The storms of the last few weeks promise a boom in mosquitoes — South Florida’s most persistent, painful pests and a growing public health concern. Some places are already abuzz.
“It’s definitely been the most active season we’ve seen in recent years,’’ said Andrea Leal, operations director for the Florida Keys Mosquito Control District.
In the Keys, bordered by mangroves and tidal marshes that are prime breeding grounds, the bite has come early and often. A district worker’s “landing rate” count of 50 — the number lighting on a bare arm in a minute — in Key Largo early this month launched spray trucks and planes. The goal is no more than three in an island chain that depends on tourists seeking tans not welts. Breezes keeping skeeters in the Everglades have helped spare Miami-Dade and Broward — so far.
For mosquito agencies and public health authorities across the state, the surge is shaping up as another season of increasing concern about mosquito-borne diseases like West Nile virus, malaria, Eastern equine encephalitis and dengue fever, which has become a rising risk in South Florida.
The flu-like virus, sometimes called “break-bone fever” because of the excruciating joint pain it can cause, emerged in Key West in 2009 with 27 cases from mosquito bites, the first in Florida since 1934. Another 66 cases were recorded in 2010; none since. But a handful have since cropped up in Miami-Dade, Broward and Palm Beach counties.
With dengue spreading globally and running at epidemic levels in many Latin and Caribbean countries, public health experts expect the disease to slowly spread in Florida, with its large populations of immigrants and international travelers. The virus is carried in the human bloodstream but transmitted by the bite of a common and difficult-to-control mosquito called Aedes aegypti.
“Miami-Dade is an entry gate,’’ said Pedro Noya-Chaveco, a biological scientist for the Miami-Dade County Health Department. “We have a lot of people traveling to endemic areas. People come here for a visit and go to other places.’’
Though there have only been a handful of infections traced directly to mosquitoes since Key West’s two small outbreaks, the state’s “imported cases” have continued to creep up each year. Through June 1, the Florida Department of Health has recorded 38, with Miami-Dade leading with 12 cases, followed by Orange with eight, Palm Beach with six and Broward with three.
Dengue effects vary widely. A mild headache for some can be a high fever, rash and severe pain in the eyes, joints and bones for others. A small percentage of cases can develop life-threatening internal bleeding called hemorrhagic fever. A first infection is rarely serious but it can be dangerous for infants or the elderly.
Some experts fear the next outbreak in Florida could be larger and more severe — particularly if it happens again in Key West.
In a recent edition of BuzzWords, the quarterly newsletter of the Florida Mosquito Control Association, University of Florida entomologist Walter Tabachnick warned that Key West was facing “a potentially catastrophic epidemic.’’
“It is almost certain that failure to aggressively combat dengue will result in many sick people and some may die as a result,’’ Tabachnick wrote. Such an event, he said, would be a double economic whammy, discouraging tourism and running up healthcare costs.