Do intravaginal practices make African women susceptible to HIV?

February saw the publication of what is probably the largest study of the association in sub-Saharan Africa between intravaginal practices – e.g. cleaning with cloth, paper or soap – and HIV incidence. It is a meta-analysis pooling data of 15,000 women deriving from 13 prospective longitudinal cohort studies.  A preponderance of HIV affected sub-Saharans are women (12 as opposed to 8 million), with 15-24 year women eight times more likely to be affected than equivalent men.  So, given a prevalence of intravaginal practices of 95% among women of certain areas, it is tempting to seek a causal link.

If the establishment of a direct causal link was ever a specific objective of the study, it has proved elusive. But the results of this analysis do indicate an increased level of HIV risk for practices such as those involving cleaning with cloth or paper (hazard ration = 1.47), and cleaning with soap (hazard ratio = 1.24).

So what are the policy implications\?  Above all, the authors urge the importance of taking into account current intravaginal practices – when considering vaginal microbicides for HIV, for a start; but also more generally in the development of new female-initiated interventions which avoid the risks attendant on some current intravaginal practices. The authors suggest, for example, that behavioural interventions successful in stopping young Americans from vaginal douching might be adaptable to the African context.

Nicola Low et al., “Intravaginal Practices, Bacterial Vaginosis, and HIV Infection in Women: Individual Participant Data Meta-analysis”, PLoS Medicine, Feb. 2011