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Mosquito-Borne Illnesses: Facts, Figures and Prevention

The Keys County Medical Director Discusses Mosquito Protection

The following, based on information from the Florida Department of Health in Monroe County and the Florida Keys Mosquito Control District, is provided to address any questions:

  • Mosquito-borne illnesses, such as dengue, chikungunya and Zika are viral diseases primarily transmitted by the Aedes aegypti mosquito, a freshwater breed common to the southeastern United States, the Bahamas, Caribbean, Central and South America as well as other tropical and subtropical locations. These diseases are normally not spread person-to-person.
  • Dengue fever, chikungunya and Zika viruses are currently not a health threat in the Florida Keys including Key West.
  • The most common symptoms of Zika virus disease are fever, rash, joint pain, and conjunctivitis (red eyes). The illness is usually mild with symptoms lasting from several days to a week. Severe disease requiring hospitalization is uncommon. Most at risk, according to health officials, are women who are pregnant or planning to get pregnant, because of the potential for the Zika to cause birth defects.
  • Some 14 people in mainland Florida and as well as others in other states have been reported as contracting Zika after visiting South America or the Caribbean, but there have been no reports of local transmissions in Florida.
  • Health officials are asking the public to be aware of the disease. The Centers for Disease Control has issued an advisory counseling pregnant women to avoid traveling to 22 Zika-affected countries and territories in Central America, South America, Mexico, the Caribbean, Samoa and the Cape Verde Islands.
  • There are no travel advisories issued either by local, state, federal or international health officials counseling people not to vacation in Florida including the Florida Keys.
  • The state of health emergency declared for seven mainland Florida counties was done so to provide preparation and funding to thwart local transmission possibiliites. It does not mean that visitors and residents should deviate from their normal lives.
  • Traditionally in Florida, mosquitoes are most active in summer and early fall and more dormant late fall through spring.
  • To help avoid being bitten by Aedes aegypti or other mosquito species, health and mosquito control officials advise using mosquito repellents that contain 20 to 30 percent DEET, picaridin or oil of lemon eucalyptus. DEET is not recommended for use on children younger than 2 months old. Wearing permethrin-treated long sleeve shirts and pants, when comfortable to do so, provides additional protection. When inside, close windows and use air conditioning. Or, if windows are open, check screens to ensure there are no holes.
  • In 2009, cases of dengue surfaced in a small area of Key West only, brought in by someone bitten by a dengue-carrying mosquito outside the U.S. However, there have been no confirmed dengue fever cases in Key West since November 2010 and no health advisories were issued discouraging travel to Key West or the Florida Keys because of the virus.
  • There has never been a report of a locally acquired case of chikungunya or Zika anywhere in the Florida Keys, according to officials at the Florida Department of Health in Monroe County.
  • The Florida Keys Mosquito Control District has an aggressive mosquito suppression and abatement program. New technologies used include aerial application of an innovative larvicide that targets the mosquito larvae and stops them from reaching adulthood. The larvicide is non-toxic to humans and animals.
  • Eliminate standing water in and around homes/vacation rentals, where mosquitoes like to breed, such as coolers, flower pots, buckets or any containers that can retain rainwater


More information is available via these links:

Or contact the Florida Department of Health in Monroe at 305-809-5653.