[Study on the strategy of interrupting schistosomiasis transmission in a hilly new endemic area of Taoyuan County].

OBJECTIVE: To develop a strategy for interrupting the transmission of schistosomiasis japonica in a hilly new endemic area. METHODS: Since 1996, chemotherapy with praziquantel (adult 40 mg/kg, child 50 mg/kg, cattle 30 mg/kg, once a year) on human beings in Taoyuan County who had ever contacted with infectious water and cattle which were herded in endemic situation was the major intervention, with focal control of Oncomelania snails in susceptible areas as supplementary one. RESULTS: The positive rate of stool examination for schistosomiasis in human and cattle reduced from 5.69% and 6.76% in 1996 to 0.04% and 0 in 2005 respectively. The positive rate of indirect hemagglutination test (IHA) in human dropped from 7.45% in 1996 to 1.61% in 2004. Though living snails were still found in most habitats, the density of infected snails decreased from 0.0036/0.11m2 in 1997 to 0 in 2005 and no infected snails were found since 2000. CONCLUSION: Due to less movement of human and cattle populations and the hilly area relatively isolated, chemotherapy combined with focal mollusciciding have been highly effective in eliminating the infection sources and interrupting transmission of schistosomiasis.

[Schistosoma japonicum in the newly identified areas in Hunan province].

OBJECTIVE: To study the major risk factors and characteristics of Schistosoma japonicum in the newly identified areas around the Dong Ting Lake. METHODS: Data was collected regarding the distribution of snails, prevalence of infection as well as the source of transmission in the newly identified areas in Hunan province from 1979 to 2003. RESULTS: In all the newly identified sites, Schistosomiasis japonica patients appeared to be the first-seen evidence, some even under acute phase. The highest infection rate among residents had reached 87.1% in the newly identified villages. Most of the new endemic areas concentrated in the ditch and beach areas that close to cities and towns. CONCLUSIONS: Evidence showed that snails had been transferred through boats and fishing nets to be disseminated. Data also revealed that the sources of transmission would include those local infected residents who had been infected in the old endemic areas and the newly imported domestic animals with infection.