Regular cervical screening is very effective in detecting cell changes at an early stage when treatment is straight forward, and in many cases the immune system will deal with the virus before it is even detected. However, if a virus is allowed to persist, it can lead to serious infection, and even, eventually, to cancer.
Causes of HPV
HPV is a Sexually Transmitted Infection (STI), but unlike other STIs, it can be found anywhere in the genital area and therefore can be spread by genital-to-genital contact, regardless of the exchange of bodily fluids. This means that condoms do not fully protect against HPV. Any sexually active person is at risk of contracting HPV, and it is thought to be most prevalent in young people, aged 16-25. While research shows that limiting the number of sexual partners can help to reduce this risk, it is important to remember that HPV is widespread and does not imply multiple partners.Other lifestyle factors can also influence the ability of your immune system to fight against HPV such as smoking, a poor diet and certain medications.
Smoking has been shown to reduce the efficacy of disease-fighting cells in the cervix, and the chemical benzpyrene, which is thought to induce cancer, has been found in the cervix of women who smoke. A poor diet also weakens the immune system, making it more likely for HPV to recur. Research has also linked the Pill to an increased risk of cervical cancer, but this increase is small and regular cervical screening should pick up on any related problems.
What is HPV?
HPV exists in over 100 different subtypes which are classified by number. Most forms are relatively harmless, causing common warts (subtypes 1, 2 and 4) and genital warts (subtypes 6 and 11). These are known as 'low-risk' types and do not lead to cancer. Often, HPV goes undetected because there are no external symptoms, and only a small percentage of people who contract it develop warts. Warts can be treated through drugs, directly applied chemicals, freezing, or surgical removal.However some forms, in particular HPV 16 and 18, are known to cause changes in cervical cells which can lead to cancer. These are known as 'high-risk' types. It can take up to twenty years for cancer to develop, preceded by the long duration of a pre-cancerous disease, known as CIN (see below).
HPV vaccines
Since 2006, two new vaccines have been licensed in the UK to prevent HPV. The first vaccine to be licensed, Gardasil, vaccinates against 4 types of HPV (6, 11, 16 and 18) which cause cervical cancer and genital warts. The second vaccine to be licensed, Cervarix, vaccinates against 2 types of HPV (16 and 18) which cause cervical cancer. Cervarix has been chosen by the NHS for a national vaccination programme for 12-13 year old girls from Autumn 2008. In Autumn 2009 there will be a ‘catch-up’ programme for girls up to the age of 18. Both types of vaccine are administered in 3 doses over 6 months. The vaccine programme will mainly be administered in schools. Both vaccines are available from GPs and private clinics.may be usefull
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