Frequency and Molecular Detection of Giardia intestinalis in Children Attending Pediatrics of Punjab, Pakistan

Background: Giardia intestinalis is the most common protozoan infecting the small intestine of human beings and a major cause of enteric infection, especially in children throughout the world. It is a highly diverse protozoan, which comprises a complex of eight genetic assemblages that are further differentiated into sub-assemblages. Objectives: A cross-sectional study was conducted to detect the frequency, molecular detection and assemblage identification of G. intestinalis in children of Punjab, Pakistan. Methods: A total of 800 stool samples were collected from children ranging 0 - 10 years of age with gastrointestinal disturbances and subjected to direct microscopy, enzyme-linked immunosorbent assay and polymerase chain reaction targeting small-subunit ribosomal RNA (SSU rRNA) and triosephosphate isomerase (tpi) genes. A predesigned questionnaire was filled prior to sampling from the guardian of each child to collect information. Results: The results indicated that the prevalence of 9.5% (76/800) was achieved by microscopy, ELISA and PCR targeting SSU-rRNA gene. The genetic DNA from 69 out of 76 (90.80%) was successfully amplified by tpi gene. Among these tpi gene-positive samples, 38 were successfully typed in assemblage B (55.07%) followed by 20 (28.98%) in assemblage A and 11 (15.94%) in mixed type assemblages (A & B). Residency and socioeconomic status were statistically associated with giardiasis. Among the clinical presentations, abdominal pain is prominent in assemblage B (57.89%) and vomiting in assemblage A (40%) type infections. Conclusions: Advanced molecular tools for giardiasis are well-adapted to get true prevalence, better discrimination of assemblages and their correlation with clinical signs.