Asymptomatic Bacterial Vaginosis in Cervical Cytology: A Preliminary Report of Incidental Finding in Routine Cervical Cancer Screening

Abstract

Background: Bacterial vaginosis is a complex pathogenic group of bacteria which can cause a wide range of symptoms in affected women in Obstetric and Gynaecological practice. Its occurrence usually indicates alteration in the normal vaginal flora expected in majority of the women of reproductive age. Amongst the maintenance agents of the vaginal health, lactobacilli occupy a prominent place. Asymptomatic bacterial vaginosis is postulated to be linked to the development of cervical intraepithelial neoplasia by some researchers while some differ in this regard. Objective: To determine the rate of occurrence of asymptomatic bacterial vaginosis and associated factors in women who underwent cervical cytology for cervical cancer screening. Study Design: A cross sectional study involving microscopic examination of cervical smears of eligible clients presenting for routine Pap smear. Setting: The study was carried out in a well woman’s facility established and manned by female medical doctors in Enugu state with the assistance of trained nursing staff. Various female cancers and other communicable and non-communicable disease screening are performed at the centre. The services are available to the general public including various parts of the state and other nearby states. Methods: This preliminary study was carried out on women presenting for cervical cancer screening between February and July 2018 in a well woman’s centre in Enugu. Information on the socio-demographic and gynaecological history of the study participants were obtained and recorded in designated proformas. Smears that showed changes suggestive of bacterial vaginosis on microscopy were set aside for further evaluation. Such changes included: a conspicuous absence of normal flora of lactobacilli; filmy background of coccobacilli replacing the lactobacilli, individual squamous cells covered by a layer of bacteria (clue cells); viable squamous cells showing reactive changes identified as increased nuclear size, perinuclear halo and binucleation. Data entry and analysis were done using statistical package for social sciences (SPSS) computer software version 21.0. Results: 285 eligible women had cervical smear done during the first six months of the 2-year project at the centre. 50.9% were above reproductive age (>45 years), 38.2% were in second half of reproductive age (31 - 45), 10.9% were in the early reproductive age (15 - 30). 13% of the women were nulliparous, 51.9% were para 1 - 4, and 35.1% were grand multiparous. Of the 285 Pap smear slides viewed, 31 had bacterial vaginosis by the above criteria. This gave a prevalence of 10.8% in the reviewed cytological smears. There was an association of bacterial vaginosis with reproductive age. There was however, no association with age at coitarche and parity. There was also, no association of bacterial vaginosis with contraceptive use. There was no association between abnormal cervical cytology and asymptomatic bacterial vaginosis with absent lactobacilli. Conclusion: Prevalence of bacterial vaginosis is significant in our study population who were asymptomatic. Cervical smear should be taken advantage of as a tool for both cervical pre-cancer and bacterial vaginosis screenings since same sample can simultaneously be used for both conditions during cytology. Bacterial vaginosis may be unlikely involved in pathogenesis of cervical intraepithelial neoplasia. Recommendation: Researchers should harmonise the standards/criteria for the diagnosis of bacterial vaginosis because there are varied criteria for the diagnosis in the literature. Given, the dual advantage of pap smear in diagnosing cervical pre cancer stages and infections, more elaborate studies are needed to determine the usefulness of treatment or otherwise of bacterial vaginosis which constitutes significant incidental findings.