Postpartum surveillance for urinary tract infection: patients at risk of developing pyelonephritis after catheterization.

Asymptomatic postpartum bacteriuria occurred in ten of 354 patients not catheterized (2.8%) and in 19 of 313 patients who were catheterized (6.1%). Obstetric lacterations were commonly associated with bacteriuric patients who were not catheterized. Primigravidas as a total group were more likely to have significant bacteriuria. Nine of 23 patients with urinary retention (39.1%), requiring catheterization for longer than 24 hours, developed asymptomatic bacteriuria; urinary tract infection tended to be progressive in these patients, ascending from lower to upper urinary tract involvement. Using the fluorescent antibody (FA) test, antibody-coated bacteria were demonstrated in specimens from five of these nine patients (56%), indicating silent renal infection.