Giardia lamblia is a widely distributed flagellated protozoan parasite that inhabits the small intestine. It is the most prominent human protozoal enteropathogen with a prevalence rate that varies from 2% to 5% in the industrialized world and 20% to 30% in the developing world. Giardiasis is more prevalent between infants and children, with no morphological distinction between different assemblages and/or genotypes. Two major assemblages of G. lamblia infect humans and other wide host range. The present study aimed to identify the genotypes of G. lamblia isolated from human and animal feces in Qalubia Governorate, and to elucidate the relationship of the different genotypes to their hosts and the possibilities for zoonotic transmission. Among 200 human fecal samples 40 were diagnosed as giardiasis by direct iodine stained smear, formol ether concentration technique and trichrome stain in addition to 45 animal fecal samples (10 cattles, 15 newly borne calves, 10 dogs and 10 sheeps) giardiasis was diagnosed in 10 cases (8 calves and 2 dogs). Then multiplex PCR technique was conducted on a total of 50 samples (40 humans and 10 animals). The triosephosphate isomerase gene was amplified from 35 of the 40 human fecal samples and 10 animal samples. Among these 35 human fecal samples 3 cases (8.6%) were Giardia genotype AI, 9 cases (25.7%) were Giardia genotype AII, 20 cases (57.1%) were genotype B (Mixed BIII and BIV ) and 3 cases (8.6%) were mixed Giardia genotype AII +BIII. among the 10 animal samples there were 8 samples (80%) (6 calves and 2 dogs) Giardia genotype AI ,2 samples (20%) were Giardia genotype AII (2 calves ). The results reported in this study indicated that Giardia genotype B (Mixed BIII and BIV ) was the most common detected genotype ,and Sub-assemblage AII accounted the majority of cases with Giardia genotype A among human cases included in this study. Among animal cases included in this study Giardia genotype AI was the most common detected genotype followed by Giardia genotype AII and Giardia genotype B not detected. Giardia genotype B showed a high prevalence in cases above 10 years. It was also found in polysymptomatic people, many of whom presented with severe diarrhea. The most vulnerable age group included (1- 10) years old individuals |
