Potential zoonotic transmission of Giardia duodenalis in semi-rural communities near Quito, Ecuador

Giardia duodenalis is the most common enteric protozoa found in humans and can cause giardiasis, a self-limited illness characterized by diarrhea, abdominal cramps, bloating, weight loss, and malabsorption. Molecular epidemiology research suggests that G. duodenalis may be transmitted from domestic animals to humans in some cases. We investigated the zoonotic transmission of G. duodenalis in a semi-rural community in Ecuador. The study was conducted between June 2014 to July 2016 in five semi-rural communities east of Quito. A total of 831 fecal samples were collected (316 from children and 515 domestic animals). Overall, 130 samples (62 children and 68 domestic animals) were positive for G. duodenalis by ELISA and microscopy. All positive samples were tested by nested PCR using the tpi gene. Sequencing results showed that assemblages (C and B) were present in both children and domestic animals.