Human Papilloma Virus (HPV)
Human papilloma viruses (HPV) are a large family of viruses that affect the skin and the lining of the mouth and genital area, also known as mucous membranes. HPV is a very common virus with over 100 different strains. (sub-types)
The types of HPV that can cause skin warts, genital warts and verrucas are known as ‘low risk’ strains and do not usually cause cell changes or develop into cancer. Some types of HPV can cause changes in the cells of the cervix or the lining of the mouth and throat. They are known as high risk HPVs (HRHPV). The changed cells have an increased risk of becoming cancerous.
HPV strains are denoted by a number. For example, HPV 6 and HPV 11 are low risk viruses. They cause genital warts but do not increase the risk of cervical cancer.
Approximately 13 strains of high-risk HPVs are responsible for causing cervical cancers. Of these, HPV 16 and 18 are the most common, and cause over 70% of cervical cancers in the UK.
Nearly all sexually-active men and women get HRHPV at some point in their lives. Eighty percent (four out of five) of the world’s population will be infected by HRHPV at some stage. HRHPV is transmitted primarily by genital-to-genital sexual contact, anal sex and, occasionally, oral sex. It can also be transmitted from same-sex partner to same-sex partner. It is important to realise that infection with HRHPV does not imply either infidelity or promiscuity as even people who have had sex with only one person in their lifetime can get it.
The body’s immune system will usually get rid of HRHPV. Since there are no symptoms of HRHPV infection, most people do not even know they have contracted the virus. In some women, for reasons we do not fully understand, the body’s immune system will fail to clear up the virus and this is known as persistent HRHPV infection. You are more likely to have persistent HRHPV infection if
- You smoke
- Are HIV positive
- Are immunosuppressed because you have received an organ transplant (e.g kidney transplant)
These are known as risk factors. However, the vast majority of women with persistent HRHPV infection have no obvious risk factors.
Most women who are infected with HRHPV do not develop cervical cancer. However, a small number of women do develop abnormal cells that may become cancerous. We cannot treat HRHPV infection but we can treat the cell changes it causes, thereby protecting women from developing cancer. These cell changes do not cause symptoms and are only detected when women attend for cervical screening (smear test). Women who have abnormal smears are referred for colposcopy and. If required, treatment. Please contact us if you are concerned about an abnormal smear.
Younger women can also be protected against HRHPV by being vaccinated. There is a vaccination program in schools but women who missed out on the school vaccination program can still receive the vaccination if appropriate. Please contact us if you are interested in receiving the vaccination
Cervical screening and HPV vaccination are important in helping to prevent cervical cancer.