The History of Toxoplasma gondii
The First 100 Years :PDF
JITENDER P. DUBEY1
United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, Animal Parasitic Diseases
Laboratory, Building 1001, Beltsville, Maryland 20705-2350
ABSTRACT. In this paper the history of Toxoplasma gondii and toxoplasmosis is reviewed. This protozoan parasite was first discovered
in 1908 and named a year later. Its medical importance remained unknown until 1939 when T. gondii was identified in tissues of a
congenitally infected infant, and veterinary importance became known when it was found to cause abortion storms in sheep in 1957. The
discovery of a T. gondii specific antibody test, Sabin–Feldman dye test in 1948 led to the recognition that T. gondii is a common parasite of
warm-blooded hosts with a worldwide distribution. Its life cycle was not discovered until 1970 when it was found that felids are its
definitive host and an environmentally resistant stage (oocyst) is excreted in feces of infected cats. The recent discovery of its common
infection in certain marine wildlife (sea otters) indicates contamination of our seas with T. gondii oocysts washed from land. Hygeine
remains the best preventive measure because currently there is no vaccine to prevent toxoplasmosis in humans.
Key Words. Biology, bradyzoite, diagnosis, life cycle, oocysts, prevention, symptoms, tachyzoite, treatment.