Giardia parasite found in North American domestic cats poses zoonotic risk

A large-scale study published in PLOS One has identified the prevalence of the protozoan parasite Giardia duodenalis in domestic cats across North America. Led by veterinarian Margaret Wingerd, the research involved the analysis of over 157,000 stool samples collected from cats in the United States and Canada.

The study found a 6.3 percent detection rate, meaning approximately one in every 16 cats tested carried the parasite. Notably, 18.5 percent of these positive cases involved the A or B genetic assemblages, which possess zoonotic potential and could potentially be transmitted from animals to humans.

While many infections remain asymptomatic, giardiasis can cause diarrhea, abdominal pain, and weakness in both humans and animals. The research indicated that younger cats are at a higher risk, with kittens showing a 10.7 percent infection rate compared to just 1.3 percent in cats aged 10 years or older. Male cats also showed a slightly higher likelihood of infection than females.