The impact of malarial infection and diet on the anaemia status of rural pregnant Malawian women

Abstract

Objective: To investigate haematological and biochemical iron indices in relation to malaria, gravida, and dietary iron status in rural pregnant Malawian women.

Design: In this self-selected sample, haemoglobin, haematocrit, red cell indices, serum ferritin, serum iron, serum transferrin, and serum transferrin receptor (TfR) were measured. Infection was assessed by a malaria slide, serum C-reactive protein, and white blood cell count. Dietary iron variables were measured by three 24-h interactive recalls.

Setting and subjects: 152 rural pregnant women recruited at 24 weeks gestation while attending a rural antenatal clinic in Southern Malawi; 36% were primagravid; 43% were gravida 2–4; 26% were gravida >5.

Results: Of the women, 69% (n=105) were anaemic (haemoglobin <110 g/l); 37% (n=39) had anaemia and malarial parasitaemia on the test day; 17% (n=26) with malaria were also classified with iron deficiency (ID) anaemia (based on serum ferritin ≤50 μg/l and Hb <110 g/l) while an additional seven with malaria were classified with ID without anaemia. In malarial-free subjects, 32% were classified with IDA (serum ferritin <12 μg/l and Hb <110 g/l) and 17% with ID (serum ferritin <12 μg/l; Hb ≥110 g/l). Serum TfR concentrations were elevated in anaemic women (P<0.01). In non-malarial parasitaemic subjects, serum TfR correlated negatively with haemoglobin (r=−0.313; P<0.001) but not serum ferritin. Of the women, 49% were at risk for inadequate iron intakes. Most dietary iron was non-haem; plant foods provided 89%; flesh foods (mainly fish) only 9%. Malarial parasitaemia and intakes of available iron impacted significantly on iron status.

Conclusion: Anaemia prevalence from all causes was high (that is, 69%); three factors were implicated: malaria, and deficiencies of iron and possibly folate, induced partly by an inadequate dietary supply and/or secondary to malarial parasitaemia.

Sponsorship: International Development Research Centre (IDRC) of Canada. Opportunities for Micronutrient Interventions (OMNI) Project. Natural Sciences and Engineering Research Council of Canada.