Cats are spreading a potentially serious parasite to an estimated 350,000 people each year, experts have warned.
Advisors to the Food Standards Agency say the micro-organism can cause serious symptoms in pregnant women and people with impaired immune systems, such as the elderly and those with cancer or HIV.
Toxoplasmosis is spread through contact with cat faeces, usually directly by handing cats, cleaning out litter trays or while gardening.
But experts from the Advisory Committee on the Microbiological Safety of Food say outdoor livestock, particular sheep and pigs, are likely to have picked up the infection through contaminated soil and water.
They have called for more research to establish how many people acquire the infection through food - and they recommend that more is done to make vulnerable groups aware of the risks.
Committee chairwoman Sarah O'Brien said: "As yet, there is no evidence to suggest that people generally should change their eating habits. I think the Food Standards Agency is right to say that most of the population can continue to enjoy lamb and beef cooked rare."
Pregnant women are already advised to cook meat thoroughly, and to wear gloves while gardening or handling cat litter.
Healthy people usually fight off the parasite without showing signs of any illness. Around 10-20% develop mild, flu-like symptoms. However, people with impaired immune systems can develop severe gastro-intestinal symptoms.
Pregnant women can pass the infection on to their unborn child - around three in 100,000 babies are stillborn, born blind or have brain damage as a result of congenital toxoplasmosis.
The report says some research suggests the infection can cause behavioural changes and schizophrenia. But the experts conclude there is not enough evidence to quantify the risk.