Haematological Parameters and Spleen Rate of Asymptomatic and Malaria Negative Children in Edo South District, Nigeria

BACKGROUND: Malaria is commonly associated with alteration in haematologic cells of infected individuals in both the acute uncomplicated and severe phases. Whether this alteration occurs in the asymptomatic phase of the disease is still being investigated. OBJECTIVES: To examine the haematocrit, thrombocytes, and monocytes levels of children with asymptomatic malaria compared with age/sex-matched controls who are malaria parasite negative and living in a stable malaria endemic region. It also set out to identify spleen rate of the children and to compare it with that observed in malaria negative controls. METHODS: One hundred well-nourished children 2–9 years old with asymptomatic malaria parasitaemia and 100 age- and sex-matched malaria negative controls were recruited by multi-stage sampling from schools in a malaria endemic region of Nigeria. Malaria diagnosis was by microscopy, and each haematologic parameter was analysed following standard protocols. RESULTS: Mean (±) monocyte count of 2.25 ± 0.9 × 10(9) cells/L observed in asymptomatic malaria children was significantly higher than 1.34 ± 0.5 × 10(9) cells/L observed in those with no malaria (p = 0.00). Mean (±) thrombocyte count was significantly lower (asymptomatic 203.64 ± 45.90 × 10(9) cells/L Vs no malaria 230.91 ± 57.40 × 10(9) cells/L) (p = 0.00). Spleen rate in the children was 15.5%. Presence of splenomegaly was not statistically significantly fewer in children with asymptomatic malaria parasitaemia (ASMP) (14/31) when compared to those who were malaria parasite negative (17/31) (χ(2) = 0.34, p = 0.57). Similarly, there was no significant difference in the mean [±] spleen length of children with ASMP (n = 14; 2.86 ± 0.9 cm) and those who were malaria negative (n = 17; 2.53 ± 0.6 cm) (t = 1.22, p = 0.23). CONCLUSION: Thrombocytopaenia and monocytosis could be pointers to malaria parasitaemia in asymptomatic phase in a stable malaria region.