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United States Department of Agriculture

Agricultural Research Service

Research Project: DEVELOPMENT OF AN INTEGRATED RISK MODEL FOR FOODBORNE ZOONOTIC PARASITES IN SWINE Title: The life cycle of Toxoplasma gondii: In Toxoplasma - Molecular and Cellular biology.

Author
item Dubey, Jitender

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: July 1, 2006
Publication Date: January 17, 2007
Citation: Dubey, J.P. 2007. The life cycle of Toxoplasma gondii: In Toxoplasma - Molecular and Cellular biology, J. W. Ajioka and D. Soldati, Horizon Scientific Press, Norwich, U.K.. pp. 3-16.

Interpretive Summary: Toxoplasma gondii is a single-celled parasite of all warm-blooded hosts worldwide. It causes mental retardation and loss of vision in children, and abortion in livestock. Cats are the main reservoir of T. gondii because they are the only hosts that can excrete the resistant stage (oocyst) of the parasite in the feces. Humans become infected by eating undercooked meat from infected animals and food and water contaminated with oocysts. A scientists at the USDA Agricultural Research Service, Beltsville Maryland reviews toxoplasmosis.The information will be of interest to biologists, parasitologists, and veterinarians.

Technical Abstract: Infections by the protozoan parasite, Toxoplasma gondii, are widely prevalent worldwide in animals and human beings. Cats are the only definitive hosts for T. gondii and all other warm-blooded animals are intermediate hosts. Cats excrete the environmentally-resistant oocysts after ingesting any of the three infectious stages of T. gondii, tachyzoites, bradyzoites, and oocysts. Humans and other hosts become infected with T. gondii by ingesting uncooked infected meat, by ingesting food and water contaminated with oocysts, or transplacentally. Cats can excrete millions of oocysts after ingesting tissues of infected animals and oocysts can survive in the harsh environment for months. Contamination of sea water can occur from the oocysts washed off the land and marine mammals can acquire T. gondii infection and some die from toxoplasmosis.

Last Modified: 11/23/2014