Can Douching Increase HIV Risk?

There have long been suggestions that the practice of douching, both vaginal and rectal, may increase the risk of HIV by removing so-called "good" bacteria from the vaginal/rectal flora while causing stresses to fragile mucosal tissues that line these organs.

Could this be true? Might practices thought to improve personal health and hygiene unwittingly increase the risk of HIV without us even knowing it?

Early Studies Spur Debate and Confusion

As far back as the late 1990s, a number of studies had indirectly linked douching to HIV and other sexually transmitted infections (STIs). Many of these studies were conducted in Africa, where it was suggested that vaginal douching not only increased the risk of bacterial vaginosis by 60% but did so most commonly in women with HIV. While the researchers could not establish a clear link between HIV and douching, they strongly suggested that the potential of transmission was high.

However, there were a number of factors that made a clear link difficult to establish. Among these was the fact of that most of the early studies were conducted in resource-limited settings, like Africa, where the general health of the population and access to care often informed the results. Most of the research has also been conducted among commercial sex workers (CSWs), whereby the association between HIV and other practices (such as condom use, anal sex, drug use) would arguably have contributed more to infection risk than douching itself.

Moreover, the results from the trials were often contradictory. One study in Kenya, for example, concluded that vaginal douching was associated with 1.5 to 2.5 times greater condom use among CSWs when compared to their non-douching counterparts. A Chinese study several years later showed just the opposite, with vaginal douching associated with far less condom use.

The contradictory nature of the research only served to fuel the on-going debate, with many claiming that there were simply too many possible spoilers to establish a clear link between HIV and douching practices.

Recent Studies Provide Greater Clarity

By 2012, a number of larger studies provided clearer insights into the potential for HIV infection among those who regularly douche.

The first, conducted as part of the HPTN 035 HIV microbicide trials, included 3,099 sexually active, HIV-negative women in Malawi, South Africa, Zambia, Zimbabwe, and Philadelphia. According to the research, over a third of the participants had bacterial vaginosis at the onset of the trial, the proportion of which did not change throughout the entire three-year course, either among women who practiced vaginal washing or those who did not.

Considered statistically relevant, the results of the HPTN 035 directly contradicted many of the earlier studies which had suggested that bacterial vaginosis—itself associated with increased HIV risk—might be spurred by vaginal douching.

A second study conducted in Los Angeles also showed no link between either vaginal or rectal douching and HIV in women. The study was particularly as 71% of the participants reported having anal sex, with 18% reporting such contact over the previous month. (Receptive anal sex remains the highest risk activity associated with HIV acquisition, as much 18 times greater than vaginal intercourse.)

HIV and Rectal Douching in Men

A final study, investigating the link between HIV and rectal douching in men who have sex with men (MSM), painted a far more complicated picture. Of the 413 MSM who practiced rectal douching, 44% had HIV vs. only 18% of those who did not douche. Douching was also associated with nearly twice the number of STIs among study participants (21% vs. 11%).

While, on the surface, the findings appeared concerning, the researchers were quick to point out that rectal douching, in and of itself, was not the cause for the increased rates. Rather, rectal douching was readily associated with practices well known to increase HIV risk, namely multiple sex partner and recreational drug use.

Simply put, among the MSM in the survey, those who douched had an average of five sex partners over the previous three months vs. non-douchers who had two. Recreational drug use is also seen to contribute to a four-fold increase in HIV transmissions when compared to non-drug-using MSM.

Based on the data, the researchers concluded that rectal douching was more a practice associated with high-risk activities than a stand-alone factor and that it was ultimately the number of sex partners that played the greatest role in the increased rates. In fact, most research today suggests that MSM with four or more sex partners within a six month period have a 32.3% greater risk of HIV irrespective of all other behavioral factors, including alcohol/drug use and condom-less sex.

The researchers concluded that rectal hygiene practices are already common, particularly among MSM, and is not likely associated with STI risk.