Dengue Outbreak Hits Key West, Fla.
5% of Key West Population Infected in 2009; New Case Suggests Ongoing Outbreak
Symptoms of Dengue Fever continued...
Illness begins three to 14 days after a bite from a mosquito carrying the virus. Symptoms may include:
- Rapid onset of high fever
- Severe frontal headache
- Bone pain
- Pain behind the eyes
- Aching muscles or joints
- Signs of bleeding (such as pinpoint red or purple spots on the skin, nosebleed, bleeding gums, blood in urine or stool, or vaginal bleeding)
- Nausea or vomiting
Many people mistake the symptoms of dengue fever for those of flu, says infectious disease specialist Mark Whiteside, MD, MPH, medical director for the Monroe County Health Department.
"It is a bad flu-type illness, and dengue's old 'breakbone fever' nickname comes from the fever and chills," Whiteside tells WebMD. "You are miserable and you might wish you were dead, but you get over it in a week or two."
Even so, fatigue and loss of appetite may linger for weeks after recovery.
There are four types of dengue virus; the Key West outbreak was type 1. A person cannot get the same type of dengue twice. However, a person who gets dengue a second time, from a different dengue strain, is at risk of severe disease. That's because antibodies to the first dengue strain fail to protect and end up enhancing infection by the second strain.
That's one of the things that worries Whiteside.
"It's often asymptomatic in kids, and I worry that many kids who may have been infected during this outbreak will get another subtype if we have a different outbreak," he says.
To keep that from happening, Key West has been conducting an extensive mosquito-control program. There's been spraying to kill adult mosquitoes, but that's not particularly effective against the Aedes aegypti and Aedes albopictus mosquitoes that carry dengue.
Both of these mosquito types live close to people's houses. They can breed in a teaspoon of water.
Experts believe that when 2% or fewer breeding sites harbor Aedes mosquitoes, disease transmission wanes. That goal is elusive. Whiteside says that a February 2010 survey of Key West breeding pools -- the time when Aedes is supposed to be at its lowest levels -- found Aedes breeding in 10% of homes.
"That is high for winter, but the same index in Old Town [the center of Key West tourism] is 15% to 20%, which is unacceptable," Whiteside says.
A beefed-up mosquito-control effort has been conducting house-to-house sweeps to bring the situation under control.
A report on the Key West dengue outbreak appears in the May 21 issue of the CDC's Morbidity and Mortality Weekly Report .