Prof. Po-Ren Hsueh
Vice Dean and Professor, College of Medicine, China Medical University (CMU), Taichung, Taiwan
Program Chairman, The Ph.D. Program for Aging, College of Medicine, CMU, Taiwan
Vice superintendent, Center of Laboratory Medicine, China Medical University Hospital (CMUH), Taichung, Taiwan
Director, Department of Laboratory Medicine, CMUH, Taichung, Taiwan
Visiting staff, Division of Infectious Diseases, Department of Internal Medicine, CMUH, Taichung, Taiwan
Adjunct Professor, Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
Taiwan Country Ambassador, American Society of Microbiology

Catheter-associated urinary tract infection (CA-UTI) is one of the most common device-associated healthcare-acquired infections (HCAIs), responsible for up to 95% of UTIs in the intensive care unit (ICU).^{1, 2}
The underlying cause of CA-UTI is bacterial biofilm formation on the urinary catheter, allowing direct introduction of bacteria into the genitourinary tract during catheter insertion.³ Despite efforts to reduce the incidence of CA-UTI, such infection remains a severe healthcare burden. Timely intervention is needed to prevent complications associated with CA-UTI.
Prof. Hsueh shares his insights into the challenges and effective strategies for managing CA-UTI, including the judicious use of fluoroquinolones.

Q1. What are some of the most common classifications of complicated urinary tract infection (cUTI)? Please provide an overview and describe the types requiring immediate medical intervention.

Typically, urinary tract infections (UTIs) are divided into uncomplicated UTIs, complicated UTIs, and community-associated versus hospital-acquired (including catheter-associated) UTIs. An uncomplicated UTI is characterized by a normal, unobstructed genitourinary tract, with no history of recent instrumentation, with symptoms restricted to the lower urinary tract.⁴ All uncomplicated UTIs are termed as lower UTIs and include cystitis, pyelonephritis, recurrent UTI, catheter-associated UTI, UTI in men, and urosepsis. cUTIs with sepsis syndrome are extremely critical, and pyelonephritis is more grave than cystitis. Complicated healthcare-associated cUTIs often require instantaneous medical intervention, as they are generally caused by multidrug-resistant gram-negative bacteria (such as ESBL-producing Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and carbapenem-resistant) or Candida spp. (including C. albicans and C. glabrata). Patients with urosepsis also demand immediate medical intervention, as a delay in antibiotic treatment may severely affect the clinical outcome.

Q2. How common is catheter-associated UTI (CA-UTI) in Taiwan? What is your overall approach to the treatment of CA-UTI?

According to the Taiwan Healthcare Associated Infection and Antimicrobial Resistance Surveillance (THAS) system, the infection density of healthcare-associated UTIs (HA-UTIs) in Taiwan in 2020 was 2.0/1000 patient-days (PDs) at medical centers and 1.8/1000 PDs at regional hospitals. The 30-day prevalence of CA-UTI in Taiwan was 4.5% in 2014. Among these, 86.6% and 91.2% of HA-UTIs were related to the use of urinary catheters in medical centers and regional hospitals, respectively. In 2020, the leading pathogens for HA-UTI were E. coli, C. albicans, Enterococcus faecium, and Candida spp. other than K. pneumoniae, Pseudomonas aeruginosa, E. faecalis, Acinetobacter baumannii, and Enterobacter spp. Strains retrieved from patients with HA-UTIs are usually more resistant, and broad-spectrum antibiotics are normally administered after urine culture is performed. We initiate regular changes in the Foley catheter after the original CA-UTI has been adequately treated, while maintaining strict aseptic conditions when the Foley catheter is inserted, and avoid unnecessary use of antibiotics unless UTI-related septicemia develops.

Q3. What are some of your key considerations when selecting antimicrobial options for patients with CA-UTI owing to short-term indwelling catheters? How do these considerations differ when treating UTIs associated with long-term catheter use?

A longer catheterization duration enhances the risk of CA-UTI. However, CA-UTI owing to short-term indwelling catheters might be due to malpractice or trauma during the use of indwelling catheters in patients, and in such cases, the etiology is more often related to wild-type pathogens with low antibiotic resistance. Conversely, patients with long-term catheter use often present higher probability of previous antibiotic exposure or harbor drug-resistant pathogens.⁵ Therefore, broad-spectrum antibiotics are typically used for such patients. Additionally, some bacteria, including P. mirabilis, P. vulgaris, Providencia rettgeri, and Morganella morganii have high urease activity, which increases urine pH and induces crystal deposition and recurrent catheter encrustation.⁵ Failure to detect and replace blocked catheters in a timely manner can lead to severe symptomatic episodes of pyelonephritis, septicemia, and endotoxic shock.⁵

Pathogen eradication is the first objective for patients with a short-term indwelling urinary catheter and CA-UTI; however, when difficult-to-treat UTI pathogens are encountered, suppression of bacterial or fungal (typically Candida spp.) load is the next goal, if they need to be treated for CA-UTI resulting in septicemia. In such cases, removal of the urinary catheter is also considered.

Q4. What are the treatment goals for patients with CA-UTI, especially when faced with the challenge of antimicrobial resistance?

The objective of treating patients with CA-UTIs is the prompt resolution of symptoms. Seven days is the recommended duration of antimicrobial treatment for patients with CA-UTI, and 10–14 days are suggested for those with a delayed response.⁶ Patients with cUTIs caused by antimicrobial-resistant pathogens generally show a delayed response, especially those with inadequate empiric therapy due to the presence of resistant strains. Precise antibiotic treatment is essential to avert inappropriate antimicrobial therapy in the era of increasing antimicrobial resistance.

Q5. What is the role of fluoroquinolones for the treatment of patients with CA-UTI? Please provide an overview of the existing evidence and guidelines supporting this regimen, including dose selection and duration of treatment.

As per 2010 CA-UTI guidelines, fluoroquinolones have been recommended by Infectious Diseases Society of America (IDSA) for treating the patients with CA-UTI.⁶ A 5-day regimen of levofloxacin may be considered in patients with CA-UTI who are not severely ill (B-III).⁶ Data are inadequate to recommend other fluoroquinolones.⁶ According to the 2022 European Association of Urology (EAU) guidelines on urological infections, a 5-day regimen of levofloxacin can also be considered in patients with CA-UTI who are not severely ill.⁷ With the rise in fluoroquinolone resistance, alternative antimicrobial agents should be chosen whenever it is possible to initiate empirical therapy based on microbiological information.

References

1. Burton DC, et al. Infect Control Hosp Epidemiol 2011;32(8):748–56.
2. Leblebicioglu H, et al. Am J Infect Control 2013;41(10):885–91.
3. Nicolle LE. Infect Dis Clin North Am 2012;26(1):13–27.
4. Mehnert-Kay SA. Am Fam Physician 2005;72(3):451–456.
5. Stickler DJ. J Intern Med 2014;276(2):120–9.
6. Hooton TM, et al. Clin Infect Dis 2010;50(5):625–63.
7. Bonkat G, et al. EAU Guidelines. Edn. presented at the EAU Annual Congress Amsterdam, the Netherlands 2022.