# 4732
Yesterday we were greeted by a flood of stories on Dengue Fever being detected in my home state of Florida.
These reports came on the heels of a CDC study suggesting as many as 1,000 Key West residents may have been recently infected with the disease.
Excerpts from the CDC’s press release follow:
Report Suggests Nearly 5 Percent Exposed to Dengue Virus in Key West
An estimated 5 percent of the Key West, Fla., population—over 1,000 people—showed evidence of recent exposure to dengue virus in 2009, according to a report from the Centers for Disease Control and Prevention (CDC) and the Florida Department of Health.
You can find coverage of the Key West story going back several months in this blog, including:
MMWR: Travel Associated Dengue Surveillance 2006-2008
MMWR: Dengue Fever In Key West
Dengue Resurfaces In Key West
The Threat Of Vector Borne Diseases
On Thursday, the story emerged that a man in Miami – who had not left the county in months – had Dengue, and yesterday, additional reports came in of Dengue in Ocala and in Orlando.
Late yesterday, we learned that the Miami case tested negative by PCR and serum antibody tests, and late yesterday it was announced that the Ocala and Orlando cases were travel associated – not locally acquired.
First this story (hat tip Dutchy on FluTrackers) from the Orlando Sentinel, then a little discussion.
Dengue fever in Orange, Marion
Neighboring Lake County is already under a mosquito-borne disease advisory after two horses tested positive for Eastern Equine Encephalitis, another disease spread by mosquitoes.
By Kevin P. Connolly, Christine Show and Walter Pacheco, Orlando Sentinel
3:56 p.m. EDT, July 16, 2010
State health officials Friday confirmed three cases of dengue fever in Orange County — shortly after reports of a suspected South Florida infection.
Test results Friday showed the suspected case in the Miami area came back negative.
The three people who tested positive for the mosquito-borne illness in Orange County did not acquire it locally. A case in Marion County also was contracted outside the U.S.
Orange County Health Department spokesman Dain Weister said two patients were infected in Puerto Rico —where the disease has reached epidemic proportions — and the other person acquired the infection in Haiti.
"It's important to remember that these cases are not endemic to this area," Weister said.
The Health Department spokesperson might well have added the word `yet’ to his statement, since the way Dengue is carried into new areas is through infected travelers that are bitten by local mosquitoes.
It may, however, take a number of such visitors bringing the virus into an area before it can gain an effective toehold and begin to circulate locally.
Or, as we saw in 2007, it only took a single infected traveler to introduce Chikungunya to Ravenna, Italy which ultimately spread to at least 290 other people.
So the precautions and warnings issued by the CDC and local health departments on Dengue prevention are still important to heed.
In order to spread, Dengue requires the right mosquito vector. And the two species best suited to transmit the virus are the Aedes aegypti and Aedes albopictus mosquitoes, which also can spread such diseases as West Nile, Malaria, Yellow Fever, and Chikungunya.
Map showing the distribution of dengue fever (red) and the distribution of the Aedes aegypti mosquito (cyan) in the world, as of 2006. Agricultural Research Service of the US Department of Agriculture.
Map showing the native habitat (blue) and recent spread (green) of the Aedes albopictus mosquito.
According to a recent report, as many as 28 states in the US have at least one of the these mosquito vectors.
Mosquitoes here in Florida (and elsewhere) may carry other diseases, such as SLE (St. Louis Encephalitis), EEE (Eastern Equine Encephalitis), and West Nile Virus.
As the Miami-Dade County Health Department reminds us, to protect yourself from mosquitoes, you should practice the “5 D's”:
- Dusk and Dawn – avoid being outdoors when mosquitoes are very active
- Dress – wear clothing that covers most of your skin
- DEET – repellents containing up to 30 percent DEET (N, N-diethyl-meta-toluamide) are recommended. Other effective mosquito repellents include picaridin, oil of lemon eucalyptus, and IR 3535. Always read label directions for approved usage before your apply a repellent. Some repellents are not suitable for children.
- Drainage – check around your home to remove standing water, where mosquitoes may lay eggs.
Getting rid of mosquito breeding sites is one of the keys to prevention.
- Clean out eaves, troughs and gutters
- Remove old tires or drill holes to drain those used in playgrounds
- Turn over or remove empty plastic pots
- Pick up all beverage containers and cups
- Check tarps on boats or other equipment that may collect water
- Pump out bilges on boats
- Replace water in birdbaths and pet or other animal feeding dishes at least once a week
- Change water in plant trays, including hanging plants, at least once a week
- Remove vegetation or obstructions in drainage ditches that prevent the flow of water
