Relationship between sexual intercourse and urinary-tract infection in women attending a clinic for sexually transmitted diseases -- Kelsey et al. 12 (4): 511 -- Journal of Medical Microbiology

The prevalence of urinary-tract infection (UTI), diagnosed by examination of a single midstream urine from sexually active women was found to be 6.4%. Significant bacteriuria was most common in women who presented within 24 h of coitus but was not related to the number of sexual partners. UTI occurred significantly more often in women who presented within 4 days of intercourse than in women seen after a longer interval. Whether frequency of intercourse affects the prevalence of UTI remains to be determined.