WALS^®

The Zika virus was first identified in Ugandan monkeys in 1947. For the next six decades, it was found in occasional cases of mild human infections across Africa and Asia. In March 2015, Brazil reported a large outbreak of rash illness – soon identified as the Zika virus infection – and within seven months, that country reported an association between Zika and microcephaly. Outbreaks and evidence of transmission soon appeared throughout the Americas, Africa, and other regions globally. To date, a total of 86 countries and territories have reported evidence of the mosquito-transmitted Zika infection.

In late July 2016, the first locally acquired Zika cases in the continental U.S. were confirmed in Miami‐Dade County. By August 31, the Centers for Disease Control (CDC) had confirmed 35 cases of locally acquired Zika in Florida. At that time, adulticides had served as Miami-Dade’s core intervention for mosquito control, but the Zika outbreak prompted the program to expand its IVM approach to include other novel, but proven interventions to help stop transmission. This led to Miami-Dade integrating a WALS strategy (both from aerial and trunk mounted applications) into their program. On August 15, 2016, the Miami Herald was among the first publications to report the dramatic effect of WALS and Vectobac WDG. Janet McCallister, a medical entomologist with the Centers for Disease Control and Prevention, was quoted as saying, “In areas without the larvicide, the adult populations are rebounding much quicker and much higher than in the area [treated] with both.” On September 19, Florida Governor Rick Scott declared Miami‐Dade County Zika-free.