[Molluscicidal effect comparison between TDS and MNSC in field].

OBJECTIVE: To compare the molluscicidal effects between "Luo-wei" (TDS), a plant molluscicide in 4 percent, and metaldehyde and niclosamide (MNSC) in the field. METHODS: A natural ecological environment with Oncomelania hupensis was selected as the test area, the test concentrations of TDS and MNSC were 2.5 g/m3 and 2 ml/m3 respectively by the immersion method; the test doses of TDS and MNSC were 3 g/m2 and 2 ml/m2 respectively by the spray method; the doses of WPN in a control group were 2 g/m3 and 2 g/m2 respectively by the two methods above-mentioned. The molluscicidal effects between TDS and MNSC were compared by using the synchronous design method and parallel comparative method. RESULTS: In the TDS group, the death rate of snails was 90.70% by immersion for 24 hours, reached to 81.40% after spraying for 7 days, and there were no significant differences among the observation time points in molluscicidal effects (P > 0.05). One day after the spraying, the death rate of snails was less in the TDS group compared with that in the MSCN group (P < 0.01), but the death rates of snails were similar in both groups 3 days after the spraying (P > 0.05). In the MSCN group, the death rate of snails was 99.17% by immersion for 24 hours, reached to 66.07% by spraying for 1 day. In the WPS group, the death rate of snails was 97.15% by immersion for 24 hours, reached to 71.43% after spraying for 1 day, and there were no significant differences (both P > 0.05). CONCLUSION: TDS has a good molluscicidal activity and stable efficacy, and the molluscicidal effect of TDS is similar to that of MSCN in the filed, but the molluscicidal sensitivity of TDS is lower than that of MSCN.

[Surveillance of schistosomiasis japonica in potential endemic areas in Hubei Province from 2008 to 2012].

OBJECTIVE: To explore the potential key risk factors of schistosomiasis transmission in potential endemic areas so as to provide the evidence for setting up the prediction and surveillance systems of schistosomiasis outbreak epidemic. METHODS: From 2008 to 2012, fixed and mobile surveillance sites in potential endemic areas of 2 counties in Hubei Province were selected. The immunological assays and stool examinations were carried out to investigate the schistosome infection situation of local people, mobile population and livestock. The distribution of Oncomelania hupensis snails was investigated in risk areas and suspicious areas, and spreading patterns of snails were observed in the rivers that directly connected with the Yangtze River. RESULTS: A total of 6 052 local people aged 6-65 years were screened by IHA immunological tests, and the positive rate of antibody was 1.19% (72/6 052). Totally 72 antibody positives were examined by Kato-Katz technique and there were no positives. A total of 5 004 mobile persons were tested by IHA immunological tests and the positive rate was 1.36% (68/5 004). Totally 68 antibody positives were examined by Kato-Katz technique and there were no positives. Totally 287.07 hm2 potential endemic areas were investigated for Oncomelania snail detection, and no snails were found. The investigation on snail spreading patterns and the surveillance on suspicious circumstances were carried out, with no snails found. CONCLUSIONS: In the schistosomiasis potential endemic areas, some positives of IHA immunological tests are found. Therefore, monitoring is still needed to be strengthened.

[Evaluation for schistosomiasis transmission control in Hongshan District of Wuhan City].

The status of schistosomiasis transmission control in Hongshan District of Wuhan City was evaluated. The schistosome infection rates of human and cattle were both below 1%, no local acute schistosomiasis patient occurred, and infected snails were not found during the period of 2008 to 2010. The files and data were well-documented. Therefore, Hongshan District reached the national criteria for schistosomiasis transmission control.

[Surveillance of schistosomiasis in Hubei Province in 2010].

OBJECTIVE: To understand the endemic situation of schistosomiasis in surveillance sites of Hubei Province in 2010. METHODS: According to The Scheme of Schistosomiasis Surveillance in Hubei Province, 207 endemic villages were selected as surveillance sites, where the surveys of residents, livestock and Oncomelania snails were carried out. RESULTS: In the 207 surveillance sites, the infection rates of residents and cattle were 1.01% and 1.14%, respectively, the densities of living snails and infected snails were 0.50 and 0.000 4 snails/0.1 m2, respectively, and the infection rate of snails was 0.08%. CONCLUSIONS: Compared with that in 2009, the endemic situation of schistosomiasis in Hubei Province in 2010 has decreased obviously, but as the repeatability of the disease, the control of infectious sources and the management of cattle should be strengthened, as well as the snail control.