Leukocyte counts in falciparum malaria in African children from an endemic area.

Total leukocyte counts were done in 180 apparently healthy rural school children aged 6-12 years in a malaria endemic area in southwestern Nigeria. Total leukocyte counts and their distribution in aparasitaemic and asymptomatic parasitaemic children were similar. Total leukocyte counts, and the relationship between the density of parasitaemic and total leukocyte counts were studied in 55 consecutive children presenting with acute symptomatic falciparum malaria. Children without parasitaemia were older and had lower total leukocyte counts when compared with children with parasitaemia (7.61 +/- 4.11 x 10(9)/L Vs 9.04 +/- 5.0 x 10(9)/L), but the difference was not statistically significant (P > 0.05). In non-hyperparasitaemic children and in hyperparasitaemic children with percentage infected red cells < 10%, there was poor correlation between density of parasitaemia and total leukocyte counts. However, at > or = 10% parasitaemia, there was a positive correlation (r = 0.55; P = 0.032) between increasing parasitaemia and leukocytosis. Combination of hyperparasitaemia ( > 5% parasitaemia) and leukocytosis ( > 12 x 10(9)/L) occurred in 15% of the children and was not a poor prognostic index in the absence of other evidence of severe or complicated disease, as response to oral mefloquine was prompt. This would suggest that in African children from an endemic area, this combination is not a reliable indicator of severity or poor prognosis in falciparum malaria.