Human papillomavirus (HPV), genital warts and related cancers - including symptoms, treatment and prevention

Human papillomavirus (HPV) is an infection of the skin and mucous membranes (the thin moist lining of many parts of the body such as the nose, mouth, throat and genitals) caused by the human papillomaviruses of which there are around 100 known strains or types.

How HPV is spread

The HPV virus is usually transmitted by close skin to skin contact, mostly through genital, oral or anal intercourse. Babies may develop infection of the respiratory tract if exposed to HPV infection during delivery.

Signs and symptoms of HPV infection

Most genital HPV infections do not have any symptoms and the infection is cleared within one to two years (the virus is no longer detectable). However, some HPV infections persist in the genital tissue and lead to abnormalities in the cells.

Some strains of HPV, considered to be ‘low-risk’, cause genital warts. Genital warts may be small, difficult to see and only detected by medical examination, or they may be much larger, joining to form warts over a centimetre in diameter.

Infection with other strains of HPV, called ‘high-risk’ strains, are associated with an increased risk for developing cancers, including cancer of the cervix, vulva and vagina, anus and penis. HPV infection can also be the cause of some cancers of the head and neck. Men who have sex with men are at higher risk of HPV-associated disease.

Diagnosis of HPV infection

Diagnosis of genital warts is made by a doctor based on the history and clinical examination. A cervical screening test may show changes in cells of the cervix caused by HPV infection.

Incubation period

(time between becoming infected and developing symptoms)

2 to 3 months, with a range of 1 to 20 months for genital warts.

It can take up to 10 years for a high-risk HPV infection to develop into cancer.

Infectious period

(time during which an infected person can infect others)

Unknown, but for genital warts it is probably for at least as long as a visible wart exists.

Treatment for HPV infection

There is no ‘perfect’ treatment for HPV infection and not everyone requires treatment. The decision to treat genital warts should be made after discussion with your doctor about the advantages and disadvantages. Within three to four months, warts will disappear in 10-20% of people even without treatment. No treatment has been demonstrated to eradicate HPV from the body or stop the transmission of infection. However, treatment may improve local symptoms and be desirable for cosmetic and psychological reasons.

Small genital warts can be removed easily by applying specific chemical paint to the wart. Several treatments are given, after which the warts usually disappear within a few weeks.

If genital warts are larger, they may be frozen off or treated by diathermy or laser treatment. Sometimes, if the warts are very large, they are best removed surgically.

Treatment is also available after an abnormal cervical screening test result, depending on the type of changes that are seen.

Prevention of HPV infection

  • A vaccine is available that can prevent infection from HPV types that are known to cause HPV related cancers and genital warts. In South Australia, children are offered the HPV vaccine at school. If you have a cervix and are fully immunised with HPV vaccine, you should continue to have regular cervical screening tests every 5 years.
  • If you have a cervix and are aged 25 to 74 years of age you should have a cervical screening test every five years until the age of 74. The first cervical screening test is due at 25 years of age or two years after the last Pap test. If the result is normal, you will be re-invited to screen in 5 years’ time.
  • Sexual partners of people with genital warts should be examined for evidence of warts, including a cervical screening test if you have a cervix.
  • Testing to exclude other sexually transmitted infections is advisable.
  • Use condoms and other barrier methods to prevent getting sexually transmitted infections, including HPV.
  • Get tested for sexually transmitted infections regularly (even if you do not have symptoms), particularly when you have new sexual partners.

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