Changes in weight gain and anaemia attributable to malaria in Tanzanian children living under holoendemic conditions.

We investigated the effect of Plasmodium falciparum malaria on weight gain and haematocrit in Tanzanian children aged 6-40 months following a malaria control scheme which combined insecticide-impregnated bed nets with chloroquine chemotherapy on demand. Data from 7 villages (3 intervention and 4 control) were collected before, and one year after, the implementation of the programme. Initially, 82% of the children were parasitaemic, 78% were anaemic (i.e., packed cell volume < 33%) and 38% were underweight (i.e., 2 standard deviations below their weight-for-age Z score). One year after implementation of the programme, children not protected by the bed nets grew 286 g less (95% confidence interval [CI] 171-402 g) in a 5 months period and were twice as likely to be anaemic (95% CI 1.4-2.7) than were children not using impregnated bed nets. Our results indicated that, under holoendemic conditions, P. falciparum infection has a marked effect on both weight gain and anaemia.