1.Comparison study on sampling methods of Oncomelania hupensis snail sur-vey in marshland schistosomiasis epidemic areas in China
An ZHAO ; Wenxin ZHANG ; Zhong YAO ; Yukuan MA ; Qing LIU ; Houlang DUAN ; Yidi SHANG
Chinese Journal of Schistosomiasis Control 2016;28(5):507-512
Objective To optimize and simplify the survey method of Oncomelania hupensis snail in marshland endemic re?gion of schistosomiasis and increase the precision,efficiency and economy of the snail survey. Methods A quadrate experimen?tal field was selected as the subject of 50 m×50 m size in Chayegang marshland near Henghu farm in the Poyang Lake region and a whole?covered method was adopted to survey the snails. The simple random sampling,systematic sampling and stratified ran?dom sampling methods were applied to calculate the minimum sample size,relative sampling error and absolute sampling error. Results The minimum sample sizes of the simple random sampling,systematic sampling and stratified random sampling meth?ods were 300,300 and 225,respectively. The relative sampling errors of three methods were all less than 15%. The absolute sampling errors were 0.221 7,0.302 4 and 0.047 8,respectively. Conclusion The spatial stratified sampling with altitude as the stratum variable is an efficient approach of lower cost and higher precision for the snail survey.