Can you catch toxoplasmosis from cat litter?
Toxoplasma gondii is a parasitic protozoan that can infect humans though its main hosts are cats. Sources of infection can be faeces of a recently infected cat, dirty vegetables, raw or partly cooked meat. Most infected humans do not even know that they have been infected, often suffering only mild, flu-like symptoms. Toxoplasmosis is the most common latent protozoan infection in humans, globally as many as one out of every three humans is thought to carry the disease. The main problem is the first infection during pregnancy: in a mother with no previous exposure and thus no immunity, the parasite will enter the foetus in 40% of cases, and may cause congenital toxoplasmosis which can damage the brains and eyes. Most babies exhibit no symptoms when born, but the defect appears later in life.
The prevalences of latent toxoplasmosis and immunity are very different in various countries. In Central Europe 50–70% of population are infected, in France almost all, 88%, of population are carriers probably because raw or lightly cooked meat is commonly consumed. In the U.S. about 11% and in the Nordic Countries about 20% carry antibodies; in the Far East the rate may be even lower. If the average prevalence is low, the risk of infection is less, but on the other hand, if a pregnant mother is infected, the risk of congenital toxoplasmosis is high since it is most probable that the mother will not have acquired immunity. The risk can be detected by antibody screening, but this is not routinely done in most countries. Due to the relatively low incidence of congenital toxoplasmosis, active screening will result in many false positives and unnecessary pregnancy losses.
During early pregnancy, toxoplasmosis is a serious general infection that may lead to abortion. Later infection may lead to chronic disease with subsequent brain or eye defects. For example, retinal defects are typical.
Immunocompromised patients are another group of humans in whom toxoplasmosis can represent a severe risk since the symptoms include inflammation of the brain or heart, pneumonia, or chorioretinitis of the eyes, and the disease may be fatal.
Pregnant women should avoid contact with cat faeces. The cat litter box should be emptied daily, because toxoplasma eggs need some time before they become infectious, and the box should be washed with very hot water. During these operations and while working in the garden, proper gloves should be worn, and the hands washed well afterwards. It is also important to wash hands thoroughly after playing with children in a sandbox.
After handling raw meat, the hands and all kitchenware need to be cleaned well. Meat being cooked for pregnant women should be well done. In particular, in high risk countries where there is a high prevalence of toxoplasmosis, it is not advisable to eat partly cooked meat and eggs, or to drink unpasteurised milk. During pregnancy, good general hygiene is more important than ever.
Toxoplasmosis is usually an innocuous infection in adults, but it can be very significant during pregnancy, since it can lead to brain or eye defects in the unborn child. Hygiene is very important in prevention of toxoplasmosis.
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