Oral HPV 'more common in men than women'
Research in the US has found that oral infection with the human papillomavirus (HPV) may be more common among men than women.
The study, published in the Journal of the American Medical Association, found that almost seven per cent of people aged 14 to 69 were infected with the virus.
Scientists found that 10.1 per cent of men were infected, compared with just 3.6 per cent of women.
HPV is linked to the development of a type of cancer known as oral squamous cell carcinoma (OSCC), but little is known about how the infection is spread, or how common it is in the mouth.
As part of the new study by scientists at Ohio State University, over 5,500 people across the US - men and women from ages 14 to 69 - were tested at mobile examination centres.
Researchers took mouth swabs and then used DNA testing to identify the HPV types people were carrying. They also asked detailed questions about their lifestyles, drug and alcohol use, and sexual behaviours.
They found that the virus was most commonly detected among people aged 30 to 34 (7.3 per cent) and those aged 60 to 64 (11.4 per cent).
Smokers were also more likely to carry HPV, along with former and current marijuana users.
But the researchers said their findings indicate that sexual activity is the most common source of oral HPV infection.
Just 0.9 per cent of participants who had never had sex were infected with oral HPV, compared with 7.5 per cent of those who had. The risk increased with the number of sexual partners that participants had during their lifetime.
The authors said their findings indicated that HPV transmission by "casual, non-sexual contact" is likely to be "unusual".
The researchers believe their findings could help scientists understand how oral HPV infection is spread and said more work needs to be done to investigate the effects of modifiable risk factors such as smoking and sexual behaviour.
They wrote: "The incidence of OSCC has significantly increased over the last three decades in several countries, and HPV has been directly implicated as the underlying cause."
The researchers point to previous studies of cervical HPV, which helped experts to develop a vaccine to prevent the infection.
But they added: "Vaccine efficacy against oral HPV infection is unknown, and therefore vaccination cannot currently be recommended for the primary prevention of oropharyngeal cancer.
"Given an analysis of US cancer registry data recently projected that the number of HPV-positive oropharyngeal cancers diagnosed each year will surpass that of invasive cervical cancers by the year 2020, perhaps such vaccine trials are warranted.
"Such trials could inform ongoing discussions regarding the benefits of HPV vaccination for males, given the higher prevalence of oral HPV infection demonstrated here as well as higher incidence of HPV-positive OSCC among men."
Jessica Harris, health information manager at Cancer Research UK, said: "As we learn how common HPV infections in the mouth are, and how they are passed on, we can understand more about who is most at risk and how people can reduce the risk of HPV-related cancers.
"Although there isn't yet any evidence to show whether HPV vaccination is effective at preventing oral HPV infections, results like these are vital to help inform prevention programmes in the future."
Copyright Press Association 2012