80 - Review of Action Thresholds from the Literature

Abstract: Many different methods are used and new methods are evolving to control nuisance and vector mosquito populations across the world. Implementation of such control methods at the optimal time has been identified as critical to maintaining the populations below unacceptable levels. The establishment of evidenced-based action thresholds is thus encouraged to achieve maximum results under available resources. A review was conducted to identify different action thresholds published worldwide since 2010 and to understand the associated surveillance characteristics. Only 87 publications filtered through the initial database identification of 1,485 publications were included in the review. Thirty publications reported originally generated thresholds, 13 publications reported a clear statistical method to develop an action threshold although there was no hard defined threshold, and 44 publications mentioned only previously generated thresholds that were used in the study. Overall, the thresholds that directly indicate disease transmission conditions outnumbered those that directly indicate mosquito abundance. The majority of the threshold originated in Asia targeting dengue and dengue vectors. The review discusses the possibility of using external data, spatial and temporal variations in thresholds, the importance of an adequate lead time to initiate control interventions as well as associated surveillance characteristics that would generate better thresholds.