Health officials in Miami-Dade County issued a mosquito-borne illness advisory on Monday after the first case of dengue was confirmed this year in a Florida resident.
The dengue virus can be spread through Aedes mosquito bites, which also spread the chikungunya and Zika virus, according to the Miami-Dade Department of Health.
Symptoms can include fever, headache, eye pain, muscle, joint and bone pain; nausea, vomiting and unusual bleeding in the nose or gums.
According to the Centers for Disease Control and Prevention, about 1 in 4 people who get dengue will develop symptoms, and 1 in 20 will become seriously ill. Babies and pregnant women are at higher risk for developing severe dengue, according to the CDC.
According to the Department of Health, most people with symptoms recover after about a week.
There is no specific treatment for dengue. However, children between 9 and 16 years old who have previously been infected could be eligible for a new dengue vaccine, according to the CDC.
Just like most pests, the weather influences mosquitoes that carry the virus.
Miami-Dade Mosquito Control Division Manager Dr. Isik Unlu explains mosquitoes do well in warm but not extreme temperatures.
"Mosquitoes, just like the country song ‘Sunny and 75 Day,’ they like sunny and 75. They do not do well with extremes," Unlu said. "If we talk about temperatures, around the 50s and 86, anything above 86 mosquitoes start struggling."
Rainfall also affects the mosquito lifecycle because more rain helps create more habitats to lay eggs, according to Unlu. Meanwhile, too much rain can wipe out the eggs.
Miami-Dade Mosquito Control Division crews have been out treating for dengue in a two-block radius where the transmission happened.
As soon as health officials know the location of someone suspected of having a mosquito-borne illness such as dengue, a treatment team is sent out immediately.
"They inspect the property and other surrounding properties. Then spray for mosquitoes and for adult mosquitoes that evening. They continue to do truck-mounted larviciding every week to keep adult mosquitoes from emerging, particularly if there’s standing water lingering around," Unlu said.
Treatments continue every two days until adult mosquito numbers start declining.
Tips to avoid infection
Florida health officials advise the "drain and cover" method to avoid attracting mosquitos that carry the virus.
Standing water from garbage cans, flower pots or other outdoor containers where rainwater collects should be drained regularly. Outside pet bowls and birdbaths should be cleaned at least twice a week. Swimming pools should be kept clean with chlorination.
"This mosquito is not coming from the saltmarsh, not coming from (a) big body of water. It is actually derived in our backyards," Unlu said. "They may have their eggs and larvae and pupae in those containers, such as flower pots, old tires, bird baths. Anything that you can think of would hold water for seven days or more. So I strongly encourage the residents to be vigilant and drain and cover that."
The "cover" method includes covering your body to avoid mosquito bites. This is especially necessary for people who work outside where the flies may be present. The health department recommends wearing shoes, socks, long pants and long sleeves. Mosquito repellent should be applied to bare skin and over the clothing.
How common is dengue in Florida?
According to the Florida Department of Health, after dengue was eradicated from the U.S., there were no dengue cases in Florida from 1934 to 2008. In 2009 and 2010, a dengue outbreak was identified in Key West that included 88 people over two years. Another outbreak in Monroe County in 2020 included nearly 50 people, according to the Florida DOH.
Several cases of the disease related to the West Nile Virus are confirmed in the Sunshine State every year. Most of these cases come from people who have traveled to dengue-endemic regions, including the Caribbean, Central and South America and Asia.