Kenyan sex workers who douche are more likely than those who do not to have bacterial vaginosis, a condition that is associated with an increased risk of HIV infection.¹ In a sample of more than 500 Nairobi sex workers, 72% of whom reported douching regularly, 49% had bacterial vaginosis and 30% were HIV-positive. Douching raised the risk of bacterial vaginosis by 60%, and bacterial vaginosis was significantly more common among HIV-positive women than among those who were HIV-negative (odds ratio, 1.5). No direct relationship was found between douching and HIV infection, however, a result that the researchers attribute to greater condom use among sex workers who douche.

To determine whether an association exists between vaginal douching and sexually transmitted infections (STIs), researchers analyzed survey data from 540 sex workers in Nairobi, Kenya, who were screened as part of a trial testing the efficacy of azithromycin for STI prevention. The survey included questions regarding douching (defined as insertion of any liquid into the vagina), sexual behavior, sexual health and reproductive history, as well as other demographic and behavioral information. The women were also given a full physical examination, including a gynecologic exam and STI screening.

Thirty percent of the women screened tested positive for HIV, while 49% tested positive for bacterial vaginosis, 16% for trichomoniasis, 10% for candidiasis, 10% for gonorrhea, 6% for syphilis and 1% for genital ulcers. Using multivariate analysis, researchers found that women who were HIV-positive had been significantly younger at the time of their first sexual experience and were significantly more likely to drink alcohol than were women who were HIV-negative. Women who were HIV-positive were also more likely than those who were HIV-negative to have bacterial vaginosis, trichomoniasis, gonorrhea and genital ulcers (odds ratios of 1.5, 2.7, 1.9 and 6.0, respectively).

Nearly three-quarters (72%) of the women surveyed reported having practiced vaginal douching; of those who did, 93% douched more than once a day and 91% after every sexual encounter. On average, the women who practiced vaginal douching did so 13 times per week. Of women who douched, 81% used soap and water, 18% water with salt, 9% water alone, 5% a commercial antiseptic and 1% a washing powder.

Researchers found a significant relationship between douching and condom use, with women who sometimes or always used condoms being 1.5 and 2.5 times as likely to douche, respectively, as women who never used condoms. Women who practiced vaginal douching were more likely than those who did not to have ever engaged in anal sex (19% vs. 5%); they also had more sexual partners per day (4.1 vs. 3.6). A significantly higher incidence of bacterial vaginosis was found among the female sex workers who douched (odds ratio, 1.6). In addition, the incidence of bacterial vaginosis increased with the frequency of douching: from 14% of those douching less than once a day to 46% of those douching once a day and 53% of those douching more often. Researchers did not find a significant association between douching and HIV infection.

The researchers point out that previous research on vaginal hygiene has found a significant relationship between douching and an increased risk of certain STIs, as well as an association between bacterial vaginosis and the acquisition of HIV. The researchers attribute the lack of a direct relationship between douching and an increased incidence of HIV to bias occurring because women who douched were also more likely to use condoms. The researchers conclude that "vaginal douching may indirectly facilitate the heterosexual transmission of HIV."--J. Rosenberg

REFERENCE

1. Fonck A et al., Sexually transmitted infections and vaginal douching in a population of female sex workers in Nairobi, Kenya, Sexually Transmitted Infections, 2001, 77(4):271-275.