So here is the clue (or CLEW): It is an important sexually transmitted infection with three initials, the first being H and the last V…
I would guess that most of you would have said HIV, but then you would be wrong. I’m thinking of HPV, which stands for Human Papilloma Virus. HPV is the most common sexually transmitted infection (STI). If you have had sex, the chances are that you have had genital HPV at some point; 50-75% of us will have.
A study in the US showed that 45% of women aged 20-24 were infected. This number slowly drops with age, but there were still 20% of 50-59 year olds infected. These figures are probably quite surprising and shocking to some of you who have never had to deal with any STIs. But if it is so common, how come many of us don’t know about it? Is it really important?
What exactly is HPV?
HPV is actually a family of viruses. Some of them are harmless and cause warts and verrucas, which are a nuisance but not serious.
However, HPV can also cause cervical cancer in women (cancer of the neck of the uterus) and anogenital cancer in men (cancer of the anus or penis). These are usually caused by the “high risk” types of HPV, such as 16 and 18.
Types 6 and 11 cause 90% of genital warts and these affect 1 in 50 sexually active women. Genital warts are not dangerous, but they can itch or bleed, look unsightly and cause distress. They take the form of small fleshy growths which can be anywhere in the genital area, including internally, and can grow even one year after the sexual contact.
HPV is highly contagious and is spread by skin-to-skin contact, so any sort of sexual activity can spread HPV, not just full penetrative sex.
Most people with HPV infection do not know that they have it as they will not have any symptoms, and thus can spread it to partners. Most people will clear it with their own immune system. However, there are some in whom the infection persists for longer and can cause changes in the cells of the cervix which, if not picked up and treated, can develop into cervical cancer.
How to prevent HPV infection
In Luxembourg, girls are offered vaccination with the Gardasil vaccine at age 12. This is fully reimbursed, but needs to be organized by the family through the family doctor or paediatrician. Doctors are not supplied with the vaccine, so a prescription needs to be issued and the patients collect the vaccine themselves from the pharmacy. It is given in 3 doses over a 6 month period, and protects against types 16, 18, 6 and 11. The idea is to vaccinate girls before they become sexually active, to avoid them becoming infected. Not only does this protect them from cervical cancer, but it will also protect them from genital warts.
Some countries are recommending routine vaccination of boys as well, to protect them against anogenital and other HPV associated cancers such as cancer of the larynx. Men who have sex with men, are at increased risk of problems from HPV so there is a good argument for offering vaccination for them, as well as groups of people who are immunosuppressed, such as those with HIV infection.
For those who have not been vaccinated, condoms can help protect, but as they do not prevent skin-to-skin contact, they cannot stop all infections from being passed on. You are at higher risk from HPV if you have had multiple partners, and having been infected with HPV, you are more likely to develop changes in your cervix and subsequent cervical cancer if you are a smoker.
The contraceptive pill and pregnancy also increase your risk of cervical cancer slightly and this is thought to be due to the effect of hormones on the cells of your cervix, making them more susceptible to damage from the HPV. Once you stop the pill, your risk returns to normal quite quickly.
But even if you are not vaccinated, if you attend for your regular pap smear test (recommended by the World Health Organisation every 3 years from the age of 25-65 years), then early changes in the cells of your cervix can be detected and treated long before they have a chance to develop into cancer.
In addition, we can now test for HPV infection. This is not recommended for women under the age of 30, as so many would come back positive. After the age of 30, if you are testing negative for HPV, the US recommendations now suggest that you only need a smear test every 5 years as your risk is lower. If you are shown to have a positive HPV test which persists, you may need to be monitored more closely.
So with the onset of vaccination and HPV testing, the landscape of HPV infection and the associated cancers should change dramatically over the next decades. This is something to celebrate for our children.
By Susie Tunstall-Pedoe, April 2013