• Infectious Diseases
• Sexual Medicine
• Epidemiology
• Public Health
• Primary Care

Human papillomaviruses (HPV) are the most common sexually transmitted infection (STI) in men, but the majority of cases are asymptomatic and clear naturally within 2 years.1 HPV has been associated with genital warts as well as anogenital and oral cancers in both sexes. HPV prevalence in men has generally been comparable to the rate of HPV infection in women; thus, any fluctuations in female HPV infections would most likely result in similar HPV infections in men. Before the introduction of female-oriented HPV vaccination in the UK in 2008, the lifetime risk of acquiring HPV was estimated to be around 75% for most sexually active individuals.2

There is little reliable data on HPV infection rates in men because HPV prevalence varies between countries and social groups, making it difficult to generalise. One multicontinental study of heterosexual men has indicated that 9 per 100 become HPV-infected each year.3 In the prevaccination era, HPV prevalence in men peaked in early adulthood (age group 21–25 years old), then remained fairly constant with increasing age.4 Approximately 16% (range 1%–84%) of men were actively infected with HPV.5 In about 70% of cases, HPV infection is cleared within 8 months, and over 95% of men do not present with HPV infection beyond 18 months from diagnosis.6 Less than 1% of infected men present with any HPV-related clinical symptoms; hence, most of them are not aware of their infection.

Only two population studies have estimated HPV prevalence in the UK. One study conducted between 1999 and 2001 as part of the National Survey of Sexual Attitudes and Lifestyles II asked participants to provide urine samples in order to detect HPV.7 The results showed that 17% of men were positive for any HPV type and 9.6% for high-risk types. The peak HPV infection occurred approximately 5 years after the initial sexual debut. Another study by Desai et al conducted in England used HPV antibody markers to detect previous HPV infection.8 The study recruited men aged 10–49 years old as part of a seroepidemiological survey in 2002–2004. The results showed that 7.6%, 2.2%, 5.0% and 2.0% of men were seropositive for types HPV6, HPV11, HPV16 and HPV18, respectively. The findings support the evidence that only a proportion of men previously infected with HPV might seroconvert. Hence, initial HPV infection not resulting in antibody response could reoccur. Nevertheless, both studies were conducted before the introduction of female HPV vaccination, and therefore more research is needed to identify whether HPV vaccination of women has had an impact on HPV rates in men in the UK.

Persistent HPV infection with HPV16 and HPV18 is associated with cancers of the cervix, anus, vagina, vulva, penis and oropharynx.9 While HPV-related penile and anal cancers are relatively rare (~1 per 100 000), it is estimated that approximately half of all head and neck cancers in men (25 per 100 000) are due to persistent HPV infection.10 Two epidemiological analyses have shown that HPV-induced oropharyngeal cancers are increasing and are affecting younger men.11 12 Despite a decrease in tobacco use (universally associated with oral cancers), there has been a rapid increase in oropharyngeal cancers in a sexually active population, especially in individuals who practise oral sexual intercourse.13 UK data on oropharyngeal cancers demonstrated that at least 37% of oral tumours are associated with HPV infection.14 Thus, there is an urgent need to protect men against HPV-related oral cancers.

HPV6 and HPV11 cause anogenital warts associated with significant physical and psychological morbidity, as well as substantial healthcare costs of approximately £58 million related to diagnosis and treatment in the UK.15 Before the introduction of HPV vaccination, there were around 40 000 cases of male genital warts each year, giving an incidence of 150 per 100 000 men per year.16 It is predicated that in the postvaccination era, the incidence of HPV-related diseases in men would decline, mirroring the sharply declining HPV incidence in women; however, the exact impact on male HPV infections is yet to be established.

In 2008, the UK introduced routine HPV vaccination of adolescent girls at school. This female-oriented programme has been very successful, achieving coverage of over 80% and dramatically decreasing the HPV infection rates in young women.17 Data from Australia, which implemented a similar vaccination strategy with quadrivalent HPV vaccination, showed a decline in HPV and genital warts in women and heterosexual men of corresponding age, suggesting that vaccinating one sex could lead to ‘herd protection’ — a population-level-acquired protection against a virus among both vaccinated and unvaccinated individuals.18 However, herd protection would not safeguard men who have sex with individuals from unvaccinated populations, such as men who have sex with men (MSM), who do not benefit from female HPV vaccination. Hence, in 2015 the UK Joint Committee on Vaccination and Immunisation (JCVI) recommended targeted HPV vaccination for sexually active MSM below the age of 46 delivered through sexual health clinics to tackle HPV-related anogenital warts and anal cancers in this population.19 Although the effectiveness of this strategy is uncertain, it is important to consider which other groups of men might not benefit from the herd protection following female-only HPV vaccination.