Health officials with the Miami-Dade County Health Department confirmed on Thursday their first case of dengue fever in 50 years. Though Liliana Rivera, director of the health department, said the person diagnosed with the potentially deadly mosquito-borne virus recovered fully after a brief hospitalization, the announcement follows a May 21 report by the U.S. Centers for Disease Control and Prevention that described more than two-dozen cases of locally-acquired dengue fever in the resort town of Key West, Fla.
Meanwhile, local media said three cases of hookworm in Miami Beach were reported on Thursday, bringing the total number of recent confirmed cases of the parasitic infection to six.
While the infections themselves may have little to do with each other, their recent emergence in and around Miami -- one of the country's southernmost urban centers -- could be a sign that these infections may be establishing a foothold in the continental United States.
"I think it's an important issue," said Dr. Peter Hotez, president of the American Society of Tropical Medicine and Hygiene. "If these were diseases common among white people in the suburbs, we would never tolerate it."
The Dengue Threat
Dengue fever -- the most common vector-borne viral disease in the world -- is an infection transmitted by mosquito bites. It can be debilitating, but is not usually fatal in otherwise healthy people. In those whose health has been compromised by poor living conditions, however, it can be deadly. Worldwide, it causes an estimated 50-100 million infections and 25,000 deaths each year.
"It's a very difficult problem," said Dawn Wesson, associate professor of tropical medicine at the Tulane School of Public Health and Tropical Medicine in New Orleans. "If it wasn't, it wouldn't be such a widespread problem around the world."
Hotez, who is also a professor at The George Washington University's department of microbiology, immunology and tropical medicine, published a study in 2008 in the journal Public Library of Science that detailed dengue and numerous other diseases that he categorizes as neglected infections of poverty.
The study led to legislation -- the Neglected Infections of Impoverished Americans Act -- that would address the problems of and urge funding for these diseases. The bill passed the House in September; it has been introduced in the Senate but has, as of yet, gone no further.
Dengue Threat Hits Miami
Dengue is a mosquito-borne disease, which means that it requires an infrastructure of sorts to spread -- in other words, the right type of mosquito. It is carried most often by the Aedes aegypti mosquito, and less frequently, by Aedes albopictus.
These mosquitoes can be found in Florida and along the Texas-Mexico border -- the same places where recent cases have occurred.
"It's no surprise that we have been seeing transmission take place in the southern parts of the U.S.," Wesson said. "I would say that it's only a matter of time before we start seeing it in other areas."
Indeed, Hotez said that there is a possibility that the strain of dengue seen in Florida could eventually travel along the coast to meet up with the strain seen in Texas. Infection with more than one strain of dengue increases the risk of dengue hemorrhagic fever, Hotez said -- and those living in Gulf states where these two strains could meet would be at highest risk of this deadly condition.
Rivera said her department has considered this threat -- particularly in light of the fact that the strain affecting the Miami patient appears to be different from the one responsible for cases further south in Key West.
"There's always that concern," Rivera said. "We're on the lookout; that's what we do."
Miami's Hookworm Problem
Those who frequent Miami Beach have been no strangers to hookworm as of late. The parasitic worms, which today are commonly spread through dogs and cats that defecate in sandy areas, were once commonplace throughout the rural Southeast. This was before 20th century efforts to promote indoor toilets, which drastically cut infections.
However, Hotez said, the hookworms currently seen on Miami Beach are a breed apart from those of last century.
"This is a different kind of hookworm than we are generally used to," he said. "These are dog hookworms that cause something called creeping eruption."
As the name suggests, this condition results in blisters and snaking tracks in the skin that emanate from the site of infection on the body.
"This is less of a disease of poverty," Hotez said. "Anybody can get creeping eruption, even wealthy tourists."
Rivera said that in her five years as director, she has not seen the hookworm problem on Miami's beaches worse than it is now. She said that a muti-agency task force is now investigating the cases that have been confirmed, as well as four other suspected cases of hookworm infection among beachgoers.
What Can You Do to Protect Yourself?
Rivera said that fortunately there are a number of steps that Floridians and other can take to keep themselves safe from these infections.
"In terms of mosquitos, the important thing is not to get bitten -- fight the bite," she said.
As for hookworm, she said that beachgoers should use foot protection when walking on the sand. They should also be careful not to expose any open wounds to the sand or soil.
Here are some more tips to stay safe:
Staying safe from dengue starts with avoiding mosquito bites if you live in or are traveling through an area where there is dengue.
The best way to reduce mosquito bites is to eliminate where mosquitoes lay their eggs, such as containers that hold water in and around the home. Don't keep water outdoors in pet bowls. Cover water storage barrels. Beware of standing water inside your home in vases holding fresh flowers; clean these at least once weekly.
Adult mosquitoes like to bite inside as well as around homes during the day or at night when lights are on. Use insect repellent day and night. When possible, wear long sleeves and pants. Check that window and door screens are secure and repair any holes. If possible, use air conditioning.
To avoid infection with hookworms, use proper footwear in areas where such infections have been reported.
Hookworm infection is relatively easily treated. See a doctor soon if you notice unusual itching or a rash on skin that has come into contact with sand or soil.
Wire reports and reports by MedPage Today contributed to this report.