Interpreting asymptomatic bacteriuria.

dipstick testing cannot lower the post-test probability sufficiently to exclude urinary tract infection if a patient presents with one or more symptoms. Urine culture, however, has a value beyond confirming the diagnosis in that it can also direct treatment, on the basis of results of tests for antimicrobial susceptibility. The table summarises the findings of two systematic reviews. When features of systemic sepsis are present—Testing of urine in patients presenting with clinical features of systemic sepsis (fever, rigors) is useful as the urinary tract is a common source of blood stream infection. Al-Hasan and colleagues documented an age adjusted incidence rate of 55.3 per 100 000 person years for urinary tract infection complicated by bacteraemia. When there are other specific indications—Testing for bacteriuria is recommended in pregnant women without symptoms suggesting urinary tract infection 6 as 2-7% have clinically significant bacteriuria. A systematic review of 14 studies and 2302 women concluded that treatment of asymptomatic bacteriuria in pregnancy reduces the incidence of pyelonephritis later in pregnancy. The overall incidence of pyelonephritis in pregnant women with asymptomatic bacteriuria is 21%, and treatment leads to a reduction in risk of 75%. Testing urine for infection is also recommended in the investigation of patients presenting with acute renal failure before major urological procedures. 9 RATIONAL TESTING Interpreting asymptomatic bacteriuria