The study conducted between the age group of 14 and 69 years showed that about 10 percent of men and 3.6 per cent of women have an oral HPV infection.
It’s not clear why oral HPV infection was more common among men than women. It could be that HPV is more likely to be transmitted through oral sex on women versus men, the researchers said. Differences in hormone levels between the sexes could also affect the duration of an infection. The findings are based on study participant’s reports of their sexual behaviour and smoking, which may not be completely accurate.
Researchers need to follow people to better understand the effects of age, gender, sexual behaviour and smoking on the incidence and duration of oral HPV infections.
Oral HPV infections cause some oropharyngeal cancers, or cancers of the tongue, the tonsils or back of the mouth. People who are infected with the strain HPV 16 are 14 times more likely to develop these cancers compared with those not infected with the virus.
While oral infection with the virus is common, cancer cases as a result of these infections are rare. In other words, most infected people don’t get cancer.
The findings also show oral HPV infections are generally sexually transmitted. People who reported engaging in oral sex were twice as likely to have an oral HPV infection as those who did not engage in oral sex. Those who had sex of any kind, including vaginal sex or oral sex, were eight times more likely to have an oral HPV infection than those who did not have sex. Among those who had 20 or more sexual partners, one in five had an oral HPV infection.
Between 1998 and 2004, incidence of new cases of oropharyngeal cancer in the United States more than tripled (from 0.8 cancers per 100,000 people to 2.6 cancers per 100,000 people). Till recently, little was known about the prevalence of oral HPV infection, and the characteristics of those who have it.
In the new study, Gillison and colleagues analyzed data from more than 5,500 men and women in the United States. Participants answered questions about their sexual behaviour and substance use. They were also asked to gargle mouthwash for 30 seconds, and cells that were exfoliated into the rinse were analyzed for evidence of HPV infection. The researchers found HPV in the cells of 6.9 percent of the participants, and HPV 16 in 1 percent.
Smokers and alcohol users also had a high prevalence of HPV. About 20 percent of those who said they smoke 20 or more cigarettes per day had oral HPV infection. As per research study, smoking may suppress the immune system, leading to longer infections with the virus.