induce partial protection against schistosome infection.
Animals ; Antigens, Helminth ; immunology ; Cloning, Molecular ; Cyclophilins ; biosynthesis ; genetics ; immunology ; DNA, Complementary ; genetics ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Immunization ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Schistosoma japonicum ; genetics ; immunology ; Schistosomiasis japonica ; prevention & control ; Vaccines, Synthetic ; biosynthesis ; immunology