The research is the first major study to document the nationwide prevalence of oral human papillomavirus, or HPV, a disease that has drawn growing attention from public health experts because it has fueled a rise in oropharyngeal cancers affecting the back of the tongue and the throat. Researchers showed last year that throat cancers caused by a particular strain of the virus, HPV Type 16, have tripled in the last 20 years. But it was unclear exactly how many people over all were carrying HPV, which exists in more than 40 forms.
By looking at thousands of people across the country, the authors of the new report found that 6.9 percent of adults and teenagers are infected with oral HPV of any kind. The virus was about three times as common in men as it was in women. And the scientists identified several behaviors that significantly raised the risk of becoming infected: increasing age, greater sexual activity and smoking cigarettes.
But the study, which was published in The Journal of the American Medical Association, also revealed some reassuring findings, said Dr. Maura L. Gillison, the chairwoman of cancer research at Ohio State University and senior author of the paper. While the overall prevalence of HPV was about 7 percent, only 1 percent, or roughly two million people, were infected with HPV 16, the strain linked to throat cancers and many cases of cervical cancer. Fewer than 10,000 cases of throat cancer caused by HPV 16 are diagnosed every year, indicating that most people with the virus do not develop cancer.