The purpose of this study is to learn about the natural history of Human Papillomavirus (HPV) infection in men. The study will also find out what factors are linked to HPV in men including other sexually transmitted diseases (STDs). If participants test positive for syphilis, gonorrhea or chlamydia, we are required by law to report the results to the Florida Department of Health. Participants will be able to get free medical treatment from the Florida Department of Health for these STDs. Participants will be given a written report of the results of the STD testing.

The study protocol will include a pre-enrollment run-in visit, a baseline visit (enrollment), and 8 additional visits after enrollment scheduled 6 months apart. Intervals of every 6 months were chosen to insure that both acquisition and loss of infections may be assessed, as studies in women indicate that median duration of oncogenic infections ranges between 7-9 months. Informed consent will occur during the run-in visit. The run-in and follow-up visits will include questionnaire administration, visual inspection of the skin and external genitalia, and the collection of urine, blood, oral cells, and penile skin samples If anogenital lesions are present at any of the clinic visits, they will be sampled as well.

Inclusion Criteria:

• Men between 18 and 70 years of age, living in Southern Florida, US; Sao Paulo, Brazil; or state of Morelos, Mexico.
• Participant has never been told that they have penile or anal cancer or genital warts.
• Willing to attend scheduled visits every 6 months in the next 4 years.

Exclusion Criteria:

• Prospective participants with symptoms of any STD (excluding HPV) during screening will not be eligible to participate in the study until the STD (Sexually Transmitted Disease) infection is gone.

1. Men ages 18-44; a pilot study group, ages 45-70;
2. residents of 3 sites - southern Florida, US, Sao Paulo, Brazil, or state of Morelos, Mexico
3. report no prior diagnosis of penile or anal cancers
4. have never been diagnosed with genital and anal warts
5. have not participated in a HPV vaccine study
6. report no prior diagnosis with acquired immune deficiency syndrome (AIDS) or human immunodeficiency virus (HIV)
7. report no current penile discharge or burning during urination
8. are not currently being treated for a sexually transmitted disease
9. have not been imprisoned or homeless during the last 6 months
10. have not been in drug treatment during the last 6 months
11. no plan to relocate in the next 4 years
12. willing to comply with 10 scheduled visits every 6 months for 4 years