The global burden of HIV, its increasing feminisation, and chronic difficulties with development of options for HIV prevention all argue for an intensified re-examination of factors influencing the efficiency of heterosexual HIV transmission. This includes vaginal practices and products used by large numbers of women worldwide to tighten, dry, warm and clean their vagina. Women’s efforts to change their genital environment can undermine each component of innate defences against pathogens.¹ In particular, vaginal practices have been linked with loss of lactobacilli and disruption of the vaginal epithelium.^2–4 These practices may therefore be an important mediator in acquisition of STI, including HIV, or worsen pre-existing infections. Despite this, surprisingly little is known about the effects of specific vaginal practices on HIV transmission dynamics.

In past decades, both cross-sectional and longitudinal studies have found an association between intravaginal cleansing and adverse reproductive outcomes, including pelvic inflammatory disease, ectopic pregnancy and bacterial vaginosis (BV).^1,5,6 BV could be an intermediary factor between vaginal practices and HIV infection (fig 1). Though much uncertainty remains about the pathophysiology of BV, its accompanying inflammatory milieu, characterised by pro-inflammatory cytokines and immune cell changes, is likely to enhance HIV transmission.⁷ Also, immunological changes with BV can stimulate HIV expression, raising HIV levels in the genital tract virus and likely the infectivity of women.⁷ Acquisition of HSV-2 may also be higher among women with BV.⁸