Three Florida counties have declared states of emergency as dengue fever spreads in the state. Pasco County, Hillsborough County and Pinellas County had issued declarations as of Sept. 23, according to news releases from each county.

The declarations give county officials greater flexibility to respond to the mosquito borne disease. Officials can accelerate mosquito control operations, make emergency purchases, coordinate response efforts and, where applicable, seek state or federal assistance or reimbursement.

Under Florida law, a local emergency declaration expires after seven days unless officials renew it. The declarations come as state surveillance data show locally acquired dengue infections across six counties.

Florida has confirmed 190 locally acquired dengue cases, according to the latest Florida Department of Health surveillance report. That report covered cases with onset through Sept. 19.

Hillsborough County accounted for 170 of those infections. Miami-Dade and Pinellas counties each reported seven, Orange County reported three, Pasco County reported two and Palm Beach County reported one.

The 190 infections were acquired locally and are separate from travel associated dengue cases reported in Florida this year. The distinction identifies infections contracted within the state rather than those associated with travel.

Dengue is a mosquito borne viral illness that can cause fever, severe aches, nausea and rash, according to the Centers for Disease Control and Prevention. In rare cases, it can lead to life threatening complications.

The disease is endemic in many tropical and subtropical regions, including Southeast Asia, the Western Pacific islands, Latin America and Africa. Although it is less common in the continental U.S., locally acquired cases have been recorded in Florida, California and Texas.

An entomologist spokesperson at the SC Johnson Center for Insect Science and Family Health, makers of OFF!, described why Florida offers favorable conditions for the mosquitoes. “The Aedes mosquitoes that can transmit dengue are active during the day and thrive in warm, humid environments like those found in Florida.”

“As dengue cases continue to be reported in the Tampa area, taking steps to help prevent mosquito bites is especially important,” the expert went on. “Staying aware of local mosquito activity and consistently protecting against bites are important steps people can take to help reduce their risk.”

The Florida Mosquito Control Association previously said crews were increasing aerial and ground treatments in areas showing dengue virus activity, according to reports. Crews were also inspecting private properties for potential mosquito breeding sites.

The association has urged residents to empty or cover standing water around their homes. The mosquito that spreads dengue is a container breeder, meaning it lays eggs in objects that collect small amounts of water.

Potential breeding locations include buckets, planters, plant saucers, tires and discarded toys. Rain gutters and birdbaths can also hold stagnant water, and mosquitoes need only one tablespoon of water to breed.

The SC Johnson Center entomologist recommended using an EPA registered insect repellent. People should review, follow and apply the directions on the repellent label to help prevent mosquito bites.

When using both sunscreen and mosquito repellent, sunscreen should be applied first, followed by the insect repellent. Users should follow the label directions for both products and reapply them as directed.

Mosquito precautions should not be limited to dawn and dusk. Because Aedes mosquitoes that can spread dengue remain active throughout the day, protection is recommended whenever mosquito exposure is possible.

The Florida Mosquito Control Association also advises people to wear long sleeves, light colors and shoes that cover the toes while outdoors. These measures add physical protection from mosquito bites.

Many people infected with dengue experience no symptoms, according to Mayo Clinic. Most of those who become sick recover within one or two weeks, but some infections can progress to severe dengue.

Symptoms typically begin four to 10 days after the bite of an infected mosquito. Warning signs can emerge quickly, often within one or two days after a fever subsides.

Those warning signs may include severe stomach pain, repeated vomiting, unusual bleeding or bruising, difficulty breathing, extreme tiredness, irritability or restlessness. People who develop warning signs of severe dengue should seek immediate medical care.