A new study found that tobacco use or exposure increases one's risk of being infected with the human papillomavirus infection type 16 (HPV16).

According to the U.S. Centers for Disease Control and Prevention (CDC), HPV is the most common sexually transmitted virus in the United States for both men and women. It usually affects the genital areas, but can also affect the mouth and throat.

Unfortunately, most people with HPV are not aware that they have it, but nearly 79 million Americans are currently infected, and an additional 14 million infections are uncovered per year. Health problems associated with HPV include genital warts, cervical, mouth and throat cancer.

Earlier studies have linked HPV16 and smoking, but a recent study performed by Johns Hopkins scientists focused more on identifying a link between tobacco chemicals and the infection.

Researchers looked at the data of 6,887 participants of the National Health and Nutrition Examination Survey. Samples of blood and urine were also collected to check for traces of tobacco-related chemicals. The analysis showed that those with higher traces of tobacco-related chemicals in the body also tested positive for HPV. Smoking three cigarettes per day increases one's risk to catching the infection by 31 percent, and 68 percent for four cigarettes.

"We found that increasing levels of tobacco exposure were associated with higher odds of oral HPV16 prevalence," said Carole Fakhry, M.D., M.P.H., an assistant professor of otolaryngology-head and neck surgery at the Johns Hopkins University School of Medicine, in a press release.

While the findings showed a direct correlation between tobacco use and HPV infections, researchers failed to expound how it happened.

"It appears that tobacco exposure increases the likelihood of having oral HPV16 infection, and although we do not yet know why, we suspect that the virus may not be cleared from the body as easily in people who use tobacco," said Gypsyamber D'Souza, Ph.D., M.S., M.P.H., an associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health and Johns Hopkins Kimmel Cancer Center.

Further details of the study were published in the Oct. 8 issue of the Journal of the American Medical Association.