Human papillomavirus (HPV) is a common infection that causes abnormal growth of tissue on the skin of the body. There are more than 100 types of HPV, some of which cause common warts found on areas like hands and feet. However, over 30 types are usually sexually transmitted and are known as genital human papillomavirus. Genital HPV is the most common sexually transmitted virus, according to the Centers for Disease Control and Prevention (CDC).
HPV should not be confused with genital herpes, another STD. Both are caused by viruses, but HPV may cause warts while herpes may cause blisters or sores. Both diseases often do not cause any symptoms. There is no cure for either disease, but in most cases, the body’s immune system will fight off HPV. With herpes, the virus lies dormant in the body and can cause future outbreaks. Unlike herpes, certain types of HPV cause cervical dysplasia (precancerous changes in the cervix) in a small percentage of women.
HPV is categorized as low-risk (which may cause genital warts) or high-risk (which can lead to precancerous changes in the cervix if untreated). Infection with certain high risk forms of HPV is a major cause of cervical cancer and is associated with other genital cancers (e.g., vulvular, anal).
Most sexually active people have been exposed to HPV at some point in their lives. The virus is transmitted by skin-to-skin contact with an infected person, usually through vaginal, oral or anal sex. Most people with HPV do not experience symptoms and do not know they are infected.
HPV is usually detected during a gynecological exam with a Pap smear, a test that detects changes on the cervix. Physicians may also perform an HPV test that identifies high-risk types of HPV.
In most cases, the body’s immune system will successfully fight off the infection. However, there are several treatments available when HPV causes warts, such as creams, cryotherapy and electrocautery.
In June 2006, the U.S. Food and Drug Administration (FDA) approved the first HPV vaccine. The vaccine offers protection against two types of HPV that cause the majority of cervical cancers. The federal Advisory Committee on Immunization Practices (ACIP) recommends the vaccine series be given to 11- and 12-year-old girls but it adds that it could be started as early as age nine if necessary. Ideally, the vaccine should be given before females become sexually active. Their recommendations also include giving the vaccine to young women ages 13 to 25 years because of its protective benefits. The HPV vaccine is expected to be available in the fall of 2006. It is considered to be the best prevention method of genital HPV for females.
Practicing safe-sex habits can also prevent infection with genital HPV. Limiting the number of sexual partners and avoiding genital contact with individuals who have had multiple sex partners reduces the risk of infection. In addition, condoms provide some protection but transmission is possible from areas not covered by the condom.
About human papillomavirus
Human papillomavirus (HPV) is a common infection that affects skin and mucous membranes. The term HPV refers to a group of viruses. They are called papillomaviruses because certain types may cause warts, or papillomas.
The term HPV actually refers to a group of viruses. According to the Centers for Disease Control and Prevention (CDC), about 100 types of HPV have been identified, over 30 of which are passed through sexual activity. The type of HPV that infects the genitals is called genital HPV, which is a sexually transmitted disease(STD). The CDC estimates that at least 50 percent of all sexually active people will develop HPV at some time in their lives.
HPV is not genital herpes, another STD. Both are caused by a virus, but HPV can cause genital warts (known as condylomata acuminatum) and herpes can cause blisters or sores. Certain types of HPV may also cause cervical dysplasia (precancerous changes in the cervix). In both cases, the patient may experience no symptoms. There is no cure for either disease, but in most cases of HPV, the body’s immune system fights off the infection, and is able to eradicate the virus from the system. With herpes, the virus lays dormant in the body and can recur.
HPV is the most common sexually transmitted disease in the United States. According to the CDC, approximately 20 million people are infected with HPV. About 6.2 million Americans get a new genital HPV infection each year, but the vast majority of people are unaware of it. The virus typically causes no symptoms or health problems in the majority of cases, according to the National Women’s Health Resource Center.
Some HPV types cause warts in areas such as hands and feet. A few types cause genital warts (single or multiple growths or bumps that appear in the genital area and can be cauliflower shaped). Certain types of genital HPV, known as high-risk HPV, are a major risk factor for cervical cancer. Several studies have suggested that HPV infection plays a role in cancers of the anus, vulva, vagina and penis, as well as some cancers of the oropharynx (the middle part of the throat that includes the soft palate, bases of the tongue and tonsils).
Almost all cases of precancerous changes in the cervix are caused by HPV. An estimated 10,000 cases of invasive cervical cancer will be diagnosed in the United States in 2006, according to the American Cancer Society and nearly 4,000 women will die from the disease. Although most people are exposed to the cell-changing types of HPV at some point in their lives, not everyone will develop abnormal cell changes.
Most women who have had genital warts in the past (but no longer have them) will not experience problems during pregnancy or childbirth. If genital warts develop during pregnancy, they may grow and/or bleed. Genital warts that grow larger during pregnancy can make it difficult for a woman to urinate. Genital warts during pregnancy may require removal by a physician. In addition, warts may very rarely block the birth canal, requiring the physician to perform a Caesarean section to deliver the baby.
In rare instances, a pregnant woman may pass HPV to her baby. As a result, warts may develop in the baby’s throat (laryngeal papillomatosis). This is a potentially life-threatening condition that requires repeated laser surgery to prevent blockage of the breathing passages. Fortunately, this is extremely rare, occurring in only one per 30,000 cases of HPV infected mothers.
It is unknown when a person with HPV can transmit the virus, how long a person with HPV is able to transmit it and why some people exposed to HPV gets warts while others do not.
Types and differences of human papillomavirus
Human papillomavirus (HPV) is a group of viruses that cause common skin warts. Papillomas are warts. Some types of HPV are sexually transmitted. Of those types, there are two categories, low-risk and high-risk:
- Low-risk. Can cause genital warts, but do not cause precancerous changes on the cervix. Most people with low-risk types of HPV do not know they are infected because they do not get warts. Warts can form weeks, months or years after sexual contact with a person infected with HPV. Genital warts are most commonly associated with HPV types 6 and 11.
- High-risk. Can cause changes that may lead to precancerous changes in the cervix if untreated. Having high-risk HPV is not the same as having cervical cancer. Usually, high-risk HPV types cause no health problems and disappear on their own. High-risk types that persist, however, are a major risk factor for cervical cancer. Sexually transmitted, high-risk HPVs include types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 69 and possibly a few others.
Risk factors and causes of HPV
Human papillomavirus (HPV) is transmitted by skin-to-skin contact with an infected person. Transmission usually occurs during vaginal, oral or anal sex. Transmission can occur even if the infected person is not experiencing warts or other symptoms.
Some research suggests that genital HPV can be transmitted through inanimate objects like towels or underwear, but more research must be conducted to fully understand these modes of transmission.
Risk factors for HPV include:
- Having multiple sex partners. Having sex with more than one person increases the risk of being infected with HPV.
- Having sex with a high-risk partner. Having sex with a person who has multiple sex partners or is known to be infected with HPV increases the risk of infection.
- Smoking cigarettes. If you have been exposed to HPV and smoke, the risk of developing symptoms increases. The risk of developing precancerous or cancerous conditions also increases.
- Having an impaired immune system. People with weakened immune systems, such as those with AIDS or certain other conditions, have an increased risk of acquiring HPV.
Signs and symptoms of human papillomavirus
Most people infected with human papillomavirus (HPV) do not know they are infected because the virus itself does not cause symptoms.
With certain forms of HPV, some people develop genital warts (single or multiple growths or bumps that appear in the genital area). Genital warts usually appear as soft, moist, pink or flesh-colored swellings. They can be raised or flat, single or multiple, small or large and sometimes appear in clusters that resemble the shape of cauliflower. Genital warts can appear within weeks or months of being infected with HPV.
Genital warts can grow inside and around the outside of the vagina, on the vulva (opening to the vagina), cervix, groin and in or around the anus.
In men, genital warts can grow on the penis, scrotum, thigh, and groin, or in or around the anus. While very rare, genital warts can grow in the mouth or throat of a person who has had oral sex with an HPV infected person.
Genital warts usually do not produce symptoms, but when symptoms are present, they may include itching and pain. In addition, the wart may be crumbly (friable).
Diagnosis methods for human papillomavirus
Human papillomavirus (HPV) is usually detected during a routine gynecological examination during which a physician reviews a patient’s medical history and does a pelvic examination. HPV is sometimes diagnosed by the visual identification of genital warts in or around the vagina, on the vulva (opening to the vagina), cervix, groin, or in or around the anus.
It may also be diagnosed with a Pap smear, which is a screening test used to detect the presence of precancerous and cancerous cells. A Pap smear can reveal changes on the cervix caused by HPV infection. HPV is most often diagnosed with a Pap smear.
For the Pap smear, the physician inserts a speculum (an instrument for examination of canals) into the vagina to observe the cervix. Then, the physician removes cells from the cervix using a small spatula and a brush or cotton swab. The cells are placed on a glass slide or into a fluid-filled bottle and sent to a laboratory for examination.
However, it is possible that the results of a Pap smear can be normal even though the patient is infected with HPV. Changes on the cervix detected through a Pap smear may not appear immediately after infection or may never appear at all. Similarly, an abnormal Pap test does not necessarily indicate the presence of HPV infection.
If the warts are small or cannot be identified by visual inspection, a physician may perform a colposcopy (a test that uses a colposcope, an instrument with magnifying lenses, to view the cervix and vagina). The physician may also apply a vinegar solution which makes abnormal tissue turn white. This test is not painful and helps the physician identify warts or other abnormal tissue. If abnormalities are detected, a sample of tissue may be removed for analysis. A biopsy may be performed on the abnormal tissue to determine the presence or absence of precancerous changes.
For women over age 30 or those with mild Pap smear abnormalities, physicians may do an HPV test. This is a DNA test that detects most of the high-risk types of HPV. It is also a test for cervical cancer. Similar to the Pap test, the HPV test involves using a small soft brush to collect cells from the cervix. The results of HPV DNA testing can help physicians determine whether further tests or treatment is necessary. It should be noted that the HPV DNA test can be performed from a liquid based pap smear or as a separate swab.
No HPV tests are available for men.
Treatment and prevention of HPV
There is no cure for human papillomavirus (HPV) but most people with HPV infections do not require treatment because the body rids itself of the virus on its own. Less than 1 percent of patients with HPV infection develop problems, such as genital warts, according to the National Women’s Health Resource Center.
There are several treatments available for genital warts, which are caused by HPV infection. Among factors that are considered in the treatment of genital warts include:
- Size and location of warts
- Number of warts
- Patient preference
- Treatment cost
- Adverse side effects
The goal of treatment is usually to remove unsightly warts and alleviate bothersome symptoms.
Some treatments are administered by patients at home and others are performed in a physician’s office. Several creams and gels are available by prescription. These are applied by the patient and are safe and easy to use. There are two different types of topical treatments:
- Antimitotic agents (drugs that inhibit cell growth by stopping cell division). This gel or solution is applied to the wart. It works by destroying the skin of the wart.
- Biological response modifier. This cream is used for treatment of external genital warts and perianal warts (warts occurring in or around the anus). It stimulates the immune system to fight off the warts.
Over-the-counter medications to treat common warts found on hands and feet should not be used to treat genital warts.
Procedures performed in a physician’s office to treat genital warts include:
- Cryotherapy. During this procedure, the wart is frozen with liquid nitrogen. Freezing causes a blister to form around the wart. Then, dead tissue sloughs off in about a week. This procedure causes minimal pain and must be performed by a physician. Cryotherapy performed on the cervix can cause a profuse watery discharge for approximately one month following the procedure.
- Chemicals and acids. There are several chemicals and acids that are applied to the surface of the wart by a physician. The chemical or acid causes a blister to form which lifts the wart off the skin so the physician can remove it. The chemical or acid does not usually cause pain, but some pain may be experienced from the resulting blister.
- Electrocautery (burning off warts with an electrical current). Genital warts are removed by burning them with a low-voltage electrified probe. This is performed in a physician’s office with local anesthesia.
- Minor surgery to remove warts. This involves cutting away the genital wart. This is performed in a physician’s office with local anesthesia.
- Laser surgery (using an intense light to destroy warts). This is typically used to remove larger or more extensive genital warts, particularly those that have not responded to other treatments. This is performed in a physician’s office with local anesthesia.
- Interferon. A human protein known to stimulate the immune system and fight viruses is injected directly into the wart. Though it is as effective as other treatments, it is chosen less frequently because of the inconvenient method of administration, frequent office visits and incidence of side effects.
Although in many cases the immune system rids the body of HPV, the virus can travel to the lower level of tissue where it remains. This can cause genital warts to come back. It is recommended that patients watch for recurrences, which most frequently occur during the first three months after treatment.
HPV is a common and manageable condition. However, living with the condition can be distressing and inconvenient. The period after diagnosis may be an especially emotional time, with many people experiencing feelings of shame and fear. As a result, people with HPV may benefit from seeking counseling or attending a support group.
In June 2006, the U.S. Food and Drug Administration (FDA) approved the first vaccine (Gardasil) for HPV. In clinical studies, the vaccine was highly effective in preventing persistent infection with two high-risk viruses, HPV 16 and 18, which cause over 70 percent of cervical cancers. The vaccine also protects against HPV types 6 and 11, which cause approximately 90 percent of genital warts.
The HPV vaccine is a recombinant vaccine, meaning that it contains no live virus. The virus in the vaccine is a genetically engineered protein and cannot cause the HPV infection. It is administered in a series of three injections into muscle tissue over a six-month period.
The CDC’s Advisory Committee on Immunization Practices (ACIP) has recommended that the vaccine be routinely given to girls aged 11 and 12. However, it can be given to girls as young as nine years old at the discretion of the physician or healthcare provider. The HPV vaccine optimally should be given before females become sexually active.
Although women who have not be exposed to HPV gain full benefits of the vaccine, it offers protective benefits to women who have been sexually active and may have been exposed to HPV. For that reason, the ACIP recommends that females between the ages of 13 and 26 also receive the vaccine.
The HPV vaccine has not been approved for use in males but clinical studies are continuing to determine its effectiveness in men. In addition, women who are allergic to yeast should not receive the vaccine. Additional studies are also being conducted to monitor pregnancy outcomes of women who have received the vaccine and the long-term effectiveness of the drug.
Women who receive the vaccine should continue to follow other prevention strategies, such as regular Pap tests and gynecological examinations. The vaccine does not protect against other STDs and women should use methods to protect themselves against the diseases.
For those who are sexually active, prevention can be difficult because most people do not know they are infected. However, there are a number of ways to reduce the risk of infection, including:
- Practicing abstinence. Refraining from vaginal, oral and anal sex with anyone.
- Being monogamous. Having a long-term relationship with an uninfected partner may prevent infection. However, the virus is so common that having sex with only one lifetime partner does not guarantee prevention of HPV infection.
- Reducing the number of sexual partners. For those not in a long-term relationship, reducing the number of sexual partners will decrease the risk of becoming infected.
- Using a condom. Latex condoms can provide some protection if they cover the area of HPV infection. New studies have indicated that regular, correct condom use can protect women from HPV infection and cervical dysplasia.
- Using a dental dam (square piece of latex placed over the vaginal or anal opening during oral sex). Using a dental dam during oral sex can reduce the risk of infection.
- Avoiding sex with a partner with genital warts. A person with visible signs of genital warts should abstain from sex until the warts are removed. This reduces the risk of spreading HPV.
- Getting regular Pap smears. While these tests do not prevent the spread of HPV, they can detect abnormal cell changes, which can lead to cervical cancer or other complications.
Spermicidal foams, creams, jellies (and condoms coated with spermicide) have not been proven to be effective in preventing the spread of HPV. In fact, they may cause microscopic abrasions that make it easier to contract a sexually transmitted disease. Spermicides are not recommended for routine use.
Ongoing research for human papillomavirus
Researchers at the National Cancer Institute and other locations are studying the human papillomavirus (HPV) to determine how it causes abnormal cell growth and how it can be prevented.
Scientists are developing new laboratory tests that will identify the types of HPVs that cause precancerous changes in the cervix. The goal of the research is to develop a test that is simple and can be widely used.
A second HPV vaccine, Cervarix, is being tested in clinical trials but has not yet been approved by the FDA. This vaccine also targets the high-risk viruses, HPV 16 and 18, which account for the majority of the cervical cancer cases.
Questions for your doctor regarding HPV
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about human papillomavirus (HPV):
- What is HPV?
- How do I know if I have an HPV infection?
- How often should I get a Pap smear?
- What happens if I have an abnormal Pap smear?
- Is it possible to have HPV even if my Pap test was normal?
- Should I have an HPV test?
- What type of HPV do I have? How does it impact my risk of developing cervical cancer?
- Should I receive the HPV vaccine?
- When will the vaccine be available?
- What are my treatment options for HPV infection and genital warts?
- How soon will I see improvement from my treatment?
- How long should I abstain from sexual relations if I have genital warts?
- What are the chances that I will develop another HPV infection?
- How does HPV affect pregnancy or my fertility?