The Aedes aegypti mosquito is present in as many as 30 percent of homes in one area of Florida, an official said. USDA/AP

Marty Baum, 59, dragged his feverish, achy bones out of bed on a hot, humid day in early September, lathered himself with mosquito repellent and attended a clean-water rally in central Florida. Most days, he prefers to be surrounded by water. Baum is an official Indian River Keeper -- a post devoted to the restoration of one of the country’s most biologically diverse estuaries in North America, along Florida’s east coast. But nothing was going to keep him away -- not even dengue fever. “I felt pretty beat-up, but bottom line, I had to be there,” he said. A week earlier, Baum was in the throes of the worst part of the tropical illness known as “break bone fever,” named for the excruciating joint pain and virulent flulike symptoms associated with the disease. “One minute I’m watching the Dolphins game on TV, and then next minute I have a 102-degree fever,” he said. “I nearly went into convulsions, I was shivering and sweating so much.” In the 2-mile perimeter encompassing Baum’s Rio neighborhood, more new cases of dengue fever have popped up. For the residents who live in the area, it’s been a summer from hell. Thursday the news got worse. “We’re in the fourth week of this and we’ve got 18 cases. It’s at a pretty serious level,” said Gene Lemire, director of the Martin County Mosquito Control District, after following the announcement of three new cases. “We’ve been to 1,500 residences, and we’re finding 28 to 30 percent of the homes where mosquitoes are breeding in their backyards.” The Florida Department of Health confirmed that the patients all contracted dengue fever from an infected Aedes aegypti mosquito. Typically, these mosquitoes thrive in tropical and subtropical mega-cities. Yet the 2-mile quaint waterfront area is hardly a metropolitan center. “Apparently it was metropolitan enough,” said Dr. Carina Blackmore, interim state epidemiologist at the Florida Department of Health.

Regaining foothold

For nearly 60 years, dengue was eradicated from the United States with the onset of mosquito-control spraying and prevention campaigns. But since 2001, outbreaks in Hawaii, Texas and Florida's Key West have signaled its return. What’s especially disconcerting is that in this recent bunch of new cases the people acquired the disease locally -- from an infected mosquito that could have bred in a teaspoon of water in tiny puddles, buckets or tires, even inside a lone bromeliad. The patients all lived in, worked in or visited the small beach communities of Rio and Jensen Beach, which border Martin and St. Lucie counties.

I think we’re seeing the tip of the iceberg in terms of cases reported in Florida.

One reason the outbreak is spreading in that very specific area is that homes with the dengue mosquito vectors are still posing a risk. Lemire said his crews are often finding mosquitoes at the same places every time because residents are not emptying containers that fill with rainwater where the mosquitoes breed.

“This is an old Florida lifestyle, and I think people are used to the heat and sitting on their porches. Mosquitoes don’t bother them like it does visitors,” he said. “We need the people to wear long pants and sleeves, use repellent and empty containers with water to get a handle on this.” Starting Friday, teams from the Florida Department of Health and Martin County Mosquito Control will be visiting homes in the Rio and Jensen Beach area, said Dr. Karlette Peck, a health officer at the Florida Department of Health in Martin County, in a press release. “This important door-to-door effort will be conducted for approximately a week in order to provide prevention information, a risk assessment survey and, with the resident’s consent, draw blood for dengue testing,” Peck said.

Role of climate change

Dengue is the world's fastest growing viral disease caused by mosquitoes. In a 2013 research review, the World Health Organization cited significant gaps in predicting future dengue outbreaks because of a greater focus on floods and warmer temperatures linked to climate change. In a study funded by the Department of Defense, two researchers at Texas Tech University found that climate change would shift rather than increase the risk for dengue outbreaks in the United States. Dengue fever most likely will become a disease the U.S. must learn to live with as climate change creates opportunities for the disease to flourish. But locals are increasingly pointing their fingers at man-made causes such as the St. Lucie River and the Indian River Lagoon -- and holding their noses at the same time. Since early summer, discharges of polluted fresh water from agricultural runoff have been gushing into the river and estuary. The result is miles of slimy green algae blooms that have killed fish, oysters, crabs, sea grasses and other marine life in the waterways. Whether the dirty runoff is the cause of the dengue outbreak is the source of significant debate in the community. “I’m not going to cry wolf and say that the pollution is doing this. I’ve talked to scientists about this, and it’s a rainwater issue,” said Baum, one of the leaders of the Save the Indian River Lagoon movement. “Somewhere in somebody’s backyard here, the dengue mosquito bred.” Lemire, of the Martin County Mosquito Control District, agreed. “This mosquitoes only lay their eggs on a side of a container, and when it rains, the containers fill with water and that’s when the eggs hatch,” he said. “There’s no relationship between the polluted waters and the mosquitoes.” But many are not buying that. “If you have raw sewage and polluted fresh water sitting on the river, how is that not going to attract mosquitoes?” said Keri West, director of business development for the local Pineapple Post newspaper. “I don’t care what officials are telling us, we’re in an economic and ecological collapse and this dengue fever is like icing on the cake.” For 25 years, West has made a home on the edge of Jensen Beach, smack in between the St. Lucie River and the Indian River Lagoon. A couple of weeks ago, she went door to door to inform her neighbors about the ways to prevent further mosquito infestations. “I don’t want to take any chances that officials are going to get the word out,” she said. “I mean, when our own river keeper got sick, I thought, ‘We have to protect ourselves.’”

Adding to the mystery

There are two types of mosquitoes that transmit the disease, and both were found in large numbers in Martin and St. Lucie counties. What’s even more striking is that this recent outbreak is more than 200 miles north of what was the epicenter of dengue fever in Florida -- Key West. In 2009 and 2010, dengue gained a foothold in the state, and 93 patients were confirmed with the disease in Key West. “I think we’re seeing the tip of the iceberg in terms of cases reported in Florida,” said Dr. Amesh Adalja, senior associate at the University of Pittsburgh School of Medicine and an expert in bioterrorism and infectious diseases. Adding more mystery to the situation is that 80 percent of the people harboring the virus show no symptoms, and because they feel normal, there’s less urgency to take precautions from getting mosquito bites.

First we can’t go in the water because it’s green and slimy from neurotoxins. Then we all get these reverse 911 calls from the health department saying they’re going to spray insecticide over our town from planes. Then we find out we have this rare, huge cluster of dengue. ... What’s next, frogs?

Dengue fever -- which cannot be spread from person to person -- is not fatal and should not be confused with the more serious dengue hemorrhagic fever, which can lead to death. However, for anyone who has had the disease, a reinfection could be much worse, because the antibodies in their bloodstream enhance the symptoms of the disease. Alex Loudakis, a captain for Sea Tow, a boat-towing service in Jensen Beach, tested negative for the virus but knows three people who had trace amounts despite showing no symptoms. “I’m only in the office about once a week, but my girlfriend lives in the area, and these days we’re not sitting on the roof staring at the stars anymore,” he said. Officials and experts worry, though, that not everyone is taking such precautions. “The fact that people don’t know that they’re sick is a huge advantage to the spread of the virus because people don’t curtail their activities,”Adalja said. “They’re going about their daily activities, doing yard work and getting exposed and bitten by mosquitoes who then pick up the virus and infect other people.”

Breeding frustration