Common warts are caused by a virus known as human papilloma virus (HPV). There are about 100 different strains of HPV. Different types of warts have been identified, and they appear on various parts of the body, but today we will look at genital warts, a highly contagious sexually transmitted infection.

Common warts are not the same as genital warts. About 90 per cent of genital warts are caused by two strains of HPV - HPV-6 and HPV-11. Most people who acquire these strains never develop genital warts or symptoms but are, nevertheless, able to transmit HPV.

In women, the warts may appear on the vulva, inside the vagina, on the cervix or on the spot between the vagina and the anus. In men, the warts may appear on the tip or shaft of the penis, on the inner side of the foreskin, the scrotum or the anus.

HPV and cervical cancer

The big deal about HPV is that strains called HPV-16 and HPV-18, plus HPV-31 and HPV-45 are strongly associated with most cervical cancers in women. Certain strains of HPV may cause cancers of the anus and the penis.

Treatment for genital warts

The aim of treatment is to get rid of visible warts. There is still no cure for the HPV but it will be cleared from the system with time (in a few years). For some people, genital warts are bothersome to look at, so removing them may also offer some psychological advantage. There is medication and surgical treatment for genital warts.

Genital-wart treatment should not be attempted at home with over-the-counter medication. Treatments are applied directly to the warts while trying to prevent the treatment from touching surrounding skin. These are not intended for use on the moist tissues of the genital area, and pain and irritation may result. So anyone with genital warts should see a doctor. However, there is a prescription cream available here called imiquimod (Aldara) which doctors prescribe for patients to apply themselves.

Medications - Imiquimod (Aldara) is a cream which helps the body's immune system fight the wart virus. Aldara costs around $4,000. Podophyllum paint (Podofilm) is a plant-based product which interferes with the growth of the warts and destroys the genital-wart tissue. It costs about $800.

Physical treatments - Trichloroacetic acid (TCA) kills genital warts by destroying proteins in the cells. This concentrated acid is applied to the wart by a doctor. This is called chemical burning. The TCA is also used for tattoo removal. A physical kind of burning called hyfrecation may be done by a doctor. The genital warts are burned with heat from a hot wire. Freezing the genital warts with liquid-nitrogen spray is called cryotherapy. Removal of genital warts by surgery is performed with a laser beam (laser treatment) or an electrical current (electrocautery). Both types of surgery 'burn' away the warts.

Vaccine - A vaccine called Gardasil protects against two strains of HPV which cause most cervical cancer, and two strains of HPV which cause most genital warts. The vaccine is best administered before girls start having sex.

Prevention of genital warts

Abstain from sex if you have genital warts. Otherwise, use a latex condom every time you have sex. This is especially important at least until the warts have been treated. The partner should be informed about the situation.

Dahlia McDaniel is a pharmacist and final-year doctoral candidate in public health at the University of London; email: yourhealth@gleanerjm.com.