Parasitology

Biography

Biography: Aliehsan Heidari

Abstract

Introduction: Despite substantial decrease of malaria prevalence in Iran in recent years, Plasmodium vivax and Plasmodium falciparum species still cause symptomatic malaria infection in southeast of the country. The aim of this study was to detect mixed species malaria infections by microscopy and nested PCR in an endemic area of Iran.
Materials and Methods: The microscopic examination of thick and thin blood films was applied to P. vivax infection. The nested PCR was carried out using the Plasmodium 18 sub-unit ribosomal ribonucleic (Ssr RNA) genes to detect the mixed species infections and to identify the malaria parasites in the blood samples. A total of 160 subjects with symptomatic malaria infections participated in the study. The blood smears were stained with 3% Giemsa and examined microscopically by two blind independent experts in microscopy.
Results: Parasitemia ranged from 120 to 10000 parasites per µl of blood with mean 9500 p/µl. In total, 1.88% and 11.25% of patients indicated mixed species infections in microscopy and nested PCR, respectively. The sensitivity of light microscopy for detection of mixed species malaria infections was 16.6% (95% CI 3-49.1). There was a significant difference between sensitivity of microscopy and nested PCR in identifying mixed species malaria infections (P=0.0009).
Conclusion: Our findings show that nested PCR assay can facilitate the better diagnosis of mixed species infections and the correct treatment of malaria patients especially in regions where prevalence of Plasmodium falciparum resistant to chloroquine is high. It is also concluded that mixed species infection is almost common in the region where both species coexist and their detection is only based on traditional microscopy that may underestimate their importance.