Evaluating Prevalence and Misdiagnosis of Plasmodium Using Microscopy Compared With Polymerase Chain Reaction Technique in Two Tertiary Care Hospitals in Rivers State, Nigeria

Background: The accurate diagnosis of etiologic agents of diseases, including Plasmodium species, is a major challenge to effective control programs in sub-Saharan Africa. Malaria misdiagnosis hinders prompt treatment of infected patients, which increases malaria morbidities and mortalities. Objectives: A study to evaluate the prevalence and misdiagnosis of Plasmodium species using microscopy and polymerase chain reaction (PCR) technique in two tertiary care hospitals in Rivers State was conducted. Methods: A cross-sectional randomized study involving 2,000 participants (age and sex were noted) was conducted from January 2016 to December 2017, and only patients arriving in the Outpatient Clinic of the selected tertiary care hospitals were recruited for this study. Intravenous blood samples (5 mL) were collected from all study participants and analyzed for the presence of Plasmodium species using Giemsa-microscopy and Real-time PCR technique. All data generated were analyzed using analysis of variance (ANOVA) and Chi-square test. A P < 0.05 was considered statistically significant. Results: The only species of Plasmodium observed in this study was Plasmodium falciparum (P. falciparum), and the overall prevalence in the study was 37.65% and 34.0% for microscopy and PCR, respectively (P > 0.05). Microscopy had a 3.5% variation and misdiagnosis of 5.5% compared with PCR. P. falciparum misdiagnosis according to age was 6.6%, 4.8%, 3.2%, 7.3% and 6.7% for age groups 0-10, 11-20, 21-30, 31- 40, and > 40, respectively while males and females had P. falciparum misdiagnosis of 6.9% and 4.5%, respectively (P > 0.05). Microscopy had sensitivity, specificity, and diagnostic accuracy of 95.8%, 94.3%, and 94.9%, respectively. Conclusions: Microscopy remains the gold standard for Plasmodium species diagnosis, and suspected malaria cases should be confirmed with an efficient laboratory diagnosis before treatment to prevent misdiagnosis or antimalarial drug resistance.