The Correlation between Clinical Signs and Genotypes of Giardia duodenalis Isolated from Patients with Giardiasis in Kerman City

Background & Aims: Giardiasis is one of the human parasitic diseases caused by a flagellate protozoan named Giardia duodenalis (G.lamblia). Giardia is one of the most common organisms causing diarrhea in human and also a common gastrointestinal parasite in vertebrates. Methods: A total of 352 stool samples were collected from patients infected with giardiasis referred to health centers in Kerman city. Samples were examined by formalin- ether concentration procedure. First, DNA extraction was performed on 30 stool samples containing adequate Giardia cysts and then PCR-RFLP was done on glultamate dehydrogenase (gdh) marker. Clinical signs of patients were recorded in a questionnaire and their relationships with molecular results were analyzed. Results: The highest rate of infection was in the age group of 0-12 years with significant difference with other age groups (P<0.0001). The most common clinical signs were abdominal pain (71.7%), diarrhea (69%), abdominal cramping (54.1%) and the least common signs were malaise (20.4%) and fever (16.1%). Of all 30 isolates, 18 samples (60%) were found as genotype All, 5 ones (16.7%) belonged to Al assemblage and 7 samples (23.3%) were BIII assemblage. There was a significant difference between genotyping of Giardia and clinical signs of diarrhea, abdominal signs and nausea (P<0.05). Conclusion: Higher prevalence of Giardiasis was found in the age group below 12 years, but clinical signs in different age groups and two sexes were identical. Assemblage A showed correlation with mild intermittent diarrhea and assemblage B had correlation with persistent diarrhea.