Haematological profiles of the people of rural southern Malawi: an overview.

An integrative review of the results of two published and two unpublished studies of anaemia in children, adolescent females, pregnant women and adults living in southern Malawi is presented. Anaemia was universally present in all age-groups, with the higher prevalences in infants (100%) and adolescent primigravidae (93.8%). Nutritional deficits of iron and vitamin A were major contributory factors but chronic malarial haemolysis also significantly contributed to the anaemia. Among boys, anaemia was more common among those with glucose-6-phosphate-dehydrogenase (G6PD) deficiency than in those without this deficiency (P<0.002). This enzymopathy, which occurred in 23.5% [95% confidence interval (CI)=16.7%-30.1%] of the male and 30% (CI=17.3%-42.7%) of the female infants examined, was also associated with neonatal jaundice. The overall prevalences of the-alpha(3.7)/alphaalpha and -alpha(3.7)/-alpha(3.7) thalassaemia genotypes were estimated at 41.0% (CI=28.3%-53.7%) and 8.7% (CI=1.5%-15.9%), respectively. Haemoglobin AS was present in 18.1% (CI=12.8%-23.4%) of the infants and haemoglobin SS in 2.5% (CI=1.4%-3.6%). As the prevalence of infection with Plasmodium falciparum was significantly higher in infants with haemoglobin AS than in those with AA (21.4% v. 6.7%; P<0.001), an increased risk of early-onset moderate parasitaemias in young infants probably stimulates the development of immunity, protecting older heterozygotes from severe malarial infection. Innovative community approaches are required to break the cycle of ill health that anaemia supports in those living in rural areas of southern Malawi. Interventions in adolescent girls could be of particular importance, as they could break the cycle in both pregnant women and their infants.

Risk factors for fetal anaemia in a malarious area of Malawi.

The prevalence of infants born with low cord haemoglobin (fetal anaemia) is high in areas where malaria and iron deficiency anaemia in pregnancy are common. The objective of the present study was to determine risk factors for fetal anaemia in an area of high malaria transmission in southern Malawi. A case control study was undertaken with fetal anaemia defined as cord haemoglobin (Hb) < 12.5 g/dl. Between March 1993 and July 1994, pregnant women attending the study hospitals for the first time in that pregnancy were enrolled. Data on socio-economic status, anthropometry, previous obstetric history and current pregnancy were collected. Malaria parasitaemia, Hb levels and iron status were measured in maternal blood at recruitment and delivery and in umbilical venous blood. Fetal anaemia occurred in 23.4% of babies. Mean (SD) cord Hb was 13.6 g/dl (1.83). Factors associated with fetal anaemia were: birth in the rainy season [adjusted odds ratio (AOR) 2.33, 95% CI 1.73-3.14], pre-term delivery (AOR 1.60, 1.03-2.49), infant Hb < 14 g/dl at 24 hours (AOR 2.35, 1.20-4.59), maternal Hb at delivery < 8 g/dl (AOR 1.61, 1.10-2.42) or <11 g/dl (AOR 1.60, 1.10-2.31). A higher prevalence of fetal anaemia occurred with increasing peripheral Plasmodium falciparum parasite density (p=0.03) and geometric mean placental parasite densities were higher in babies with fetal anaemia than in those without (3331 vs 2152 parasites/microl, p=0.07). Interventions should aim to reduce fetal anaemia by improving malaria and anaemia control in pregnancy and by addressing the determinants of pre-term delivery.