Variation in haematological parameters in children less than five years of age with asymptomatic Plasmodium infection: implication for malaria field studies

During the season of high malaria transmission, most children areinfected by Plasmodium, which targets red blood cells (RBCs),affecting haematological parameters. To describe these variations, we examinedthe haematological profiles of two groups of children living in amalaria-endemic area. A cross-sectional survey was conducted at the peak of themalaria transmission season in a rural area of Burkina Faso. After informedconsent and clinical examination, blood samples were obtained from theparticipants for malaria diagnosis and a full blood count. Of the 414 childrenincluded in the analysis, 192 were not infected withPlasmodium, whereas 222 were asymptomatic carriers ofPlasmodium infection. The mean age of the infected childrenwas 41.8 months (range of 26.4-57.2) compared to 38.8 months (range of22.4-55.2) for the control group (p = 0.06). The asymptomatic infected childrentended to have a significantly lower mean haemoglobin level (10.8 g/dL vs. 10.4g/dL; p < 0.001), mean lymphocyte count (4592/µL vs. 5141/µL; p = 0.004),mean platelet count (266 x 103/µL vs. 385 x 103/µL; p < 0.001) and mean RBCcount (4.388 x 106/µL vs. 4.158 x 106/µL; p < 0.001) and a higher meanmonocyte count (1403/µL vs. 1192/µL; p < 0.001) compared to the controlgroup. Special attention should be applied when interpreting haematologicalparameters and evaluating immune responses in asymptomatic infected childrenliving in malaria-endemic areas and enrolled in vaccine trials.