Predominance of Giardia intestinalis assemblage B in diarrhoeic children in Sharkia, Egypt

Abstract

Background: Giardia intestinalis (G. intestinalis) is one of the most common human enteric protozoa that infect Egyptian children, causing most of the diarrhoeic outbreaks worldwide. Identification of G. intestinalis assemblage is important because of its role in determining sources of infection, in understanding the ecological and clinical impact of giardiasis, and hence its management and control.Objective: Study of this cross-sectional sample aimed to determine the genotypes of G. intestinalis isolated from the feces of diarrhoeic children attending outpatient clinic of Zagazig University hospital.Subjects and Methods: A single fecal sample was collected from each child (n=126). All samples were subjected to microscopic examination by direct wet mount before and after formal- ethyl acetate concentration. Positive samples were amplified by nested PCR (nPCR) and sequenced for intra and inter assemblage identification targeting tpi gene.Results: Microscopic examination revealed detection of G. intestinalis in 38 samples (30.2%). In 36 (28.6%) samples there was assemblage B predominance in 34 (94.4%) isolates, among which 24 (70.6%) were subgenotype BIV and 10 (29.4%) were sub-genotype BIII. Only 2 (5.6%) samples had assemblage A; all of them were AII subgenotype. All studied patient`s demographic and clinical data showed no significant association with Giardia infection or prevailing Giardia assemblages.Conclusion: G. intestinalis is the prevailing intestinal pathogen in diarrhoeic Egyptian children, with Giardia assemblage B predominance. These findings necessitate physicians’ attention and further genetic studies in Egypt and other endemic areas targeting different genetic loci, with the inclusion of larger population samples. This will lead to a better understanding of the ecological and clinical impact of giardiasis, its management and control.