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

Adama Gansane,Alfred Tiono,Noelie Bere Henry,Jean-Baptiste Yaro,Issa Nebie Ouedraogo,Amadou Tidiani Konate,Amidou Diarra,Sombie Benjamin,Sodiomon Bienvenu Sirima,Issiaka Soulama,Esperance Ouedraogo

doi:10.1590/0074-0276108052013017

Abstract

During the season of high malaria transmission, most children are infected by Plasmodium, which targets red blood cells (RBCs), affecting haematological parameters. To describe these variations, we examined the haematological profiles of two groups of children living in a malaria-endemic area. A cross-sectional survey was conducted at the peak of the malaria transmission season in a rural area of Burkina Faso. After informed consent and clinical examination, blood samples were obtained from the participants for malaria diagnosis and a full blood count. Of the 414 children included in the analysis, 192 were not infected with Plasmodium, whereas 222 were asymptomatic carriers of Plasmodium infection. The mean age of the infected children was 41.8 months (range of 26.4-57.2) compared to 38.8 months (range of 22.4-55.2) for the control group (p = 0.06). The asymptomatic infected children tended to have a significantly lower mean haemoglobin level (10.8 g/dL vs. 10.4 g/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 RBC count (4.388 x 106/µL vs. 4.158 x 106/µL; p < 0.001) and a higher mean monocyte count (1403/µL vs. 1192/µL; p < 0.001) compared to the control group. Special attention should be applied when interpreting haematological parameters and evaluating immune responses in asymptomatic infected children living in malaria-endemic areas and enrolled in vaccine trials.

Highlights

Malaria remains a major public health problem in Africa (Snow et al 1999, Rowe et al 2006)
The parasite species infecting the children were as follows: 200 (90.1%) children were infected with P. falciparum, one (0.4%) child was infected with P. malariae, 15 (6.6%) children had mixed infections with both P. falciparum and P. malariae and seven (1%) children had mixed infections with both P. falciparum and P. ovale
The cross-sectional survey was conducted at the peak of the malaria transmission season, a time when morbidity and mortality related to malaria are very high

Summary

Introduction

Malaria remains a major public health problem in Africa (Snow et al 1999, Rowe et al 2006). As malaria parasites target red blood cells (RBCs), haematological changes are one of the most common complications and play a major role in the outcomes of the disease. Several blood constituents, including RBCs, platelets and leucocytes, are affected during malaria and serious anaemia is the most common complication in children with severe malaria in the rural areas of Burkina Faso and other parts of Africa (Stein & Gelfand 1985, Amodu et al 1998, Richards et al 1998, Schellenberg et al 1999). To determine the potential of these variations as confounding factors at a future malaria vaccine trial site, we examined the haematological profiles of children less than five years of age with asymptomatic Plasmodium infection and living in an area of Burkina Faso in which malaria is endemic

Objectives

Results

Conclusion