Prevalence and epidemiology of aerobic vaginitis and bacterial vaginosis in Portuguese women Pedro Vieira-Baptista1, Sara Tavares1, Joana Lima-Silva1, Jorge Beires1, Gilbert Donders2 1Centro Hospitalar de São João, Porto, Portugal 2Femicare,Clinical Research for Women, Tienen, Belgium 3Department of Obstetrics and Gynecology, Antwerp University Hospital, Belgium INTRODUCTION: Bacterial vaginosis (BV) is a well-known condition of disturbed vaginal flora. However, also other entities are responsible for abnormal vaginal flora, such as aerobic vaginitis (AV), a term coined by Donders et al in 2002. Like BV, it is associated with major obstetrical and gynaecological complications, but still gets little attention. OBJECTIVES: To evaluate the prevalence and associated factors with both BV and moderate/severe AV in Portuguese women. MATERIAL AND METHODS: Cross-sectional study, conducted between June 2014 and February 2016, consisting of the systematic collection of vaginal discharge to a slide, in women referred for Pap smear. The slides were evaluated blindly (wet mount microscopy – phase contrast 400x) by one of the authors, according to Donders’ criteria. The Student’s t-test was used for continuous variables, the Fisher’s exact test for categorical variables and Pearson’s correlation coefficient to test the correlation and dependence between variables. A p-value <0.05 was considered statistically significant. RESULTS: r= 0.4559 p= 0.217 AV 7.4% (71/959) BV 15.5% (149/959) Mean age 43.6±11.5 years p=0,5 Mean age 42.6±10.4 years r= 0.4096 p= 0.273 n=959 41.4±10.92 years (21-75 years old) AV prevalence p= BV prevalence Smoking Yes 4.1% (6/148) 0.2 20.3% (30/148) No 6.8% (41/605) 15.7% (95/605) Menopause 12.0% (23/192) 0.013 16.7% (32/192) 0.7 6.3% (48/767) 15.3% (117/767) Contraception None/tubal ligation 7.3% (16/229) 17,4% (43/247) vs. Oral contraceptives 4.2% (13/310) 11.3% (35/310) 0.05 Condoms 14.3% (7/49) 0.08 IUD 10.0% (2/20) 0.6 35.0% (7/20) 0.07 IUS 7.6% (5/66) 0.8 16.7% (11/66) 1.0 IUD/IUS 8.1% (7/86) 20.9% (18/86) 0.5 Progestins (implant, pill) 7.2% (5/69) 20.1% (14/69) n=95 CONCLUSIONS: AV had about half the prevalence of BV in Portuguese women (7.4% vs. 15.5%); AV was more common in postmenopausal women; There seemed to be a trend for AV to be more frequent in condom users; BV was less prevalent in OC users; There seemed to be a trend for BV to be more frequent in IUD, but not in IUS, users. REFERENCES: Donders, G. et al. Definition of a type of abnormal vaginal flora that is distinct from bacterial vaginosis: aerobic vaginitis. BJOG 109, 34–43 (2002) Donders, G., Bellen, G. & Rezeberga, D. Aerobic vaginitis in pregnancy. BJOG 118, 1163–70 (2011)