Molecular evidence of mixed P. vivax and P. falciparum infections in northern Islamic Republic of Iran.

This study compared basic microscopy with molecular detection of Plasmodium species. According to thick-film microscopy, 100% of 142 malaria cases in Pars-Abad, Ardebil province, were infected with a single species, P vivax. However, nested polymerase chain reaction (PCR) detected mixed species infections of both P. vivax and P. falciparum in 7.0%. In Mazanderan province, 2/20 blood films were diagnosed with only P. falciparum and 18/20 with only P. vivax. However, nested PCR detected 17/20, 2/20 and 1/20 with P. vivax only, P. falciparum only and mixed species respectively. The unexpected presence of P. falciparum urges prompt investigation and immediate treatment of malaria cases in this region.