Relation of Entomological Parameters and Dengue Transmission to Develop the Optimal Model and Threshold for Dengue Epidemics

An observational analytical study, year-long entomological surveys were carried out in selected villages in Tirunelveli district. The vector breeding indices were compared with the incidence of cases in each of the selected sites. Concurrent epidemiological data were used to relate the entomological risk. The values at lower 95% confidence limit of 1.34% of St. aegypti positive water storage containers, 7.85 St. aegypti positive water storage containers per 100 houses and 18.02 St. aegypti pupae per 100 houses in water storage breeding sources have been determined to be the threshold level above which the chances in dengue transmission would be higher. The lower 95% confidence limit of 19.9 St. aegypti pupae per 100 houses can also be considered as threshold level when the estimates were made irrespective of the type of breeding habitats. Proof-of-concept of how to search for the optimal model and threshold for dengue epidemics is determined.