The effect of oral iron therapy during treatment for Plasmodium falciparum malaria with sulphadoxine-pyrimethamine on Malawian children under 5 years of age

Abstract

In sub-Saharan countries, although malaria and malaria-associated anaemia are major public health problems, the usefulness of supplementary iron treatment for children with malaria-associated anaemia is unknown. In a 6-week period during the 1995 rainy season, 222 Malawian children aged <5 years, who sought treatment for malaria, had ⩾ 500 parasites/µl blood and at least 5 g haemoglobin (HB)/dl blood and whose parents gave consent, were randomized into a prospective study comparing the efficacy of sulphadoxine-pyrimethamine only (SP), SP plus daily iron (SPD) and SP plus weekly iron (SPW) as treatment for malaria-associated anaemia. The patients had their HB concentrations measured on enrolment (day 0), just before antimalarial treatment, and on days 3, 7, 14, 21 and 28; 215 (96·8%) completed the 28-day study. Among the children with 5–8 g HB/dl on enrolment, HB gain by the end of the study was significantly greater than in the children with >8 g HB/dl initially (4·1 v. 2·2 g/dl; P<0 05), and those in the SPD group gained significantly more HB by days 21 and 28 (3·6 and 4·9 g/dl, respectively) than those in either the SPW (2·7 and 3·7 g/dl, respectively) or the SP groups (2·6 and 3·5 g/dl, respectively); there was no difference in HB gain between the SP and SPW groups. Type of treatment had no apparent effect, at any time during the study, on HB gains in those patients who had >8 g HB/dl on enrolment. Thus the children with 5–8 g HB/dl on enrolment benefited from daily iron therapy whereas those with >8 g HB/dl derived no significant benefit; improvement in HB depended most on whether enrolment HB was ⩽ 8·0 g/dl. As treatment with an effective antimalarial drug resulted in HB gains, irrespective of treatment group or HB concentration at enrolment, the anaemia observed may be mostly related to malaria. However, as a larger proportion of the iron-treated patients failed to clear their parasitaemias than of those given SP alone, oral iron may inhibit SP action. It is therefore recommended that, for children with both malaria and malaria-associated anaemia, the malaria should first be cleared with an effective antimalarial drug, such as SP, before the anaemia, if it still persists, is treated with iron.