Comparing the results of light microscopy with the results of PCR method in the diagnosis of Plasmodium vivax

• Main Author: Ali-Akbar Haghdoost, Shahrzad Mazhari , Kambiz Bahadini
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2006-06-01
• Series: Journal of Vector Borne Diseases
• Subjects: Diagnosis; Iran; light microscopy; malaria; PCR
• Online Access: http://www.mrcindia.org/journal/issues/432053.PDF

Background & objectives: Although polymerase chain reaction (PCR) is a new technique in thediagnosis of malaria with very high accuracy; light microscopy is still conventional diagnosticmethod in Iran. In this study we checked the accuracy of light microscopy using the results of PCRas gold standard in Iran.Methods: The blood samples were collected from 124 febrile cases in Kahnooj district. The bloodslides were read by microscopists, and double checked by experts in provincial referral laboratory.DNA samples were processed by PCR to amplify species-specific sequences of 18s subunit ribosomalribonucleic acid (18ssrRNA) genes of Plasmodium vivax and P. falciparum.Results: The sensitivity and specificity of microscopy in the detection of Plasmodium spp infectionwere 77% (95% CI: 46–94%) and 100% (95% CI: 95–100%), correspondingly. Also, the estimatedpositive and negative predictive values were 100% (95% CI: 66–100%) and 97% (95% CI: 91–99%), respectively.Interpretation & conclusion: According to these results, we believe that the accuracy of lightmicroscopy in the diagnosis of malaria in Kahnooj was acceptable. Expert micorscopists in endemicareas of Iran such as Kahnooj and available equipments in one hand and expensive PCR test on theother hand may convince that in current situation we do not have to change the diagnostic method.