Circulating platelets and malaria severity: two sides of the same coin among inhabitants of a tropical savannah region, Nigeria.

Abstract

Changes in circulating platelets during different grades of malaria are of major concerns, and its etiology is poorly understood. We appraised and evaluated the role of circulating platelets in the determination of the severity of malaria among a cohort of outpatients living in Ilorin, Nigeria. A hospital-based case-control study of outpatients visiting public health facilities within the locality voluntarily enrolled for this study. Blood samples from 1162 malaise patients were screened using routine microscopy for Plasmodium parasite species identification, and their respective circulating platelet levels were determined. Seven hundred and seventy-five individuals (775, 66.7%, p<0.001) were malaria-positive. Samples from 387 (33.3%) uninfected healthy individuals were used as controls. Individuals with uncomplicated malaria (UCM) and complicated malaria (CM) across age group were notable (p<0.05). Children ≤5 years had the highest number of individuals with CM (103, 45.2%) with a relative risk ratio of 4.005 (95% CI: 2.964-5.413). UCM (471, 40.5%) occurred more than CM (304, 26.2%) (p>0.05) across the groups. The geometric mean, 95% CI, median, and IQR of populations with malaria thrombocytopenia were higher (181, 110.94±2.207, 106.59-115.30, 118.00, and 39.00) than thrombocytosis (78, 624.64±13.131, 598.49-650.79, 623.00, and 208). Seemingly, health controls recorded insignificant morbidity with respect to platelet counts. High P. falciparum parasitemia is inversely correlated with platelet count, and its' morbidity is associated with the manifestation of several malaria pathogenesis. Thrombocytopenia is a silent pathophysiological attribute that can trigger other cofactors during severe malaria disease. Although further studies are pertinent in order to specifically clarify its relevance to clinical disease spectrum.