Meanwhile, nearly three out of every 10 women in their late teens suffer recurrent bouts of chlamydia - another common sexually transmitted infection, often with no symptoms, that can lead to pelvic inflammation and infertility. The findings of the Yale University study of more than 400 women aged 14 to 19 were higher than expected, Reuters reports.

Protein in frontline HIV battle

Cells in the mucous lining of human genitals produce a protein that appears to devour human immunodeficiency virus (HIV) - possibly helping contain the spread of Aids. Researchers from the Vrije University Medical Centre in Amsterdam say the protein may indicate new ways to curtail the spread of HIV. The behaviour of the Langerin protein in the laboratory experiments may explain why HIV has a relatively low infection rate, healthday.com reports.

Drink your way to health

Older men who drink moderate amounts of alcohol appear to be healthier and function better physically than those who abstain or drink to excess. That's the finding of a California Pacific Medical Centre study of almost 6,000 men, aged 65 and over. Moderate drinkers - defined as those who had seven to 20 drinks a week - scored up to 5 per cent better on physical-function tests (walking, climbing stairs and doing heavy housework) than abstainers or heavy drinkers, Reuters reports. Moderate drinkers also tend to be healthier than teetotallers or problem drinkers, although the research didn't indicate why.

High-fat licks ovulation problems

A few scoops of high-fat, rather than low-fat, ice cream may improve fertility, based on the unexpected findings of an eight-year Harvard University study of more than 18,500 married nurses. Those who ate two or more weekly servings of low-fat dairy foods had an 85 per cent higher risk of ovulation problems than those who ate one or less. But women who ate one or more daily servings of high-fat dairy foods were 27 per cent less likely to have ovulation problems, WebMD reports. 'We certainly weren't expecting low-fat dairy to have an effect,' says team leader Jorge Chavarro. Nonetheless, he doesn't recommend ice cream binges and says more research is needed.

Perilous brush with epilepsy

Australian researchers report three rare cases of people suffering epilepsy - triggered by brushing their teeth. The University of Melbourne team say the rhythmic action may have stimulated the brain area that triggered the seizures in the two men and woman, in their 30s and early 40s, WebMD reports.

Jason Sankey is a tennis professional