A cross-sectional study on Plasmodium infection was conducted among 158 febrile patients (65 males
and 93 females) reporting to Oyo State Hospital, Oyo, South-western Nigeria. Parasitological and
haematological examinations of the blood samples were conducted. An overall infection rate of 29.7%
was observed with parasite densities ranging from 96 - 64680 asexual parasites/µL blood. The
percentages of infected male and female individuals were 27.7 and 31.2%, respectively. The least
(12.5%) and the highest prevalence (44.4%) were recorded in age groups <1 and 6 - 15 years
respectively. Malaria prevalence and parasitaemia were independent of age and sex (P>0.05). The total
leucocytes and lymphocytes decreased with parasites densities, while neutrophils increased with
parasitaemia but with insignificant relationships (P>0.05). The neutrophils and lymphocytes in infected
and non-infected individuals were (54.0, 55.6%) and (45.9, 43.73%) respectively. The mean packed cell
volume (PCV) of the blood in all positive cases in all age groups was lower than in negative individuals.
The malaria prevalence in this study was low. Therefore, considerable efforts should further be made to
reduce its occurrence below the risk level mostly among the most susceptible groups. Advocacies on
the practices of Intermittent Preventive Treatment (IPT) and use of Insecticide Treated Nets (ITNs)
should further be promoted.