Ingestion of cat feces containing oocysts: This can occur through hand-to-mouth contact following gardening, cleaning a cats litter box, contact with childrens sandpits; the parasite can survive in the environment for months. Ingestion of untreated, unfiltered water through direct consumption or utilization of water for food preparation. Ingestion of unpasteurized milk and milk products, particularly goats milk. Ingestion of raw seafood.Cats excrete the pathogen in their feces for a number of weeks after contracting the disease, generally by eating an infected intermediate host that could include mammals (like rodents) or birds. Oocyst shedding usually starts from the third day after ingestion of infected intermediate hosts, and may continue for weeks. The oocysts are not infective when excreted. After about a day, the oocyst undergoes a process called sporulation and becomes potentially pathogenic. In addition to cats, birds and mammals including human beings are also intermediate hosts of the parasite and are involved in the transmission process. However the pathogenicity varies with the age and species involved in infection and the mode of transmission of T. gondii.Toxoplasmosis may also be transmitted through solid organ transplants. Toxoplasma-seronegative recipients who receive organs from recently infected Toxoplasma-seropositive donors are at risk. Organ recipients who have latent toxoplasmosis are at risk of the disease reactivating in their system due to the immunosuppression occurring during solid organ transplant.
Recipients of hematogenous stem cell transplants may experience higher risk of infection due to longer periods of immunosuppression.Heart and lung transplants provide the highest risk for toxoplasmosis infection due to the striated muscle making up the heart, which can contain cysts, and risks for other organs and tissues vary widely. Risk of transmission can be reduced by screening donors and recipients prior to the transplant procedure and providing treatment. Pregnancy precautions
Congenital toxoplasmosis is a specific form of toxoplasmosis in which an unborn fetus is infected via the placenta. Congenital toxoplasmosis is associated with fetal death and miscarriage, and in infants, it is associated with hydrocephalus, cerebral calcifications and chorioretinitis, leading to encephalopathy and possibly blindness. A positive antibody titer indicates previous exposure and immunity, and largely ensures the unborn fetus safety. A simple blood draw at the first prenatal doctor visit can determine whether or not a woman has had previous exposure and therefore whether or not she is at risk. If a woman receives her first exposure to T. gondii while pregnant, the fetus is at particular risk.Not much evidence exists around the effect of education before pregnancy to prevent congenital toxoplasmosis. However educating parents before the baby is born has been suggested to be effective because it may improve food, personal and pet hygiene.