- Genital warts are caused by a family of similar sexually transmitted viruses.
- Infection with these viruses does not always lead to symptoms.
- These viruses can also be transmitted to an infant during childbirth.
- There is no cure for genital warts virus infection, but the warts can be treated.
Genital warts have been described since ancient times. The viruses that cause the warts are varieties of the human papillomavirus (HPV). These viruses have an incubation period (interval between exposure to infection and appearance of the first symptom) of one to eight months. The infectivity (risk of infecting others) is highest soon after development of the lesion. Transmission is usually sexual, with more than 50% of contacts being affected. Their appearance around the anus may be related to anal intercourse, but not necessarily. The entire lower genital tract is usually involved, although it may be without obvious symptoms.
Once a person is infected, it is possible to clear the virus if the body develops an appropriate immune response. But, because the virus only infects the most superficial layers of skin and does not enter the bloodstream, the virus may evade the immune system to the extent that the virus may remain on the skin of the infected person for life. It is estimated that over 50% of sexually active adults are infected with the virus at some point in their lives, with men and women being equally affected. The risk of being a carrier rises with the number of sexual partners.
In men they occur within the urethra (tube from the bladder), on the shaft of the penis, the scrotum and the anus. In women, the warts occur on the vulva, the vaginal wall, the cervix and the anus.
HPV types 6 and 11 are the dominant causes of genital warts. These types are not associated with cancer of the vulva, anus, cervix or penis. HPV 16 and 18 are independent infections associated with cervical cancer.
HPV is transmitted through skin-to-skin contact, usually during sexual intercourse. During intercourse the virus can enter cells of the skin or mucosal layers of the genital tract through small breaks and multiply there. It may remain dormant or multiply further, causing a wart. The wart is possibly most contagious, but the virus in invisible lesions (subclinical lesions) can also be transmitted. This makes it difficult to prevent the spread of genital warts.
Condoms provide a mechanical barrier if they are used correctly, but the virus can also be located on the scrotum or the vulva, and infect the other partner during sex.
Although the virus can be transmitted during birth, this type of transmission is very rare (about 0.05% of individuals with HPV infection will deliver an infant with vocal cord infection by the virus). There is evidence that children acquire papillomavirus infections of many varieties long before they become sexually active; the routes of infection in children are not understood at this time.
Who gets it?
All individuals who engage in sexual activity (that is nearly every human being) are at risk of acquiring HPV infection. It is without doubt the most common sexually transmitted infection in the world. Since the virus is transmitted through skin-to-skin contact, it is important to note that penetration is not essential for the transmission of the virus between individuals. Genital to genital contact is sufficient to enable transmission of the virus. The infection rate of HPV in South Africa is unknown, but it is estimated that about 100 000 to 200 000 new cases are found every year. Infection rates of 5% to 10% are common among young adults. Sophisticated analysis finds HPV DNA (genetic material) in the cells of 25% to 50% of all patients attending gynaecology clinics.
Sexual activity with multiple partners and without protection from condoms massively increases the risk of any sexually transmitted disease, and genital warts are no exception.
Those with decreased immune system function are more susceptible to this infection and the warts may enlarge rapidly during pregnancy.
Symptoms and signs
Genital warts appear as painless, flesh-coloured or greyish-white growths on the vulva (along the greater and lesser labia - the lips - at the entrance to the vagina), anus or penis. They can be so small that they are only visible under a microscope, or they may gain a cauliflower-like appearance, which can be unsightly, itchy or mildly painful. When very large or extensive, they can even prevent intercourse or childbirth. When they infect the vagina, a discharge can develop and there may be painful intercourse. In men the warts may appear as tiny growths around the tip or shaft of the penis.
Your doctor will gather important clues by asking you about the history of your complaint. He or she will examine the lesions and will often be able to make a diagnosis on the basis of their characteristic appearance.
Other diseases can be present simultaneously and therefore blood tests are often performed to exclude syphilis, gonorrhoea and other sexually transmitted diseases. Swabs may be collected for culture.
The risk for acquiring genital warts increases in proportion to the number of sexual contacts with an infected person, whether this is the same person or different people. You can decrease your risk by limiting your number of sexual contacts and by using condoms.
If your partner has noticed a wart or genital lesion, he or she should see a doctor. If a sexually transmitted disease is then identified, you should be treated as well.
If you start a new relationship and either you or your partner have had previous sex partners, use condoms without exception for the first six months. Then you should both be tested for sexually transmitted diseases. This should include blood tests for Aids and syphilis, and a Pap smear for the female partner.
Women can acquire several types of the HPV virus. When infected with more than one type, the risk of cervical cancer increases. Pap smears are extremely important for all sexually active women.
There is no specific antiviral medication or vaccine available for the treatment of genital warts. Conventional treatments will remove the warts using surgical techniques, but the virus usually remains in the infected area and may cause recurrences even if the whole growth or wart is removed. Unfortunately there is little evidence that removing the visible lesion (the wart) reduces the risk of transmission. The treatment of genital warts is usually for cosmetic reasons and sometimes because large lesions cause physical problems. Recurrences occur in 1/3 to 2/3 people, whatever treatment is used. On the other hand, visible genital warts can spontaneously disappear in up to 1/3 of people, without treatment, within a few months of their appearance.
Non-prescription remedies should not be used for genital warts. The genital area is too sensitive for these drugs and they can damage the skin. The warts can also be confused with other sexually transmitted diseases that need to be treated properly.
Good nutrition, adequate vitamin intake, avoiding smoking, proper sleep and stress reduction may strengthen your immune system so that it can bring the virus under control.
- Podophyllin may be applied every two to four days; the solution should be applied only to the lesions, since normal skin will otherwise burn (normal skin should be protected by applying Vaseline around the wart prior to placing the podophyllin to the wart).
- Tri or Bi-chloroacetic acid can be applied weekly.
- Imiquimod is a cream that stimulates the local immune system to cause clearance of HPV and is used for treating mild to moderate warts.
- 5 Fluorouracil is no longer recommended
These agents should not be used if you are pregnant, as they are absorbed by the body and may harm the unborn baby.
- Alpha-interferon, an immune-stimulating medication, may be injected into the lesions in severe cases which have not responded to other treatment. The immune system consists of cells and proteins that attack and destroy infections and foreign cells. When the immune system is working well, it can keep the virus under control, but otherwise virus growth can become unchecked. Interferon cannot eradicate the viruses, but may help to treat some manifestations of the infection. In some studies, the drug cleared warts in half the subjects. Interferon can be used when lesions recur despite other treatments.
- Recently, a new anti-viral drug known as cidofovir has shown promising results in the treatment of papillomavirus infections, notably for recurring laryngeal papillomas in babies and children.
When lesions are large, treatment with medication may not be effective. Large genital warts may be treated with cryotherapy. In this procedure, lesions are frozen with liquid nitrogen or solid carbon dioxide (dry ice). A laser can also be used. When the diagnosis is not clear, surgical excision is required and a pathologist examines the lesion.
The outcome depends largely on immune system competence: in up to a third of people the lesions disappear within three to four months; in others there is persistence and spread. While the various treatment options may be initially successful, recurrences are common. Fortunately, genital warts very rarely pose a significant health risk.
When to see your doctor
Whenever genital lesions develop, a doctor should be seen to establish an accurate diagnosis. Often genital warts cause a great deal of anxiety; this can be helped by obtaining realistic information about the disease, along with supportive counselling.
Vaginal discharge and painful intercourse should also arouse suspicion of a genital infection, and require a visit to a doctor.
Regular Pap smears of the cervix are generally advised in women over 35 years in order to detect abnormalities that may indicate premalignant or suspicious cell growth. These suspicious cells in the cervix may indicate early changes in cell growth, known as cervical intraepithelial neoplasia or CIN that may have occurred due to infection with particular "high-risk" types of HPV, like types 16 and 18. CIN lesions are early warning signs of cervical cancer. It is important to note however, that the types of HPV that cause genital warts, types 6 and 11, do NOT cause cancer of the cervix.
Reviewed by Professor Lynette Denny, Gynaecology Oncology Unit, Department Obstetrics & Gynaecology, University of Cape Town/Groote Schuur Hospital, August 2008