An introduction of a nationwide sampling survey on schistosomiasis in China.

AIM: In order to know the present status of the endemicity of schistosomiasis and to evaluate the control effect during 1990-1995, a second nationwide sampling survey on schistosomiasis japonica was undertaken during September and November of 1995.
METHODS: A stratifying and clustering random sampling technique was used in the survey. Serological test, circumoval precipitin test or indirect hemagglutination assay were used for preliminary screening. Stool examination using hatching technique and Kato-Katz technique was applied for identification of the infected persons and intensity of infection and hatching test only for survey of domestic animals.
RESULTS: In 195 sampled villages from endemic areas, a total of 224,819 people were examined. The infection rate of residents was 4.89% and the infection rate of farm cattle was 9.06%. In the 169 sampled villages from endemic areas under control, only 17 out of 18,302 children were identified as infected by stool examination from Hubei and Sichuan Provinces. From the results of the survey, the number of infected persons, and the number of infected farm cattle and water buffaloes were estimated to be 865,084 and 100,251, respectively, in the whole country.
CONCLUSION: As compared with the data in 1989, a reduction of 47.2% in infected persons and about 50% in infected farm cattle and water buffaloes, respectively, was shown.