Human papilloma virus (HPV)

What is HPV?

The human papilloma virus (HPV) is a common virus. Over 100 different types of HPV have been identified and each is known by a number. Each type affects certain parts of the body: for example, HPV types 1, 2 and 4 are associated with the common warts that can arise on the hands and feet. Types 6 and 11 can cause genital warts.

Some HPV types, most commonly types 16 and 18, can lead to abnormal changes in the cells of the cervix (neck of the womb or uterus). The changes are known as CIN (cervical intra-epithelial neoplasia). Not all women with these types of HPV develop CIN. For many people, HPV infection is temporary and most people affected will not have any lasting cell changes.

CIN

CIN is not a cancer, but in some women it can develop into cancer over a number of years if it is left untreated. Treatment for CIN is very effective, and the risk of CIN coming back after treatment is low.

How HPV is spread

HPV in the genital area is spread through skin contact, mainly during sexual contact. The virus can affect both men and women. Many people do not have any symptoms and are unaware that they have HPV. For some people with particular types of HPV, visible warts occur. These can be treated effectively (see Treatment, below). The virus may be inactive for weeks, months and, for some people, possibly even years after infection.

HPV is more easily passed on to another person when there are visible warts present. For this reason, whilst warts are present and for at least three months after treatment, it is advisable to avoid touching the affected area during sex.

Often, exactly how a person gets the virus is uncertain; and it is not always possible to find a sexual explanation. Some people believe that there may be other ways of spreading the virus that have not yet been identified.

How it is diagnosed

A woman may be told that she has HPV when she receives her cervical screening result. If an HPV infection is present, changes in the appearance of the cells can sometimes be seen when they are looked at under a microscope during cervical screening.

Some women with particular types of HPV may notice visible warts, which appear as flat smooth small bumps, or larger cauliflower-like lumps. Warts do not lead to cancer and may appear on their own or in groups. They may itch, but are usually painless. HPV produces visible warts only in around 30% of people, leaving 70% of people with HPV who have no signs of the infection.

Treatment of genital warts

In most people HPV disappears on its own. However, visible warts may need to be treated. Treatment is usually given at a local genitourinary medicine clinic or sexual health clinic.

Warts can be removed by:

• various forms of surgery
• freezing
• chemicals or drugs applied directly to the warts

The treatment used will depend on the extent of infection, and the position of the warts.

Although external warts are sometimes clearly visible, sometimes it is possible to see them properly only by looking at the cervix through a special device like a small microscope (colposcope).

Only obvious visible warts can be treated. Unfortunately there is no definite cure for HPV. Warts may return after initial treatment, meaning that the treatments may need to be repeated.

After treatment

After any treatment, the area should be kept clean and dry. It is advisable to wear cotton underwear and loose clothing. Sexual intercourse should be avoided until the area has healed, which usually takes 2–4 weeks.

If you have HPV but no visible warts

At the moment no treatment is given if you have HPV without warts. However, there are things that you can do to help your immune system to fight the virus.

If you have HPV:

• try to stop smoking
• if you have more than one sexual partner use condoms during sex. Condoms may help to prevent the spread of HPV, although using them does not guarantee protection
• have regular cervical smears (according to the national cervical screening programme).

Having HPV does not automatically mean that changes will occur in the surface cells of your cervix (CIN). This is because not all HPV types lead to these changes and HPV infection alone does not cause CIN. Other factors such as cigarette smoking, or a lowered immune system, can encourage cell changes in the cervix.

Research

A vaccine to prevent women from becoming infected with HPV is currently being developed. The results of trials with the vaccine have been good but it is still likely to be some years before the vaccine is available.

Your feelings

Many women feel frightened when they are first told that they have HPV or CIN, and worry that they may develop cancer. You may find the treatments embarrassing and frightening, and may feel tense, tearful or withdrawn. At times these feelings can be overwhelming and hard to control.

Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to friends or family, while others prefer to seek help from people outside their situation. Others may prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is available if you need it.

References

This section has been compiled using information from a number of reliable sources including;  

• Oxford Textbook of Oncology (2nd edition). Souhami et al. Oxford University Press, 2002.
• Cancer and Its Management (4th edition). Souhami and Tobias. Oxford Blackwell Scientific Publications, 2003.
• Principles & Practice of Gynaecologic Oncology (3rd edition). Hoskins et al. Lippincott Williams and Wilkins, 2000.
• Liquid-based cytology for cervical screening (review). Technology Appraisal No 69. National Institute of Clinical Excellence, October 2003.

For further references, please see the general bibliography.