Abstract

Keddie C.M.O

Giardia lamblia is a flagellated protozoa that infects the intestinal tract of a wide range of mammalian hosts, including both wild and domestic animals as well as humans. Two genotypes A and B are commonly reported among humans. The purpose of this study was to investigate the genotypes of G. lamblia among adult infected cases in Ahvaz, southwest of Iran. Fecal samples were collected from 50 patients who had been tested positive to G. lamblia. The samples were analyzed by semi-nested polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) using the gdh gene. Our results indicate 38 and 16% assemblages of BIII and AII, respectively. Mixed infections with both assemblages AII and BIII were also detected in 46% of the positive samples. This higher rate of mixed infection in the region may be explained by the common occurrence of repeated and cumulative infection by the parasite in the study area or may reflect environmental contamination of water resources. Therefore, it seems further studies are needed to clarify the route of infection in the study area.