balantidiasis

Balantidiasis is a protozoan infection caused by infection with Balantidium coli.

==History== The first study to generate balantidiasis in humans was undertaken by Cassagrandi and Barnagallo in 1896. However, this experiment was not successful in creating an infection and it was unclear whether Balantidium coli was the actual parasite used. The first case of balantidiasis in the Philippines, where it is the most common, was reported in 1904. left|frame|A trophozoite of Balantidium coli Currently, Balantidium coli is distributed worldwide but less than 1% of the human population is infected. Pigs are a major reservoir of the parasite, and infection of humans occurs more frequently in areas where pigs commingle with people. This includes places like the Philippines, as previously mentioned, but also includes countries such as Bolivia and Papua New Guinea. Pigs are not the sole species capable of hosting B. coli. For example, the parasite also has a high rate of occurrence in rats. In a Japanese study that analyzed the fecal samples in 56 mammalian species, Balantidium coli was found to be present not just in all the wild boars tested (with wild boars and pigs being considered the same species), it was also found in five species of non-human primate: Chimpanzee (Pan troglodytes), White-handed gibbon (Hylobates lar), Squirrel monkey (Saimiri sciurea), Sacred baboon (Comopithecus hamadryas), and Japanese macaque (Macaca fuscata). In other studies, Balantidium coli has also been found in species from the order Carnivora.