2 cases of locally-acquired dengue fever reported in Florida Keys

According to data from the Centers for Disease Control and Prevention, as of early July there were more than 700 cases of dengue fever in the continental U.S. with only eight cases that were acquired in the states. Nearly 10 million people around the globe have reportedly been infected with the virus, which has already surpassed last year’s entire count.

KEY WEST, Fla. – The Florida Department of Health is warning that mosquitoes in the Keys may carry diseases following the diagnosis of dengue fever in two residents of the upper islands.

These locally-acquired cases mark the seventh and eighth reported in the Lower 48 this year, with over 700 cases identified as travel-related.

The infections come days after the Centers for Disease Control and Prevention warned health providers of a spike in cases across the Americas.


Nearly 10 million people around the globe have reportedly been infected with the virus, which has already surpassed last year’s entire count.

In response to the new cases in the Sunshine State, the Florida Keys Mosquito Control District has intensified door-to-door inspections, expanded spraying operations and deployed additional mosquito traps.


Health experts say dengue fever is not contagious and is transmitted by the Aedes aegypti mosquito.

The mosquito species is known to feed at any time of the day and not solely at dawn and dusk, which increases the risk to humans.

"Wherever you have a significant number of mosquitoes and warm hot environments is where you see dengue transmission," Dr. Stacey Rizza, a Mayo Clinic infectious diseases specialist, previously told the Mayo Clinic News Network.

Similar to other mosquito-borne illnesses, the virus has no known cure, and symptoms are treated with medication.


Symptoms include aches, nausea, vomiting, difficulty breathing and fatigue.

According to medical experts, symptoms usually begin four to ten days after infection and only about one out of four people will get sick.

The CDC says a blood test is the only way to confirm an infection, as symptoms often resemble other illnesses.

The dengue virus has four serotypes: dengue virus 1, dengue virus 2, dengue virus 3 and dengue virus 4. 

The infection of one does not provide immunity against the others so that people can be infected multiple times.

"Infection with one DENV generally induces life-long protection against infection from that specific DENV but only protects against other DENVs for several months to years," the CDC stated.


Wet summers often turn Florida into a mosquito haven

Mosquitoes typically thrive in the Sunshine State due to the warm, humid air, but for South Florida, issues surrounding the pests can be especially problematic.

Torrential rainfall in early June that dropped upwards of 25" of precipitation in less than 48 hours caused standing water for days, leading to enhanced breeding grounds.

Mosquitoes lay their eggs in or near motionless bodies of water, and the larvae develop within just a few days.

"Most species present here take only between seven to 10 days to go from egg to biting adult," Dr. John-Paul Mutebi, division director of the Miami-Dade County Mosquito Control, said after the heavy rainfall.

Mosquitoes are regularly tested in the state for diseases such as St. Louis Encephalitis, West Nile, Eastern Equine Encephalitis, malaria, dengue and yellow fever.

These diseases can vary widely in their impact, ranging from mild to potentially life-threatening conditions.

Preventive measures are crucial in combating these insects and include using effective repellents, wearing appropriate clothing and installing screens to keep insects from entering indoor spaces.