Comparison of polymerase chain reaction, microscopy, and rapid diagnostic test in malaria detection in a high burden state (Odisha) of India

Abstract

Precise identification of Plasmodium species is critical in malaria control and elimination. Despite several shortcomings, microscopy and rapid diagnostic test (RDT) continue to be the leading diagnostic methods. Polymerase chain reaction (PCR) is the most sensitive method but its dependency on advanced laboratory and skilled workers limits its use. Here, we compared the diagnostic performance of microscopy, RDT, and PCR in clinically suspected patients from a high malaria burden state (Odisha) of India. The diagnostic performance (sensitivity, specificity, positive predictive value, and negative predictive value) of all three methods was compared using microscopy and PCR as the gold standard. PCR identified 323 (76.5 %) positive cases out of 422 samples, whereas microscopy and RDT identified only 272 (64.4 %) and 266 (63.0 %) positive cases, respectively. The sensitivity of RDT and microscopy for detecting malaria and P. falciparum cases was >80% compared to that by PCR. However, the sensitivity in identifying P. vivax (57.0 %) and a mixture of P. falciparum and P. vivax (18.0 %) was poor. We highlight application of PCR in malaria diagnosis and its benefits in reducing the transmission. This emphasizes the need for incorporation of molecular diagnostic approaches for effective elimination strategies.

Keywords: Malaria; PCR; RDT; microscopy; plasmodium.

Figure 1.

Venn diagram showing comparative malaria prevalence by microscopy, RDT, and PCR

Figure 2.

Flow diagram showing malaria diagnosis using microscopy, RDT, and PCR in Kalahandi District of Odisha