DETERMINANTS OF HIGH-RISK HPV SEROPREVALENCE AND DNA PREVALENCE IN MID-ADULT WOMEN

Thesis (Master's)--University of Washington, 2014Objective: To estimate high-risk (hr) HPV seroprevalence and DNA prevalence then identify determinants of seropositivity and DNA-positivity in mid-adult women. Methods: We conducted a cross-sectional analysis of 378 females at the University of Washington who were between 30 and 50 years of age and self-reported no history of prophylactic HPV vaccination. Vaginal samples were tested for HPV genomic DNA using polymerase chain reaction for type-specific detection of HPV-16/18/31/33/35/39/45/51/52/56/58/59/68. Blood samples were tested for type-specific antibodies to the same HPV types using a Luminex-based assay. Health and sexual history were obtained via self-reported questionnaires. Risk factors for seropositivity to hr HPV, and hr HPV DNA-positivity were assessed using Poisson regression models to obtain prevalence ratios (PRs). Results: The mean (SD) age of participants was 38.7 (6.1) years, and the median lifetime number of male sex partners was 7. Over two-thirds (68.0%) of participants were seropositive for any of the 13 high-risk HPV types, and 14.8% were DNA positive for any hr HPV type. In multivariable analyses, married women or those living with a partner were less likely to be seropositive compared to single or separated women (adjusted prevalence ratio [aPR] = 0.84, 95% CI: 0.74-0.96). In addition, compared to women who had never used hormonal contraceptives, those who were current (aPR = 1.54, 95% CI: 1.03-2.32) or former users (aPR = 1.66, 95% CI: 1.12-2.48) were more likely to be seropositive. Women with lifetime numbers of sex partners equal to or more than 15 were borderline statistically significantly more likely to be seropositive compared to those with 0-2 partners (aPR=1.22, 95%CI: 0.98-1.53). Similar associations were seen with DNA positivity. In addition, there was a strong association between smoking status and DNA positivity to any hr HPV type with increased likelihood in women who were current smokers compared to women who had never smoked (aPR =2.30 95% CI: 1.26-4.22). Conclusion: Our results suggest that the majority of mid-adult women had evidence of current or prior hr HPV infection. Measures of probable increased exposure to HPV infection (single or separated marital status, increased lifetime number of sex partners and hormonal contraceptive use) were associated with both seropositivity and DNA positivity to hr HPV whereas being a current smoker was positively associated with hr HPV DNA positivity only