Papilloma Viral Infection

Human papillomavirus (HPV) is the most common viral infection spread through intimate contact, affecting most sexually active people at some point in their lives. While many infections clear on their own, some types can cause warts or lead to serious cancers years later.

Table of contents

• What is Human Papillomavirus
• Types of HPV
• How Common is HPV
• Symptoms and Health Problems
• How HPV Spreads
• Risk Factors
• Connection to Cancer
• Diagnosis and Testing
• Treatment Options
• Prevention and Vaccination

What is Human Papillomavirus

Human papillomavirus (HPV) is a common virus that can affect different parts of your body. It is a non-enveloped, double-stranded, circular DNA virus from the Papillomaviridae family^[4]. The virus enters the body through breaks in the skin or mucous membranes and infects cells at the surface layer^[4].

HPV affects the skin and can cause various types of growths. There are over 100 different types of HPV, and more than 180 subtypes have been identified^[1][5]. Many types cause warts on your hands, feet, and face. About 30 to 40 HPV types can affect your genital area, including your genitals, anus, mouth, and throat^[1][7].

Types of HPV

HPV types are grouped based on whether they put a person at risk for cancer. The virus types are often called “non-oncogenic” (wart-causing) or “oncogenic” (cancer-causing)^[3].

Low-risk HPV types do not cause cancer but can cause warts. HPV types 6 and 11 are the most common low-risk types. They cause more than 90% of genital warts^[12][3]. These same types also cause juvenile and adult recurrent respiratory papillomatosis, a condition where warts grow in the airways^[4].

High-risk HPV types can cause precancerous cell changes that may lead to cancer. HPV types 16 and 18 are the most dangerous high-risk types. They account for 66% of all cervical cancers and almost 90% of HPV-related cancers of the mouth, throat, or tonsils^[2][5]. Five additional high-risk types (31, 33, 45, 52, and 58) account for another 15% of cervical cancers^[12].

How Common is HPV

HPV is the most common viral sexually transmitted infection in the United States and worldwide^[1][7]. The infection is extremely widespread. More than 42 million Americans are infected with types of HPV that can cause disease. About 13 million Americans, including teenagers, become infected each year^[3].

Nearly everyone who is not vaccinated will get HPV at some point in their lives^[3]. Most people who are sexually active get HPV soon after they become sexually active^[12]. Roughly 14 million people get the infection each year in the United States alone^[1].

The good news is that most HPV infections do not cause health problems. Nine out of 10 HPV infections go away on their own within two years without any treatment^[3][5]. Most people with HPV never develop symptoms or health problems from it and never know they have been infected^[16].

Symptoms and Health Problems

HPV usually does not cause any symptoms. Most people who have it do not realize they are infected and do not have any problems^[11][19]. However, when HPV does not go away on its own, it can cause health problems.

The most visible sign of HPV infection is warts. Different types of HPV produce different kinds of warts:

• Genital warts appear as small bumps or groups of bumps in the genital area. Some appear flat, while others look like small cauliflower-like bumps or tiny stem-like bumps^[2]. In women, genital warts can appear on the vulva, near the anus, on the cervix, or in the vagina. In men, they appear on the penis, scrotum, or around the anus^[2]. Genital warts may appear weeks, months, or even years after infection with low-risk HPV^[1].
• Common warts appear as rough, raised bumps, usually on the hands and fingers^[2].
• Plantar warts are hard, grainy growths that usually appear on the heels or balls of the feet and may cause discomfort^[2].
• Flat warts are flat-topped, slightly raised sores that can appear anywhere on the body^[2].

Genital warts rarely cause pain but might itch or feel tender^[2]. High-risk forms of HPV often don’t cause symptoms until they’ve progressed to cancer^[1].

How HPV Spreads

HPV is spread through intimate skin-to-skin contact. You can get HPV by having vaginal, anal, or oral sex with someone who has the virus, even if they don’t have signs or symptoms^[1][3]. The virus is transmitted through close skin-to-skin touching during sex^[16].

A person with HPV can pass the infection to someone even when they have no visible signs or symptoms^[16]. You do not need to have penetrative sex to get HPV. The virus can spread through any skin-to-skin contact of the genital area^[7].

You can get HPV the first time you have sex. You do not have to have sexual contact with many people to get HPV^[11][16]. HPV can also spread from mother to baby during pregnancy, though this is less common^[5].

It is difficult to know when you first got HPV. You can develop symptoms years after having sex with someone who has the infection^[16]. The virus can lie dormant in your system for months or even many years before the emergence of genital warts or cell abnormalities^[7].

Risk Factors

Several factors increase your risk of getting HPV or developing health problems from the infection:

• Sexual activity, early age of first sexual intercourse, and number of sexual partners^[4]
• Smoking^[4]
• Use of oral contraceptives for more than 5 years^[4]
• Poor immune function or being immunosuppressed^[1]
• Exposure to radiation and UV light^[4]

People who are sexually active can get HPV. If you are sexually active, you can get HPV even if you have had sex with only one person^[16]. Individuals with persistent HPV infection and those who have multiple sexual partners are at very high risk for acquiring more HPV subtypes^[4].

Connection to Cancer

Persistent infection with high-risk HPV is the strongest risk factor for development of HPV-related precancers and cancers^[12]. It is important to understand that HPV alone does not cause cancer but requires additional triggers like smoking, folate deficiency, UV light exposure, immunosuppression, and pregnancy^[4].

HPV has been linked to several types of cancer. Nearly all cervical cancer is due to HPV, with types 16 and 18 accounting for 70% of all cases^[1]. Between 60% and 90% of other HPV-related cancers are also linked to the virus^[5].

Cancers linked to high-risk HPV include:

• Cervical cancer
• Anal cancer
• Penile cancer
• Vulvar cancer
• Vaginal cancer
• Cancers at the back of the throat, called oropharyngeal cancer, including the base of the tongue and tonsils^[2][11]

Every year in the United States, HPV causes about 36,000 cases of cancer in both men and women^[3]. An estimated 34,800 new HPV-related cancers occurred every year during 2012–2016^[12].

The process from HPV infection to cancer takes time. The virus itself doesn’t turn into cancer. High-risk strains of HPV infection can cause precancerous cell changes. These cell changes can eventually lead to cancer if they aren’t managed, but this process can take years or decades to happen^[1]. Screenings, like Pap smears, can help detect these precancerous cells before they turn to cancer^[1].

Diagnosis and Testing

A healthcare professional might be able to diagnose HPV infection by looking at warts^[10]. Genital warts can usually be diagnosed by visual examination^[16].

There is no blood test for HPV^[11]. However, it is possible to test for some types of HPV using other methods. As of recent years, the primary test for cervical screening is an HPV test done using a vaginal swab or cervical sample^[7].

For women, cervical cancer screening tests can find changes in the cervix that might lead to cancer. Screening may include:

• Pap tests (sometimes called a Pap smear): A sample of cells from the cervix or vagina goes to a lab to look for changes that can lead to cancer^[10]
• HPV tests: Testing cells from the cervix can identify the DNA of the types of HPV that are linked to genital cancers. This test is recommended for women 30 and older^[10]
• Colposcopy: A procedure to check for abnormal cells if other tests show concerning results^[1]

If an HPV test is positive, it means a person has one of the high-risk types of HPV. There will usually be further testing in discussion with your healthcare provider^[7]. If an HPV test is negative, it means that the high-risk types of HPV being tested for were not detectable^[7].

HPV testing is not generally part of routine sexual health check-ups for males or females outside of cervical screening. This is partly because in some people the virus is “hibernating” at levels that are not detectable by testing^[7].

Routine screening for women aged 21 to 65 years old can prevent cervical cancer. Getting regular Pap smears to screen for cervical cancer is important, usually beginning at age 21^[1][16].

Treatment Options

There is no treatment for the HPV infection itself^[11][19]. Most HPV infections do not cause any problems and are cleared by your body within 2 years^[11][19]. An HPV infection itself cannot be treated, but doctors can treat the health problems that HPV causes^[8].

Only genital warts and high-grade cell abnormalities are treated. There is no treatment for HPV that is “silent,” meaning it has no symptoms^[15].

Treatment for genital warts: If warts don’t show symptoms, treatment is optional. Warts often go away without treatment, particularly in children^[13]. However, if untreated, genital warts may spontaneously resolve, remain unchanged, or increase in size or number^[13]. Some people may choose to wait for spontaneous resolution instead of undergoing treatment^[13].

Available treatments for genital warts include:

• Medicines applied directly to warts, such as salicylic acid (for common warts, not genital), imiquimod, podofilox, or trichloroacetic acid^[10][14]
• Freezing with liquid nitrogen, called cryotherapy^[10]
• Burning or surgical removal^[10][14]

Medicines may need to be used many times before warts go away^[10]. Most patients require multiple treatments over weeks to months^[13]. Recurrence is noted in 20–30% of patients regardless of the chosen therapy^[13]. Genital warts can come back even after treatment^[14].

Treatment for precancerous cell changes: If HPV causes cell changes in the cervix or other areas, treatments may include medicines applied to the affected area or various surgical procedures^[8].

Treatment for HPV-related cancers: People who have HPV-related cancers usually get the same types of treatment as people who have cancers that HPV does not cause. An exception is for people who have certain oral and throat cancers, who may have different treatment options^[8].

Prevention and Vaccination

You cannot fully protect yourself against HPV, but there are several things you can do to lower your chances of getting HPV and avoid the health problems it can cause^[11][16].

HPV vaccine: The most reliable way to prevent HPV infection is vaccination. The HPV vaccine is safe and effective and can protect against diseases (including cancers) caused by HPV when given in the recommended age groups^[16].

Three HPV vaccines have been licensed in the United States. Currently, only the 9-valent vaccine (9vHPV), called Gardasil 9, is available. It targets HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58^[12]. This vaccine protects against the types of HPV that cause most cases of genital warts and cervical cancer, as well as some other cancers^[11].

Vaccination recommendations include:

• Routine HPV vaccination for all adolescents at age 11 or 12 years, though it can start as early as age 9^[12]
• A 2-dose vaccine schedule (at 0 and 6–12 months apart) for people who start vaccination before their 15th birthday^[12]
• A 3-dose vaccine schedule (at 0, 1–2, and 6 months apart) for people who start on or after their 15th birthday and for immunocompromised people regardless of age^[12]
• Catch-up vaccination through age 26 years for those not vaccinated previously^[12]

The HPV vaccine series is most effective when given before a person is exposed to the virus^[3]. The vaccines provide the most protection when people get them before they become sexually active^[8].

Vaccines have been shown to be very safe, with robust data from more than 120 million doses distributed in the United States^[12]. Studies have also demonstrated reductions in genital warts and the HPV types contained within the vaccine^[12].

Women who have received the HPV vaccine should still continue routine cervical cancer screening^[12].

Other prevention methods:

• Use condoms correctly every time you have sex. This can lower your chances of getting HPV, but HPV can infect areas the condom does not cover, so condoms may not fully protect against getting HPV^[16][11]
• Be in a mutually monogamous relationship or have sex only with someone who only has sex with you^[16]
• If you or your partner have genital warts, stop having sex until you no longer have warts. We do not know how long a person is able to spread HPV after warts go away^[16]
• The most reliable way to avoid infection is to not have anal, vaginal, or oral sex^[8]