Men should be screened for Chlamydia too, say scientists

The bacterial infection Chlamydia may cause infertility in men as well as women, heard delegates at the American Society for Reproductive Medicine in Washington DC this week. A study of 143 infertile men, infected with Chlamydia and another common sexually transmitted disease (STD), mycoplasma, found that 35 per cent of the sperm in these men was damaged, a figure 3.2 times higher than in healthy men.

Dr Jose Fernandez of the Juan Cana-lejo University Hospital in La Courina, who led the study, reported that microscopic examination of the sperm from these men revealed shape and swimming defects, lower concentrations and higher instances of a form of genetic damage called 'DNA fragmentation'. 'We found there was a three-fold increase in the fragmentation of DNA in sperm cells compared with controls, and this could have a potential role in sub-fertility', he said.

Of 193 men seeking fertility treatment with their partners in Monterey, Mexico, the researchers found that 143 of these were infected by both viruses and that, after treating both partners with antibiotics, 85.7 percent became pregnant. Dr Fernandez believes these improved pregnancy rates can only be explained by the 'significant decrease in DNA damage' seen in men following the four months of antibiotic treatment. But despite this 'dramatic difference' further research will be needed to confirm this link, he said.

The NHS screening programme estimates that 1 in 10 sexually active 18-25 year olds in the UK are affected by Chlamydia, a disease which can render women permanently infertile if left untreated, but which manifests no symptoms in the majority of people.

It has long been known that around 40 per cent of women infected with the disease develop pelvic inflammatory disease, potentially leading to permanent damage to the Fallopian tubes and increased risk of infertility. However, this is the first indication that Chlamydia can also cause infertility in men.

Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield and Secretary of the British Fertility Society, warned that there is a risk of the disease 'getting out of control' if action is not taken. 'We have got to encourage men as well as women to go for screening, but men are more reluctant to do this if they don't have symptoms', he said.

The study highlights the importance of sexually active people of both sexes attending the routine screening checks already offered in most UK clinics. However better ways of reaching the younger generation are needed, urges Dr Pacey. 'It is the 18 to 25 age group that is of most concern', he told the BBC. 'There should be a page on FaceBook you can log into and sort screening out'.