Is Human Papillomavirus (HPV) a sexually transmitted infection (STI)?

Is HPV a Sexually Transmitted Infection?

Yes, HPV (Human Papillomavirus) is definitively a sexually transmitted infection and is, in fact, the most common STI in the United States and worldwide. 1, 2

Transmission Characteristics

HPV is primarily transmitted through sexual contact, specifically:

• Vaginal and anal intercourse are the most common routes of transmission 1
• Oral-genital contact can also transmit the virus 1
• Genital-to-genital contact without penetration can transmit HPV, though this is less common 1
• Skin-to-skin contact in genital areas allows transmission even when condoms are used, as areas not covered by condoms remain vulnerable 1

Epidemiology and Prevalence

The burden of HPV as an STI is substantial:

• Over 6 million new infections occur annually in the United States 1
• Approximately 20 million people (15% of the U.S. population) are currently infected 1
• 50-80% of sexually active individuals will acquire HPV at some point in their lifetime 1, 2
• The highest prevalence occurs in sexually active adolescents and young adults, with 27-46% of young women infected at any given time 1
• Most people acquire HPV shortly after becoming sexually active, with over 50% of college-age women infected within 4 years of first intercourse 1

Key Clinical Characteristics as an STI

Natural History

• Most infections (70-90%) clear spontaneously within 1-2 years without causing symptoms or health problems 1, 3
• The majority of infections are asymptomatic, meaning most infected individuals never know they have HPV 1
• Persistent infection with high-risk types can lead to cervical cancer, anal cancer, oropharyngeal cancer, and other anogenital cancers 1
• Low-risk types (HPV 6 and 11) cause 90% of genital warts 1

Important Counseling Points for Patients

When discussing HPV as an STI, the Centers for Disease Control and Prevention recommends conveying these messages:

• HPV infection does not indicate sexual infidelity in a relationship, as the virus can remain dormant for years before detection 1, 3
• Partners in long-term relationships typically share HPV, even without symptoms 1
• Even individuals with only one lifetime sexual partner can acquire HPV if that partner was infected 1
• The virus can be transmitted even when no visible signs or symptoms are present 1, 3

Prevention Strategies

As with other STIs, prevention focuses on:

• HPV vaccination before sexual debut is the most effective prevention strategy, with near 100% efficacy against vaccine-type infections 1, 4
• Consistent condom use reduces but does not eliminate transmission risk, as HPV can infect areas not covered by condoms 1, 3
• Limiting number of sexual partners reduces exposure risk 1
• Complete sexual abstinence is the only definitive method to avoid HPV infection 1

Common Pitfalls in Understanding HPV as an STI

• Do not assume visible symptoms are required for transmission—most HPV infections are completely asymptomatic 1
• Do not equate HPV detection with recent sexual activity—the infection can persist in a dormant state for years or decades 3
• Do not assume condoms provide complete protection—unlike some other STIs, HPV transmission can occur through skin-to-skin contact in areas not covered by condoms 1
• Do not conflate genital warts with cancer risk—the HPV types causing warts (6,11) are different from those causing cancer (16,18) 1