Study: More Than 4 in 5 MSM on PrEP Have High-Risk HPV

Investigators in France say that although pre-exposure prophylaxis (PrEP) use among men who have sex with men (MSM) is an important strategy in HIV prevention, its use has also been linked to a high prevalence of anal and oral high-risk human papillomavirus (HR-HPV) infection.

A new study published in the journal Open Forum Infectious Diseases offers some of the latest findings showing that although an increase in PrEP availability and use can lead to a sharp decline in new HIV diagnoses, new cases of sexually transmitted infections (STIs) are still prevalent. According to the investigators of the study, use of a once-daily antiretroviral pill has a clinical and epidemiological impact on HIV new infections, but PrEP can also lead to an increase in sexual behaviors such as condomless anal intercourses with different partners, adding to the risk for anal STIs such as chlamydia, syphilis, and gonorrhea among MSM taking PrEP.

“Another unsuspected growing health problem that could silently rise in this population group is anal infection with high-risk (HR)-HPV and related anal cancers,” the investigators report. “Pursuing risk sexual behaviors such as condomless receptive anal intercourse and increased number of sexual partners in HIV-negative MSM uptaking PrEP enhances a sexual behavior strongly associated with high-risk acquisition of anal HR-HPV in MSM. Furthermore, oral infection by HR-HPV increases the risk to develop oropharyngeal cancer, and MSM are found to be at higher risk for oral HR-HPV infection than the general population.”

Investigators studied 61 MSM, who had not received an HPV vaccine, from June to October 2018. Among the study group, the mean age was 36.1 years and about 1 in 3 men were in a stable relationship. About 72% reported having had sexual intercourse with at least 10 partners in the last 12 months, and nearly 30% reported at least 50 partners in that time. In addition, 21.3% of participants reported always using a condom during sex, 75.4% reported inconsistent use of condoms during sex, and 3.3% reported never using condoms during sex.

Among study participants, 57 (93.4%) had anal HPV infection, including 50 (81.9%) participants with HR-HPV that can lead to HPV-related cancers. Investigators found anal infection with multiple HPV genotypes in 73.8% of participants and multiple HR-HPV infections containing an average of 3.1 HR-HPV genotypes per anal specimen in 44.3% of the MSM in the study. HR-HPV type 33 was the most prevalent genotype, followed by HPV-42, HPV-53, HPV-51, HPV-6, and HPV-70. Although all age groups had high rates of HPV infection, 100% of participants older than 50 years had HPV and rates of HR-HPV were highest in MSM ages 19 to 29 years.

Study investigators also found that having no more than 10 different sexual partners in the last 12 months constituted a protective factor for anal infection with multiple HPV genotypes. “MSM reporting condomless receptive anal intercourse were 10.4-fold more likely to have anal HPV infection than those having exclusively insertive anal intercourse,” the research team added. “These findings confirm that the risk of anal STIs acquisition is strongly associated with the sexual behavior and the number of sexual partners in MSM population.”

Although PrEP will continue to be key to preventing new HIV infections, the study investigators emphasize the need for PrEP sexual behavioral interventions and education, anal bacterial STI treatment when necessary, regular anoscopy, anal and oral HPV DNA screening, and HPV vaccination with the 9-valent Gardasil 9 vaccine for eligible MSM.