From the Guidelines
Empiric treatment for asymptomatic patients with white blood cells (WBC) in urine is not recommended, as pyuria accompanying asymptomatic bacteriuria is not an indication for antimicrobial treatment 1.
Key Considerations
- The diagnosis of asymptomatic bacteriuria should be based on results of culture of a urine specimen collected in a manner that minimizes contamination 1.
- Asymptomatic bacteriuria is defined as 2 consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts ≥10^5 cfu/mL for women, and a single, clean-catch voided urine specimen with 1 bacterial species isolated in a quantitative count ≥10^5 cfu/mL for men 1.
- Certain populations, such as pregnant women, should be screened for bacteriuria by urine culture at least once in early pregnancy, and they should be treated if the results are positive 1.
Treatment Approach
- If treatment is deemed necessary based on risk factors or clinical context, a urine culture should be obtained to guide targeted therapy 1.
- Nitrofurantoin or trimethoprim-sulfamethoxazole (TMP-SMX) may be considered as first-line options, but only after a urine culture has been obtained 1.
- The duration of antimicrobial therapy should be 3–7 days, and periodic screening for recurrent bacteriuria should be undertaken following therapy 1.
Special Populations
- Pregnant women, immunocompromised patients, and those with urological abnormalities require closer monitoring and may need more aggressive treatment approaches 1.
- Screening for and treatment of asymptomatic bacteriuria is recommended before certain urologic procedures, such as transurethral resection of the prostate, but not for other populations, such as premenopausal, nonpregnant women, diabetic women, or older persons living in the community 1.
From the Research
Empiric Treatment for WBC in Urine with No Symptoms
- The presence of white blood cells (WBC) in urine without symptoms is often referred to as asymptomatic bacteriuria, which is a common clinical condition that may not require treatment 2, 3, 4.
- The Infectious Disease Society of America (IDSA) guidelines recommend against screening and treatment for asymptomatic bacteriuria in healthy adults, including non-pregnant pre- and postmenopausal women, and patients with diabetes mellitus, long-term indwelling catheters, or spinal cord injuries 2, 4.
- Treatment of asymptomatic bacteriuria has not been shown to improve patient outcomes and may lead to unnecessary consequences, such as increased antimicrobial resistance, Clostridioides difficile infection, and increased healthcare costs 2, 3.
- Antibiotic treatment for asymptomatic bacteriuria may be considered in certain cases, such as in pregnant women or individuals undergoing endourological procedures associated with mucosal trauma 2, 4.
- Nitrofurantoin and fosfomycin are commonly used antibiotics for the treatment of uncomplicated urinary tract infections (UTIs), but their use in asymptomatic bacteriuria is not recommended unless there is evidence of potential benefit 5, 6.
- The clinical efficacy of nitrofurantoin for treating uncomplicated UTIs has been shown to be comparable to other antibiotics, with fewer side effects reported 6.
- However, the evidence for the use of nitrofurantoin in asymptomatic bacteriuria is limited, and more robust research is needed to determine its effectiveness and safety in this context 6.