Toxoplasmosis is a common disease found in birds and mammals across North America. The infection is caused by a parasite called Toxoplasma gondii and infects about 20 out of every 100 people in North America by the time they are adults.

Most people who are infected do not show any signs of the disease. Those who do get sick may experience 

• fever
• sore throat
• sore muscles
• tiredness
• glands in the neck, armpits or groin can become swollen, but are usually not sore
• in some cases the infection can also cause temporary blurred vision or loss of vision

In particular, persons who are pregnant or have a weak immune system due to AIDS, cancer or organ transplants should follow the advice in HealthLInk BC File #43: Toxoplasmosis. 

The incubation period is from five to 23 days.

All animals and birds can be infected with the toxoplasmosis parasite. The parasite enters the muscles of a bird or animal when it eats raw meat or drinks the milk of another animal that is infected. Cats can also spread the parasite in their feces. Humans can become infected with toxoplasmosis when changing a cat litter box or working in an area contaminated with cat feces. 

Common ways for people to become infected with toxoplasmosis include: 

• eating raw or undercooked meats
• drinking unpasteurized milk
• cleaning cat litter boxes
• working in gardens or playing in sandboxes that contain cat feces

Less common ways for people to become infected with toxoplasma include: 

• drinking water contaminated with toxoplasma
• although extremely rare, by receiving an infected organ transplant or blood transfusion

Pregnancy and toxoplasmosis 

If you are pregnant or are thinking of becoming pregnant soon, be sure to follow the advice in the HealthLink information (see above) on how to avoid infection. 

A growing fetus can become infected with the toxoplasmosis parasite. This can happen if someone is infected with the parasite while pregnant or slightly before becoming pregnant. Infection in the unborn child early in pregnancy can result in miscarriage, poor growth, early delivery or stillbirth. If a child is born with toxoplasmosis he/she can experience eye problems, hydrocephalus (water on the brain), convulsions or mental disabilities. 

Treatment of an infected pregnant woman may prevent or lessen the disease in her unborn child. Treatment of an infected infant will also lessen the severity of the disease as the child grows.

Outward signs of toxoplasmosis and the demonstration of antibodies in the blood's serum, or identification of the parasite in the body's tissues are ways to diagnose toxoplasmosis.

Most people will recover from toxoplasmosis without treatment. However, medication is available from your family doctor to treat the infection. Treatment may be needed if the eyes or heart are affected or if the infection occurs in pregnant people or persons with weak immune systems or long lasting diseases (e.g. AIDS or cancer).

• order or cook your meat well done
• do not eat raw or undercooked meat
• wash your hands, utensils, and cutting boards after handling raw meat to prevent contamination of other foods
• do not drink unpasteurized milk from any animal
• be careful not to accidentally swallow dust when cleaning the cat litter box; clean the litter box daily so that the parasite does not have a chance to become infectious
• avoid cleaning cat litter boxes if you are pregnant or trying to become pregnant
• wear gloves when cleaning the cat litter box, then wash your hands
• place a secure lid on your sandbox to prevent cats from using it as a litter box
• wear gloves when gardening, then wash your hands
• persons who are pregnant or have a weak immune system due to AIDS, cancer or following organ transplants and who are concerned about the quality of the water in their community should consult with their doctor about whether they should be treating their drinking water or using bottled water

Cats and you 

Just like other family members, your pet cat can pass disease on to you. Most cats which are infected do not appear sick. The cat's faeces contain the parasite for only two weeks after the cat is infected. However, the feces themselves may remain infectious for well over a year. 

Cats which have been raised indoors, have never caught and eaten mice or birds, and who have never been fed raw meat are not likely to be infected. A stray or unfamiliar cat which appears sick should not be handled but should be reported to the SPCA or to the pound. 

Here are some tips to help you continue to enjoy your pet cat:

• wash your hands after patting, brushing or being licked by your cat
• clean out the litter box every day
• dispose of cat faeces in a plastic bag in the garbage
• do not compost the cat litter, or dispose of the litter near your garden
• see a vet if there are any signs of illness in your cat
• don’t feed raw meat to your cat