The prevalence of Cryptosporidium infection in humans, animals, and water sources in Korea.

Cryptosporidium is a zoonotic protozoan parasite of humans and animals and an important waterborne pathogen worldwide. In the Republic of Korea, Cryptosporidium infection has been reported in humans, livestock, companion animals, and water sources, but the available epidemiological data remain limited and fragmented across studies. This study summarized the prevalence, species distribution, and epidemiological characteristics of Cryptosporidium in Korea. Relevant publications were retrieved from PubMed, Web of Science, Google Scholar, and the Korea Citation Index from June 1991 to July 2025, and a meta-analysis was conducted to estimate pooled prevalence by host group. The overall pooled prevalence was 7.1% (95% CI, 4.6-11.0%), with significant differences among host groups. In humans, prevalence was relatively high in rural areas in the 1990s but generally decreased in later studies. In cattle, prevalence varied widely and remained substantial, particularly in young calves. In pigs, earlier studies mainly reported C. parvum, whereas recent molecular studies identified C. scrofarum and C. suis. Limited studies in goats reported relatively high prevalence, whereas data in chickens remained scarce. In companion animals, prevalence was generally low to moderate, with C. canis and C. felis predominating in dogs and cats, respectively. Cryptosporidium oocysts were also detected in environmental water sources, and a waterborne outbreak caused by C. parvum was reported in Seoul in 2012. Overall, Cryptosporidium remains relevant to both veterinary and public health in Korea. Continued surveillance and further molecular epidemiological studies are needed to better understand transmission patterns and zoonotic risk.