Zika Defense: Hunting The Mosquitoes That Transmit Zika Virus In Florida
SLIDESHOW: The subject of all the fuss: Aedes aegypti, the yellow fever mosquito. Both it and Aedes albopictus can spread Zika, and are found year-round throughout Florida.
Meet the sentinel chickens. This flock, and others all across Orange County, are checked weekly for mosquito-borne illnesses that show up in birds before humans.
Don’t worry: Chickens who test positive for a mosquito-borne illness aren’t put down, they get new homes.
A centrifuge is used to prep the chicken blood to be sent out to a lab for testing.
“We send these samples to the state health laboratory,” said Kelly Deutsch, assistant manager of the Mosquito Control Division. “They get checked for West Nile Virus, Saint Louis encephalitis, Eastern equine encephalitis, and the Highlands J virus.”
Those little black specks aren’t tadpoles; they’re mosquito larvae.
If your eyes are good enough, you can spot the distinctive white stripes on the yellow fever mosquito.
The war chest of mosquito-fighting tools. Big-time fogger in the back, hand-held fogger, larvicide and traps.
It’s a trap: There’s a fan that sucks mosquitoes into this trap. And the bait is human-scented. Ew.
This simple device allows for workers to collect the mosquito larvae and hatch them in a lab. The dark cup and lighter stick attracts the mosquitoes by resembling a naturally-occurring environment, like a knot in a tree.
This is the dipper, used by mosquito control workers to collect water samples in the field and look for larvae in the field.
Outside a used tire shop off Orange Blossom Trail in Orlando, there are racks and racks of tires exposed to the weather – a favorite hiding spot for mosquito larvae.
In particular, Aedes aegypti and Aedes albopictus, commonly known as the yellow fever mosquito and the Asian tiger mosquito. These are the mosquitoes that can transmit Zika virus from person to person.
Amador Rodriguez, operations supervisor for Orange County Mosquito Control Division, walks up to a tire that’s collected rain water. He uses a dipper, basically a cup at the end of a long stick, to get a sample.
“And we have some right here,” Rodriguez said.
The little black mosquito larvae wriggle around in the cup. They look like tiny tadpoles.
Kelly Deutsch, assistant manager of Orange County Mosquito Control Division, said it’s almost a guarantee that the larvae we’re looking at are one of the two breeds that can transmit Zika. That’s because the yellow fever mosquito and the Asian tiger mosquito love man-made structures like tires, flower pots, and garbage cans…anything that can hold water in your backyard.
Florida Gov. Rick Scott declared a public health emergency in the four Florida counties with confirmed cases of travel-related Zika. Florida now has nine confirmed cases of travel-acquired Zika virus in Miami-Dade, Hillsborough, Lee and Santa Rosa counties. Scott’s order directs public health officials to target residential neighborhoods with backpack mosquito spray measures.
But this kind of work, hunting and pecking for mosquito larvae, is the bread and butter of mosquito control all across Florida. Spraying to kill adult mosquitoes is a last line of defense. Going after the larvae – before they can transmit Zika – is a better approach, officials said.
The World Health Organization this week called Zika a public health emergency. The virus has been linked to a severe birth defect.
You might think of mosquito control as nuisance control. Not so, said Dr. Christopher Hunter, director of Orange County’s Health Services Department. Mosquito control is under the auspices of health services.
Orange County spends about $2 million a year on mosquito control, and workers inspected more than 29,000 sites last year.
“My opinion is yes, we’ll see [Zika],” Hunter said. “We see it with Dengue, with chikungunya, we see it with all these others, I think it will happen.”
Orange County has extra risk factors for Zika. One, the tourism industry brought in 1.9 million visitors from South America in 2014, where nine countries have active Zika transmissions.
But Central Florida is also home to large populations that have family in countries like Puerto Rico and Haiti. The worry is someone may spend a few weeks in a country with Zika and bring it back.
Dengue, chikungunya and Zika are all spread by the same mosquitoes, and those mosquitoes live in Florida year-round.
“Many of these are viruses that don’t have specific treatments,” Hunter said. “So the best way we can avoid people getting ill is controlling the vector, controlling the mosquito. From a public health perspective, it’s much simpler to control the mosquito population than the virus itself.”
Hunter said there’s a level of personal responsibility when it comes to the two breeds of mosquitoes that can spread Zika. People need to look for standing water on their property.
“These mosquitoes don’t travel far from where they breed,” Hunter said. “So if you have them in your yard or around where you live, they’re almost certainly breeding nearby.”
WMFE is a partner with Health News Florida, a statewide collaborative reporting on health care.
Health reporting on WMFE is supported in part by AdventHealth.
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