The Keys now have 11 cases of dengue fever. Health officials are trying to get answers

Health officials Tuesday confirmed an 11th case of mosquito-borne disease dengue fever this year in the Florida Keys.

All cases so far have been in Key Largo in the northern end of the island chain, according to the Florida Department of Health. Eight cases were confirmed the last week of June alone, according to the health department’s Florida Arbovirus Surveillance report.

Alison Kerr, Florida Keys spokeswoman for the department, said officials “are currently conducting epidemiological studies to determine the origin and extent of these infections.”

According to the health department, officials believe all of the cases were locally acquired. The most recently infected person has been treated and is expected to make a full recovery, Kerr said.

There has been one case of dengue fever in neighboring Miami-Dade this year, said Olga Connor, spokeswoman for the county health department.

Dengue is transmitted through the bite of the female Aedes aegypti mosquito, an invasive species that also spreads diseases like yellow fever, Zika and chikungunya.

Symptoms appear within 14 days of being bitten by the infected mosquito and include severe muscle aches and pains, fever and sometimes a rash, according to the health department.

The Florida Keys Mosquito Control District has stepped up its operations in Key Largo in response to the growing number of cases. The agency’s helicopter and trucks are targeting both adult Aedes aegypti and larvae, spokesman Chad Huff said.

District workers are also doing door-to-door house inspections at homes and businesses in Key Largo to check for adult mosquitoes and larvae.

The district’s helicopter is normally fueled and resupplied with larvicide at Florida Keys/Marathon International Airport. But the chopper is now using the stadium at Key Largo School as a landing zone where it can be reloaded, Huff said.

“This increases our time over the target as opposed to transiting to and from Marathon,” Huff said Tuesday.

Mosquito Control and health officials say they need residents’ help in stopping the spread of the disease by eliminating potential Aedes aegypti breeding grounds. That means cleaning gutters and dumping standing water by overturning and removing empty pots, buckets, trash cans, recycling bins, pet bowls and children’s toys.

Also, people should flush fresh water into bromeliads, hanging plants and bird feeders, Huff said. The district also urges boat owners to check tarps for standing water.

Meanwhile, an international biotech company is awaiting approval from the Mosquito Control District’s elected board of commissioners for approval to conduct an experiment on a controversial project to eliminate Aedes aegypti in the Keys through the use of genetically modified mosquitoes.

The company, Oxitec, has already won the approval of the U.S. Environmental Protection Agency and the Florida Department of Agriculture and Consumer Services for the project.

Oxitec plans on releasing millions of lab-grown eggs containing male Aedes aegypti mosquitoes, which, according to the company, will have sex with local female mosquitoes. But the males have a birth control mechanism designed within them that stops them from impregnating the females.

Several national and local environmental groups oppose the plan.

“Why should we worry about an experiment with a synthetic man-made species, on our community, in a National Marine Sanctuary where ecotourism drives the economy,” Barry Wray, executive director of the Florida Keys Environmental Coalition, said in a statement.