Plasmodium ovale in a highly malaria endemic area of Senegal

During 4 months, from June to September 1990, the population of Dielmo village, Senegal, an area of intense and perennial malaria transmission, was enrolled in a follow-up study including daily clinical surveillance and bi-weekly malaria parasitaemia monitoring. Thick blood film examinations indicated that 48.5% of children (49/101) and 32.4% of adults (34/105) were infected at least once by #Plasmodium ovale$ during the study period ; 148 distinct episodes of patent parasitaemia were observed, with estimated maximum durations of 3-115 d. The mean duration at first decreased significantly with age, from 11.4 d in children under 5 years old to 4.2 d in adults aged 40-59 years, but then increased in older adults to 7.0 d. In all age groups, most infections were asymptomatic. Only high parasitaemias were significantly associated with fever ; 3 clinical malaria attacks due to #P. ovale$ were seen during the study period. (Résumé d'auteur