Bacterial vaginosis (BV) has been associated with human papilloma virus infection (HPV) and abnormal Pap smears. However, most studies neglect the existence of another entity, which sometimes is confused with BV: aerobic vaginitis (AV). This study intended to evaluate the relation between major Pap smear abnormalities (MPSA), HPV infection and AV or BV.
Cross sectional study, conducted between June 2014 and February 2016, consisting of the systematic collection of vaginal discharge to a slide, previously to the Pap smear. The slides were evaluated blindly by one of the authors, according to Donders’ criteria. All Pap smears were read at the institution’s laboratory; cobas® HPV (Roche©) test was performed in most smears.
Out of 959 cases, 832 (86,8%) were enrolled at the Cervical Pathology Unit of our institution. The mean age of patients was 41.4±10.92 years.
There were 13.6% (130/959) of cases of Pap smear worse than LSIL and 46.1% (436/946) were high risk (HR) HPV positive. The prevalence of BV was 15.5% (149/959) and that of moderate or severe AV was 7.4% (71/959). Women with BV had a relative risk (RR) of having a MPSA of 1.36 (IC 95% 0.92-2.01) while in those with AV the RR was 1.76 (IC 95% 1.10-2.79). If AV and BV were considered together (abnormal vaginal flora, AVF) the RR was 1.62 (IC 95% 1.16-2.27).
Neither AV nor BV were significantly associated with HR HPV infection as such (43.7% [31/71] vs. 54.7% [479/875], p=0.083 and 52.7% [78/148] vs. 54.1% [432/798], p=0.788, respectively). Stratifying for the genotypes (16, 18 and other HR HPV) there were also no differences.
AV, but not BV, was associated with major Pap smear abnormalities. However, if AV is misclassified as BV, an association still can be found between AVF and Pap smear abnormalities. Neither AV nor BV were associated with HPV infection, in the absence of cervical lesions.