Impact of seasonality on the prevalence and risk factors of Giardia lamblia infections among the aborigines

Abstract

Objective: To determine the prevalence and risk factors of Giardia (G.) lamblia infections among the aboriginal community during the wet and dry seasons. Methods: A total of 473 stool samples from the aborigines in Temerloh, Pahang, Malaysia were collected during wet (n=256) and dry seasons (n=217). Smear of all the PVA-preserved stool samples were subjected to Trichrome staining and microscopic examination under 1 000 x magnification (Nikon eclipse E100) for the detection of G. lamblia. Positivity was recorded based on the presence of G. lamblia in trophozoite and/or cyst forms. Results: The prevalence of giardiasis was 12.10% and 8.29% during the wet and dry season, respectively. Age of less or equal to 15 years old and presence of other family members with G. lamblia infection were found to be the significant risk factors to acquire G. lamblia infections during both seasons. Untreated water supply was the significant risk factor of giardiasis during the dry season. This study highlighted the possibility of anthroponotic transmission of G. lamblia during both seasons and waterborne transmission during the dry season in the aboriginal community. Conclusions: This study suggests that seasonal variation plays an important role in the prevalence and risk factor of G. lamblia infection in the aboriginal community. Therefore, close contact with Giardia-infected family members and water-related activities or usage of untreated water must be avoided to reduce the burden of G. lamblia infection in this community.