duration of exposure to infective mosquitoes may also influence the severity of the disease.

The clinical manifestations of malaria are varied. The classic description of an individual progressing episodically from shaking chills through intense fevers to drenching sweats is characteristic but not universal. In areas where malaria is common, infected individuals may have symptoms that mimic other diseases, making a correct diagnosis difficult. The problem of diagnosis is especially difficult in children, who may have high blood levels of parasites but relatively mild symptoms. In areas where health workers are unfamiliar with malaria, or with patients in whom the range of symptoms may not point clearly to malaria, misdiagnosis is a serious problem.

Severe and complicated malaria, generally due to infection with P. falciparum, is a medical emergency. In the absence of prompt intervention, the patient's condition can deteriorate rapidly, often ending in death (Figure 2-1). About 80 percent of deaths from the disease result from cerebral malaria, a state of altered consciousness, sometimes including coma, in patients infected with P. falciparum. Renal failure, hypoglycemia, severe anemia, pulmonary edema, and shock may also play a role in fatal malaria.

FIGURE 2-1 An African child with severe malaria. (Photo courtesy of Dr. Terrie Taylor, IOM Malaria Committee member)