Bacterial vaginosis (BV) is characterized by dramatic changes in the vaginal ecosystem. Women without evidence of vaginal infection may exhibit transient changes in their flora. We prospectively followed up women by using diaries and self-obtained vaginal smears to correlate behaviors with changes in flora. The majority of women (38/51, 78%) had significant, although transient, changes. Behaviors associated with unstable flora were a history of BV, a greater number of partners, and more frequent episodes of receptive oral sex. Only the latter remained significantly associated in the multivariate analysis. Variables that were associated with day-to-day variability in the flora included use of vaginal medication, menses, greater number of partners, spermicide use, more frequent vaginal intercourse, and less frequent use of condoms. Only a minority of women (11/51, 22%) maintained a "normal" lactobacillus-predominant flora. Factors associated with instability of the flora are similar to those epidemiologically associated with BV.

These results are consistent with host response-mediated resolution of infection in a minority of patients and have implications regarding public health efforts to control chlamydial infection.

This study suggests that few patients take medications as prescribed and that self-report substantially underestimates medication noncompliance. Despite poor compliance, there were few treatment failures.

A substantial proportion of patients with genitourinary symptoms attending public STD clinics delay seeking care for a week or more, increasing their likelihood of complications and of transmission of infection to others. Interventions to promote more timely clinic attendance may help reduce STD morbidity in the United States.