Prevalence of Plasmodium falciparum identified in people using microscopy, rapid diagnostic test and PCR in the prefecture of Siguiriya/Guinea

Introduction: Malaria remains one of the leading causes of medical consultations in the tropics. In Guinea, this disease is primarily caused by Plasmodium falciparum. Objective: To determine the prevalence of malaria in a population. 

Material and Methods: This is a prospective study lasting eight months, from October 5, 2022, to May 30, 2023. Diagnostic of malaria was done using microscopy, rapid diagnostic tests, and polymerase chain reaction (PCR). 

Results: A total of 4352 people were included in the study, 50% of whom were children under 5 years of age. The rapid diagnostic test (RDT) for malaria was positive for Plasmodium falciparum in 5.10% of cases. The diagnosis of Plasmodium by thick blood smear (SBS) was positive in 5.85% of cases (255/4352), and the thin blood smear allowed the determination of the Plasmodium falciparum species in all SBS-positive cases. The molecular method (PCR) applied to the 255 SBS-positive samples showed the presence of Plasmodium falciparum DNA in 96.47% of the SBS-positive samples (246/255). Extrapolation of PCR results positive for Plasmodium falciparum DNA to all 4352 subjects in the study gave a prevalence of 5.65% (246/4352). DNA prevalence according to age groups after PCR showed that 118 children under 5 years of age (47.96%) were carriers of Plasmodium falciparum DNA compared to 128 individuals over 5 years of age (52.03%) also carriers of Plasmodium falciparum. 

Conclusion: The results of this present study showed a significant prevalence of Plasmodium falciparum in the population studied, and malaria diagnosis by microscopy remains the reference method; therefore, the rapid diagnostic test serves as a quicker means of diagnosis and the PCR technique is not usually used routinely because of the generally higher costs of molecular methods.