Molecular genotyping of Giardia lamblia assemblages by conventional polymerase chain reaction in rural and urban areas in Egypt

Abstract

Background: Giardiasis is one of the most important parasitic gastro-intestinal infections that affect humans worldwide. Children are the most affected age group either in developing or developed countries. Genotyping of Giardia lamblia by molecular techniques classified it into eight assemblages; of which, assemblages A and B are potentially zoonotic pathogens. This study was done to investigate the prevalence of different Giardia lamblia genotypes by conventional polymerse chain reaction (PCR), and to explore the environmental and patientsʼ sociodemographic factors that may affect the disease prevalence. Methods: Two hundreds fecal samples were collected at Damanhour General Hospital from patients with gastrointestinal diseases. All samples were examined microscopically, and the positive ones were investigated by conventional PCR. Results: Giardiasis was detected in 92 (46%) samples. Eighty-eight samples gave positive results by PCR, 18% of which were assemblage A, 70.5% were assemblage B, and 11.5% were mixed infection of both assemblages. The infection was more prevalent in males, rural patients and the highly educated ones. Conclusion: This study presents critical and demonstrative data regarding public health in Egypt. The results reveal that the prevalence of giardiasis is high among both rural and urban patients, particularly in children. It also prevails in patients of all education levels, and patients dealing and not dealing with animals. Moreover, we recommend PCR amplifying the triose phosphate isomerase (tpi) gene in fresh fecal samples as a very effective method for the diagnosis and genotyping.