Male fertility at risk from chlamydia

The most common sexually transmitted disease in Britain may harm men's fertility by causing genetic damage to their sperm, research has shown.

Chlamydia is widely known to damage women's fertility by causing scarring and blockages in the fallopian tubes, but the latest study is the first strong evidence to suggest it reduces male fertility too.

Cases of chlamydia have risen sharply in the UK since the mid-1990s. It now infects more than 100,000 people, the majority of whom are 18 to 25. More than half of those who test positive are unaware they have the infection because there are often no clear symptoms.