What Is Human Papillomavirus?

Overview

Human papillomavirus (HPV) is the collective name for a group of over 100 related viruses. HPV commonly infects the cutaneous (skin) and mucosal (mouth, throat, genital area and anus) surfaces. Thus, most HPV-related cancers are squamous cell carcinoma (SCC).² 

As it commonly affects the cutaneous and mucosal surfaces, it is transmitted by sex (oral, vaginal or anal) and skin-to-skin contact of the genital area, though HPV is not found in blood or body fluids (e.g. semen).⁵ Transmission can also be vertical, that is, from mother to newborn baby.

HPV is a public health burden due to the complexity of surveillance because most of the time, the infection is asymptomatic, the variable presentation of the different viral types, and the long period between infection and disease (for example, it can take as long as three weeks to eight months after primary infection before genital warts develop, and over ten years before the manifestation of invasive cancer). The risk factors for HPV infection include a weak immune system (e.g. HIV), having a new sexual partner, becoming sexually active at an early age, having multiple sexual partners, etc. Peak incidence is usually soon after first sexual exposure.

HPV viruses are grouped based on whether they cause cancerous changes or not:² 

• Low-risk HPV (lrHPV), such as types 6 and 11 mostly cause genital warts and rarely lead to cancer 
• High-risk HPV (hrHPV), such as types 16 and 18, can cause cancers of the cervix, vulva, vagina, penis and anus, and head and neck if the immune system fails to clear the virus 

The majority of people with HPV remain asymptomatic, and the infection usually resolves spontaneously within 1-2 years. 

Currently, there is no treatment for HPV, so prevention is important. As HPV is an STI, condoms offer some protection. However,  they do not eliminate the risk of sexual transmission because the virus can be found in areas that are not covered by a condom, such as on the skin in and around the genital area. Protection can also be gained from the HPV vaccine, but it does not protect against all types of HPV.

HPV is the most common sexually transmitted infection (STI) globally.¹ Worldwide, high-risk HPVs cause about 5% of all cancers, accounting for an estimated 570,000 AFABs (assigned female at birth) and 60,000 AMABs(assigned male at birth) each year.²  

In the UK, HPV was the most common sexually transmitted infection (STI) before the introduction of the HPV vaccine program in 2009. A study showed a steep increase in HPV infections in AFABs from the mid-teenage years, while another pointed to MSM (AMABs who have sex with AMABs) between 18–40 years having one or more HPV types. Meanwhile, 40% of the AFABs between 20 to 24 years old had a type of high-risk virus which causes cancer. Still, HPV infection is prevalent in the UK. In the general population, approximately 3.2% of AFABs have cervical infections at a given time.

Causes of human papillomavirus

You might get infected with HPV when the virus enters your body through cuts or small tears on your skin. You can also get infected through skin-to-skin contact or through sexual intercourse with an infected individual. If you are pregnant and contract HPV it increases the chances of the baby getting infected as well. 

Signs and symptoms of human papillomavirus

Most people with HPV infection are unaware as they don’t develop symptoms. The infection usually resolves spontaneously within 1-2 years as the immune system clears the virus.

Genital warts

If infection is by low-risk HPV and symptoms develop, they manifest as genital warts. These are painless growths or lumps around the vagina, cervix, vulva, penis, scrotum, urethra (urine opening), anus, groin, or thigh. The colour is usually skin-coloured or darker but can be variable, and there may be itching, redness, discomfort, or occasional spontaneous bleeding.3 The warts may be raised or flat, single or multiple, small or large, or clump together in a cauliflower-like shape. Treatment options for genital warts include ablation (vaporisation, resection, coagulation, or excision) or topical agents.³ Untreated genital warts may heal spontaneously, persist, or increase in size or number.

Cancer

If the infection is by high-risk HPV, the progression from HPV infection to cervical cancer is as follows: HPV infection, the persistence of that infection, progression to precancerous lesions and eventually invasion. The progression from precancerous lesions to cancer is the critical stage so HPV infection needs to be cleared before this stage.⁴ Symptoms generally depend on the location of the pre-cancerous lesions. If this occurs in the cervix, there are usually no symptoms at the precancerous stage, which is why regular cervical cancer screening is important. In other sites of the body, precancerous lesions may cause symptoms like itching or bleeding, while cancerous lesions may cause symptoms like bleeding, pain, or swollen glands. Cervical cancer is very common, while other HPV-related cancers are rare. Normally, cervical abnormalities persist longer and progress more quickly in AFABs who have carcinogenic HPV infections than in AFABs who have non-carcinogenic infections or no HPV.⁴ 

Though HPV does not have any negative effect on fertility, family planning and pregnancy, pregnancy hormones may cause an increase in the size and number of genital warts if present (this is uncommon and rarely causes issues).

Management and treatment for human papillomavirus

Currently, there is no treatment for HPV, so prevention is important. As HPV is an STI, condoms offer some protection but do not eliminate the risk of sexual transmission because the virus can be found in areas that are not covered by a condom, such as on the skin in and around the genital area. Protection can also be gained from the HPV vaccine, but it does not protect against all types of HPV. 

Genital warts can be treated, however, and because there is no cure for HPV, these warts can reappear in the same or other places. Topical medications (such as salicylic acid, imiquimod, podofilox and trichloroacetic acid) may need to be applied directly to the lesions for weeks or months before effects are seen. Surgical (ablative) procedures include cryotherapy (freezing with liquid nitrogen), electrocautery (burning the wart with an electrical current), surgical removal and laser surgery. Pre-cancerous lesions found during colposcopy are removed either by cryosurgery, laser, surgical removal, loop electrosurgical excision procedure (LEEP) or cold knife conization. 

Diagnosis of human papillomavirus

There are no HPV tests that indicate if an individual has the virus or not. Diagnosis is usually made when symptoms occur. Genital warts are diagnosed clinically, though laboratory tests are recommended in some situations.³ Some of the tests your healthcare provider might run to diagnose HPV are:

• A biopsy is indicated if pigmented and ulcerated lesions are present or to confirm the diagnosis if the patient is immunocompromised
• HPV tests can conducted to detect the high-risk strains of the virus that may lead to cervical cancer if left untreated 
• Colposcopy is required if your healthcare provider notices any abnormal cells during biopsy
• A vinegar (acetic acid) solution test can be used to identify difficult-to-see flat lesions. Vinegar solution is applied to the genital area, and if HPV-infected, it turns the white 

Preventing human papillomavirus

Some of the ways to reduce your chances of contracting HPV are: 

HPV is transmitted by direct skin-to-skin contact, so using condoms during sexual intercourse will offer partial protection. Full protection is not possible with condoms because they do not cover the entire skin and mucosal surface that comes into contact during sexual intercourse. 

Routine cervical screening is another way of preventing high-risk HPV, as abnormal cervical changes can be detected before the precancerous lesions. It is still recommended for all AFABs above 25 years to have regular cervical screening despite completing the doses because the vaccine does not protect against all types of HPV that can cause cervical cancer.

Finally, vaccination is the best chance of preventing HPV infection, especially if given before becoming sexually active. Vaccines cannot help treat the already existing virus in the body but can protect from the new strains that the body hasn’t contracted. The vaccine can be given to persons who are already sexually active to prevent the acquisition of new HPV strains. 

FAQs

Who is at risk of human papillomavirus?

The risk factors for HPV infection include a weak immune system (e.g. HIV), having a new sexual partner, becoming sexually active at an early age, having multiple sexual partners and having non-monogamous partners. Peak incidence is usually soon after first sexual exposure.

Is human papillomavirus contagious?

HPV is highly contagious. The infection commonly affects the cutaneous (skin) and mucosal (mouth, throat, genital area, and anus) surfaces, so it easily spreads during sex (oral, vaginal, or anal) and skin-to-skin contact with the genital area.⁵

How common is human papillomavirus?

Though it is not the most common STI in the UK, it is still very common. In the general population, approximately 3.2% of AFABs have cervical HPV-16/18 infection at a given time. In the unvaccinated population, over 70% will be infected, and the majority of people in stable long-term relationships will infect their partners.

HPV is the most common sexually transmitted infection (STI) worldwide, with HPVs responsible for 630000 cancers each year.² 

When should I see a doctor?

Most HPV infections are asymptomatic and will clear within 1-2 years. However, it is advised to see your GP if you notice you have genital warts, if the genital warts cause discomfort or irritation, or if you notice changes to your cervix. 

Summary

Human papillomavirus (HPV) is the most common sexually transmissible infection (STI) in the world. The term HPV refers to a family of viruses which are further categorized as low-risk HPVs (LR-HPVs), which are responsible for anogenital and cutaneous warts, and high-risk HPVs (HR-HPVs), which are responsible for oropharyngeal (oral, tonsil, and throat areas) and anogenital (cervical, anal, vulvar, vaginal, and penile) cancers. Most sexually active people will be infected at least once in their lifetime, though they remain asymptomatic. HPV is diagnosed clinically but there are confirmatory laboratory tests available if doubts exist. There is no specific treatment for the HPV virus, but there are treatments available for genital warts and precancerous lesions. The spread of HPV can be prevented through safe sexual practices such as using condoms during sex, routine cervical screening and HPV vaccination. Make sure to schedule regular screening appointments with your healthcare provider. Please visit your GP if you are suspicious of contracting HPV.