By Stan Deresinski, MD, FACP, FIDSA

Clinical Professor of Medicine, Stanford University

Dr. Deresinski reports no financial relationships relevant to this field of study.

SYNOPSIS: New guideline recommendations indicate that the only unequivocal indications for screening and treatment of asymptomatic bacteriuria are pregnancy and undergoing endoscopic urologic procedures associated with mucosal injury.

SOURCE: Nicolle LE, Gupta K, Bradley SF, et al. Clinical Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Diseases Society of America. Clin Infect Dis 2019; March 21. doi: 10.1093/cid/ciy1121. [Epub ahead of print].

The Infectious Diseases Society of America has published their recommendations, which are few in number, regarding the indications for screening and treatment of asymptomatic bacteriuria.

Groups to screen and treat are:

  • Pregnant patients;
  • Patients undergoing endoscopic urologic procedures with associated mucosal trauma; target antimicrobial therapy with administration of only one to two doses with initiation 30 to 60 minutes prior to the procedure.

Groups for whom screening and treating asymptomatic bacteriuria is NOT recommended include:

  • Infants and children;
  • Healthy pre- and postmenopausal nonpregnant women;
  • Functionally impaired older women and men residing in the community or long-term care facilities;
  • Diabetic individuals;
  • Patients who received renal transplants more than one month previously;
  • Recipients of non-renal solid organ transplants;
  • Patients with impaired voiding resulting from spinal cord injury (taking into account that symptoms may be atypical, such as due to autonomic dysfunction);
  • Patients with short- or long-term bladder catheterization;
  • Patients undergoing non-urologic surgery;
  • Patients undergoing placement of an artificial urinary sphincter or penile implant or living with such a device; patients undergoing this surgery should receive standard operative antibiotic prophylaxis.

The guideline authors were unable to provide a recommendation for the following because of inadequate evidence:

  • Patients with high-risk neutropenia (absolute neutrophil count < 100 cells/mm3 with anticipated duration 7 days);
  • Patients undergoing removal of a bladder catheter.

Older patients with functional and/or cognitive impairment with or without a fall who have known bacteriuria but without local urinary symptoms or systemic signs of infection but with acute mental status change should undergo evaluation for other causes of their symptoms rather than antibiotic administration. For those with sepsis syndrome and no localizing source, broad-spectrum antimicrobial therapy directed at both urinary and non-urinary pathogens is indicated.


The prevalence of asymptomatic bacteriuria is approximately 1% in school-age girls, almost 5% in sexually active premenopausal women (in whom it is often transient) and in pregnancy, and > 20% in community-dwelling women > 80 years of age. It is rarely present in healthy males, but occurs at elevated frequency in elderly community-dwelling men.

In general, antibiotic treatment of asymptomatic bacteriuria is contraindicated because the personal and societal risks of this approach are real and the benefit is nonexistent. A recent study of 68,265 veterans concluded that “receipt of antimicrobial therapy with activity against asymptomatic bacteria organisms identified in preoperative cultures was not associated with reductions in the risk for postoperative infections, including urinary tract infections and surgical site infections.”1 In a 2018 systematic review and meta-analysis, the authors found no benefit from screening and treatment of asymptomatic bacteriuria in patients undergoing joint arthroplasty.2

Prevention of inappropriate screening and treatment of asymptomatic bacteriuria is an important antimicrobial stewardship activity and, frequently, a frustrating one. Adherence to this guideline will be associated with decreased occurrence of adverse reactions to unnecessarily administered antibiotics, the decreased occurrence of Clostridioides difficile infection, and reduced selective pressure that leads to antimicrobial resistance. However, altering clinician behavior in this domain often is difficult and frustrating — but increasingly important.


  1. Salazar JG, O’Brien W, Strymish JM, et al. Association of screening and treatment for preoperative asymptomatic bacteriuria with postoperative outcomes among US veterans. JAMA Surg 2018; Dec. 12. doi: 10.1001/jamasurg.2018.4759. [Epub ahead of print].
  2. Gómez-Ochoa SA, Espín-Chico BB, García-Rueda NA, et al. Risk of surgical site infection in patients with asymptomatic bacteriuria or abnormal urinalysis before joint arthroplasty: Systematic review and meta-analysis. Surg Infect (Larchmt) 2019;20:159-166.