Evaluation of microscopy and rapid diagnostic tests in screening clinically suspected malaria patients in a hospital setting in Umuahia, Nigeria
Malaria is a life-threatening disease caused by the protozoa of the genus Plasmodium. Infection of individual is through the bites of infected female Anopheles mosquitoes. This study evaluated the performance of microscopy and rapid diagnostic tests (RDTs) in diagnosing malaria. A total of 400 clinically suspected malaria patients that attended Obioma Hospital in Umuahia North Local Government Area of Abia State from September to December, 2015, who gave their consents were included in the study and examined using microscopy and RDTs. Thick and thin blood smears prepared on clean grease free slides from venous blood aseptically collected from each respondent and stained with Field stains A and B were examined for the presence of malaria parasite. Serological diagnosis was performed using CareStartTm malaria HRP2 (Pf) kits and First Response malaria HRP2 (Pf) kits. Prevalence rates were 40.3%, 34.3% and 34.5% by microscopy, CareStartTm malaria HRP2 (Pf) and First Response malaria HRP2 (Pf) RDTs respectively. Chi-square test showed no significant difference (x2 = 3.216, p>0.05) between microscopy and RDTs. The males were more infected (41.0%) than the females (33.3%) with no significant difference between the diagnostic methods. Prevalence in age group 6-15 years was observed to be highest for both microscopy and RDTs (x2 = 2.447, p>0.05). CareStartTm malaria HRP2 (Pf) and First Response malaria HRP2 (Pf) sensitivities were 89.8% and 86.1% respectively and specificities were 96.4% and 97.1% respectively. The result of this study showed that clinical diagnosis cannot be relied upon for accurate diagnosis of malaria in endemic areas. Training medical personnel on parasite-based malaria diagnosis and encouraging them to always verify the clinical signs and symptoms of malaria of their patients with laboratory tests before commencing treatment is advocated.
Keywords: Malaria; microscopy; RDT; clinically suspected malaria patients