Evaluation of malaria multiplex/nested PCR performance at low parasite densities and mixed infection in Iran: A country close to malaria elimination

• Published in: Infection, genetics and evolution Vol. 65; pp. 283 - 287
• Main Authors: Mirahmadi, Hadi, Shahrakipour, Azam, Mehravaran, Ahmad, khorashad, Alireza Salami, Rahmati-Balaghaleh, Mansour, Zarean, Mehdi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2018
• Subjects: Iran; Light microscopy; Malaria; Multiplex/nested PCR; Plasmodium; Plasmodium; Light microscopy; Malaria; Iran; Multiplex/nested PCR
• ISSN: 1567-1348; 1567-7257
• DOI: 10.1016/j.meegid.2018.08.005

Malaria is still a major public health problem in subtropical and tropical regions. The rapid and accurate diagnosis of malaria remains a challenge in most of the endemic areas. The primary objective of the present study was to evaluate the performance of multiplex/nested PCR in detecting Plasmodium falciparum at low parasite densities and mixed infection. The study was performed in the Sistan-Baluchestan province of the southeastern Iran, from May 2015 to July 2016. A total of 105 patients suspected to malaria infection were enrolled in the study. The obtained DNA products, extracted from the thick/thin films, were analyzed by multiplex/nested PCR using genus-specific primers and compared with light microscopy. 43 samples were confirmed to be infected by microscopic examination. Among 43 microscopically diagnosed P. falciparum cases, 11.4% (12/105) were confirmed by multiplex/nested PCR, 36.2% (38/105) were confirmed as P. vivax, 1.9% (2/105) had mixed infections with P. falciparum and P. vivax. Among microscopy-negative samples, 10 samples turned malaria-positive in nPCR. In multiplex/nested PCR, the rate of mixed infections was 8.6% (9/105). When compared to LM, the sensitivity, specificity, positive predictive value and negative predictive value of multiplex/nested PCR were calculated to be 82.8, 91.5, 92.3 and 81.1%, respectively. In this study, we showed that microscopic examination of blood smears does not reliably distinguish Plasmodium species in the case of mixed infections. Therefore, it seems that multiplex/nested PCR is a good candidate for examining the presence of malaria parasites in clinically suspected but microscopically negative cases. •1-This research was done in order to Implementation of Malaria Elimination Program in Iran.•2-The use of Multiplex/nested PCR test was able to detect all microscopy-positive samples as well as single or mixed infections and submicroscopic infections that were missed by Light Microscopy.•3-DNA extraction was attempted from Giemsa-stained blood smears on glass slides from all patients with suspected malaria.