T. gondii, the parasite that causes toxoplasmosis, is spread widely through the human and animal population but domestic cats have a unique role in it’s life-cycle. While other animals can carry T. gondii, it is only in the gut of domestic cats that it can reproduce. The parasite is excreted into the environment in the faeces of the cat.
Fortunately, the immune systems of most humans and animals are robust enough to suppress the infection so that it causes no harm.
It is in people and animals with weakened immune systems and pregnant women that it become a danger.
Toxoplasmosis in cats
Most cats infected with T. gondii show no signs of disease. However, when the cat’s immune system is suppressed, including young kittens and cats with feline leukemia virus or feline immunodeficiency virus, full-blown toxoplasmosis may occur.
Kittens born to queens infected with T. gondii in the womb can become infected via the placenta or via suckling. Illness is common and the severity varies with the stage of gestation at the time of infection.
The most common symptoms of toxoplasmosis in cats include fever, loss of appetite, and lethargy. Treatment is by a course of antibiotics and the outcome depends on how soon treatment was started and which organs in the cats are affected.
Toxoplasmosis in people
Most people carrying T. gondii will experience no symptoms but there are two serious exceptions. People undergoing treatment for cancer or HIV or other treatments that suppress their immune systems are at risk of serious infection. This is most usually detected by a blood test.
Toxoplasmosis in pregnant women is particularly dangerous. Getting toxoplasmosis shortly before or during pregnancy can pass the parasite through the placenta to the baby. This increases the risk of miscarriage, stillbirth or serious health problems including vision problems, blindness, developmental delays and learning difficulties.
Cat owners, or people whose garden is frequented by cats, can safeguard themselves and their families by:
- wearing gloves and washing hands after gardening
- emptying and washing litter trays frequently
- washing hands after handling litter trays and utensils
- not allowing cats on food preparation surfaces
- covering children’s sandboxes
People without cats can ingest T, gondii by eating raw meat, eating unwashed fruit or vegetables or by drinking unpasteurised milk.
It is estimated that one in three people in the world have been, or are carrying, T. gondii but with a few precautions, you and your family will likely be unaffected.
You can find more about Toxoplasmosis in this comprehensive article.