[Surveillance of schistosome antibodies in population in mountainous schistosomiasis endemic regions in China].

OBJECTIVE: To understand the dynamics of schistosome antibodies in population in mountainous schistosomiasis low endemic regions, China, so as to provide the evaluation reference for immunodiagnosis. METHODS: The people who consecutively received the indirect heamagglutination assay (IHA) for schistosomiasis and Kato-Katz technique were enrolled in this study in Guixiang Village, Danling County, Sichuan Province from 2006 to 2011. The positive rates for schistosome antibodies, antibody titers and eggs per gram (EPG) were analyzed. RESULTS: A total of 353 people were investigated in this study from 2006 to 2011. The positive rates for schistosome antibodies decreased from 20.73% to 13.67%, and the geometric mean reciprocal titer (GMRT) decreased from 1.63 to 1.06. The antibodies tended to be negative in most antibody-positive people and the GMRT decreased gradually. The antibodies remained negative in most antibody-negative people. After chemotherapy in parasitology confirmed patients, the positive rate for schistosome antibodies decreased from 100% to 20%, and the GMRT decreased from 34.29 to 1.58. There was a highly positive correlation between GMRT and EPG (r = 0.94, P < 0.05). CONCLUSION: The positive rate for schistosome antibodies in population in mountainous schistosomiasis low endemic regions is relatively high (13.67%). The standardization of immunodiagnostic methods is necessary and the suitable diagnostic reagents should be developed in this region.

[Effect of ecological civilized homestead construction on schistosomiasis control].

OBJECTIVE: To evaluate the effect of Ecological Civilized Homestead Construction on schistosomiasis control. METHODS: The data of ecological civilized homestead construction and schistosomiasis control were collected and analyzed in Meiwan Village, Shuangqiao Town, Danling County, Sichuan Province from 2004 to 2010. RESULTS: Ecological Civilized Homestead Construction was carried out from 2004 to 2010. Totally 454 bio-gas pools were built. All the farmers used well water. The popularized rates of the household bio-gas pool, sanitary toilet, sewage treatment pool reached 100%. The number of cattle was 4, which decreased by 91.30% compared with that in 2004, and all the cattle were fed in captivity. The schistosome infection rates of populations were 0.26% and 0.30% in 2005 and 2008, respectively, and nobody was infected in other years. The infection rate of cattle was 0 from 2004 to 2010. The awareness rate of knowledge about schistosomiasis control achieved 100% in the population over 6 years old. Most of the farmers could use certain protective measures while they were farming. CONCLUSION: The effect of ecological civilized homestead construction on schistosomiasis control is remarkable.

[Effect of comprehensive control pattern on soil-transmitted nematodiasis in Danling County].

The comprehensive control pattern centering on health education, deworming and improving drinking water and lavatories was adopted to control soil-transmitted nematodiasis in Danling County, Sichuan Province from 2007-2009. In 2009, the infection rate of soil-transmitted nematodes decreased from 57.12% of the baseline survey in 2006 to 10.06%.

[The immunogenicity and safety of 10 microg recombination yeast hepatitis B vaccine applied in expanded population].

OBJECTIVE: To assess the feasibility of the 10 microg recombination yeast hepatitis B vaccine in the expanded applicable population group aged 5 - 18. METHODS: People with both HBsAg and anti-HBs negative were selected to take two-stage clinical experiment and the safety and immunogenicity were observed. Safety observation was conducted in 925 subjects, while 568 for immunogenicity. The observation group (aged 5 - 18) included 493 subjects, and (age > 18) 75 enrolled in control group. For the observation group, there were three sub-groups including a child group (141, aged 5 - 6), early youth group (177, aged 12 - 13), and youth group (175, aged 16 - 18). Both groups were administered with 10 microg recombination yeast hepatitis B vaccines with 3 doses at 0 month, 1st month, 6th month. To assess the immunogenicity, the vaccination reactions were observed during the following 4 weeks in order to assess the vaccine safety. The blood samples were taken during 4 - 6 weeks after fully vaccinated, and then anti-HBs were tested with RIA and analyzed by comparing the positive rate of anti-HBs, the geometric mean titer (GMT) and the protective rate between the two groups. RESULTS: Both observation and control group didn't show any general reactions, adverse events following immunization (AEFI) or coincidental cases when observed at 0.5 h, 6 h, 24 h, 48 h, 72 h, 1 week, 2 weeks, 3 weeks, 4 weeks after being vaccinated. The result of serum test showed, the positive rates of child group, early youth group, youth group and control group were respectively 100.00% (141/141), 97.18% (172/177), 98.29% (172/175) and 89.33% (67/75); the GMTs of anti-HBs were respectively 440.28, 875.38, 467.80, 131.06 U/L; the protective rates were respectively 100.00% (141/141), 97.18% (172/177), 97.14% (170/175) and 86.67% (65/75). The positive rate, GMT and protective rate of the experimental group were all higher than that of control group (chi(2)(positive rate) = 12.77, 5.12, 7.99; t(GMT) = 3.89, 4.13, 5.91; chi(2)(protective rate) = 16.81, 8.60, 8.44; P < 0.05). CONCLUSION: This vaccine could be expanded to 5 - 18 year-old population with safety and effectiveness, the positive rate and protective rate of anti-HBs were both higher than that of control group.