Comparison of molecular tests for the diagnosis of malaria in Honduras

Malaria Journal

Methodology

Gustavo A Fontecha¹  Alexandre M De Oliveira²  Mitra Poorak³  Venkatachalam Udhayakumar³  Naomi W Lucchi³  Engels Banegas⁴  Meisy Mendoza⁴  Rosa E Mejia⁴  Tamara Mancero⁵ 

[1] MEIZ-Microbiology School, National Autonomous University of Honduras (UNAH), Tegucigalpa, Honduras;Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Road, 30333, Atlanta, GA, USA;Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Road, 30333, Atlanta, GA, USA;Atlanta Research and Education Foundation, Decatur, GA, USA;National Malaria Laboratory, Health Ministry, Tegucigalpa, Honduras;Pan American Health Organization (PAHO), Tegucigalpa, Honduras;

关键词: Malaria;    Mixed Infection;    Rapid Diagnostic Test;    Multiplex Polymerase Chain Reaction;    Nest Polymerase Chain Reaction;   

DOI  :  10.1186/1475-2875-11-119

 received in 2012-01-18, accepted in 2012-04-18,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundHonduras is a tropical country with more than 70% of its population living at risk of being infected with either Plasmodium vivax or Plasmodium falciparum. Laboratory diagnosis is a very important factor for adequate treatment and management of malaria. In Honduras, malaria is diagnosed by both, microscopy and rapid diagnostic tests and to date, no molecular methods have been implemented for routine diagnosis. However, since mixed infections, and asymptomatic and low-parasitaemic cases are difficult to detect by light microscopy alone, identifying appropriate molecular tools for diagnostic applications in Honduras deserves further study. The present study investigated the utility of different molecular tests for the diagnosis of malaria in Honduras.MethodsA total of 138 blood samples collected as part of a clinical trial to assess the efficacy of chloroquine were used: 69 microscopically confirmed P. falciparum positive samples obtained on the day of enrolment and 69 follow-up samples obtained 28 days after chloroquine treatment and shown to be malaria negative by microscopy. Sensitivity and specificity of microscopy was compared to an 18 s ribosomal RNA gene-based nested PCR, two single-PCR reactions designed to detect Plasmodium falciparum infections, one single-PCR to detect Plasmodium vivax infections, and one multiplex one-step PCR reaction to detect both parasite species.ResultsOf the 69 microscopically positive P. falciparum samples, 68 were confirmed to be P. falciparum-positive by two of the molecular tests used. The one sample not detected as P. falciparum by any of the molecular tests was shown to be P. vivax-positive by a reference molecular test indicating a misdiagnosis by microscopy. The reference molecular test detected five cases of P. vivax/P. falciparum mixed infections, which were not recognized by microscopy as mixed infections. Only two of these mixed infections were recognized by a multiplex test while a P. vivax-specific polymerase chain reaction (PCR) detected three of them. In addition, one of the day 28 samples, previously determined to be malaria negative by microscopy, was shown to be P. vivax-positive by three of the molecular tests specific for this parasite.ConclusionsMolecular tests are valuable tools for the confirmation of Plasmodium species and in detecting mixed infections in malaria endemic regions.

【 授权许可】

Unknown   
© Fontecha et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.