From the Guidelines
Yes, a urinary tract infection (UTI) can cause bacteremia, which is the presence of bacteria in the bloodstream. This typically occurs when bacteria from the urinary tract ascend and breach the protective barriers, entering the bloodstream. Bacteremia from UTIs is more common in complicated UTIs, particularly pyelonephritis (kidney infection), and in patients with risk factors such as urinary obstruction, immunosuppression, pregnancy, diabetes, or anatomical abnormalities of the urinary tract.
Key Points to Consider
- Symptoms of UTI-associated bacteremia include fever, chills, rapid heart rate, low blood pressure, confusion (especially in elderly patients), and sometimes sepsis.
- Treatment requires prompt administration of appropriate antibiotics, typically intravenous options like ceftriaxone, gentamicin, or piperacillin-tazobactam, depending on local resistance patterns and patient factors, as seen in the guidelines for the treatment of infections caused by multidrug-resistant gram-negative bacilli 1.
- Hospitalization is often necessary, especially for elderly patients or those with significant comorbidities.
- The progression from UTI to bacteremia occurs because uropathogens like E. coli have virulence factors that allow them to adhere to and invade the urinary epithelium, eventually gaining access to the bloodstream when local host defenses are overwhelmed.
Diagnosis and Management
- For suspected UTI, urinalysis and urine cultures should be performed, especially in patients with acute onset of UTI-associated symptoms and signs, such as fever, dysuria, gross hematuria, new or worsening urinary incontinence, and/or suspected bacteremia 1.
- In residents with long-term indwelling urethral catheters, evaluation is indicated if there is suspected urosepsis, especially in the context of recent catheter obstruction or change 1.
- The minimum laboratory evaluation for suspected UTI should include urinalysis for determination of leukocyte esterase and nitrite level by use of a dipstick and a microscopic examination for WBCs 1.
From the Research
UTI and Bacteremia
- A urinary tract infection (UTI) can cause bacteremia, as evidenced by several studies 2, 3, 4.
- Bacteremia is often concomitant with severe UTI, and the treatment outcome has not been well studied 2.
- According to a retrospective chart review, bacteremia caused by UTI was observed in 59 patients, and intravenous antibiotics were sequentially converted to oral agents in 48 patients 2.
Risk Factors for Bacteremia
- Solid organ malignancy, elevated neutrophil count, elevated C reactive protein, and pyuria are independent risk factors for bacteremia in patients with UTI 3.
- Older age is associated with higher mortality in patients with bacteremic UTI 4.
- Community-acquired infection acquisition and E. coli UTI are both independently associated with lower mortality 4.
Treatment and Antibiotic Resistance
- Antibiotic agents can be converted to a culture-directed oral antibiotic safely in patients with bacteremia caused by UTI 2.
- However, there is a high risk of recurrence in patients treated with a steroid or immunosuppressant 2.
- The linear trend of increasing antimicrobial resistance among gram-negative isolates should be considered when empiric therapy is selected 4.
- Piperacillin/tazobactam has the lowest resistance rate for urinary tract infections with gram-negative pathogens 5.