Feline friends?

A report showing that 350,000 people in the UK become infected with the Toxoplasma parasite each year has raised new concerns about its risks and has prompted a rethink of the dangers posed by cats.

A link between serious mental disorders, including schizophrenia, and the parasite, which is spread by cats, was observed, but studies reported in 2009 and extended in 2011 by a team from the University of Leeds' Faculty of Biological Sciences led by Dr Glenn McConkey provided key genetic evidence that the parasite Toxoplasma gondii could change production of dopamine in the brain.

Disruption of dopamine regulation is believed to be involved in a number of human psychological issues.

The work helped trigger a Food Standards Agency (FSA) review of the threat posed by Toxoplasma that reported this week and attracted wide media interest.

The FSA's Advisory Committee on the Microbiological Safety of Food (ACMSF) recommended further research into routes of Toxoplasma transmission and identification of risks of infection.

Toxoplasmosis is relatively common, with 10-20% of the UK population thought to carry the parasite as cysts.  Most people with the parasite do not suffer apparent health problems. However, the impact on high risk groups including unborn children and people with immune deficiencies means that Toxoplasma ranks second among food pathogens in terms of its impact on public health.