A study published online in JAMA on Thursday suggests 7% of men and women in the US carry the Human papillomavirus (HPV), the virus that causes a distinct form of cancer that affects the part of the throat that sits at the back of the mouth. The study suggests oral HPV infection is predominantly sexually transmitted, and estimates that men are nearly three times more likely to have the virus than women.

Maura L. Gillison, Professor in the College of Medicine at Ohio State University (OSU), and others carried out the study.

They note in their introduction that we already know oral HPV infection causes a subset of oropharyngeal squamous cell carcinomas (OSCCs) and that these are linked to sexual behavior. (Oropharyngeal squamous cell carcinomas not caused by HPV are linked to chronic use of tobacco and alcohol).

Also, there is evidence that this type of cancer is on the rise in men in the US, but what is not so clear is how common HPV is in the American population.

So Gillison and colleagues set out to measure the prevalence of HPV among men and women in the US.

They drew their data from the National Health and Nutrition Examination Survey (NHANES) 2009-2010, which via mobile centers, samples representative cross-sections of the US population (excluding those serving in the armed forces and who are in institutions).

The data covered 5,579 men and women aged 14 to 69, who gave an oral sample (a 30-second oral rinse and gargle with mouthwash). They also gave demographic information via interviews that included questions about sexual behavior and substance use.

The oral samples were tested (using polymerase chain reaction or PCR) to see if they contained any HPV DNA.

The results showed that:
  • The prevalence of oral HPV infection was 6.9%.

  • The prevalence of HPV type 16 (the type that is most strongly linked with OSCCs) was 1.0%.

  • Oral HPV infection rates were highest among those aged 30 to 34 years, and 60 to 64 years.

  • Men had a significantly higher rate of infection than women (10.1% versus 3.6%).

  • Infection was less common among men and women without a history of any type of sexual contact, than among those who did have such a history.

  • The rate of infection went up in line with number of sexual partners and cigarettes smoked per day.
The authors conclude:

"Among men and women aged 14 to 69 years in the United States, the overall prevalence of oral HPV infection was 6.9%, and the prevalence was higher among men than among women."

"Our data provides evidence that oral HPV infection is predominantly sexually transmitted," they note.

Written by Catharine Paddock PhD