At least three counties in Florida have declared states of emergency over a mosquito-borne illness that is rapidly spreading.
Hillsborough, Pasco and Pinellas counties declared local states of emergency to try and control the spread of the mosquito population as dengue fever cases continue to rise.
Hillsborough County issued the emergency Thursday and Bonnie Wise, the county administrator, signed the executive order to go into effect on Friday.
Pasco County issued its state of emergency on Wednesday and Pinellas County commissioners decided to declare its emergency in a meeting on Thursday.
A local state of emergency can be in effect for seven days unless officials rescind it or extend it.
According to the CDC, Florida has reported 392 cases, including 183 locally acquired cases. Last year, Florida saw 72 local cases and 445 internationally acquired cases.
The Florida Department of Health reports 160 dengue fever cases in Hillsborough County, seven in Pinellas County and two in Pasco County. Thirty-eight new local cases were recorded in just the last week.
Dengue is often called ‘breakbone fever’ because patients who get sick with the virus typically develop a sudden high fever along with a pounding headache, pain behind the eyes and deep aches in the muscles, joints and bones.
Dengue fever spreads through the bite of infected Aedes mosquitoes, mainly the Aedes aegypti (pictured above), a species commonly found in Florida
The US is seeing an increase in dengue fever cases, including locally acquired cases. There have been 484 travel-associated cases and 184 locally acquired ones in the contiguous US, including those in Florida and one in Virginia.
A CDC report from earlier this year showed there was a 359 percent rise in average annual dengue cases in the US in 2024 compared to the 2010-2023 annual average.
In 2024, the most recent data available in the report, a record 3,798 dengue fever cases were reported, an increase from the average of 828. Among the cases, 97 percent were travel-associated and the remaining three percent – 105 cases – were locally acquired.
Among all the patients, 36 percent were hospitalized and three percent of cases were severe. There were six deaths.
Dengue spreads through the bite of infected Aedes mosquitoes, mainly Aedes aegypti, a species commonly found in Florida.
These mosquitoes thrive in warm cities and can breed in as little as a bottle capful of standing water.
Dengue fever often causes an asymptomatic infection, but in some patients it can trigger life-threatening internal bleeding, respiratory distress and heart failure.
It can also lead to shock and organ failure, especially of the liver, brain and heart.
Health officials say about 40 to 80 percent of people infected with dengue fever do not develop any symptoms, but if symptoms do develop, they appear abruptly about five to seven days after infection.
Warning signs include a fever above 100F (38C), severe headache, pain behind the eyes, bone, joint or muscle pain, and bleeding in the gums.
Some patients also develop redness of the skin on the face within the first 24 to 48 hours of symptoms emerging.
In severe cases, patients may also suffer from severe abdominal pain, persistent vomiting and lethargy.
Patients may also develop dengue shock syndrome, a condition where severe bleeding leads to a rapid drop in blood pressure and causes the body to go into shock.
The above shows all dengue cases, local and international, by state for 2026 as of September 23
Children under five, adults over 65 and pregnant women are considered to be most at risk from the virus.
Dengue was virtually eradicated from the US in the 1970s, but sporadic outbreaks have been recorded since, particularly in warmer states, including Florida and California. Most cases recorded in the US are linked to international travel.
There is no specific cure for dengue fever and treatment consists of supportive care and therapies to manage symptoms and complications.
Doctors recommend patients with mild symptoms drink plenty of fluids and take Tylenol to ease pain.
In severe cases, patients may be admitted to the hospital for supportive care, an IV, blood pressure monitoring and a transfusion to replace lost blood.
To protect against dengue fever, there is a three-dose vaccine available, which is recommended for children aged nine to 16 years. It slashes the risk of a symptomatic infection by about 80 percent.
