Larval survey and spatial epidemiological analysis of vector Aedes aegypti to study the risk of dengue outbreak in India

Abstract

In view of increasing incidences of dengue infections in India, a precautionary comprehensive management study based on entomological survey, statistical analysis and Global Positioning System (GPS) in six villages (around Hyderabad) of Medchal-Malkajgiri District was carried out. The present article includes the results of (1) investigating the prevalence of Aedes aegypti mosquito, identifying the sites of its breeding through entomological survey and understanding its significance using container index (CI), house index (HI), breteau index (BI) and breeding preference ratio (BPR) (2) investigating the relationship between the types of containers with presence of larvae using logistic regression and (3) visualizing the pattern and association between the positive houses and breeding development sites using a combination of (GPS) and Google Earth Pro software. The entomological survey explored highest vector abundance (with Density Index (DI) of 8) at village Malkaram, followed by Mandaipalle with DI of 7. Further, logistic regression substantiated higher odds ratio of larvae presence for villages Mandaipalle and Upparpalle, compared to Malkaram. This was further corroborated from the visual pattern obtained using google earth which displayed the presence of highest breeding development sites in the vicinity of positive houses in Malkaram. The obtained data was shared with public health workers as it authenticated the reasons for the recent diagnosis of dengue cases in Malkaram and Mandaipalle villages. Identifying the positive houses and breeding development sites can help the public health workers use the vector control measures efficiently. Thus the proposed technique of combining Google Earth with GPS in entomological survey is recommended, especially for the public health workers of developing countries like India as it is a simple and cost effective method.