From the Guidelines
Asymptomatic bacteriuria should only be treated with antibiotics in pregnant women and patients undergoing urologic procedures where mucosal bleeding is anticipated. For pregnant women, treatment is recommended to prevent complications such as pyelonephritis, preterm birth, and low birth weight. Common antibiotic regimens include nitrofurantoin 100 mg twice daily for 5-7 days, amoxicillin-clavulanate 500/125 mg twice daily for 3-7 days, or cephalexin 500 mg four times daily for 3-7 days. For urologic procedures, a single dose of antibiotics just before the procedure is typically sufficient, such as trimethoprim-sulfamethoxazole 160/800 mg or ciprofloxacin 500 mg.
Key Considerations
- Treatment is not recommended for other populations including the elderly, diabetics, those with spinal cord injuries, catheterized patients, or other asymptomatic individuals, as studies have shown no benefit and potential harm from unnecessary antibiotic use 1.
- The rationale for this selective approach is to minimize antibiotic resistance, adverse drug effects, and Clostridioides difficile infections while only treating when there is clear evidence of benefit.
- The Infectious Diseases Society of America and the US Preventive Services Task Force recommend screening for and treatment of asymptomatic bacteriuria in pregnant women, but not in other asymptomatic individuals 1.
Clinical Implications
- Clinicians should avoid treating asymptomatic bacteriuria in patients with neurogenic lower urinary tract dysfunction, except in pregnant women and before urologic procedures with anticipated urothelial disruption or upper tract manipulation 1.
- The use of antibiotics should be guided by urine culture results and clinical judgment, taking into account the potential risks and benefits of treatment.
Evidence Summary
- Multiple studies have demonstrated the benefits of treating asymptomatic bacteriuria in pregnant women, including reduced risk of pyelonephritis and low birth weight 1.
- In contrast, studies have shown no benefit and potential harm from treating asymptomatic bacteriuria in other populations, including the elderly, diabetics, and those with spinal cord injuries 1.
From the Research
Asymptomatic Bacteriuria Treatment
Asymptomatic bacteriuria (ABU) is a condition where bacteria are present in the urine without any symptoms of a urinary tract infection. The decision to treat ABU with antibiotics depends on various factors, including the patient's health status and the presence of certain risk factors.
- Pregnant Women: Treatment of ABU in pregnant women is recommended, as it can reduce the risk of symptomatic UTI, low birthweight, and preterm delivery 2, 3, 4.
- Urological Surgery: ABU should be treated prior to transurethral resection surgery, as it can reduce the risk of postoperative UTI 2, 5.
- Other Patient Groups: For most people, including those with diabetes, postmenopausal women, elderly institutionalized patients, and patients with renal transplants, treatment of ABU is not beneficial and may be harmful 2, 3, 6.
- Risk of Antimicrobial Resistance: Unnecessary treatment of ABU can lead to increased antimicrobial resistance, Clostridioides difficile infection, and increased healthcare costs 3, 6.
Screening and Treatment Guidelines
The Infectious Disease Society of America (IDSA) recommends screening for ABU in pregnant women in the first trimester and treating if positive 3. Individuals undergoing endoscopic urologic procedures should also be screened and treated for ABU if necessary.
- Antibiotic Stewardship: Antibiotic stewardship programs aim to reduce unnecessary treatment of ABU and promote appropriate use of antibiotics 3.
- Harmless and Protective: Some studies suggest that ABU is harmless and even protective against symptomatic UTI episodes, and should not be treated unless there is a specific reason to do so 5.