Master's Project Title:

Type-Specific Human Papillomavirus Results at the Time of Cytological Screening in a Clinic-Based Population of Women in the United States: Prevalence, Persistence Rates, and Likelihood of Persistence

MCH Student:

Elizabeth M. Ralston, Zhong-ze LI, MS, Ronald C. McGlennan, MD, Wendy L. Hellerstedt, MPH, PhD, Levi S. Downs, Jr., MD

Date of Defense:

August 20, 2007


Objective: To report the type-specific prevalence, persistence rates, and the likelihood of persistence of human papillomavirus (HPV) in a cohort of women undergoing cytological screening in the United States.

Study Design: We retrospectively evaluated HPV prevalence in women who had type-specific polymerase chain reaction (PCR) HPV testing performed as a component of their cytologic screening. We determined rates of persistence and the likelihood of persistence in a subset of women with two sequential test results. Through a comparison of PCR results and hypothetical pooled test results, we illustrated the occasion where pooled HPV testing methods mask true HPV type-specific clearance.

Results: We reviewed the PCR results of 73,371 women for HPV prevalence and analyzed a subset of 953 women for persistence. HPV was detected in 31% of women and high-risk HPV was detected in 23%. HPV-16, -53, -52, and -31 were the most prevalent types. Of the 953 with two consecutive tests, 39% had persistent HPV infection. High-risk HPV persistence was detected in 34% of women who initially were positive for high-risk HPV. The likelihood of persistence was highest among the high-risk group of viruses with genotypes similar to HPV -16. We compared the rates of persistence in our type-specific results to projected persistence rates determined by hypothetical pooled tests. We found that 19% of women classified as having a persistent high-risk HPV infection based on a pooled analysis did not have persistent infection when type-specific results were considered, instead they had a newly present high-risk HPV that a pooled test would not have distinguished.