Toxoplasma gondii is considered the second leading cause of foodborne-related deaths and the fourth leading cause of foodborne-related hospitalizations in the United States.The protist responsible for toxoplasmosis is T. gondii. There are three major types of T. gondii responsible for the patterns of toxoplasmosis throughout the world. There are types I, II, and III. These three types of T. gondii have differing effects on certain hosts, mainly mice and humans due to their variation in genotypes. Type I: virulent in mice and humans, seen in people with AIDS. Type II: non-virulent in mice, virulent in humans (mostly Europe and North America), seen in people with AIDS. Type III: non-virulent in mice, virulent mainly in animals but seen to a lesser degree in humans as well.Current serotyping techniques can only separate type I or III from type II parasites.Because the parasite poses a particular threat to fetuses when it is contracted during pregnancy, much of the global epidemiological data regarding T. gondii comes from seropositivity tests in women of childbearing age. Seropositivity tests look for the presence of antibodies against T. gondii in blood, so while seropositivity guarantees one has been exposed to the parasite, it does not necessarily guarantee one is chronically infected. History
Toxoplasma gondii was first described in 1908 by Nicolle and Manceaux in Tunisia, and independently by Splendore in Brazil. Splendore reported the protozoan in a rabbit, while Nicolle and Manceaux identified it in a North African rodent, the gundi (Ctenodactylus gundi). In 1909 Nicolle and Manceaux differentiated the protozoan from Leishmania.
Diagnosis and treatment
The most reliable test for EPI in dogs and cats is serum trypsin-like immunoreactivity (TLI);  a low value indicates EPI. Fecal elastase levels may also be used for diagnosis in dogs.In dogs, the best treatment is to supplement the animals food with dried pancreatic extracts. There are commercial preparations available, but chopped bovine pancreas from the butcher can also be used. (Pork pancreas should not be used because of the rare transmission of pseudorabies). Symptoms usually improve within a few days, but lifelong treatment is required to manage the condition. A rare side-effect of use of dried pancreatic extracts is oral ulceration and bleeding.Because of malabsorption, serum levels of cyanocobalamin (vitamin B12) and tocopherol (vitamin E) may be low. These may be supplemented, although since cyanocobalamin contains the toxic chemical cyanide, dogs that have serious cobalamin issues should instead be treated with hydroxocobalamin or methylcobalamin.Cyanocobalamin deficiency is very common in cats with EPI because about 99 percent of intrinsic factor (which is required for cyanocobalamin absorption from the intestine) is secreted by the pancreas. In dogs, this figure is about 90 percent, and only about 50 percent of dogs have this deficiency.Cats may suffer from Vitamin K deficiencies. If there is bacterial overgrowth in the intestine, antibiotics should be used, especially if treatment is not working. In dogs failing to gain weight or continuing to show symptoms, modifying the diet to make it low-fiber and highly digestible may help.