Dengue (pronounced den’ gee) is a disease caused by any one of four closely related dengue viruses (DENV 1, DENV 2, DENV 3, or DENV 4). The viruses are transmitted to humans by the bite of an infected Aedes aegypti mosquito. Symptoms have been described as flu-like without the respiratory problems and include a high fever lasting 5-7 days, body aches, pain behind the eyes, rash, nausea or vomiting. All of the symptoms may not be present in the patient.

It is possible but that doesn’t mean likely. Although there have been a number of cases of locally acquired Dengue Fever in the upper keys, the threat of contracting the disease is relatively low especially if you take a few simple precautions to avoid getting any mosquito bites at all. A reputable mosquito repellent, long sleeves and pants and closed windows and doors are all EXTREMELY effective preventative measures. Dengue is mostly vectored by the bite of the Aedes aegypti mosquito, which favors more populated urban areas where fresh water is likely to pool in open containers, pool tarps, birdbaths, etc.

The Florida State Department of Health in Monroe County reports that there have been three cases of locally acquired Dengue Fever in Monroe County in 2024. Prior to that, Monroe County lost logged a significant outbreak in 2020  when more than 70 active, locally acquired Dengue cases were recorded. The other most recent outbreak took place in Key West in 2009 and 2010. Because a prolific number of Dengue cases continue to be reported in Cuba and Puerto Rico and because of Monroe County's proximity to these 'hot spots', Dengue will continue to be a concern for FKMCD in the Florida Keys. 

The Florida Department of Health in Monroe County is the best source of information if you are experiencing symptoms or have other questions about mosquito borne diseases. Call the Florida Department of Health in Monroe County at 305-293-7500. 

You are also encouraged to visit their website: Florida Department of Health in Monroe

If you would like to learn more about the control measures being utilized by The Florida Keys Mosquito Control District to stop the spread of Dengue Fever, please click HERE to read the latest Press Release.

DHF is a more severe form of dengue infection only seen in about 10% of those people with dengue. Occasionally the patient suffering from dengue may develop bleeding. Common sites for bleeding are nose, gums or skin. Sometimes, the patient may have coffee ground vomiting or black stools. This indicates bleeding in gastro intestinal tracts and it is serious. The patient with dengue who has bleeding has dengue hemorrhagic fever (DHF). Rarely the patient suffering from dengue may develop shock, then it is called dengue shock syndrome (DSS).

It can be fatal if unrecognized and not properly treated in a timely manner. DHF is caused by infection with the same viruses that cause dengue fever. With good medical management, mortality due to DHF can be less than 1%.

Dengue is transmitted to people by the bite of an Aedes aegypti mosquito that is infected with a dengue virus. The mosquito becomes infected with dengue virus when it bites a person who has dengue virus in their blood. The person can either have symptoms of dengue fever or DHF, or they may have no symptoms. After about one week, the mosquito can then transmit the virus while biting a healthy person. Dengue cannot be spread directly from person to person.

Dengue should be suspected when you have sudden onset of high fever that persists for as much as 5 days. Monroe County Heath Department or your local physician should be contacted and seen.

The highly domestic mosquito Aedes aegypti rests indoors, in closets and other dark places. Outside it rests where it is cool and shaded. The female mosquito lays her eggs in water containers in and around the homes, and other dwellings. These eggs will develop, become larvae, and further develop into adults in about 5 days in the warm summer months and longer than a week in the cooler months.

Yes. There are many people who are infected with the virus and do not suffer from any signs or symptoms of the disease. 70% of the people who have dengue will not show symptoms.

There is no specific medication for treatment of a dengue infection. Persons who think they have dengue should use analgesics (pain relievers) with acetaminophen and avoid those containing aspirin. They should also rest, drink plenty of fluids, and consult a physician. If they feel worse (e.g., develop vomiting and severe abdominal pain) in the first 24 hours after the fever declines, they should go immediately to the hospital for evaluation.

Most people who suffer from dengue fever recover in 1-2 weeks time. Some may feel tired for several weeks. However, if symptoms persist after this period, consult a doctor.

Outbreaks of dengue occur primarily in areas where Aedes aegypti (sometimes also Aedes albopictus) mosquitoes live. This includes most tropical urban areas of the world. Dengue viruses may be introduced into areas by travelers who become infected while visiting other areas of the tropics where dengue commonly exists.

There is no vaccine for preventing dengue. The best preventive measure for residents living in areas infested with Aedes aegypti is to eliminate the places where the mosquito lays her eggs, primarily artificial containers that hold water.

Items that collect rainwater or to store water (for example, plastic containers, 55-gallon drums, buckets, or used automobile tires) should be covered or properly discarded. Pet and animal watering containers and vases with fresh flowers should be emptied and cleaned (to remove eggs) at least once a week. This will eliminate the mosquito eggs and larvae and reduce the number of mosquitoes present in these areas.

Using air conditioning or window and door screens reduces the risk of mosquitoes coming indoors. Proper application of mosquito repellents containing 20% to 30% DEET as the active ingredient on exposed skin and clothing decreases the risk of being bitten by mosquitoes. The risk of dengue infection for international travelers appears to be small. There is increased risk if an epidemic is in progress or visitors are in housing without air conditioning or screened windows and doors.

In fact, the community is the key to dengue prevention. As elaborated above, prevention of dengue relies heavily on preventing the mosquito (Aedes aegypti) that transmits dengue from breeding inside and in the vicinity of homes. Every household can undertake the very simple measures to prevent existing water collections from becoming places for breeding of Aedes aegypti by draining out water from various containers, by regular changing of water plus cleaning flower vases and other items or, in the case of unused items, by discarding/destroying them.

Since the mosquito does not travel far, “house cleaning” by all members of a community will ensure that no breeding places exist, preventing dengue from occurring.

The main strategy in the prevention and control of dengue is “source reduction”, or prevention of breeding places, mentioned above.