It is estimated that 500 million people worldwide have been infected by toxoplasma. In the UK it is thought that 20-30% of the UK population may have antibodies (markers in the blood which show exposure to a specific infection) to toxoplasma in their blood. Many infected humans have no signs, or just mild flu-like symptoms, but toxoplasmosis can be severe in babies and young children, the elderly, and people with a supressed immune system, such as those with AIDS or after organ transplants.
Despite the high numbers of people who appear to come across toxoplasma in their lives, it is thought relatively few of these exposures are from infected cats. This is because:
- Cats only have infectious faeces for less than two weeks
- Indoor cats that are not fed raw meat are unlikely to have toxoplasma
- Cats do not carry the parasite on their fur, so stroking your cat is unlikely to result in exposure
- Infection cannot be passed via bites or scratches
- Eggs in cat faeces take several days to become infectious, so regular litter tray cleaning means it is likely most eggs in cat faeces in the home will not lead to infection.
The more common routes of infection of people are:
- Eating raw meat
- Eating unwashed fruit and vegetables
- Drinking unpasteurised milk
- Contact with contaminated soil
- Infection in the womb, if the mother gets toxoplasma whilst pregnant.
It is this final route of infection that is most heavily seen in the media – it is for this reason that pregnant women are advised not to empty cat litter trays.
While it is important to take normal hygiene precautions when handling cats, it should be noted that studies have shown that having a cat, or working with cats, causes little or no increase to your risk of contracting toxoplasma.
If you think you may have been exposed to toxoplasma, and are concerned, always contact your doctor for advice.