From the Guidelines
Asymptomatic bacteriuria should not be treated with antibiotics in most populations, except in specific cases such as pregnant women and patients undergoing urologic procedures with mucosal bleeding. The most recent and highest quality study, the 2024 European Association of Urology guidelines on urological infections, recommends against screening or treating asymptomatic bacteriuria in women without risk factors, patients with well-regulated diabetes mellitus, postmenopausal women, elderly institutionalized patients, patients with a dysfunctional and/or reconstructed lower urinary tract, patients with a renal transplant, and patients before arthroplasty surgery 1.
Key Points
- The 2019 American Urological Association guideline also recommends against treating asymptomatic bacteriuria in patients, citing a strong recommendation with evidence level Grade B 1.
- The 2019 Infectious Diseases Society of America guideline recommends screening and treatment of asymptomatic bacteriuria in pregnant women to decrease pyelonephritis, based on prospective randomized studies from the 1960s to 1980s 1.
- A 2015 Cochrane review confirmed that antimicrobials probably reduce the risk of pyelonephritis in pregnant women with asymptomatic bacteriuria, and may reduce the risk of low birth weight and preterm labor 1.
Rationale
The rationale for not treating asymptomatic bacteriuria is that bacteria often colonize the urinary tract without causing infection or harm, and unnecessary antibiotic treatment disrupts normal flora, selects for resistant organisms, and exposes patients to medication side effects without clinical benefit.
Exceptions
The exceptions where treatment is recommended include:
- Pregnant women, to prevent pyelonephritis and preterm birth 1.
- Patients undergoing urologic procedures with mucosal bleeding, as recommended by the 2024 European Association of Urology guidelines 1.
From the Research
Evidence for Not Treating Asymptomatic Bacteriuria
- The study published in the Journal of Clinical Microbiology in 2020 2 suggests that screening and treatment of asymptomatic bacteriuria is not recommended in several patient populations, including pediatric patients, healthy nonpregnant women, older patients, diabetic patients, and patients with an indwelling urethral catheter.
- A systematic review and meta-analysis published in European Urology in 2017 3 found that treating asymptomatic bacteriuria was not beneficial for most people and may be harmful, except for pregnant women and those undergoing urological surgery.
- A study published in The American Journal of Medicine in 2022 4 emphasized that asymptomatic bacteriuria does not lead to urinary tract infections in most scenarios, and antibiotic treatment has not been shown to improve patient outcomes, except for pregnant women and individuals undergoing endoscopic urologic procedures.
Patient Populations Where Treatment is Not Recommended
- Pediatric patients 2, 4
- Healthy nonpregnant women 2, 3
- Older patients in the inpatient or outpatient setting 2
- Diabetic patients 2, 4
- Patients with an indwelling urethral catheter 2, 4
- Patients undergoing nonurologic surgeries 2
- Nonrenal solid-organ transplant recipients 2