Among sexually experienced adults, prevalence of human papillomavirus (HPV) infection was primarily reflective of higher number of lifetime sexual partners, specifically >5 lifetime sexual partners, according to study results published in Clinical Infectious Diseases.
Using data from the 2013-2016 National Health and Nutrition Examination Survey (NHANES), researchers examined the relationship between current and past sexual behaviors on prevalent burden of HPV infection stratified by sex, age group, and number of lifetime sexual partners. The analysis included 5093 participants aged 18-59 years who had an evaluable HPV test, reported at least 1 lifetime sexual partner, and had not received an HPV vaccination.
The primary outcomes included the crude prevalence of genital vaccine-type HPV, defined as the detection of ≥1 genotype in the Gardasil-9 vaccine (6, 11, 16, 18, 31, 33, 45, 52, or 58), genital high-risk HPV infection defined as the detection of ≥1 high-risk HPV genotype (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, or 68), and any genital HPV infection defined as the detection ≥1 of the 37 possible genotypes. Since the HPV vaccine is presumed to prevent only newly acquired infections, the crude prevalence of each outcome was also calculated after excluding participants at highest risk for newly acquired infection, defined as those who reported a new sexual partner within the past 12 months.
Among both men (n=2495) and women (n=2598), the distribution of race/ethnicity, marital status, and cigarette smoking status varied substantially by age group. Among men, the median number of lifetime sexual partners increased with age: 5 for persons aged 18 to 26 years, 8 for persons aged 27 to 45 years, and 10 for persons aged 45 to 59 years (interquartile range [IQR] 3-12, 3-19, and 5-20, respectively). Among women, the median number of lifetime sexual partners was 5 across all age groups. Conversely, the proportion reporting a new sexual partner in the past 12 months substantially decreased with older age in both men and women: 40.7% and 28.4% among persons aged 18 to 26 years, 16.6% and 10.5% among persons aged 27 to 45 years, and 9.3% and 3.5% among persons aged 45 to 59 years, respectively.
In each age group, genital HPV prevalence was higher among persons with >5 lifetime sexual partners compared with 1 to 5 lifetime sexual partners in both men and women. There were only slight reductions in HPV prevalence after removing participants who reported a new sexual partner in the past 12 months. Among men with >5 lifetime sexual partners, the adjusted prevalence of 9-valent vaccine type HPV infection was 20% in the full group (95% CI, 16.6-23.3) compared with 18.8% (95% CI, 15.0-22.6) among those with no new sexual partners. Among women with >5 lifetime sexual partners, the adjusted prevalence of 9-valent vaccine-type HPV infection was 13.4% in the full group (95% CI, 9.9-17.0) compared with 12.1% (95% CI, 8.8-15.4) among those with no new sexual partners.
Despite having a large nationally representative sample, there were some notable limitations. Not all individuals provided genital samples or questionnaire data. While NHANES is the largest population-based survey of HPV prevalence, the sample size was still insufficient to allow for more granular stratification of lifetime sexual partners and age. Plus, since DNA extraction method used in NHANES results in an increased test sensitivity, this “may explain why HPV prevalence is relatively high in older adults, such as post-menopausal women, who may be more likely to have low viral load infections,” noted the researchers.
“Thus, when discussing the risks/benefits to vaccination of adult men and women for clinical decision making, it will be important to incorporate the likely ongoing risk of HPV infection due to recurrence of previously acquired and controlled infections as well as risks of new acquisitions,” concluded the researchers.
Rositch AF, Patel EU, Petersen MR, Quinn TC, Gravitt PE, Tobian AAR. Importance of lifetime sexual history on the prevalence of genital human papillomavirus among unvaccinated adults in NHANES: implications for adult HPV vaccination [published online July 25, 2020]. Clin Infect Dis. doi:10.1093/cid/ciaa1050
This article originally appeared on Infectious Disease Advisor