An infamous mosquito-borne illness once again rears its ugly head

Malaria, that old-fashioned scourge of tropical explorers and canal workers, is returning with a vengeance, and not just in hidden corners of the world. The reason: burgeoning numbers of anophelinemosquitoes are now spreading the disease. From the 1960s to the mid-1990s, malaria was under control everywhere except sub-Saharan Africa, thanks to a widespread eradication program utilizing the pesticide DDT. For the past five years, however, malaria has reinvaded a broad swath from Asia to the Americas, with rare occurrences even reported in the United States. "This is not a disease of other people anymore," says Robert Desowitz, a professor of epidemiology at the University of North Carolina at Chapel Hill. "It's becoming everyone's nightmare now."

The surge in malaria cases stems in part from the curtailed use of DDT through government regulations and outright prohibitions (the UN is scheduled to vote on a worldwide ban this summer). Third World countries can't afford to combat the spread with expensive alternative pesticides like deltamethrin, which breaks down more quickly than DDT. But even more disconcerting is the malaria parasite's tenacious adaptability: A growing percentage of Anopheles now carry strains of malaria that are invulnerable to preventive drugs, even Lariam, the most popular anti-malaria prophylactic for Americans.

Hot spots are scattered across Africa, Asia, and South America. In Sri Lanka, cases have risen from 17 in 1963 to more than 200,000 35 years later. In Peru, the rate of infection has increased 300 percent since 1990. And last year in Kenya, epidemics erupted through a number of highland villages situated above 6,000 feet—confounding scientists who believed Anopheles couldn't survive the cold, high-elevation temperatures long enough to spread the disease. "Basically," says Desowitz, "if you go to these places, you bite the bullet and realize you can get very sick."

While the current drug-resistant strains of malaria, which commonly result in symptoms like intense chills, sweating, and high fever, are medically treatable, the Centers for Disease Control and Prevention in Atlanta says it will be a few years until new prophylactics are available. Although serious, the outbreak poses far less of a threat to travelers than it does to those living in the Third World. "If you're going to take a vacation to a tropical country, you're not exposing yourself as much as the locals," says Donald Roberts, a leading expert in tropical public health. "But for them, it's a way of life. A miserable way of life." —GRETCHEN REYNOLDS

Photo: Oliver Meckes