Abstract:

Objective To evaluate the control effects on soil-transmitted helminth (STH) infection after cessation of prevention measures in eight demonstration plots. Methods After cessation of intervention measures in 2009, a survey was made on the soil-transmitted helminth infection, the awareness of hygiene knowledge and the popularity of sanitary toilet and tap water in Kaiyang County in Guizhou Province, Tunchang County in Hainan Province, Guixi City in Jiangxi Province, Tongcheng City in Anhui Province, Yueyang County in Hunan Province, Xiangyun County in Yunnan Province, Rong County in Guangxi Zhuang Autonomous Region and Danling County in Sichuan Province from September to November in each year of 2011-2015. Data were analyzed with chi-square test. Results The overall infection rates of soil-transmitted helminthes in the pilot plots from 2011 to 2015 were 6.1% (490/8 005), 5.8% (474/8 146), 5.5% (447/8 066), 5.8% (477/8 164) and 4.0% (305/7 688), respectively. The infection rates of hookworms, A. lumbricoides and T. trichiura decreased from 3.8% (303/8 005), 1.6% (125/8 005) and 1.1% (84/8 005) to 2.3% (177/7 688), 1.0% (78/7 688) and 0.3% (24/7 688), respectively. From 2011 to 2015, the highest infection rate of STH was found in Tunchang County in Hainan Province (19.2%, 195/1 015; 19.7%, 209/1 063; 20.6%, 215/1 046; 22.6%, 235/1 038; and 11.2%, 114/1 022, respectively). The age group with the highest infection rate of A. lumbricoides was 5-9 years from 2011 to 2014 and 50-59 years in 2015. The age group with the highest infection rate of hookworms was > 60 years from 2011 to 2015(6.2%, 76/1 231; 5.1%, 67/1 328; 6.0%, 88/1 476; 6.2%, 118/1 894; 2.7%, 54/2 032). The infection rate of STH was 5.5% (1 090/19 805) in males and 5.3% (1 050/19 904) in females, with no significant gender difference (P > 0.05). The questionnaire pass rate on health knowledge and hygienic behavior was 93.2% (1 129/1 211), 94.9% (1 142/1 203), 94.1% (1 134/1 205), 92.3% (973/1 054) and 94.9% (854/900), respectively, from 2011 to 2015. The popularity rate of tap water increased from 33.2% (187/564) in 2011 to 59.4% (209/352) in 2015 and the popularity rate of sanitary toilet increased from 71.3% (402/564) in 2011 to 77.3% (272/352) in 2015. Conclusion The STH infection rate has remained at a low level since the termination of integrated control measures in 2009, which indicats that the control strategy has achieved sustainable effect in the pilot counties.

Key words: Soil-transmitted helminth, Integrated control, Pilot county, Effect evaluation