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Malaria no longer spreading in FL; other mosquito-borne diseases still a threat; chickens affected


Malaria no longer spreading in FL; other mosquito-borne diseases still a threat; chickens affected

Sep 12, 2023 | 4:19 pm ET
By Jackie Llanos
Malaria no longer spreading in FL; other mosquito-borne diseases still a threat; chickens affected
Plane sprays insecticide on a field. Credit: Eric Brehm / Unsplash

After a flurry of malaria cases in Sarasota the past few months, the county and adjacent Manatee County are no longer under a mosquito-borne illness alert. However, other parts of Florida are still under the threat of dengue, West Nile virus and Eastern Equine Encephalitis virus.

No one has obtained malaria in the state since July, according to the latest Florida Department of Health arbovirus surveillance report. Hence, an alert is not needed in Sarasota and Manatee, but people should remain vigilant of symptoms that may appear after a mosquito bite, state mosquito experts said during a briefing hosted by the Florida Mosquito Control Association.

“That doesn’t mean that we don’t want people to take precautions because there’s still a possible risk, but we’re out of the alert status, which is fantastic,” said Wade Brennan, director of the Sarasota County Mosquito Control District. “Our integrated pest management programs have been very effective and efficient at eliminating this risk.”

On the other hand, Broward, Escambia and Miami-Dade counties are still under alert because of locally acquired cases of West Nile virus and dengue. The Florida Department of Health didn’t report any cases in its latest report. But, so far this year, three cases of West Nile virus emerged in Escambia and 17 cases of dengue emerged in Broward and Miami-Dade.

“One of the problems with dengue fever is that there are no vaccines … the only way to control the virus is to control the mosquito, and the only thing we have to use really or the main thing is chemistry,” said Phil Goodman, the chairman of the Florida Keys Mosquito Control District. “As a chemist myself, I can tell you there’s not a lot of new developments in chemical pesticides for mosquito control. So, we need some new technologies. The ones that we have mosquitoes are becoming very resistant to them.”

Other threats

The local spread of malaria has caused concern, but for Sandra Fisher-Grainger, the president of the mosquito association, Eastern Equine Encephalitis virus, or EEE, and West Nile virus are scarier.

“It’s [EEE] a very serious disease with about 30% mortality, but I’d say the majority of survivors have lifelong neurological symptoms, and West Nile virus may actually manifest itself as a neuro-invasive disease-causing disability as well,” Fisher-Grainger said. She is also the director of Hernando County Mosquito Control.

St. Johns and Suwanee are under mosquito-borne illness advisories after two people contracted EEE in the counties in June and July, respectively. There aren’t any vaccines or medicines to treat EEE, and most cases occur in Gulf Coast states, according to the Centers for Disease Control and Prevention (CDC).

There are also active mosquito-borne illness advisories in effect for Bay, Hardee, Jefferson, Nassau, Orange, Polk and Walton counties:

  • Hardee and Polk had one case each of dengue.
  • Bay detected an asymptomatic blood donor with West Nile virus in August.
  • Jefferson had two horses tested positive for EEE.
  • Nearly 50 chickens in Nassau tested positive for EEE and West Nile virus antibodies.
  • More than 20 chickens had EEE and West Nile virus antibodies in Orange County. One chicken had antibodies for Highlands J virus, which is a mosquito-borne illness that is rarely seen in humans.
  • In Walton, 54 chickens had antibodies for EEE and West Nile virus, five chickens had antibodies for Highlands J virus and one chicken had antibodies for St. Louis encephalitis virus, which is mostly asymptomatic in humans

Those chickens have been used by mosquito-control efforts to see what kind of mosquito-borne illnesses are in a given area.

The threat of mosquito illnesses spreading occurs after hurricanes pass through a region and when there are more people traveling to countries where mosquito illnesses are common, the experts said during the briefing. From Sept. 3 – 9, the Florida Department of Health reported 16 cases of dengue from people who traveled abroad.

People can avoid the diseases by wearing CDC-approved repellents and long sleeves and getting rid of standing water near their homes.

“It’s never the time to try to take care of yourself by using those home remedies,” Brennan said.