tampabay.com

New West Nile cases don't alter fight plan

Pinellas officials say a mosquito control routine in place works. Here's more about it, the disease and things you can do.

By WILL VAN SANT and LISA GREENE
Published August 3, 2005


When a 27-year-old man was diagnosed with West Nile virus Friday, Pinellas County ramped up its mosquito eradication efforts and began sending out crews daily to kill the insects, which carry the sometimes fatal disease.

On Tuesday, officials said they had no plans to again escalate their fight against mosquitoes, despite the announcement Monday that two more county residents had contracted the virus. One victim is a 78-year-old man, the other an 85-year-old woman.

County spokeswoman Marcia Crawley said there are actually fewer mosquitoes in Pinellas than normal for this time of year and that further measures are not needed. If the threat persists, however, Crawley said the county could seek mosquito eradication help from the state.

Pinellas County Mosquito Control, a division of the Highway Department, is handling the eradication. Here are some answers to questions about how Mosquito Control does its job and how to identify West Nile:

How do they know there are fewer mosquitoes than normal?

Forty mosquito traps are set up throughout the county. The traps are checked weekly to gauge the population levels of different mosquito species.

How does the eradication effort work?

Between 2:45 and 6:45 a.m., trucks travel throughout the county and kill adult mosquitoes with a fog. Two products are used, Anvil and AquaReslin, both approved for use by the Environmental Protection Agency.

Between 6:45 a.m. and 3:15 p.m., crews target mosquito larvae in breeding areas. They use three products: VectoBac, VectoLex and Altosid. The chemicals, also approved by the EPA, come in a liquid form that can be sprayed or in granules that dissolve in water.

If I see a lot of mosquitoes, can I get the county to come and spray in my neighborhood?

Yes, call (727) 464-7503 and put in a request.

What is the latest on West Nile virus in our area?

In the past week, three people in Pinellas County tested positive for West Nile. They are the first Pinellas residents ever reported to have the disease and the first cases reported in Florida this year. All three are recovering, local health officials said Tuesday.

Why does Pinellas County have three cases at once?

Mosquitoes carrying West Nile have been in Pinellas for at least three weeks, when the Health Department reported that four of its sentinel chickens tested positive for the virus. It takes three to 14 days for people to develop symptoms, so mosquitoes may have infected several people before the first human case was reported.

Where did it come from?

West Nile virus first showed up in the United States in New York City in 1999, and has spread across the country. It was first reported in Uganda in 1937. Israel also had a large outbreak in 1957. In the U.S., it appears as a seasonal illness, with human cases starting in the summer and peaking in the fall.

How does it spread?

The virus is spread by infected mosquitoes, most often a member of the Culex species. Mosquitoes also spread it to birds. Infected birds, in turn, spread it to other mosquitoes that bite them.

What are the symptoms?

Most people who get infected never know it. Up to 20 percent of those infected get symptoms that include fever and body aches, nausea and vomiting and sometimes a skin rash. Symptoms can last for a few days or several weeks.

About one infected person in 150 gets severe symptoms affecting the nervous system: high fever, stiff neck, disorientation, coma, muscle weakness, vision loss and paralysis. These symptoms can last for weeks and can be fatal or cause permanent damage.

Should I worry?

Last year, 2,539 human cases were reported across the United States. Of those, 100 people died, two of whom lived in Florida.

Who is most at risk?

People over 50 are more likely to develop serious symptoms. But doctors also see cases of paralysis, similar to polio, in healthy young adults.

How is it treated?

There's no specific treatment, but people who develop more serious cases are hospitalized so they can receive IV fluids, breathing help and other supportive care.

How do I keep mosquitoes from biting?

Avoid being outside at dusk and dawn. Wear long sleeves and long pants. Wear mosquito repellent, such as DEET, Picaridin or oil of lemon eucalyptus. Another repellent, permethrin, can be put on clothing, but not directly on skin.

The American Academy of Pediatrics recommends that DEET not be used on babies under 2 months old. Oil of lemon eucalyptus should not be used on children under 3 years old.

What else can I do?

Get rid of standing water, where mosquitoes lay their eggs. Clean out eaves and gutters; store pots, canoes and small boats upside down; and change water in birdbaths and pet dishes. Check for holes in window and door screens.

Sources: Centers for Disease Control and Prevention, Florida Department of Health, Times files.