Infectious Diseases : Airport Malaria, Break-Heart Fever

by Food and Drug Administration (FDA)

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Airport Malaria

International jet-setting has fostered recent outbreaks of malaria in the United States. Malaria is such a common import to countries that the term "airport malaria" was coined to describe the outbreaks of the disease that have occurred among travelers. About 1,000 cases of malaria are imported into this country each year, according to CDC. Malaria causes flu-like symptoms, and in severe cases can cause coma, severe anemia, kidney failure, difficulty breathing, or death. The disease is passed from person to person by mosquitoes that harbor the malaria-causing parasites.

Malaria was a major problem in this country during George Washington's time and, until the 1930s, was a major killer in the southern states. The disease was virtually eradicated from the United States by 1955, following a major campaign in which mosquito-infested areas were sprayed with the pesticide DDT and swamps were drained or filled with oil that killed mosquito larvae. People were also encouraged to screen the windows of their homes.

Similar efforts worldwide shrank malaria's territory, but only temporarily as mosquito-control efforts abated, mainly due to a lack of funds, and mosquitoes resistant to the effects of pesticides increased. According to the National Institute of Allergy and Infectious Diseases, each year malaria now infects 300 million to 500 million people globally and kills as many as 3 million.

There's concern that malaria might once again take root in the United States because most states harbor mosquitoes that can carry malaria parasites. Particularly disturbing are the recent small outbreaks of malaria in California, Florida, Texas, New Jersey, and New York City. Most of these cases were probably spread by infected immigrants or migrant workers via local mosquitoes, according to CDC.

"The reintroduction of significant malaria into this country is ... very possible," said Philip Coyne, M.D., medical officer in FDA's division of anti-infective drug products.

Malaria can often be effectively treated with quinine or related compounds. Drug-resistant strains of malaria parasites are posing a problem worldwide, however, and raising the need for new antimalarial drugs. FDA approved Halfan (halofantrine) in 1992. Its developer, SmithKline Beecham, Inc., has chosen not to market it in the United States. Some strains of malaria are already resistant to it. Other antimalarial drugs and vaccines are currently being tested.

Break-Heart Fever

Another mosquito-spread illness on the rise worldwide and likely to make a comeback in this country is dengue, which an 18th century Philadelphia doctor called "break-heart fever" because of the depression that often ensues following the illness. Dengue, which is caused by a virus, is characterized by a sudden onset of high fever accompanied by severe headache and muscle, joint and eye pain. A red rash can also develop all over the body. The rash may be accompanied by itching and scaling.

A severe form of dengue, known as dengue hemorrhagic fever, causes bleeding from the mouth, nose and vagina. Gastrointestinal bleeding and numerous bruises also often occur. Such bleeding can trigger a loss of blood pressure that can cause the body to go into shock. As many as 1 out of every 10 people who develop dengue hemorrhagic fever dies. There is no treatment for dengue and dengue hemorrhagic fever, although vaccines for the disorders are currently being developed.

Over the last 15 years, as mosquito control programs abated, dengue has spread like wildfire. In the 1980s, major outbreaks spread throughout Latin America, including Mexico, and the incidence of dengue hemorrhagic fever skyrocketed.

The United States hasn't had any major epidemics of dengue since the 1940s. But there are travelers to this country who come down with the disease each year, and a small number of people have developed dengue from local mosquitoes in Texas. Both species of mosquitoes that carry the dengue virus are firmly established in several southeastern states.

People traveling to dengue- and malaria-infested areas should use DEET-containing insect repellent and stay in lodgings with screened windows and mosquito nets for sleeping. Preventive drug therapy for malaria is also advised. Travelers should consult with their physicians about such treatment before leaving the country.

Other Health Threats

Other possible resurgent and emerging diseases include a dangerous kind of E. coli infection spread by contaminated meat, drug-resistant cholera, deadly Ebola infection, and a new disease called human granulocytic ehrlichiosis, which is spread by the type of ticks that can also carry Lyme disease.

Experts can't predict if any of these diseases will become a great problem. The best protection is to be aware of the possibility and take precautions to prevent their spread. As a 1992 National Academy of Sciences report on emerging infections points out, "despite a great deal of progress in detecting, preventing, and treating infectious diseases, we are a long way from eliminating the human health threats posed by ... a broad array of microbes."

Worldwide Prevention Efforts

"Prevention is so much better than healing because it saves the labor of being sick," said Thomas Adams, a 17th century English preacher. Experts convened by the National Academy of Sciences suggest:

Surveillance — to keep an extensive global lookout for new or reemerging infections so the health community can develop the appropriate containment measures before diseases spread to plague-like proportions.

Research — to help understand the factors that foster emergence of infectious diseases, and to develop better surveillance, diagnosis, treatment, and prevention tactics.

Vector control — to limit the spread of diseases transmitted by such vectors as insects and rodents by eradicating them.

Public education and behavioral change — To prevent spread of diseases through travel, poor personal hygiene, improper food handling, drug abuse, and high-risk sexual behavior.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.