Everything you need to know about HPV

Human papillomavirus or HPV refers to a group of viruses that infect the skin and mucus linings of humans. Around 4 in 5 UK adults will be infected with HPV during their lifetime. 

There are over 200 different types of HPV. Most are not harmful and do not cause any symptoms though some types of HPV can cause genital warts or warts elsewhere on the body. 

A small group of HPV types can cause changes in infected cells that increase the risk of particular cancers in women and men. 

Here, we will explore HPV types, how HPV is spread, and symptoms of infection, as well as how HPV is treated and how to prevent infection. 

Types of HPV

HPV types that are spread through sexual activity can be categorised into 2 main groups: 

• Low-risk HPV – this includes HPV 6 and HPV 11, which cause genital warts 
• High-risk HPV – there are currently 14 high-risk HPV types (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68); HPV 16 and HPV 18 together are responsible for 7 in every 10 cases of cervical cancer in the UK

The remaining types of HPV, which are not spread through sexual activity, can cause warts elsewhere on the body, such as the hands and feet. 

How is HPV spread?

HPV can be spread through anal, oral and vaginal sex. However, the exchange of bodily fluids and penetrative sex are not needed for HPV to spread. 

This is because HPV is highly contagious and can be spread through close skin-to-skin contact, which occurs during sexual activity without the act of penetration. 

A person with HPV can spread the infection through sex or close skin-to-skin contact even if they have no visible symptoms. 

HPV can also be spread by sharing sex toys that have not been cleaned properly – as per the manufacturer’s instructions – between use with different people or between use on different parts of the body. 

HPV and genital warts 

Genital warts are one of the most common sexually transmitted infections (STIs) in the UK. They are most often caused by HPV 6 and HPV 11. It can take several weeks or months after infection before genital warts develop.  

They appear as small, rough bumps, either alone or in small groups, and can develop on the penis, the skin between the genitals and anus (perineum), in the mouth and throat, and around the vagina and/or anus.

Genital warts can vary in colour from white and red to skin-coloured or darker than the surrounding skin. 

They can be soft or firm and can cause discomfort during sex. They can also be itchy, painful and sometimes bleed. 

If you have genital warts, you may notice blood in your urine and have difficulty urinating. 

HPV and warts (non-genital warts)

HPV can cause warts to develop on skin anywhere on your body. However, non-genital warts often occur on the hands, feet and legs. 

As with genital warts, they are highly contagious and can spread through skin-to-skin contact. They can also spread through sharing items contaminated with infected skin cells, such as towels or razors.

Non-genital warts can be grouped according to their appearance and/or location, and include: 

• Common warts – hard lumps with a raised, rough surface, which are most often caused by HPV 2 and HPV 4
• Flat warts – smooth bumps that are flattened on top and are usually less than half a centimetre wide; they are usually caused by HPV 3, 10 and 28
• Filiform warts – long, thin bumps that tend to occur on the face near the eyelids and lips; they are usually caused by HPV 1, 2, 4, 27 and 57
• Mosaic warts – groups of tiny, white raised bumps that form a tile-like pattern and usually occur on the soles of the feet and palms of the hand; they are caused by HPV 2
• Plantar warts – flat, round bumps with black dots within them that occur on plantar surfaces, that is, the soles of the feet; they are most often caused by HPV 2 and 4

HPV and cervical cancer

The vast majority (99.7%) of cervical cancer cases in the UK are caused by infection with high-risk types of HPV. However, if you are infected with a high-risk type of HPV, this does not mean you will develop cervical cancer – between 1 and 3 women in every 20 with high-risk HPV will go on to develop cervical cancer. 

Symptoms of cervical cancer include: 

• Abdominal pain 
• Heavier periods that last longer
• Pelvic pain especially during sex
• Vaginal bleeding after sex and/or in between periods
• Vaginal discharge that is watery, bloody and foul-smelling 

To reduce the prevalence of cervical cancer, all girls aged 12–13 in the UK are offered an HPV vaccination and all women and individuals with a cervix aged 25–64 are offered cervical screening every 3 years. 

HPV and cancer 

HPV infection not only increases the risk of cervical cancer but also anal cancer, penile cancer, vaginal cancer, vulval cancer, and certain types of head and neck cancer, such as tonsillar cancer and oropharyngeal cancer.

To reduce the prevalence of these types of cancer, the HPV vaccine is not only offered to all girls aged 12–13 in the UK but since 2019, has also been offered to all boys aged 12–13. 

Risk factors for HPV infection

You do not need to have multiple partners to become infected with sexually transmitted HPV and you can become infected the first time you have sex with anyone. However, you are more likely to become infected if you have multiple sexual partners.

Your risk of HPV infection is also higher if you have a weakened immune system eg if you have HIV or AIDS, or are taking medication that suppresses your immune system, such as after an organ transplant or if you are having chemotherapy.

Skin-to-skin contact with someone who is infected with HPV also increases your risk of infection. 

Do you need to get tested for HPV?

It is important to get tested for HPV if you are having sex with a new partner or multiple partners. 

This is because HPV often causes no symptoms, so you may not be aware that you are infected. However, you can still spread the infection without having symptoms.

Also, as HPV can be spread without penetrative sex or the exchange of bodily fluids, wearing a condom during sex does not offer complete protection as skin-to-skin contact will still occur. 

It is also important to talk to your sexual partners about their sexual health and whether they have been tested recently.  

How is HPV infection diagnosed? 

Cervical screening

Cervical screening tests for infection of the mucus lining of the cervix (the entrance to the womb) with high-risk types of HPV, that is, the types that increase the risk of cervical cancer.  

It involves lying back on a table, with your feet together, knees bent and legs apart. A tube-shaped plastic tool called a speculum will be inserted into your vagina and opened to gain better access to your cervix. 

Next, a small brush will be inserted to collect some cells from your cervix. The cells will be sent to a lab for testing.  

If you test positive for high-risk HPV, the cells collected will be examined under a microscope to check for abnormal changes in their appearance, which can indicate that the cells are at risk of becoming cancerous. 

Your care team will then discuss next steps with you, which may include a procedure to more closely examine your cervix (colposcopy) and/or remove the abnormal cells. 

Attending regular cervical screening is important to reduce your risk of developing cervical cancer due to HPV infection.

Sexual health clinic check-ups

Sexual health testing does not focus on high-risk types of HPV – in women or individuals with a cervix, high-risk HPV is tested for via cervical screening, while in men, there is currently no test for high-risk HPV. 

Instead, sexual health testing focuses on diagnosing genital warts, which are caused by low-risk HPV. In both men and women, this involves a physical examination of the affected area to look for signs of genital warts. 

Treating HPV infection

Most cases of HPV infection do not produce symptoms and go away on their own without treatment within two years. 

In cases where HPV causes genital warts, these warts can sometimes clear up without treatment within six months. 

When treatment is needed, it focuses on removing or destroying the affected tissue but does not target HPV itself. This is because there is currently no cure for HPV infection. 

Genital warts are, therefore, treated either by applying a cream that boosts your body’s own immune system to fight off the infection or by removing the warts. Genital warts can be removed with cryotherapy (ie freezing the tissue) or surgery. 

If your cervix is infected with high-risk HPV, your doctor may recommend a procedure called a colposcopy. This involves inserting a speculum into your vagina and opening it to insert a small telescope-like device (colposcope) with a light and a camera on the end. 

This allows your doctor to more closely examine your cervical tissue to look for signs of abnormal changes that suggest a high risk of the cells developing into cancer. If these high-risk changes are detected, treatment to remove the abnormal tissue can be performed during your colposcopy. 

There are several different procedures for removing abnormal cervical tissue, including large loop excision of the transformation zone (LLETZ), needle excision of the transformation zone (NETZ) and a cone biopsy. 

Preventing HPV infection and spread

As mentioned earlier, regular check-ups at a sexual health clinic are important to help diagnose genital warts and, therefore, prevent the spread of HPV. It is also helpful to talk to your sexual partners about their sexual health and inform them if you have tested positive for HPV, have genital warts or are concerned that you may be infected. 

You can also reduce your risk of HPV infection by getting vaccinated against HPV. In the UK, the national HPV vaccination programme vaccinates all children aged 12–13 years. 

If you missed out on this vaccination when you were aged 12 or 13, the HPV vaccine is available for free on the NHS for women and girls aged under 25 and all boys and young men born after 1 September 2006. 

HPV vaccination is also available for free on the NHS for men aged 45 or under who have sex with other men, transgender individuals who share a similar risk profile as men who have sex with men, individuals with HIV and sex workers.