ABSTRACT
Adult residents of holoendemic malaria regions in Africa have a naturally acquired immunity (NAI) to malaria that renders them more resistant to new infections, limits parasitemia, and reduces the frequency and severity of illness. Given such attributes, it is not clear how one might evaluate drug or vaccine efficacy in adults without serious confounding. To determine symptomatic and asymptomatic malaria attack rates in adults of northern Ghana, 197 men and women underwent curative therapy for any pre-existing malaria infections at the start of the high transmission (wet) season. They were monitored for first parasitemia and first clinical episode of infection by Plasmodium falciparum over a 20-week period (May-October 1996). The cumulative incidence of primary infection by P. falciparum was 0.98 and incidence density of infection was calculated to be 7.0 cases/person-year. Symptoms were reported by 19.5% of the individuals at the time of first recurrent parasitemia. Incidence of infection, parasite density, and the frequency of symptoms were comparable in males and females. The results suggest that NAI did not provide these adults with significant defense against rapid re-infection and suggest that this population-infection design could serve to demonstrate the efficacy of a drug or vaccine in preventing parasitemia.
Subject(s)
Antimalarials/therapeutic use , Malaria, Falciparum/drug therapy , Malaria, Falciparum/epidemiology , Plasmodium falciparum/growth & development , Quinine/therapeutic use , Adolescent , Adult , Animals , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Antimalarials/administration & dosage , Cohort Studies , Doxycycline/administration & dosage , Doxycycline/therapeutic use , Endemic Diseases , Female , Ghana/epidemiology , Humans , Incidence , Malaria, Falciparum/prevention & control , Male , Middle Aged , Multivariate Analysis , Parasitemia/drug therapy , Parasitemia/epidemiology , Parasitemia/prevention & control , Quinine/administration & dosage , RecurrenceABSTRACT
Beginning in 1991, case reports of coccidioidomycosis in California increased dramatically, pursuant to a variety of natural and demographic factors. This highly infectious fungal disease with propensity to disseminate widely, mimic other conditions, and cause pathology at locations distant in place and time is readily treatable if recognized at an early stage. The concentration of military bases in endemic areas and the mobility of military personnel suggest a heightened potential for case presentations elsewhere and a need for elevated diagnostic suspicion on the part of military physicians worldwide. We review three cases of disseminated disease recently referred to our facility.
