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. MATERIALS AND METHODS Study type and populations: This cross-sectional study sample included 126 children (5 to 12 years old),

Genotyping of Giardia duodenalis in children in upper Egypt using assemblage- specific PCR technique

“…Unlike our findings, several studies reached different conclusions. Homan and Mank [25] reported that the prevalent genotype in asymptomatic individuals was Giardia Assemblage A, and El-Badry et al [4] in Egypt and others in different countries reported no substantial association between Giardia genotype and clinical presentation [21,22]. Differences in study design, criteria for selecting study populations, and small sample size may explain contradictory findings that were observed in our study and may limit the scope of this study.…”

“…Genomic DNA of G. duodenalis was identified in 35 of 40 microscopically positive samples (87.5%). False-negative PCR results in Giardia detection were previously reported [4,[40][41][42]. Such results were attributed to factors that may affect the DNA yield, such as the presence of DNA inhibitors in stool samples, sample preservation conditions, and the method or type of DNA extraction kit [43].…”

“…Human giardiasis prevalence in developed nations ranges from 1 to 8% of the population; however, in developing countries, it exceeds 30% of the population [9]. The prevalence rate in Egypt is up to 30.2% [4].…”

Giardia lamblia affecting humans in Sohag governorate and its related symptoms

“…These results agreed with Bernard et al [12], Who stated that the highest prevalence was between 3 to 5 years, and Mohran et al [9], who stated that, the highest prevalence was between 1 -10 years. These results disagreed with Heehong et al [13], and El-Badry et al [14], who stated that giardiasis was highest in children aged 6 to 12 years. As regards severity of diarrhea, in the present study, diarrhea was classified into mild, moderate, and severe.…”

Giardia lamblia affecting humans in Sohag governorate and its relation with some physical measurements

“…[9], who stated that, the highest prevalence was between 1 -10 years. These results disagreed with Heehonget al [13], and El-Badryet al [14], who stated that giardiasis was highest in children aged 6 to 12 years. The results of this study showed that there was a decrease in weight, height, weight for height, and body mass index of children with Giardia infection by different proportions.…”