uncertain fraction of those who survive (approximately 10 percent) have persistent neurologic deficits at the time of hospital discharge (Carme et al., 1993). Thus, the long-term effects of cerebral malaria on central nervous system development and function (including the ability to learn) are important unresolved questions with major implications for global health and development. Severe malarial anemia produces hemoglobin levels of less than 5 grams per 100 milliliters of blood —less than one-third the normal hemoglobin (Warrell et al., 1990). Although severe malarial anemia is widely prevalent until age 3, its peak incidence occurs around 6– 7 months of age (Marsh, 1992; Miller et al., 1994). Kidney failure is a common complication of malaria infection, and a major cause of death among nonimmune immigrants (Trang et al., 1992; Warrell et al., 1990; Weber et al., 1991).
The importance of malaria for the U.S. military is enormous. In Vietnam, for example, nearly 10 percent of soldiers had the disease in late 1965, and attack rates for some units were as high as 60 per 100 soldiers each year. Overall, malaria was the most important cause of hospitalization other than combat wounds (Neel, 1973). Peace Corps volunteers also have intense malaria exposures. During the late 1980s, drug-resistant P. falciparum infection caused serious illnesses in approximately 1,600 Peace Corps workers in West Africa alone. Finally, tourists are at increasing risk, even with short-term exposure, as demonstrated by recent reports of transit passengers being infected with malaria while waiting on planes that were being refueled in West Africa (Isaacson, 1989; Lobel et al., 1993). Over 1,000 cases of malaria are known to occur each year in tourists returning to the United States.
Malaria transmission can occur in the United States. With the return of infected veterans after World War II, the Korean War, and the Vietnam War, and the arrival of infected Southeast Asian refugees, reports have confirmed transmission of malaria by indigenous anopheline mosquitoes to U.S. residents who had never left the country (Luby et al., 1967; Maldonado et al., 1990).
When a substantial proportion of a country's population is ill with malaria for five or six months each year, sustained economic development is very difficult to achieve. Countries thus compromised cannot easily become active trading partners with the United States, nor are they positioned to decrease their dependence on