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 b 5. Results: Of the women, 69% (n 105) were anaemic (haemoglobin`110 gal); 37% (n 39) had anaemia and malarial parasitaemia on the test day; 17% (n 26) with malaria were also classi®ed with iron de®ciency (ID) anaemia (based on serum ferritin 50 mgal and Hb`110 gal) while an additional seven with malaria were classi®ed with ID without anaemia. In malarial-free subjects, 32% were classi®ed with IDA (serum ferritiǹ 12 mgal and Hb`110 gal) and 17% with ID (serum ferritin`12 mgal; Hb ! 110 gal). Serum TfR concentrations were elevated in anaemic women (P`0.01). In non-malarial parasitaemic subjects, serum TfR correlated negatively with haemoglobin (r 7 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%;¯esh foods (mainly ®sh) only 9%. Malarial parasitaemia and intakes of available iron impacted signi®cantly on iron status. Conclusion: Anaemia prevalence from all causes was high (that is, 69%); three factors were implicated: malaria, and de®ciencies of iron and possibly folate, induced partly by an inadequate dietary supply andaor secondary to malarial parasitaemia.

The aetiology of anaemia during pregnancy: a study to evaluate the contribution of iron deficiency and common infections in pregnant Ugandan women

“…Given that available commercial immunoassays for sTfR are not standardized (41) , it is only possible to compare sTfR concentrations across studies that have used the same commercial kit. Mean sTfR concentration obtained in the current study compares well with findings from studies that have used the Ramco sTfR kit (42)(43)(44)(45) . Serum sTfR concentration does not appear to be affected by infectious or inflammatory conditions (46) except for malaria, which in some studies has been observed to increase sTfR levels (47)(48)(49) while in at least one other study caused a decrease in sTfR (50) .…”

Soluble transferrin receptor for the evaluation of erythropoiesis and iron status

“…On the other hand, some studies have found that depletion of iron stores also produced a moderate elevation of sTfR over levels observed in non-iron-deficient pregnancies [122,127], particularly at time of labor [128]. Others have found that among anemic as well as among nonanemic pregnancies, sTfR values are not influenced by iron stores [82,124]. Thus, elevated sTfR levels in late third trimester may help identify iron-deficient erythropoiesis with satisfactory specificity but low sensitivity, but reduced erythropoiesis limits the possibility of detecting iron deficiency in the rest of pregnancy [123,128,129].…”

Correlation between serum transferrin receptor and percentage of parasitemia in malaria. A preliminary report

“…Ineffective erythropoiesis has been described in studies of the bone marrow of patients with anemia and malaria (Phillips et al, 1986). Several studies found abnormalities in sTfR levels in the patients with malaria (Huddle et al, 1999;Stoltzfus et al, 2000). However, most studies were descriptive observations of infected compared to non-infected cases and as a consequence any conclusion could not be definitive.…”

“…However, Huddle et al (1999) found that malaria was not associated with sTfR concentrations that related to the hemoglobin level. These studies were descriptive describing observations in infected and non-infected cases and the conclusions were contradictory.…”