Abstract:
Background: The commonly accepted gold standard diagnostic method for detecting malaria is a microscopic
reading of Giemsa-stained blood films. However, symptomatic diagnosis remains the basis of therapeutic care for
the majority of febrile patients in malaria endemic areas. This study aims to compare the discrepancy in malaria and
anaemia burdens between symptomatic diagnosed patients with those diagnosed through the laboratory.
Methods: Data were collected from Western Kenya during a follow-up study of 887 children with suspected cases
of malaria visiting the health facilities. In the laboratory, blood samples were analysed for malaria parasite and
haemoglobin levels. Differences in malaria prevalence between symptomatic diagnosis and laboratory diagnosis
were analysed by Chi-square test. Bayesian probabilities were used for the approximation of the malaria and
anaemia burdens. Regression analysis was applied to: (1) determine the relationships between haemoglobin levels,
and malaria parasite density and (2) relate the prevalence of anaemia and the prevalence of malaria.
Results: The prevalence of malaria and anaemia ranged from 10% to 34%, being highest during the rainy seasons.
The predominant malaria parasite was P. falciparum (92.3%), which occurred in higher density in children aged
2‒5 years. Fever, high temperature, sweating, shivering, vomiting and severe headache symptoms were associated
with malaria during presumptive diagnosis. After conducting laboratory diagnosis, lower malaria prevalence was
reported among the presumptively diagnosed patients. Surprisingly, there were no attempts to detect anaemia in
the same cohort. There was a significant negative correlation between Hb levels and parasite density. We also
found a positive correlation between the prevalence of anaemia and the prevalence of malaria after laboratory
diagnosis indicating possible co-occurrence of malaria and anaemia.
Conclusion: Symptomatic diagnosis of malaria overestimates malaria prevalence, but underestimates the anaemia
burden in children. Good clinical practice dictates that a laboratory should confirm the presence of parasites for all
suspected cases of malaria.