What is Toxoplasma gondii?

Toxoplasma gondii is a common zoonotic parasite of mammals, including people, and birds. The parasite is genetically highly variable with many different strains that vary in how much damage they cause to the host. Wildlife in urban areas may be exposed to more virulent ‘domestic’ strains of Toxoplasma gondii. Healthy wildlife infected with Toxoplasma gondii may remain healthy because their immune system produces antibodies that keep the infection under control. If an animal’s immune system is suppressed due to disease or stress infection with Toxoplasma gondii may cause toxoplasmosis, which is rapidly fatal.

 

Toxoplasma gondii profile

Toxoplasma gondii is a single-celled parasite with a complex life cycle. In cats, the parasite reproduces sexually and environmentally resistant oocysts are passed in the faeces. These oocysts can then infect other hosts when they are accidently eaten. Within these hosts, the parasite reproduces asexually and may spread throughout the body.

 

How is Toxoplasma gondii spread?

Sources of Toxoplasma gondii include environmental contamination by domestic cats, exposure to cat faeces, and food or water that has been contaminated by cat faeces.

Eating oocysts is not the only way in which the parasite can be spread. People and animals can also become infected by eating the meat from an animal that has the parasite. Food, particularly meat scraps left in gardens to encourage wildlife, is a common source of Toxoplasma gondii in wildlife. In Perth, quenda taken to wildlife carers with neurological disease due to infection with Toxoplasma gondii are most likely to be infected as a result of eating household scraps, especially if these scraps contain raw or partly cooked meat.

Is this a problem for wildlife?

Toxoplasma gondii is common in wildlife, however large-scale die offs have not been reported. Most cases of clinical disease in wildlife are in captive animals. There have been increasing reports of infection with Toxoplasma gondii in quenda and other marsupials in rehabilitation. The illness and added stress of being captive can cause deadly toxoplasmosis. Reports of outbreaks of severe toxoplasmosis in captive animals have led to a perception that this infectious disease is contributing to population decline in free-ranging wildlife.

 

Did you know:

  • The most common source of infection with Toxoplasma gondii in people and cats is raw or partly cooked meat.
  • Cats rarely have symptoms when infected, so you don’t know if your cat has been infected.
  • Cats only spread Toxoplasma gondii in their faeces for a few weeks following infection with the parasite. This stops by itself therefore it does not help to have your cat’s faeces tested for Toxoplasma gondii.

 

Download the ‘Toxoplasma and Wildlife’ information sheet.