Human Papilloma virus
What is Genital HPV Infection?
Genital human papillomavirus (also called HPV) is the most common sexually transmitted disease or infection (STD). There are more than 40 HPV types that can infect the genital areas of males and females. These HPV types can also infect the mouth and throat. Most people do not even know that they are having HPV infection. HPV is not the same as herpes or HIV (the virus that causes AIDS). These are all viruses that can be passed on during sex, but they cause different symptoms and health problems.
Genital warts (HPV) facts
- Genital warts are caused by infection with a subgroup of the human papillomaviruses (HPVs).
- Another subgroup of the HPVs that infect the anogenital tract can lead to precancerous changes in the uterine cervix and cause cervical cancer.
- HPV infection is now considered to be the most common sexually-transmitted infection (sexually transmitted disease, STD) in the U.S., and it is believed that at least 75% of the reproductive-age population has been infected with sexually-transmitted HPV at some point in life.
- HPV infection is common and does not usually lead to the development of warts, cancers, or even symptoms.
- HPV infection of the genital tract is transmitted through sexual contact, although non-sexual transmission is also possible.
- In many cases genital warts do not cause any symptoms, but they are sometimes associated with itching, burning, or tenderness.
- Condom use seems to decrease the risk of transmission of HPV during sexual activity but does not completely prevent HPV infection.
What is human papillomaviruses (HPVs)?
HPV lives in the body’s epithelial cells. These are flat and thin cells found on the skin’s surface and also on the surface of the vagina, anus, vulva, cervix, penis head, mouth, and throat.
There are over 100 types of human papillomaviruses (HPVs) that infect humans. Of the 100 HPV types, about 60 types cause warts on areas such as the hands or feet. More than 40 types can infect the genital tract and anus (anogenital tract) of men and women and cause genital warts known as condylomata acuminata or venereal warts. A subgroup of the HPVs that infect the anogenital tract can lead to precancerous changes in the uterine cervix and cause uterine, cervical cancer. HPV infection also is associated with the development of other anogenital cancers in women. The HPV types that cause cervical cancer also have been linked with both anal and penile cancer in men as well as a subgroup of head and neck cancers in both women and men. Genital warts and HPV infection are transmitted primarily by sexual intimacy, and the risk of infection increases as the number of sexual partners increase.
The most common HPV types that infect the anogenital tract are HPV types 6, 11, 16, and 18 (HPV-6, HPV-11, HPV-16, and HPV-18). Other HPV types can also cause the anogenital tract infection. Among these, HPV-6 and HPV-11 are most commonly associated with benign lesions such as genital warts and mild dysplasia of the cervix (potentially precancerous changes in the appearance of cervical cells under a microscope) and are termed “low-risk” HPV types. In contrast, HPV-16 and HPV-18 are the types found in the majority of cervical and anogenital cancers as well as severe dysplasia of the cervix. These belong to the so-called “high-risk” group of HPVs. These are responsible for about 70% of cervical cancers in women. Other high-risk HPV viruses include 31, 35, 39, 45, 51, 52, 58, and a few others.
Other, different HPV types infect the skin and cause common warts elsewhere on the body. Some types of HPVs (for example, HPV 5 and 8) frequently cause skin cancers in people who have a condition known as epidermodysplasia verruciformis.
How common is HPV infection?
HPV infection is now considered to be the most common sexually-transmitted infection (sexually transmitted disease, STD) in the U.S., and it is believed that at least 75% of the reproductive-age population has been infected with sexually-transmitted HPV at some point in life. It is believed that over 6 million people become infected with HPV every year in the US, and approximately 50% of those infected are between the ages of 15 and 25.
You’re more likely to get HPV if you:
- Have sex at an early age
- Have many sex partners
- Have a sex partner who has had multiple partners
While many people think HPV is mostly a problem for teens or young adults, HPV can infect men and women of any age. In fact, the latest statistics from the CDC found that:
- 19% of women 50 to 59 were infected with HPV virus
- 27% of women 20 to 24 were infected with HPV virus
- 45% of women 14 to 19 were infected with HPV virus
HPV infection is common and does not usually lead to the development of warts, cancers, or even symptoms. In fact, the majority of people infected with HPV have no symptoms or lesions at all. Determination of whether or not a person is infected with HPV involves tests that identify the genetic material (DNA) of the virus. Furthermore, it has not been definitely established whether the immune system is able to permanently clear the body of an HPV infection. In many cases, a person will test positive for HPV infection and then have negative HPV tests for months to years, only to have a positive test result at a later time. It is presently unclear if this is due to a latent (continuing but hidden) viral infection or if the person has become re-infected with the virus.
Asymptomatic people infected with HPVs (those without HPV induced warts or lesions) are still able to spread the infections to others through sexual contact.
It is important to note that in the U.S. and other developed countries, screening and early treatment of precancerous changes of the cervix have dramatically reduced the incidence of cervical cancer. In developing countries lacking the medical infrastructure or financial means to implement a screening system, the incidence of cervical cancer resulting from HPV infection is much higher. In fact, cervical cancer develops in around 500,000 women each year worldwide, and, in many countries, it is the most common cancer to kill women.
How do people get HPV?
HPV is passed on through genital contact, most often during vaginal and anal sex. HPV may also be passed on during oral sex and genital-to-genital contact. HPV can be passed on between same sex partners, even when the infected partner has no symptoms.
A person can have HPV even if years have passed since he or she had sexual contact with an infected person. Most infected persons do not realize they are infected or that they are passing the virus on to a sex partner. It is also possible to get more than one type of HPV.
Very rarely, a pregnant woman with genital HPV can pass HPV to her baby during delivery. In these cases, the child can develop Recurrent Respiratory Papillomatosis (RRP), a rare condition in which warts grow in the throat. In children, this is also referred to as juvenile-onset Recurrent Respiratory Papillomatosis (JORRP).
What are the signs, symptoms and potential health consequences of HPV?
Most people with HPV do not develop symptoms or health problems from it. In 90% of cases, the body’s immune system clears HPV naturally within two years. But there is no way to know which people who get HPV will go on to develop cancer or other health problems.
- Sometimes, certain types of HPV can cause genital warts in males and females. Rarely, these types can also cause warts in the throat — a condition called recurrent respiratory papillomatosis or RRP.
- Other HPV types can cause normal cells in the body to turn abnormal, and might lead to cancer over time. These HPV types can cause cervical cancer and other, less common cancers, including cancers of the vulva, vagina, penis, anus, and head and neck (tongue, tonsils and throat) .
- The types of HPV that can cause genital warts are not the same as the types that can cause cancer.
How is HPV infection diagnosed?
HPV sometimes can be suspected by changes that appear on a Pap smear, since pap smears identify infected abnormal cells that may be precursors to cancer. While HPV infection can lead to precancerous changes in the cervix that are recognized on the Pap smear, the Pap smear itself cannot definitely establish the diagnosis of HPV infection, unless special testing is carried out on the material obtained from the Pap smear. When there is an abnormal Pap smear, the doctor often will do advanced testing on the material to determine if, and which kind, of HPV may be present. HPV also can be detected if a biopsy from a genital wart or from the uterine cervix is sent to the laboratory for analysis.
Is there a DNA test for types of HPV infection?
In 2009, the U.S. FDA approved the first DNA tests for diagnosis of the common cancer-causing HPV types in cervical samples. Two tests known as Cervista HPV 16/18 and Cervista HPV HR are used to diagnose the presence of DNA from the two most common HPV types associated with cancer, HPV 16 and 18, and all “high risk” or cancer-associated HPV types, respectively. These tests do not replace standard Pap smear testing or clinical examination and are used in combination with traditional screening methods to help estimate a woman’s risk and aid in management decisions
How are genital warts diagnosed?
Genital warts are quite common. Approximately 500,000 new cases of genital warts are diagnosed each year in the U.S. A typical appearance of a genital wart may prompt the physician to treat warts without further testing, especially in someone who has had previous history of genital warts. Genital warts usually appear as small, fleshy, raised bumps, but they sometimes can be extensive and have a cauliflower-like appearance. They may occur on any sexually-exposed area. Over 90% of genital warts are caused by HPV-6 and HPV-11, the so-called “low risk” HPV types.
Treatment of HPV:
External genital warts
There is no cure or treatment that can eradicate HPV infection, so the only currently possible treatment is to remove the lesions caused by the virus. Unfortunately, even removal of the warts does not necessarily prevent the spread of the virus, and genital warts frequently recur. None of the available treatment options is ideal or clearly superior to others.
- A treatment that can be administered by the patient is a 0.5% solution or gel of podofilox (Condylox). The medication is applied to the warts twice daily for 3 days followed by 4 days without treatment. Treatment should be continued up to 3-4 weeks or until the lesions are gone. Podofilox may also be applied every other day for a total of three weeks.
- Alternatively, a 5% cream of imiquimod (Aldara, a substance that stimulates the body’s production of cytokines, chemicals that direct and strengthen the immune response) is applied by the patient three times a week at bedtime, and then washed off with mild soap and water 6-10 hours later. The applications are repeated for up to 16 weeks or until the lesions are gone.
- Only an experienced physician can perform some of the treatments for genital warts. These include, for example, placing a small amount of a 10%-25% solution of podophyllin resin on the lesions, and then, after a period of hours, washing off the podophyllin. The treatments are repeated weekly until the genital warts are gone.
- An 80%-90% solution of trichloroacetic acid (TCA) or tetrachloride acid (BCA) can also be applied weekly by a physician to the lesions. Injection of 5-flurouracil epinephrine gel into the lesions has also been shown to be effective in treating genital warts.
- Interferon alpha, a substance that stimulates the body’s immune response, has also been used in the treatment of genital warts. Treatment regimens involve injections of interferon into the lesion every other day over a period of 8 to 12 weeks.
- Alternative methods include cryotherapy (freezing the genital warts with liquid nitrogen) every 1 to 2 weeks, surgical removal of the lesions, or laser surgery. Laser surgery and surgical excision both require a local or general anesthesia, depending upon the extent of the lesions.
What are the potential health problems of HPV?
Genital warts usually appear as a small bump or groups of bumps in the genital area. They can be small or large, raised or flat, or shaped like a cauliflower. Health care providers can diagnose warts by looking at the genital area. Warts can appear within weeks or months after sexual contact with an infected partner, even if the infected partner has no signs of genital warts. If left untreated, genital warts might disappear, remain unchanged, or increase in size or number. Warts will not turn into cancer.
Cervical cancer usually does not have symptoms until it is quite advanced, very serious and hard to treat. For this reason, it is important for women to get regular screening for cervical cancer (pap smear). Screening tests can find early signs of disease so that problems can be treated early, before they ever turn into cancer.
Other HPV related cancers might not have signs or symptoms until they are advanced and hard to treat. These include cancers of the vulva, vagina, penis, anus, and oropharynx (cancers of the back of the throat, including the base of the tongue and tonsils).
Recurrent respiratory papillomatosis (RRP) causes warts to grow in the throat. It can sometimes block the airway, causing a hoarse voice or troubled breathing. Although rare, RRP can occur among adults and children.
Prevention of HPV:
There are several ways that people can lower their chances of getting HPV:
Vaccines against HPV:
Vaccines can protect males and females against some of the most common types of HPV. This is the first vaccine to be developed against a known risk factor for the development of a cancer.HPV vaccines are given in three doses over six months. It is important to get all three doses to get the best protection. The vaccines are most effective when given before a person’s first sexual contact, when he or she could be exposed to HPV.
- Girls and women: Two vaccines (Cervarix and Gardasil) are available to protect females against the types of HPV that cause most cervical cancers. One of these vaccines (Gardasil) also protects against most genital warts. Gardasil has also been shown to protect against anal, vaginal and vulvar cancers. Both vaccines are recommended for 11 and 12 year-old girls, and for females 13 through 26 years of age, who did not get any or all of the doses when they were younger.
- Boys and men: One vaccine (Gardasil) protects males against most genital warts and anal cancers. This vaccine is recommended for boys aged 11 or 12 years, and for males aged 13 through 21 years of age, who did not get any or all of the three recommended doses when they were younger. Young men, 22 through 26 years of age, may get the vaccine.The vaccine is also recommended for men who have sex with men (MSM) and immunocompromised males through age 26 years, who did not get any or all of the doses when they were younger.
For those who choose to be sexually active, condoms may lower the risk of HPV infection. To be most effective, they should be used with every sex act, from start to finish. Condoms may also lower the risk of developing HPV-related diseases, such as genital warts and cervical cancer. But HPV can infect areas that are not covered by a condom – so condoms may not fully protect against HPV.
People can also lower their chances of getting HPV by being in a faithful relationship with one partner; limiting their number of sex partners; and being with a partner who has had no or few prior sex partners. But even people with only one lifetime sex partner can get HPV. And it may not be possible to determine if a partner who has been sexually active in the past is currently infected. Not having sex is the only sure way to avoid HPV.
How can people prevent HPV-related diseases?
There are ways to prevent the possible health effects of HPV, including two common problems: genital warts and cervical cancer.
- Preventing Genital Warts: One vaccine (Gardasil) protects against most genital warts in men and women (see above).
- Preventing Cervical Cancer: Two vaccines (Cervarix and Gardasil) protect against most cervical cancers in women (see above). Cervical cancer can also be prevented with routine cervical cancer screening (Pap test) and follow-up of abnormal results. The Pap test can find abnormal cells on the cervix so that they can be removed before cancer develops. Abnormal cells often become normal over time, but can sometimes turn into cancer. These cells can usually be treated, depending on their severity and on the woman’s age, past medical history, and other test results. An HPV DNA test, which can find certain HPV types on a woman’s cervix, may also be used with a Pap test in certain cases. Even women who were vaccinated when they were younger need regular cervical cancer screening because the vaccines do not protect against all cervical cancers.
- Preventing Anal and Penile Cancers: One vaccine (Gardasil) protects against most anal cancers. There is no routinely recommended screening test for anal or penile cancer because more information is still needed to find out if such tests can be effective. There are no data on efficacy of the vaccine to prevent cancers of the penis, but most HPV-related cancers of the penis are caused by the HPV types prevented by the vaccines.
- Preventing Cancers of the Oropharynx (also called oropharyngeal cancer; cancers of the back of the throat, including the base of the tongue and tonsils): There is no approved test to find early signs of oropharyngeal cancer because more information is still needed to find out if such tests can be effective. There are no data on efficacy of the vaccine to prevent cancers of the oropharynx but most HPV-related cancers of the oropharynx are caused by the HPV types prevented by the vaccines.
- Preventing Juvenile-Onset Recurrent Respiratory Papillomatosis (JORRP): Cesarean (“C-section”) delivery is not recommended for women with genital warts to prevent JORRP in their babies. This is because it is not clear that cesarean delivery prevents JORRP in infants and children. There are no data on efficacy of the vaccine to prevent recurrent respiratory papillomatosis but most cases are caused by the HPV types prevented by the one of the vaccines (Gardasil).
Screening of cervical cancer:
Cervical cancer is the easiest female cancer to prevent, with regular screening tests and follow-up. Two tests can help prevent cervical cancer or find it early—
- The Pap test (or Pap smear) helps find precancerous cell changes on the cervix that might become cervical cancer if they are not treated appropriately.
- The HPV test checks for the virus that can cause these cell changes on the cervix. It may be used to screen for cervical cancer, with the Pap test, in women aged 30 years and older. It also may be used to provide more information when a Pap test has unclear results.
Currently, there is no routine screening test recommended for other HPV-related health effects, such as genital warts or other HPV associated cancers (cancers of the vulva, vagina, anus, penis, and oropharynx ). The Pap test does not screen for cancers other than cervical cancer.
Although there is no routine screening test for other HPV associated diseases, you should visit your doctor regularly for checkups.
What should a person do if exposed to someone with genital warts?
Both people with HPV infection and their partners need to be counseled about the risk of spreading HPV and the appearance of the lesions. They should understand that the absence of lesions does not exclude the possibility of transmission and that condoms are not completely effective in preventing the spread of the infection. It is important to note that it is not known whether treatment decreases infectivity.
Finally, female partners of men with genital warts should be reminded of the importance of regular Pap smears to screen for cervical cancer and precancerous changes in the cervix, since precancerous changes can be treated and reduce a woman’s risk of developing cervical cancer. Similarly, men should be informed of the potential risk of anal cancers, although it is not yet been determined how to optimally screen for or manage early anal cancer.
Is HPV vaccine safe?
All vaccines used in the United States are required to go through years of extensive safety testing before they are licensed by the U.S. Food and Drug Administration (FDA). Once in use, they are continually monitored for their safety and effectiveness.
There are two human papillomavirus (HPV) vaccines, Gardasil and Cervarix. These vaccines are available to protect females against the two HPV types that cause most cervical cancers. Gardasil was studied in more than 29,000 males and females, and Cervarix was studied in over 30,000 females during clinical trials.
Most HPV vaccine distributed in the US has been Gardasil. As of June 22, 2011, approximately 35 million doses of HPV vaccine were distributed in the U.S. and VAERS received a total of 18,727 reports of adverse events following Gardasil vaccination: 17,958 reports among females and 346 reports for males, of which 285 reports were received after the vaccine was licensed for males in October 2009. Cervarix has been in use outside of the U.S. prior to licensing by the FDA.
Both HPV vaccines are currently being monitored for any adverse events, especially rare events not identified in the study trials.
HPV and Cancers:
Several types of cancer are associated with HPV:
- Cervical cancer: The most common HPV-associated cancer. Almost all cervical cancer is caused by HPV.
- Vulval cancer: About 50% are linked to HPV.
- Vaginal cancer: About 65% are linked to HPV.
- Penile cancer:About 35% are linked to HPV.
- Anal cancer: About 95% are linked to HPV.
- Oropharyngeal cancers (cancers of the back of the throat, including the base of the tongue and tonsils): About 60% are linked to HPV. [Note: Many of these cancers may be related to tobacco and alcohol use]
Most of the time, HPV clears by itself within two years and does not cause health problems. It is thought that the immune system fights off HPV naturally. It is only when certain types of HPV stay in the body for many years that it can cause these cancers. It is not known why HPV goes away in most, but not all cases. There is no way to know which people will go on to develop cancer or other health problems.