Findings from a meta-analysis of 65 studies conducted in 35 countries indicate that nearly a third of men older than 15 years are infected with human papillomavirus (HPV), and 1 in 5 are carriers of high-risk HPV (HR-HPV). These estimates provide further weight to arguments in favor of vaccinating boys against HPV to prevent certain types of cancer.
"Our results support that sexually active men, regardless of age, are an important reservoir of HPV genital infection," wrote the authors. "These estimates emphasize the importance of incorporating men into comprehensive HPV prevention strategies to reduce HPV-related morbidity and mortality in men and ultimately achieve elimination of cervical cancer and other HPV-related diseases."
Literature Review
HPV infection is the most common sexually transmitted viral infection worldwide. More than 200 HPV types can be transmitted sexually, and at least 12 types are oncogenic. Previous studies have shown that most sexually active men and women acquire at least one genital HPV infection during their lifetime.
Although most HPV infections are asymptomatic, they can lead to cancer. Indeed, HPV is involved in the development of cervical, vulval, and vaginal cancers, as well as oropharyngeal and anal cancers, which also affect the male population. More than 25% of cancers caused by HPV occur in men.
Despite these observations, fewer epidemiologic studies have assessed HPV infection in men than in women. To determine the prevalence of HPV infection in the male population, Laia Bruni, MD, MPH, PhD, an epidemiologist at the Catalan Institute of Oncology in Barcelona, Spain, and her colleagues collated data from 65 studies conducted in 35 countries pertaining to males older than 15 years.
In this literature review, the researchers selected studies that reported infection rates in males without HPV-related symptoms. Studies conducted exclusively in populations that were considered at increased risk for sexually transmitted infections (STIs) were excluded. Overall, the analysis included close to 45,000 men.
Prevalent HPV Genotype
Testing for HPV was conducted on samples collected from the anus and genitals. The results show a global pooled prevalence of HPV infection in males older than 15 years of 31% for any HPV and 21% for HR-HPV. One of these viruses, HPV-16, was the most prevalent HPV genotype (5% prevalence).
HPV prevalence was highest among young adults. It stabilized and decreased from age 50 years. Between ages 25 and 29 years, 35% of men are infected with HPV. It should be noted that prevalence is already high in the youngest group, reaching 28% in males between the ages of 15 and 19 years. The variations are similar for HR-HPV infections.
This age-related change is different from rates in women. Among the female population, HPV prevalence peaks soon after first sexual activity and declines with age, with a slight rebound after ages 50–55 years (ie, often after or around the time of menopause), wrote the researchers.
The results also show country- and region-based disparities. The pooled prevalence for any HPV was highest in Sub-Saharan Africa (37%), followed by Europe and Northern America (36%). The lowest prevalence was in East and Southeast Asia (15%). Here again, the trends are similar with high-risk HPV.
Preventive Measures
"Our study draws attention to the high prevalence, ranging from 20% to 30% for HR-HPV in men across most regions, and the need for strengthening HPV prevention within overall STI control efforts," wrote the authors.
"Future epidemiological studies are needed to monitor trends in prevalence in men, especially considering the roll-out of HPV vaccination in girls and young women and that many countries are beginning to vaccinate boys."
In France, the HPV vaccination program was extended in 2021 to include all boys between the ages of 11 and 14 years (two-dose schedule), with a catch-up course in males up to age 19 years (three-dose schedule). This is the same vaccine program as for girls. It is also recommended for men up to age 26 years who have sex with other men.
The 2023 return to school will see the launch of a general vaccination campaign aimed at 7th-grade students, both boys and girls, with parental consent, to increase vaccine coverage. In 2021, vaccine uptake was 43.6% in girls between the ages of 15 and 18 years and scarcely 6% in boys, according to Public Health France.
Two vaccines are in use: the bivalent Cervarix vaccine, which is effective against HPV-16 and HPV-18, and the nonavalent Gardasil 9, which is effective against types 16, 18, 31, 33, 45, 52, and 58. Both provide protection against HPV-16, the type most common in men, which is responsible for more than half of cases of cervical cancer.
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.