The Bali STD/AIDS study: association between vaginal hygiene practices and STDs among sex workers.

OBJECTIVES: To assess the association between genital cleansing practices and the prevalence of sexually transmitted diseases and of sexual health knowledge among female sex workers in Bali, Indonesia.
METHODS: Low priced commercial sex workers (CSWs) participated in the Bali STD/AIDS Study, a 3 year educational project evaluating the effect of education on the subsequent use of condoms and the prevalence of STDs and AIDS. Structured interviews, genital evaluation, laboratory evaluation for STDs, and treatment were performed. Vaginal cleansing characteristics including frequency, type, and reasons for use, were evaluated. Associations between these characteristics and the presence of bacterial and viral genital infections were assessed.
RESULTS: Of 625 female sex workers evaluated between May and July 1998, 99.1% used substances, such as soap and toothpaste, to clean the vagina at least daily, with 69.3% performing this after each intercourse. The women using such cleansers after each client did not differ from those using them once or less daily in education, AIDS and condom use knowledge, time working as a CSW, or number of clients in the previous day. However, they were younger than those using vaginal cleansers daily or less, and reported lower condom usage in the past week. Several genital symptoms, such as discoloured discharge and odour, were reported less by women with the highest frequency of vaginal cleanser use. Prevalence of genital infections in this population of women was substantial, with bacterial infections more prevalent than viral infections. Infections were not associated with the type of cleanser used, using a genital cleanser on the day of examination, or using a cleanser after each client versus daily or less, except for candida colonisation, which was more prevalent in women cleansing after each client (OR=1.87, 95% CI 1.21, 2.90). However, symptomatic candida vulvovaginitis (positive culture plus presence of symptoms) was not associated with the prevalence of genital cleansing. Women using genital cleansing in part for "infection avoidance" (39.7%) were more likely to have heard of STDs and AIDS, but were less knowledgeable about these infections, compared with women not citing this reason for genital cleansing.
CONCLUSION: Commercial sex workers in low priced brothels in Bali have a high rate of genital infections, with lower rates of viral compared with bacterial infections. Genital cleansers, on a daily or after each intercourse schedule, are used routinely. Although genital cleansing after each intercourse was associated with fewer genital symptoms, the prevalence of STDs did not differ significantly based on this frequency, and the women's knowledge of STDs and AIDS was less than that of women cleansing less often. The effect of genital cleansing in general on STD and AIDS prevalence could not be assessed in this population owing to the lack of a non-cleansing cohort. Further study to elucidate the effect of vaginal cleansing practices on STD prevalence and resistance is needed.