医学微生物学与诊断

Performance Evaluation of Plasmodium falciparum Histidine-Rich Protein 2 Rapid Diagnostic Test, when Compared to Microscopy

Abstract

Nfor Omarine Nlinwe, Sule Mahnu Ammahdou and Kamga Henri- Lucien

Introduction: In malaria diagnosis, a highly sensitive and specific test will ensure appropriate administration of antimalarial treatment, hence promoting a parasite-based diagnosis as recommended by the World Health Organization (WHO). The Global Malaria Program recommends that suspected clinical malaria could be confirmed using the quality assured Rapid Diagnostic Test (RDT) and microscopy diagnostic tools. This study was designed to assess the performance of Plasmodium falciparum Histidine-Rich Protein 2 (PfHRP2-RDT), with respect to age and parasite density.
Methodology: This study was carried out in the Bamenda Regional Hospital Laboratory, with 381 patients enrolled into the study by convenient sampling technique. A simple questionnaire, microscopy and PfHRP2-RDT techniques were used to collect data on sex, age, and malaria status of the study participants. Both descriptive statistics and analysis of variance were used for data analysis.
Results: Results by microscopy show that up to 68.55% (109/159) of the males and 41.89% (93/222) of the females were infected. About 55.44% of those infected were younger children (≤ 5 yrs) and young adults (�?18 yrs to ≤ 35 yrs), with up to 68.81% of the infections being mild parasitemia. Results by microscopy and PfHRP2-RDT were not the same, and the difference between the daily variation in test results was significant at P=0.0012. With microscopy as the standard, the sensitivity, specificity, positive predictive value and negative predictive value of PfHRP2-RDT were; 100%, 92.75%, 94.26% and 100% respectively.
Conclusion: The microscopy technique indicated low specificity and positive predictive values. Hence, in order to ensure an effective parasite-based malaria diagnosis, a microscopy confirmatory test is recommended for every PfHRP2-RDT positive result.