Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 5, 2004
Publication Date: June 20, 2004
Citation: Dubey, J.P. 2005. Toxoplasmosis - a waterborne zoonosis. Veterinary Parasitology 126: 57-72. Interpretive Summary: Infection by the single-celled parasite Toxoplasma gondii causes mental retardation and loss of vision in congenitally infected children. It is transmitted by eating undercooked infected meat or food contaminated with oocysts (resistant form of Toxoplasma) excreted in cat feces. Dr. Dubey summarizes information on oocyst-transmitted toxoplasmosis in humans and animals. This paper will be of interest to public health workers, veterinarians, parasitologists and bioogists.
Technical Abstract: Humans become infected with Toxoplasma gondii mainly by ingesting uncooked meat containing viable tissue cysts or by ingesting food or water contaminated with oocysts from the feces of infected cats. Circumstantial evidence suggests that oocyst-induced infections in humans are clinically more severe than tissue cyst-acquired infections. Until recently, water borne transmission of T. gondii was considered uncommon but a large human outbreak linked to contamination of a municipal water reservoir in Canada by wild felids and the widespread infection by marine mammals in the U.S.A. provide reasons to question this view. The present paper reviews information on the biology of oocyst-induced infections of T. gondii in humans and animals and examines possible importance of transmission by water.