Locally acquired dengue cases in Hillsborough County have climbed to 95, prompting an intensified mosquito-control operation across the Tampa Bay area, including support from neighbouring Pasco County.
The county now accounts for the vast majority of Florida’s 111 locally acquired cases. Pinellas County has recorded five cases, while Pasco has reported two, according to the latest figures from the Florida Department of Health.
Hillsborough recorded 36 additional cases in the space of a week, in what mosquito-control officials have described as an unprecedented surge.
“We have not seen anything like this before,” said Eric Long, operations superintendent for Hillsborough County Mosquito Management Services. He said staff were working longer hours and at weekends to treat affected areas and protect residents.
Helicopters deployed in dengue response
The response has been expanded beyond county boundaries, with the Pasco County Mosquito Control District sending a helicopter, spray equipment and personnel to assist Hillsborough at the request of the local health department.
Pasco officials said the regional approach was necessary because people regularly travel between communities, allowing mosquito-borne disease to cross county lines. The district has previously said its aerial operations are guided by mosquito surveillance, rainfall, standing water and evidence of larvae or adult mosquito activity.
Residents in parts of Tampa may see low-flying orange and charcoal-coloured helicopters during daylight hours. The aircraft are applying liquid Bti, a larvicide aimed at mosquito larvae in standing water. Hillsborough County said the product breaks down naturally and is not harmful to people, pets, fish, birds or beneficial insects when used as directed.
Initial treatment areas include Wellswood, Riverside Heights and East Tampa. Hillsborough County said the operation was expected to take about two days, depending on weather, wind and aviation conditions.
Hillsborough’s own helicopters generally operate between 4am and 6am, targeting adult mosquitoes. The county has also been carrying out ground treatments and monitoring traps after dengue virus activity was detected in mosquito populations.
Other counties have also been involved in the wider response. Officials said aerial operations could continue for several weeks to disrupt the mosquito life cycle and reduce populations to a level at which transmission can no longer be sustained.
Adriane Rogers, executive director of the Pasco County Mosquito Control District, said the outbreak could not be treated as an isolated problem affecting one jurisdiction.
“Thousands of people move throughout the Tampa Bay region every day between counties, and mosquito-borne disease moves with people,” she said. “What happens in a neighbouring community can directly affect the health of Pasco County residents.”
Advice for residents
Health officials are urging people to reduce their exposure to mosquitoes by wearing light-coloured clothing that covers the arms, legs and ankles, and by using an insect repellent containing DEET or another recommended active ingredient.
Residents are also being asked to empty or cover anything that can collect water, including buckets, flowerpots, toys, tyres and containers left outdoors. Even small amounts of standing water can provide breeding sites for Aedes mosquitoes, which are capable of transmitting dengue.
People who develop symptoms such as fever, severe muscle or joint pain, nausea, vomiting or a rash are advised to seek medical guidance and mention the possibility of dengue, particularly if they have not recently travelled to an area where the virus is common.
