Environment

Zika mosquito numbers up, so are control efforts across Miami-Dade

Miami-Dade County officials say they will increase inspections and ground-spraying this weekend after traps began showing high numbers of Aedes aegypti mosquitoes that can spread the Zika virus. Inspectors will be armed with backpack foggers like the one Carlos Varas, a Miami-Dade County mosquito inspector, used last year.
Miami-Dade County officials say they will increase inspections and ground-spraying this weekend after traps began showing high numbers of Aedes aegypti mosquitoes that can spread the Zika virus. Inspectors will be armed with backpack foggers like the one Carlos Varas, a Miami-Dade County mosquito inspector, used last year. emichot@miamiherald.com

A rising number of Zika-spreading mosquitoes across Miami-Dade County and on Miami Beach is triggering more aggressive control efforts, Miami-Dade County officials said Friday.

In recent weeks, about 160 traps posted around the county to monitor for Aedes aegypti mosquitoes, the urban mosquito that carries the virus, are increasingly catching more mosquitoes, said Miami-Dade County division director Gayle Love. That’s prompting mosquito officials to up their campaign to prevent another outbreak of the virus that last year made the county ground zero with the first active transmission zones in the continental U.S.

Protestors gather at City Hall in Miami Beach against the spraying of naled over the ocean to eradicate Zika.

With the exception of Miami Beach, Love would not say where numbers are high, only that traps countywide are averaging 16 mosquitoes. Anything above 10 is considered high.

Wherever they find high trap numbers, county officials plan on sending inspectors armed with back-pack foggers that apply a pyrethroid-based adulticide, she said. They will also spread an organic larvicide if they encounter breeding.

backpack zika fogging
Fran Middlebrooks, a groundskeeper at Pinecrest Gardens, used a blower to spray pesticide during a 2016 outbreak of Zika in Miami-Dade County. Gaston De Cardenas MIAMI HERALD

On the Beach, where last year’s transmission zone covered 4.5 square miles — about two-thirds of the city — workers will concentrate on an area between South Pointe Park and 63rd Street, Love said. Workers will also fan out across the ritzy islands in Biscayne Bay, where all but Rivo Alto, Belle Isle and Sunset Island 3 have high numbers, she said.

“These are female Aedes aegypti, the ones that will bite you, that are in the traps,” Love said.

So far this year, Florida health officials have confirmed 29 travel-related Zika cases in Miami-Dade County but no locally acquired infections. Statewide, health officials have confirmed 72.

Last year, neighborhoods in Wynwood, Little River and the Beach became the first spots in the nation, along with Puerto Rico, where people began contracting the virus. Federal, state and local officials responded with an aggressive war on the mosquitoes, which increase the risk of infection as their numbers rise.

The U.S. Centers for Disease Control and Prevention found that a combination of aerial spraying with the controversial pesticide naled and an organic larvicide succeeded in driving down mosquito populations. But critics have repeatedly complained that naled, which is banned in Europe and kills bees, butterflies and other pollinators, is too risky, with not enough known about its potential health effects.

After being criticized last year for doing too little in advance of the season despite repeated warnings, county officials this year continued spreading larvicides throughout the winter and spring to keep the traditional mosquito season that arrives with summer rain under control.

mosquito trap
Mosquito traps, like this one set in the 1200 block on Drexel Avenue last year, are showing the number of mosquitoes in the county are increasing. C.M. GUERRERO. EL NUEVO HERALD

So far this season, the county has sprayed naled twice to control pesky marsh mosquitoes, which do not carry the virus.

Last week, a Miami Beach doctor asked a U.S. district judge to order an emergency injunction to stop the aerial spraying. A status conference on the complaint is scheduled for July 12.

Follow Jenny Staletovich on Twitter @jenstaletovich

  Comments