Are intravaginal practices associated with human papillomavirus and the development of cervical cancer? A systematic literature review

Abstract

Background Intravaginal practices (IVPs) are behaviours undertaken by women in diverse global settings for the promotion of hygiene and sexual health. Although evidence is inconclusive, it has been suggested that they may be harmful and associated with adverse gynaecological outcomes. The objective of this study was to investigate whether there is an association between IVPs, human papillomavirus (HPV) infection and the development of cervical cancer. As human immunodeficiency virus (HIV) infection may be a factor accelerating progression, recent evidence on the association between IVPs and HIV was also considered. Methods A systematic review of primary observational studies was carried out according to PRISMA (Preferred Reporting Items for Systematic Reviews) guidelines. A detailed search strategy was developed and modified for use in six databases and grey literature sources, searching from 01 January 1990 to 03 June 2019. Due to marked heterogeneity, narrative synthesis was used to combine findings. Results Twenty studies met the review criteria. The majority of studies were cross-sectional, and of moderate to low quality. A total of 14,493 participants were included, from 15 countries. IVP prevalence ranged from below 10% to over 90% across study populations. Six of eleven studies found an increased risk of HPV infection with IVPs; five of seven studies found an increased risk of cervical disease with IVPs. Two studies examining association of IVPs with risk of HIV infection were identified: both found associations with intravaginal cleansing, one found an association with intravaginal insertion. Potential moderator variables including the types of substances used, the frequency, timing and duration of IVP use were assessed: evidence was conflicting and inconsistent. Conclusions Current evidence is largely suggestive of a harmful association between IVPs and the development of cervical cancer. However, significant methodological limitations were recognised; there is a need for well-designed studies using consistent definitions and classifications.