Geographical disparities in human papillomavirus herd protection

Variation in cervical cancer screening test utilization and results in a United States-based program

BACKGROUND

Little is known about cervical cancer screening strategy utilization (cytology alone, cytology plus high-risk human papillomavirus [HPV] testing [cotesting], primary HPV testing) and test results in the United States.

METHODS

Data from the Centers for Disease Control and Prevention's National Breast and Cervical Cancer Early Detection Program were analyzed for 199,578 persons aged 21-65 years screened from 2019 to 2020. Screening test utilization and results were stratified by demographic characteristics and geographic region. Age-standardized pooled HPV test positivity and genotyping test positivity were estimated within cytology result categories.

RESULTS

Primary HPV testing was performed in 592 persons (0.3%). Among the remaining 176,290 persons aged 30-65 years, cotesting was utilized in 72.1% (95% confidence interval [CI] 71.9-72.3%), and cytology alone was utilized in 27.9% (95% CI 27.7-28.1%). Utilization of cytology alone varied by geographic region, ranging from 18.3% (95% CI 17.4-19.1%) to 49.0% (95% CI 48.4-49.6%). HPV genotyping test utilization among those with positive pooled HPV test results was 33.9%. In persons aged ≥30 years, variations in age-adjusted test results by region were observed for pooled HPV-positive test results and for HPV genotyping-positive test results.

CONCLUSIONS

Cervical cancer screening strategy utilization and test results vary substantially by geographic region within a national screening program. Variation in utilization may be due to regional differences in screening test availability or the preferences of healthcare systems, screened persons and/or clinicians. Test result variations may reflect differing risk factors for HPV infections by geographic region.

Geographical disparities in human papillomavirus herd protection

BACKGROUND

Human papillomavirus (HPV) vaccination has occurred unequally across the United States, potentially contributing to uneven vaccine-type HPV prevalence between regions. We examined whether emerging vaccine-related herd protection exhibits regional differences among unvaccinated girls and women.

METHODS

We evaluated the prevalence of vaginal HPV among women 14-59 years of age from 2003 to 2014 using repeated cross-sectional data from the National Health and Nutrition Examination Survey (NHANES). Women who provided an adequate vaginal swab sample were included. Vaginal prevalence of vaccine-type HPV (types 6, 11, 16, 18) were examined in four regions of the United States between 2003 and 2014. We examined vaccine-type HPV prevalence in 2007-2014 in each US census region among younger participants (14-34 years old) stratified by vaccination status to determine whether one or both groups contributed to uneven HPV prevalence.

RESULTS

A total of 12 175 participants 14-59 years of age met inclusion criteria. Vaccine-type HPV prevalence decreased in all regions. Vaccine-type HPV varied by region only among unvaccinated 14-34 year olds, with a higher prevalence in the Midwest (13.8%, 95% confidence interval (CI): 10.7-17.0) and South (12.5%, 95% CI: 10.2-14.8) compared to the Northeast (8.9%, 95% CI: 6.5-11.2). No regional variation in vaccine-type HPV prevalence was observed among vaccinated participants.

CONCLUSIONS

Higher prevalence of vaccine-type HPV among unvaccinated women in the South and Midwest may contribute to regional disparities in HPV-related cancer incidence, as emerging herd immunity may not be as strong in those regions.