Spaced review
Questions from modules you have finished come back here over the following days to weeks, and again at growing intervals after each correct answer. Answering after a gap is what makes it stick.
Nothing due right now.
A 74-year-old nursing-home resident with a chronic indwelling catheter is admitted for cellulitis. He is afebrile with no urinary symptoms. An admission urine culture grows Enterococcus and E. coli, each >100,000 CFU/mL, with pyuria.
Bacteriuria with pyuria in an afebrile catheterized patient without urinary or systemic signs is ASB, and catheter-associated ASB shouldn't be treated [1, 10].
A 29-year-old at 13 weeks' gestation has an asymptomatic screening urine culture growing group B Streptococcus at 100,000 CFU/mL.
ASB in pregnancy is treated [1, 15]. GBS bacteriuria in pregnancy also means she should receive intrapartum GBS prophylaxis.
A 69-year-old woman with diabetes is admitted for a diabetic foot infection. A routine urine culture grows E. coli 100,000 CFU/mL. She has no dysuria, frequency, or flank pain and is afebrile.
In a randomized trial in women with diabetes, treating ASB didn't reduce symptomatic UTI and caused more adverse effects [8]. Diabetes isn't an indication to treat [1].
Your hospital's initiative to reduce ASB treatment focuses on which urine cultures get ordered, rather than on reminding clinicians not to prescribe after a positive result. Why?
In the Michigan statewide initiative, nearly all of the improvement came from diagnostic stewardship, meaning fewer unnecessary cultures. The share of patients with ASB who were treated after a positive result barely changed [7].
An 80-year-old woman with dementia is admitted after a fall. She is at her baseline mental status, afebrile, with no urinary symptoms and a benign exam. The ED's urine culture grows E. coli 100,000 CFU/mL with pyuria.
A fall with bacteriuria but no urinary or systemic signs calls for a falls workup, not antibiotics. Pyuria doesn't turn ASB into UTI [1, 6].
A 58-year-old kidney transplant recipient, 8 months post-transplant on stable immunosuppression, has an asymptomatic surveillance urine culture growing E. coli 100,000 CFU/mL. Creatinine is at baseline. She is afebrile with no urinary symptoms.
In the BiRT randomized trial, treating ASB in kidney transplant recipients 2 or more months after transplant didn't reduce symptomatic UTI, and it increased antibiotic exposure and resistance [9]. IDSA recommends against treatment beyond the first month [1].