what are the signs and symptoms of balantidium coli?

Answer 1

Balantidium coli is a species of ciliate protozoan, and is the only one that is pathogenic in humans.
It is carried by pigs, wild boars, rats, primates (including humans), horses, cattle and guinea pigs.
It is transmitted within or between these species mostly via fecal transmission.
Pigs are the most significant reservoir hosts, though they show few if any symptoms.
Cysts are the parasite stage responsible for transmission of balantidiasis. The host most often acquires the cyst through ingestion of contaminated food or water. Following ingestion, excystation occurs in the small intestine, and the trophozoites colonize the large intestine. Both cysts and trophozoites are identifiable by a large, "sausage shaped" macronucleus...

they usually show less symptoms...

hope this helps