Human papilloma virus (HPV)

How is HPV transmitted?

HPV is passed on through genital contact, usually during vaginal and anal sex, as well as during oral sex. People with weakened immune systems, such as those on chemotherapy or people with HIV are more susceptible to HPV infection.

Symptoms of HPV

It's estimated that by the age of 27, most sexually active people have been exposed to some strain of HPV, usually without them knowing, and very rarely do doctors know which strain.
Most people with HPV don’t develop symptoms or further health problems, as in around 90 per cent of cases the body’s immune system has naturally cleared it within two years.
However, certain types of HPV (most commonly strains 6, 11, 16 and 18) can cause genital warts in men and women, while other HPV strains (especially 16, 18 and 39) can cause cellular changes that lead to cancer of the cervix and possibly other less common but serious cancers including:

• vulval cancer
• cancer of the vagina
• cancer of the penis
• anal cancer
• head and neck (tongue, tonsils and throat) cancers

It’s possible to have HPV present years after sexual contact with an infected person, and it’s also possible to be exposed to more than one strain of HPV.
There is currently no easy way to spot which people affected by HPV exposure will go on to develop cancer or other serious health problems.
Very rarely, a pregnant woman can pass HPV to her baby during birth and the child can develop recurrent respiratory papillomatosis – a chronic lung condition where growths block the airways.

HPV tests

If you feel you’ve been at risk of HPV, a simple inspection by your GP or at your local genitourinary medicine (GUM) clinic may reveal genital warts around the perineum, genital area, inside the vagina and around the anus. However, the absence of warts doesn’t mean you’ve not been exposed.
To find your nearest GUM clinic:

• Call the Department of Health's Sexual Health Helpline on 0800 567123.
• Use the FPA's GUM clinic search.

The NHS cervical cancer screening programme in the UK involves regular testing of women to look for pre-cancerous changes in their cervical cells. Originally called a pap smear, the cells taken from the cervix are now examined in a slightly different way (although a woman won't herself notice any difference in how the test is done). So the test is no longer called a smear, but simply a cervical cancer screening test.
It’s also possible to test these cells for the presence of the DNA of high risk HPV strains (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68). This is known as HPV Triage. If a woman's screening result shows mild abnormalities (known as borderline or mild dyskaryosis) then an HPV test will be carried out her cells. This test helps to decide how significant any such abnormalities are. If HPV is not found the changes are not likely to be important and she will not need to be screened for another three years. But if HPV is found then there is an increased risk that the abnormalities could lead to cancer, and she will be invited to go for a more intensive test called a colposcopy, to look very closely at the cervix to see whether any treatment is needed.
There is no similar screening programme for the other cancers that result from HPV infection. The possibility of regular anal cell sample tests has been discussed, to screen for anal cancer in gay and bisexual men and in those who are HIV-positive, where anal cancer is more common, but it’s not yet an established practice.

HPV treatments

As there is no treatment for the virus itself, health management is based on prevention, by advising condom use and vaccination.
There is treatment for some of the diseases that HPV can cause, including:

• Genital warts, which can be cauterised or treated chemically.
• Abnormal cervical cells, which can be removed by various techniques.

HPV and cancer risks

We don't fully understand the way in which HPV affects cells. Both high-risk and low-risk strains of HPV can cause the growth of abnormal cells, but only the high-risk types of HPV appear to lead to cancer.
Several types of cancer (up to five per cent worldwide), while linked to other risk factors, are now also associated with HPV exposure:

• cervical cancer (the most common HPV-associated cancer)
• vulval and vaginal cancer (40 to 70 per cent linked to HPV)
• penile cancer (possibly 40 per cent linked)
• anal cancer (around 85 per cent linked)
• cancers of the head and neck (although most are linked to tobacco and alcohol use, it’s now thought about 25 per cent of mouth and 35 per cent of throat cancers may be linked to HPV exposure (in particular HPV strain 16)

HPV vaccination

Two vaccines have been produced to protect against HPV, and several more are in development:

• Cervarix - since September 2008 this vaccine has been routinely offered by the NHS to young girls in the UK (usually in year 8, i.e. aged 12-13), before they become sexually active, to protect against strains 16 and 18, which cause the majority of cervical cancers. It consists of a series of 3 injections given over 6 months.
• Gardasil - from September 2012 the NHS will offer girls treatment with this more comprehensive vaccine, which protects against strains 6, 11, 16 and 18, and also gives protection against the commonest strains that cause genital warts. Boys are not routinely offered vaccination against HPV although many argue that they should be.
• read more : http://www.bbc.co.uk/health/physical_health