A COMMON parasite can increase a women’s attractiveness to the opposite sex but also make men more stupid, an Australian researcher says.

About 40 per cent of the world’s population is infected with Toxoplasma gondii, including about eight million Australians.

Human infection generally occurs when people eat raw or undercooked meat that has cysts containing the parasite, or accidentally ingest some of the parasite’s eggs excreted by an infected cat.

The parasite is known to be dangerous to pregnant women as it can cause disability or abortion of the unborn child, and can also kill people whose immune systems are weakened.

Until recently it was thought to be an insignificant disease in healthy people, Sydney University of Technology infectious disease researcher Nicky Boulter said, but new research has revealed its mind-altering properties.

“Interestingly, the effect of infection is different between men and women,” Dr Boulter writes in the latest issue of Australasian Science magazine.

“Infected men have lower IQs, achieve a lower level of education and have shorter attention spans. They are also more likely to break rules and take risks, be more independent, more anti-social, suspicious, jealous and morose, and are deemed less attractive to women.

“On the other hand, infected women tend to be more outgoing, friendly, more promiscuous, and are considered more attractive to men compared with non-infected controls.

“In short, it can make men behave like alley cats and women behave like sex kittens”.

Dr Boulter said the recent Czech Republic research was not conclusive, but was backed up by animal studies that found infection also changes the behaviour of mice.

The mice were more likely to take risks that increased their chance of being eaten by cats, which would allow the parasite to continue its life cycle.

Rodents treated with drugs that killed the parasites reversed their behaviour, Dr Boulter said.

Another study showed people who were infected but not showing symptoms were 2.7 times more likely than uninfected people to be involved in a car accident as a driver or pedestrian, while other research has linked the parasite to higher incidences of schizophrenia.

“The increasing body of evidence connecting Toxoplasma infection with changes in personality and mental state, combined with the extremely high incidence of human infection in both developing and developed countries, warrants increased government funding and research, in particular to find safe and effective treatments or vaccines,” Dr Boulter said.

Source: http://www.news.com.au/story/0,10117,20975555-29277,00.html