Experts have called for an expansion of the human papillomavirus (HPV) vaccination campaign to cover boys.

The call comes as a new study found a high rate of cancer-causing HPV infection in men who have sex with men.

Human papillomavirus infection is the most common sexually transmitted infection in Ireland and worldwide.

It is highly prevalent among those who are sexually active.

Researchers from Trinity College Dublin and St James's Hospital found the incidence of HPV-associated anal cancer is increasing.

Men who have sex with men (MSM), particularly those co-infected with HIV, are disproportionately affected.

In the study of MSM in Ireland, half of whom were HIV positive, the researchers found two-thirds of those they tested had HPV.

A quarter were infected with a particular type of HPV associated with a majority of anal cancers.

HPV also now accounts for approximately 20% of head, neck and throat cancers in Ireland and the incidence is on the increase.

Since 2010, girls in Ireland have been able to receive the HPV vaccine as part of a national vaccination programme.

Vaccine coverage and completion in girls is greater than 85%. 

However, the scientists say this new research strengthens the case for extending the HPV vaccination programme to all boys, with catch-up and targeted vaccination of high-risk groups such as MSM and those with HIV.

The research was published in the leading peer-reviewed international journal HIV Medicine.