Malaria in Nigeria: a revisit.
The frequency of asymptomatic malaria parasitaemia was investigated in rural and urban school-children aged six to 12 years in southwestern Nigeria between January 1987 and October 1988. Asymptomatic parasitaemia was detected in the rural school-children all year round with the lowest parasite rate in January and the highest in July, corresponding to the mid-dry and wet seasons respectively. Asymptomatic parasitaemia was also common amongst urban school-children, but the frequency was lower than in the rural children. Parasite density was less than or equal to 1000 microliters-1 in 42% of parasite-positive asymptomatic children and was greater than 10,000 microliters-1 in only 20% of them. Mass treatment with chloroquine, to which the parasites were fully sensitive, was followed by the same rate of re-infection in the parasite-positive and parasite-negative groups. Of 7713 patients clinically diagnosed as having malaria 4425 were found to have parasitologically-proven malaria, and of these 4239 had pure Plasmodium falciparum malaria. Of the patients with falciparum malaria only 4.6% were below the age of one year. In 47% the parasite count was less than or equal to 1000 microliters-1, and it was over 10,000 microliters-1 in 37% and over 250,000 microliters-1 in 16%. There was no significant difference between the asymptomatic children and the acutely ill patients in the percentage with parasite densities less than or equal to 1000 microliters-1, but the percentage with parasite densities greater than 10,000 microliters-1 was significantly greater in the acute malaria patients than in those with asymptomatic parasitaemia.
Salako
L A
LA
Clinical Pharmacology Unit, University College Hospital, Ibadan, Nigeria.
Ajayi
F O
FO
Sowunmi
A
A
Walker
O
O
D000367:Age Factors; D000818:Animals; D002648:Child; D002738:Chloroquine / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008288:Malaria / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology* / Q000469:parasitology; D008297:Male; D009549:Nigeria / Q000453:epidemiology; D010963:Plasmodium falciparum; D012423:Rural Health; D012621:Seasons; D014504:Urban Health
D002738:Chloroquine