Urinary tract infections and bacterial vaginosis are common conditions. Based on clinical observations, Harmanli and associates noted that urinary tract infections might occur more frequently in women who had bacterial vaginosis. Therefore, they evaluated the risk of urinary tract infections in women with and without bacterial vaginosis.

Women attending inner-city family planning and gynecology clinics were asked to participate in the study. Data collected included history of vaginal infections and sexually transmitted diseases; reproductive, contraceptive and sexual history; and evidence of serious medical conditions, including diabetes mellitus and a compromised immune system. Women who were pregnant or had serious medical conditions were not included in the study. Women were also excluded if they reported use of diaphragms, douches or spermicides.

For each of the 129 women accepted into the study, symptoms were documented, and a pelvic examination was performed. Samples were collected for a saline wet mount preparation and whiff test, vaginal pH and cultures for Chlamydia trachomatis and Neisseria gonorrhoeae. Clean-catch urine specimens for analysis and culture were obtained from all participants. Diagnosis of urinary tract infection was based on the finding of at least 100,000 organisms per mL of urine. Regression analysis was used to estimate the relationship between patient characteristics and bacterial vaginosis or urinary tract infection.

Of the 129 women examined, 67 met diagnostic criteria for bacterial vaginosis; 15 (22.4 percent) of these women also had a urinary tract infection. Of the 62 women without bacterial vaginosis, six (9.7 percent) had a urinary tract infection. The two groups of women were well matched in race and age (range: 17 to 48 years in the women with bacterial vaginosis and 18 to 46 years in the women without bacterial vaginosis). Frequency of sexual intercourse was strongly related to bacterial vaginosis and urinary tract infection.

The authors concluded that women with bacterial vaginosis are at increased risk for urinary tract infections. Frequency of sexual intercourse may be a risk factor for both conditions. The authors suggested that screening for one condition might be prompted by diagnosis of the other. Searching for associated conditions might be especially significant in pregnant women because of potential perinatal problems related to these infections.