Transmission factors of schistosomiasis japonica in the mountainous regions with type of plateau canyon and plateau basin.
OBJECTIVE
To provide the scientific basis for formulating the control strategies of schistosomiasis japonica in mountainous regions in China Schistosomiasis Control Programme.


METHODS
We selected Chuanxing Village in Sichuan Province and Zhonghe Village in Yunnan Province as the two pilot areas for an epidemiological investigation according to their geographical and topographical characteristics, i.e. plateau canyon and plateau basin, respectively. Concentrated-egg hatching method in nylon tissue bag and Kato-Katz technique were used for the survey on prevalence rate and intensity of infection of man and domestic animals. Questionnaires were applied to investigating the infection sources, community behavior and the socioeconomic status. Snail survey and detection of cercaria-infested water bodies were conducted using routine techniques.


RESULTS
The results showed that in the endemic areas with plateau canyon, the key infection source was cattle. The infection rate in women was higher than that in men. The pattern of water-pollution was wild feces and the pollution source was cattle feces. Snails and infectious snails were distributed over the rice fields and the resident was infected through production activities. In plateau basin, the key infection source was human beings. The infection rate in men was higher than that in women. The pattern of water pollution was fertilization. The pollution source was human feces. Snails and infectious snails were distributed over the canals and ditches and the resident was infected through production and daily activities.


CONCLUSIONS
Therefore, it was suggested that the mountainous endemic areas should be divided into two sub-types, i.e., plateau basins and plateau canyons. The different control strategies should be formulated in accordance with the environmental situations and socioeconomic factors in the two kinds of endemic areas.
Zheng
J
J
Institute of Parasitic Diseases (IPD), Chinese Academy of Preventive Medicine (CAPM), Shanghai.
Gu
X
X
Qiu
Z
Z
Hua
Z
Z
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002417:Cattle / Q000469:parasitology*; D002648:Child; D002681:China / Q000453:epidemiology; D004197:Disease Reservoirs; D004199:Disease Vectors; D005260:Female; D006266:Health Education; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015995:Prevalence; D012554:Schistosomiasis japonica / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D012908:Snails / Q000469:parasitology*