A Comparative Study on Three Sampling Methods of <i>Oncomelania hupensis</i>

Abstract

The <i>oncomelania hupensis</i> snail is the unique host of schistosomiasis. Schistosomiasis is closely related to the spatial distribution of the snail. It is important to control schistosomiasis susceptible areas and eliminate <i>oncomelania hupensis</i> by optimizing, simplifying the snail sampling method, and obtaining the snail's statistics. A 50m × 50m experimental field was selected from the Chayegang marshland of Henghu farm in the Poyang Lake region, and the sampling frame (0.33m × 0.33m in size) used by the present schischtosomiasis control departments served as the basic sampling unit to conduct continuously push-broom survey of the snail. The count number of the snail, vegetation species, plant height and plant coverage were investigated. The average number of the snail were estimated under three assumed sampling scenarios: simple random sampling, systematic sampling and spatial stratified sampling. The results show that the relative errors of the average number in three sampling schemes are very close, 10.82%, 12.85% and 10.11% respectively, and the absolute errors are 0.310, 0.319 and 0.06 respectively, which demonstrate that the spatial stratified sampling has obvious advantages, its estimation accuracy of the snail can be improved remarkably.