Comparative haematological parameters of HbAA and HbAS genotype children infected with Plasmodium falciparum malaria in Yemen.

BACKGROUND: Sickle haemoglobin (HbS) is known to offer considerable protection against falciparum malaria. However, the mechanism of protection is not yet completely understood. In this study, we investigate how the presence of the sickle cell trait affects the haematological profile of AS persons with malaria, in comparison with similarly infected persons with HbAA. This study is based on the hypothesis that the sickle cell trait plays a protective role against malaria. METHODS: Children from an endemic malaria transmission area in Yemen were enrolled in this study. Hematological parameters were estimated using manual methods, the percentage of parasite density on stained thin smear was calculated, haemoglobin genotypes were determined on paper electrophoresis, ferritin was measured using enzyme-linked immunosorbent assay, serum iron and TIBC were assayed using spectrophotometer, transferrin saturation index was calculated by dividing serum iron by TIBC and expressing the result as a percentage. Haematological parameters were compared in HbAA- and HbAS-infected children. RESULTS: Falciparum malaria parasitaemia was confirmed in the blood smears of 62 children, 44 (55.7%) of AA and 18 (37.5%) AS, so there was higher prevalence in HbAA children (P = 0.047). Parasite density was lower in HbAS- than HbAA-infected children (P = 0.003). Anaemia was prominent in malaria-infected children, with high proportions of moderate and severe forms in HbAA (P = 0.001). The mean levels of haemoglobin, packed cell volume, reticulocyte count, platelets count, lymphocytes, eosinophils, and serum iron were significantly lower while total leukocytes, immature granulocytes, monocytes, erythrocyte sedimentation rate, transferrin saturation, and serum ferritin were significantly higher in HbAA-infected children than HbAS-infected children. CONCLUSION: Infection with Plasmodium falciparum malaria caused more significant haematological alterations of HbAA children than HbAS. This study supports the observation that sickle cell trait seems to be a beneficial genetic factor that resists malaria, since inheriting it protects against significant haematological consequences of malaria.

Placental malaria, anaemia and low birthweight in Yemen.

A cross-sectional study was conducted during the period of August 2007-April 2008 at Al-Wahda Teaching Hospital in Yemen to investigate prevalence and risk factors for placental malaria and anaemia and their effects on birthweight. Sociodemographic characteristics were gathered, maternal haemoglobin was measured and blood films were examined for malaria. Newborn birthweight was recorded. Out of 900 parturient women, malaria blood films were positive in 32 (3.6%) cases: in six sets of peripheral, placental and cord samples; in 15 placental and cord samples; and in 11 placental samples only. Malaria was not associated with age and parity, but it was significantly associated with history of fever [odds ratio (OR) 8.5, 95% CI 3.7-19, P<0.001], rural residence (OR 2.5, 95% CI 1.1-5.3, P=0.01) and rainy season (OR 5.1, 95% CI 1.7-15.2, P=0.003). Overall, 694 (77.1%) out of these 900 women had anaemia (Hb<11g/dl) and 16 (1.8%) patients had severe anaemia (Hb<7g/dl). Anaemia was not associated with age, parity and malaria. Low birthweight was significantly associated with malaria (OR 5.7, 95% CI 1.7-18.5; P=0.004). Thus, preventive measures (bednets and intermittent preventive treatment) should be employed for pregnant women regardless of their age or parity.