Risk factors for second urinary tract infection among college women

To better understand the etiology of recurrent urinary tract infection (UTI ), the authors followed a cohort of 285 female college students with first UTI for 6 months or until second UTI. A first UTI due to Escherichia coli w as followed by a second UTI three times more often than was a non-E. coli f irst UTI (24 vs. 8%; p = 0.02). In a logistic regression analysis limited t o the 224 women from the University of Michigan Health Service and the Univ ersity of Texas at Austin Health Service from September 1992 to December 19 94, with a first UTI due to E. coli, vaginal intercourse increased the risk of a second UTI with both a different (odds ratio (OR) = 1.60, 95% confide nce interval (CI): 1.19, 2.15) and the same (OR = 1.37, 95% CI: 0.91, 2.07) uropathogen, as did using a diaphragm, cervical cap, and/or spermicide (sa me uropathogen: OR = 1.53, 95% CI: 0.95, 2.47; different uropathogen: OR = 1.77, 95% CI: 1.22, 2.58). Condom use decreased the risk of a second UTI ca used by a different uropathogen (OR = 0.68, 95% CI: 0.48, 0.99) but had no effect on a second UTI caused by the same E. coli (OR = 0.99; 95% CI: 0.66, 1.50). Type or duration of treatment was not associated with a second UTI. Although the risk of second UTI is strongly influenced by sexual behavior, women with a first UTI caused by E. coli are more likely than are those wi th a non-E, coli first UTI to have a second UTI within 6 months.