Aedes mosquito responses to control interventions against the Chikungunya outbreak of Dire Dawa, Eastern Ethiopia

Arboviral infections are re-emerging diseases of public health concern circulating among wild animals and human populations due to shortage of strong entomological data in addition to increasing urbanization, transportation and mosquito adaptation to complex environment in Ethiopia. This study assessed the response of Aedes mosquito to interventions (environmental management and Chemical (Temephos and Propoxure) spray) made to control the Chikungunya outbreak in Dire Dawa, Eastern Ethiopia. A before and after intervention entomological study design was used to address all villages, with simple random sampling technique. To determine the vector density, entomological indices (House index, Container index, Bretaeu index and Pupae index) were calculated. A total of 1297 containers were inspected in 800 households for the presence of Aedes immature and adult. Out of 1297 containers inspected, 1128 (87%) were found be Aedes larvae/pupae positive. A total 1289 mosquitoes were collected, 1264 (98%) were Aedes and the rest 25 (2%) were Culex mosquitoes. The house index, container index, bretaue index and pupae index before and after control intervention was (90.125%, 7.4%), (92.87%, 14.75%), (141.75%, 20.5%) and (1431.5, 4%) respectively. The infestation indices of Aedes mosquitoes drastically reduced after control interventions which imply that deploying integrated vector control intervention, like environmental management, insecticidal applications are effective in Aedes mosquito control during outbreaks of arboviral diseases. Permanent and comprehensive sentinel sites should be established fort continuous surveillance of vector status and diseases to halt cyclic transmission.