132 - Outbreak! When you’re under a microscope without insecticide resistance data

Abstract: Knowing if insecticide resistance is present in an area before an outbreak occurs is critical. During routine years mosquito control usually does not garner much public attention. During an outbreak, not only do routine control activities intensify, but there is often increased scrutiny by public officials, the press, and the public. This was true in Miami, FL during the 2016 Zika virus outbreak. The Miami Dade Mosquito Control program was conducting intensive mosquito control against Aedes aegypti under the assumption that because they never sprayed where this mosquito was causing disease, there was no insecticide resistance. Cases continued despite their intensive control efforts in several concentrated control areas and with the added stress of dealing with outside scrutiny. Insecticide resistance testing was initiated to determine the most effective chemicals and application rates needed to kill Ae. aegypti in the area. Once insecticide resistance was detected in both lab and field trails, effective spray strategies were developed to better control local mosquitoes. Resistance was found to varying degrees for all pyrethroids tested but mosquitoes were susceptible to organophosphates. The strategy adopted included house inspections and treatment as needed, aerial spraying with naled, truck spraying with deltamethrin (at an effective application rate) and area-wide larviciding (WALS) using both trucks and aircraft.