A Systematic Evaluation of Dengue Vector Surveillance, Tainan City, Taiwan, 2011-2013

Abstract

Outbreaks of dengue fever (DF) are more common in southern than northern Taiwan, with primary transmission through Aedes aegypti mosquito vectors. A dengue vector surveillance system (DVSS) was established in 2005, with the objectives of characterizing dengue vector distribution and evaluating the effectiveness of DF control measures. We evaluated DVSS in Tainan City, a southern city in Taiwan with DF transmission. During 2011-2013, Ae. aegypti predominance was found in 31% of 36 districts. Breteau, container and household indices decreased following district-level vector control campaigns in 2011 and 2013. Levels of data validity and entry error types were more than 90% and less than 10% respectively. Program completeness was found to be low at 17%, primarily influenced by rural neighborhood findings. Completeness of pupal indices was unsatisfactory (12%), limited by time and manpower in collecting pupae. This evaluation of DVSS showed that the system collected complete and valid data necessary for meeting the surveillance objectives. We recommended that completeness of DVSS be further improved in rural districts, pupal index be removed from routine dengue vector surveys, and on-the-job training of survey personnel be established and maintained.
 
Keywords: dengue, dengue vector surveillance system, Ae. aegypti, Taiwa