Contradictory data exist on the importance of abnormal vaginal microbiota, especially bacterial vaginosis (BV), on the natural history of human papillomavirus (HPV) infections. This is why we studied the effects of BV and yeast infection on outcomes of HPV infection, as well as the risk factors for the outcomes on asymptomatic women participating in the Finnish Family HPV (FFHPV) Study during a 6-year-follow-up (FU).
Asymptomatic pregnant women (n=329) were enrolled in third trimester of their index pregnancy. Cervical scrapings were collected for HPV testing at baseline and at 6, 12, 24, 36 mo and six-year-follow-up (FU)-visits. At the same time points also a routine cervical pap smear was taken. HPV genotyping was done with nested PCR and Multimetrix Assay to determine the point prevalence and persistence of the HPV infections. Pap smears were scored for BV and yeast infection. Covariates of the outcomes were analyzed using generalized equation (GEE) and Poisson regression.
Altogether, 76.6% (252/329) of the women tested HPV-positive at least once during the six-year FU. BV was detected in 57.4% (189/329) and yeast infection in 22.9% (73/329) of the women. HPV+ samples presented with significantly more abundant leucocytes in the Pap smear (p=0.023). BV (OR 2.75, 95% CI 1.77-4.27) and yeast infection (mild, moderate, severe) (p=0.007) were strongly linked with HPV positivity. In addition, BV was significantly associated with the HPV persistence (p=0.024; OR 2.15, 95% CI 1.13-4.08) while no such link was found between yeast infection and HPV persistence.
BV and candida infection were associated with prevalent cervical HPV-infection. In the longitudinal setting, BV was linked with HPV persistence implicating a possible significance as an important co-factor for chronic HPV infections.