ABSTRACT
This chapter provides state-of-the-art overviews on foodborne diseases caused by Balantidium coli in relation to their etiology, biology, epidemiology, clinical presentation, pathogenesis, diagnosis, treatment, and prevention. Balantidium coli is the only ciliated protozoan known to infect humans and is also the largest protozoan infecting humans and nonhuman primates. As a zoonotic organism, pigs form its asymptomatic natural reservoir, and other animals may also be involved. Balantidium coli is widely distributed, although its infection in humans is uncommon. In contrast to the low prevalence rates in humans, this parasite frequently occurs in pigs and nonhuman primates. Balantidiosis appears to be a problem mostly of developing countries. In addition, B. coli can act as an opportunistic parasite in immunosuppressed hosts living in urban environments, where pigs are not a factor in infection. Balantidium coli has two stages in its life cycle: trophozoites and cysts. It is a facultative anaerobe but it grows well in both aerobic and anaerobic media.
