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Thu September 12, 2013
Shots - Health News

Florida Officials Swat At Mosquitoes With Dengue Fever

Originally published on Fri September 13, 2013 4:29 pm

Public health officials in Florida are once again scrambling to contain an outbreak of dengue fever, a disease spread by mosquitoes.

Until 2009, when it surfaced in Key West, the tropical disease hadn't been seen in Florida in more than 70 years.

Now there are concerns dengue may establish a foothold in the state.

Mosquito control is always important in Florida, but in July it became urgent in Stuart, a quiet community on the state's Atlantic coast. Bob Washam of the Martin County health department says he heard about cases of a disease that seemed related but that doctors couldn't identify.

"Initially the physicians felt that it might have been a chemical or something like that, because three people were sick," Washam says.

Testing showed that it was dengue fever. So far, health officials have turned up 18 cases of the disease in Martin County and neighboring St. Lucie County. All of the cases seem to have been contracted in a few neighborhoods in Stuart.

A Debilitating Disease

On a tree-lined street in a neighborhood of small cottages, Gene Lemire with Martin County's mosquito control department is checking one of his traps.

"These other mosquitoes could be our little disease-transmitting mosquitoes," he says. "We'll have to take them back to the lab."

The species Lemire is looking for, Aedes aegypti, is the one most likely to carry the dengue virus. He says they lay their eggs on the sides of containers, and the eggs hatch once water covers them. And then, he says, they "come out as an adult ready to bite somebody."

In Rio, a community overlooking the St. Lucie River, Lemire points out potted plants, boats, tarps and other containers — all potential breeding areas.

For the past month, his crews have been going door to door, emptying water from buckets and dropping larvicide tablets into larger containers in an effort to control the mosquito.

When diagnosed and treated, dengue is rarely fatal. But it is debilitating and accompanied by a high fever, rash and joint pain so severe that it's been called "breakbone fever."

"They got it right," says Marty Baum. Baum and his girlfriend both contracted dengue and have since recovered. "There's absolutely no comfortable way to be. If you lie still, it hurts. If you move, it hurts."

He thinks they got it from mosquitoes in her backyard one evening. "At 9 o'clock at night, watching a Miami Dolphin football game, I was fine. A 10 o'clock my fever was 102 and I was almost convulsive with shivers."

Not The Final Outbreak

It's not unusual for travelers to the Caribbean, Africa or Latin America to return home with a case of dengue acquired overseas. But in Stuart, dengue spread to the local mosquito population, says Dr. Aileen Chang, an expert on dengue fever at the University of Miami Health System.

And those mosquitoes have infected others with the disease. It's an outbreak similar to one seen in Key West in 2009 and 2010.

Only about a quarter of those infected with dengue become sick enough to see a doctor. So far, health officials haven't been able to identify the person who brought dengue to the area.

In Stuart — and everywhere there's a dengue outbreak — officials find themselves in a race against the disease. They have to work to educate the public and control the mosquito population before it spreads more.

Dr. Chang has been advising health authorities in Stuart, and judging from the numbers of cases coming in, she believes this particular outbreak may have peaked. But it's not likely to be the last, she says.

"The temperature and weather patterns are changing. We're seeing more dengue throughout the entire world," she says. "So now, having it creep up to Florida, the most southern part of the U.S., is not that surprising."

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Transcript

AUDIE CORNISH, HOST:

In Florida, public health officials are once again scrambling to contain an outbreak of dengue fever. Dengue is spread by mosquitoes and until 2009, when it resurfaced in Key West, the tropical disease hadn't been seen in Florida for more than 70 years. Now, as NPR's Greg Allen reports from Miami, there are concerns that the latest outbreak may be a sign that dengue has established a foothold.

GREG ALLEN, BYLINE: Stuart is a quiet, seaside community on Florida's Atlantic coast. On a tree-lined street in a neighborhood of small cottages, Bob Lemire is checking one of his traps. [POST-BROADCAST CORRECTION: Lemire's first name is Gene.] Lemire is with Martin County's Mosquito Control Department.

GENE LEMIRE: Now, these other mosquitoes could be our little, disease-transmitting mosquitoes. We'll have to take them back to the lab. And there's probably - what? One, two, three, four, five, six...

ALLEN: The species Lemire is looking for is the one most likely to carry the dengue virus, Aedes aegypti. For the past month, his crews have been going door to door, emptying water from buckets, dropping larvicide tablets into larger containers; all in an effort to control the mosquito. In Rio, an older community overlooking the St. Lucie River, Lemire points out potted plants, boats, tarps and other containers, all potential breeding areas.

LEMIRE: Aedes aegypti is a species that lays their eggs only in containers. So they're going to lay their eggs on the side of the container. They're going to wait for water to go over those eggs; and then they go through the hatching process and then come out as adult, ready to bite somebody.

ALLEN: Mosquito control, always important in Florida, became urgent in Stuart, in July. Bob Washam, of the Martin County Health Department, says he heard about cases of a disease that seemed related, but that doctors couldn't identify.

BOB WASHAM: Initially, the physicians felt that it might have been a chemical, or something like that, because three people were sick.

ALLEN: Testing showed it was dengue fever. So far, health officials have turned up at least 18 cases of the disease in Martin and St. Lucie counties. All of the cases seem to have been contracted in a few neighborhoods in Stuart. Today, the Martin County Health Department announced it will begin taking blood samples from randomly selected households, to see how far the disease has spread. When diagnosed and treated, dengue is rarely fatal. But it is debilitating - accompanied by a high fever, rash, and joint pain so severe it's been called breakbone fever.

MARTY BAUM: They got it right. If you lie still, it hurts. If you move, it hurts.

ALLEN: Marty Baum and his girlfriend both contracted dengue and have since recovered. He thinks they got it one evening from mosquitoes in her backyard.

BAUM: At 9 o'clock at night, watching the Miami Dolphin football game, I was fine. At 10 o'clock, my fever was 102, and I was almost convulsive with shivers.

ALLEN: It's not unusual for travelers to the Caribbean, Africa or Latin America to return home with a case of dengue acquired overseas. But what's happened in Stuart is that dengue has now spread to the local mosquito population, and those mosquitoes have infected others with the disease. It's an outbreak similar to one seen in Key West in 2009 and 2010. Dr. Aileen Chang is an expert on dengue fever at the University of Miami.

DR. AILEEN CHANG: A traveler comes back from Puerto Rico or any other endemic location - basically, any country that is in the tropics - they can come back and spread it to the local mosquito population. So that's what has appeared has happened here in the Keys and now, in Martin and St. Lucie County.

ALLEN: So far, health officials haven't been able to identify the person who brought dengue to the area. Dr. Chang has been advising health care authorities in Stuart. And judging from the numbers of cases coming in, she believes this outbreak may have peaked. But with climate change and other trends, she says it's not likely to be the last.

CHANG: The temperature and weather patterns are changing. We're seeing more dengue throughout the entire world. So now, having it creep up to Florida, the most southern part of the U.S., is not that surprising.

ALLEN: In Stuart and every time there's a dengue outbreak, health authorities find themselves in a race against the disease. They have to work to educate the public, and control the mosquito population before dengue spreads and risks, once again, becoming endemic in the United States.

Greg Allen, NPR News, Miami. Transcript provided by NPR, Copyright NPR.