Hadi Mirahmadi1, Azam Shahrakipour1, Ahmad Mehravaran1, Alireza Salami Khorashad1, Mansour Rahmati-Balaghaleh2, Mehdi Zarean3. 1. Infectious Diseases and Tropical Medicine Research Center, Resistant Tuberculosis Institute, Zahedan University of Medical Sciences, Zahedan, Iran; Department of Parasitology and Mycology, Zahedan University of Medical Sciences, Zahedan, Iran. 2. Infectious Diseases and Tropical Medicine Research Center, Resistant Tuberculosis Institute, Zahedan University of Medical Sciences, Zahedan, Iran; Department of Parasitology and Mycology, Zahedan University of Medical Sciences, Zahedan, Iran. Electronic address: ma.rahmati@zaums.ac.ir. 3. Department of Parasitology and Mycology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Cutaneous Leishmaniasis Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address: Zareanm@mums.ac.ir.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.
BACKGROUND: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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.
Authors: Hadi Mirahmadi; Azam Shahrakipour; Ahmad Mehravaran; Mansour Rahmati-Balaghaleh; Mehdi Zarean; Soodabeh Etemadi; Mehdi Shahraki; Rahmat Solgi Journal: Am J Trop Med Hyg Date: 2022-01-31 Impact factor: 3.707
Authors: Anatoly V Kondrashin; Lola F Morozova; Ekaterina V Stepanova; Natalia A Turbabina; Maria S Maksimova; Evgeny N Morozov Journal: Malar J Date: 2018-10-04 Impact factor: 2.979