Background: One early measure of HPV vaccine impact would be reduction in prevalence of HPV types 6, 11, 16, 18 in cervical specimens from young women.
Objectives: To assess baseline HPV prevalence in cervical specimens collected from females prior to HPV vaccine use in two MCOs.
Methods: Cervical specimens collected during routine cervical cancer screening from 11-29 year old females who had no prior HPV vaccination were consecutively sampled from 2006-2007. In Northern California Kaiser Permanente (NCK), the sample was a swab in Specimen Transport Media (Qiagen, Valencia, CA, USA), and in Northwest Kaiser Permanente (NWK) the sample was a SurePath (TriPath Imaging, Burlington, NC, USA) liquid cytology specimen. Specimens were sent to CDC and evaluated for 37 HPV genotypes using the Roche Linear Array.
Results: A total of 10,209 specimens were evaluated. Overall, 3588 (35%) specimens had any HPV type detected, and this was similar by site (37% in NCK and 33% in NWK). The most common detected type (7.5%) was HPV 16. Prevalence of HPV 6, 11, 16 or 18 was 11.4% and did not vary by site; prevalence was 18% among 11-19 year old females (14% HPV 16 or 18), 12% among 20-24 year old women (10% HPV 16 or 18), and 7% among 25-29 year old women (6% HPV 16 or 18). Among specimens from women with low grade squamous intraepithelial lesions (n=396), 37% had HPV 16 or 18 detected; among specimens from women with high grade squamous intraepithelial lesions (n=31), 64% had HPV 16 or 18 detected.
Conclusions: HPV is commonly detected from women attending routine cervical cancer screening; HPV-16 was most common. HPV vaccine-type prevalence was highest among 11-19 year old females.
Implications for Programs, Policy, and/or Research: Baseline data on HPV prevalence from two MCOs may be useful to evaluate HPV vaccine impact.