Gynaecological infections as risk determinants of subsequent cervical neoplasia

A longitudinal cohort study was carried out to determine whether gynaecolog ical infections other than human papillomavirus (HPV) are also related to t he subsequent increased risk of cervical neoplasia. The study comprised 191 14 women attending the organized mass screening in Finland in 1985-1990 wit h cytologically detected HPV, Actinomyces, herpes simplex, Trichomonas vagi nalis, or yeast. The women were followed-up for subsequent preinvasive lesi ons and invasive cancers until the end of 1994 by linkage to the nation-wid e Cancer Registry. Standardized incidence ratios (SIR) with rates for the w hole of Finland as reference and 95% confidence intervals (CI) were estimat ed. Trichomonas vaginalis and HPV were associated with a high relative risk of cervical cancer, SIR 6.4 (CI 3.7-10, preinvasive lesion and invasive ca ncer combined) and SIR 5.5 (CI 4.2-7.2, preinvasive lesion and invasive can cer combined), respectively. Herpes simplex was rarely detected, but the hi ghest and statistically most significant point estimate was observed (SIR 1 2, CI 2.4-34, preinvasive lesion and invasive cancer combined). Neither Act inomyces nor yeast was associated with a significantly increased risk of ce rvical cancer. None of these results could be accounted for by the confound ing effect of the other infections. Our results, based on a prospective des ign, lead us to propose that Trichomonas vaginalis and herpes simplex virus are also predictors for cervical neoplasia.