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Human papillomavirus (HPV) and genital warts

Michael Carter, Selina Corkery
Published: 22 October 2013

The human papillomaviruses (HPV) are a family of over 100 strains of virus, of which over 40 can affect the genital area (these strains can also affect the mouth and throat. Genital warts were the second-most commonly diagnosed STI in the UK in 2012, with especially high rates in young people. Young gay men have been found to have particularly high rates of anal HPV in some research. Having HPV has been linked to a higher risk of becoming infected with HIV in some research.

Some strains of HPV can lead to cervical or anal cancer. This risk of this is higher in people with HIV because there is more chance that the virus will become re-activated due to loss of immunity, although both cervical and anal cancer are relatively rare in people with HIV. Very rarely, high-risk types of HPV can also cause vulval, vaginal, penile and some mouth and throat cancers. Being on HIV treatment, with an undetectable viral load, and having a higher CD4 cell count (certainly over 200) can reduce the risk of developing HPV-related cancers.

Transmission

HPV can be contracted during unprotected anal, vaginal or oral sex, by other close physical contact with the genital area or by sharing sex toys, even if the infected partner has no obvious signs or symptoms of HPV. It is possible to have more than one strain of HPV at any time.

It is possible for a mother to pass HPV on to her baby during delivery, but this is rare.

Prevention

Using a condom for anal, vaginal and oral sex offers a degree of protection from infection with HPV, or from passing on the virus to somebody else. However, protection isn’t complete as the skin around the genital area may also carry the infection. Don’t share sex toys, or cover them with a condom or wash them between uses.

People who are sexually active are advised to have regular sexual health check-ups, where HPV and other sexually transmitted infections can be tested for. Most HIV treatment centres have an associated sexual health clinic where free and confidential treatment can be obtained without referral from your GP or your HIV doctor.

Two vaccines have been approved that offer protection against certain strains of HPV, including those that have the highest risk of leading to cervical or anal cancer. In the UK, vaccination with Gardasil (which protects against the high-risk HPV strains 16 and 18, as well as 6 and 11, which cause 90% of genital warts) is currently only available to teenage girls. Vaccination is likely to have the greatest benefit  before young people become sexually active. If you have already been exposed to the HPV types covered by the vaccine, being vaccinated will not reduce the risk of future disease caused by HIV. Sexual health experts in the UK have made a strong argument for the cost-effective public health benefits of vaccinating young men as well, and the UK's Joint Committee on Vaccination and Immunisation will make a decision in 2014 when more research has been completed. 

There are no recommendations about the use of these vaccines in people with HIV. There is some evidence that there could be health benefits to older gay men being vaccinated, even if they have already been infected with one or more of the strains covered by the vaccination.

It is possible to pay to have the vaccination as a private patient.  If you are considering this, make sure that you talk to your HIV doctor and have a blood test to see if you are already infected with the strains of HPV the vaccine protects against.

Symptoms

Most strains of HPV do not cause obvious symptoms, so people may not realise they have the infection. 

Most cases of visible genital warts are caused by strains 6 and 11. They can take up to a year to develop after infection takes place. The warts can look and feel much like those that may appear on other parts of the body – small nodules with either a smooth or rougher texture. They can appear singly or in ‘cauliflower’-like clusters. They are usually painless, but can become itchy or inflamed. Occasionally they may bleed.

In women, warts may appear on the inside or outside of the vagina, on the neck of the cervix, in or around the anus and on the thighs. In men, warts may appear on the tip or shaft of the penis, in or around the anus, on the scrotum or the urethra.

Diagnosis

For women, cervical screening (a smear test) is used to detect pre-cancerous cellular changes called dysplasia early, before cancer develops. A small sample of cells from the cervix are examined under a microscope, to see if there are any changes in the cells which suggest a risk of cervical cancer developing in the future.

HIV-positive women are recommended to have cervical screening when they are first diagnosed with HIV, six months later, and then at least once a year.

The value of regular screening of the anal canal for pre-cancerous cells is less clear, and it is not currently recommended as standard, although some clinics offer it. You may want to ask about screening, especially if you have already had anal warts. 

Genital warts are diagnosed by visual and manual examination of the genital and anal area.

Treatment

In most cases, the immune system naturally clears infection with HPV. In some cases, the infection persists and can cause other health problems, such as warts and cancers.

If you have visible warts, there are several treatments, none of which cure HPV. Treatment can involve applying topical creams or liquids, freezing, laser treatment or surgery. These procedures may feel a little uncomfortable; for some, you will have a local anaesthetic. Sometimes treatment will need to be repeated, or a combination of different methods used.

HPV vaccination is not effective against current infections.

If screening shows that you have developed pre-cancerous cells in your cervix or anus, there is treatment available. If caught early, treatment for these changes is very effective. 

If you are diagnosed with genital warts, you may be referred to see a health adviser. Health advisers can give you information about safer sex and how to protect your own and other people’s sexual health. They may also be able to help you, where possible or practicable, to contact your sexual partners so they can be tested or treated if necessary.

Human papillomavirus (HPV) and genital warts

Contact NAM to find out more about the scientific research and information used to produce this factsheet.

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.