Infection Prevention and Control

Catheter-associated Urinary Tract Infections: Prevention

An infection prevention and control (IPC) team can impact the incidence of CAUTI in their facility by supporting and promoting implementation of preventive measures. A key first step is to establish the correct diagnosis of a CAUTI given that recognizing it is a challenge because bacteria can be present in a patient's urine without causing infection. This includes deciding which one of the two main international definitions of CAUTI the facility plans to use. Preventive measures include using standardized indications for catheter use which will help avoidance of catheters when necessary, as well as following the recommended procedures for catheter insertion and management; these will lower the risk of CAUTI in your facility.

Learning Objectives

By the end of this module, you will be able to:

  • recognize the criteria and challenges involved in diagnosing CAUTI according to the most frequently used standardized definitions;
  • explain the four key principles and practices of CAUTI prevention interventions;
  • describe the proper procedures for catheter preparation and insertion; and
  • describe urine sampling and testing procedures.

Learning Activities

  • Defining CAUTI (10 min)

    While preparing to do some work on the prevalence of CAUTI in their facility, the IPC team at the Udaipur Central Health Centre has discovered that many of the facility’s health care workers (HCWs) use different criteria to define CAUTI. Some are unaware of the existence of formal definitions and work from their own knowledge and experience; others are aware of the definitions established by the CDC and other international organizations. The IPC team did a quick survey of staff in the intensive care unit (ICU) (where patients are most susceptible to infection) and the maternity ward (where catheter insertion is common in this facility). The working definition of CAUTI was consistent within each ward, but different between the two wards.

    In either a notebook or the text box below, list three or four reasons why using different definitions for the same condition would be problematic. Click or tap the Compare Answer button to see what the IPC team determined:

    In the next activity, you will read more about the different definitions of CAUTI.

  • Definitions, Criteria and Recognition (15 min)

    Before you start conducting CAUTI surveillance, you must decide which criteria you will use to define CAUTI. Ideally, you should use standardized definitions, such as those developed by the Centers for Disease Control and Prevention (CDC) and the European Centre for Disease Prevention and Control (ECDC). The criteria used include signs and symptoms the HCW looks for, and laboratory tests to consider. The CDC and ECDC definitions of CAUTI have some differences; their application influences whether a patient is considered to have a CAUTI—which in turn will impact treatment decisions. We will explain more on the challenges this presents next.

    Click or tap the tabs below to learn more about the CDC and ECDC definitions.

    CDC Definition of CAUTI1

    Patient must meet criteria 1, 2, and 3 below:

    1. Patient had an indwelling urinary catheter that had been in place for over two calendar days (in the inpatient location) on the date of event AND was either:

      present for any portion of the calendar day on the date of event

      OR

      removed the day before the date of event.

    2. Patient has at least one of the following signs or symptoms:
      • fever (> 38.0°C): to use fever in a patient aged over 65 years of age, the indwelling urinary catheter needs to be in place for more than two calendar days on date of event;
      • tenderness above the pubic bone (with no other recognized cause);
      • pain/tenderness in the area of the back overlying the kidneys (with no other recognized cause);
      • urinary urgency (cannot be used when catheter is in place);
      • urinary frequency (cannot be used when catheter is in place);
      • painful or difficult urination (cannot be used when catheter is in place).
    3. Patient has a urine culture with no more than two species of organism identified, at least one of which is a bacterium of ≥ 105 CFU/mL [refer to CDC comments in the manual for details].
    colony-forming unit
    ECDC Definitions of UTI2

    UTI-A: Microbiologically Confirmed Symptomatic UTI

    1. Patient has at least one of the following signs of symptoms with no other recognized cause: fever (> 38 °C), urgency, frequency, dysuria, or suprapubic tenderness; and
    2. patient has a positive urine culture—that is, ≥ 105 microorganisms per mL of urine with no more than two species of microorganisms.

    UTI-B: Not Microbiologically Confirmed Symptomatic UTI

    1. Patient has at least two of the following with no other recognized cause: fever (> 38 °C), urgency, frequency, dysuria, or suprapubic tenderness; and
    2. at least one of the following:
      • positive dipstick for leukocyte esterase and/or nitrate;
      • pyuria urine specimen with ≥ 10 WBC/mL or ≥ 3 WBC/high-power field of unspun urine;
      • organisms seen on Gram stain of unspun urine;
      • at least two urine cultures with repeated isolation of the same uropathogen (Gram-negative bacteria or S. saprophyticus) with ≥ 102 colonies/mL urine in nonvoided specimens;
      • ≤ 105 colonies/mL of a single uropathogen (Gram-negative bacteria or S. saprophyticus) in a patient being treated with effective antimicrobial agent for a urinary infection;
      • physician diagnosis of a urinary tract infection; and/or
      • physician institutes appropriate therapy for a urinary infection.

    UTI-C: Asymptomatic Bacteriuria

    Patient has no fever (> 38 °C), urgency, frequency, dysuria, or suprapubic tenderness and either of the following criteria:

    1. patient has had an indwelling urinary catheter within seven days before urine is cultured, and
    2. patient has a urine culture, that is, ≥ 105 microorganisms per mL of urine with no more than two species of microorganisms;
    3. patient has not had an indwelling urinary catheter within seven days before the first positive culture; and
    4. patient has had at least two positive urine cultures ≥ 105 microorganisms per mL of urine with repeated isolation of the same microorganism and no more than two species of microorganisms.

    Comparing Definitions—Challenges in Recognizing CAUTI

    There is no international agreement on definitions used in the surveillance of CAUTI, but the CDC and ECDC definitions have both been validated and are the most commonly used.

    CDC: Because the CDC definition requires a positive culture result, it is challenging to use in settings with no laboratory. Unlike the ECDC definition, the CDC definition states that the indwelling urinary catheter must have been in place for at least two days before the onset of symptoms for a diagnosis of CAUTI to be made.

    ECDC: The ECDC definition has advantages in that it enables a diagnosis to be made without the need for microbiology laboratory support—i.e., using a urine dipstick test. It is interesting to note that this definition can be applied to identify CAUTI if a urinary catheter is present and in situ within seven days of the onset of signs and symptoms.

    Both definitions emphasize that you must not consider asymptomatic bacteriuria as a UTI.

    The challenge is to decide on a definition that is agreed upon and consistently applied within your facility. Be sure to engage hospital management to agree upon which definition to use, and to use a multimodal strategy to ensure staff are aware of and use that definition in their daily practice.

    Note: The important thing to remember is that deciding on a definition that is used by all staff at your facility will allow for the most consistent and accurate measurement of CAUTI.

    These standardized definitions from the CDC and ECDC are important in determining the true burden of infection. Patients with long-term catheters will often have high concentrations of bacteria in the urine without having an infection (asymptomatic bacteriuria). The presence of bacteria alone is not a reliable indicator for infection; it does not differentiate between colonization and infection.

    Surveillance Definition Versus Clinical Diagnosis

    Surveillance definitions are used for a different purpose than those used in the context of clinical diagnosis. Surveillance definitions involve the use of standardized criteria that surveillance staff or researchers can use to study and identify trends in a population (i.e., for epidemiological rather than clinical purposes). In some situations, a clinical diagnosis is influenced by the symptoms a patient displays and may be made even when the surveillance definition is not met. However, in the special case of CAUTI it is important to establish the presence of infection, applying standardized criteria, before starting any treatment.

  • Four Key IPC Principles and Practices (10 min)

    Always use a multimodal strategy to guide implementation of CAUTI prevention interventions. For more information, see Improving Infection Prevention and Control at the Health Facility Guide on the Resources page. The following four principles and practices are critical for CAUTI prevention. Click or tap on the icons representing each principle.

    1. Avoid unnecessary urinary catheters.

    1.1. Each patient must be assessed for the need of a catheter, and the reasons ticked against the criteria noted on a checklist (in addition to alerts/reminders, prompts and use of bladder scans).

    2. Insert urinary catheters using aseptic technique.

    2.1. Hand hygiene must be performed at the right moments.

    2.2. Proper insertion technique (maintaining sterile field) must be used.

    2.3. Specific equipment is required, including:

    • catheter insertion pack or appropriate individual sterile supplies;
    • sterile urinary catheter (one extra in case of contamination);
    • urinary catheter bag;
    • two pair of gloves: one clean and one sterile;
    • waterproof drape;
    • saline or sterile antiseptic solution;
    • syringe with sterile water in the amount designated by the catheter manufacturer;
    • water-soluble sterile lubricant OR anaesthetic gel;
    • sterile cleansing balls and forceps;
    • urine receptacle, sterile specimen container; and
    • other: adequate lighting, sheet for draping patient, clean trolley with waste bag attached to it, hand hygiene materials.

    2.4. Implementation support should be provided through the use of algorithms, checklists, nurse empowerment, training and competency development, and good documentation.

    3. Maintain urinary catheters based on recommended guidelines .

    3.1. Secure catheter to prevent irritation of the urethra.

    3.2. Maintain an unobstructed urine flow.

    3.3. Maintain a sterile, continuous closed drainage system.

    3.4. Maintain the drainage bag below the level of the bladder and off the floor; empty when indicated.

    3.5. Perform hand hygiene—i.e., the 5 Moments—specific to catheter care.

    3.6. Perform regular meatal hygiene, i.e., once per day, after bowel action.

    3.7. Support should also be provided through the use of algorithms, checklists, nurse empowerment, training and competency development, and good documentation.

    4. Review urinary catheter necessity daily and remove promptly if not needed.

    4.1. Address the importance of timely removal to reduce CAUTI risk:

    • Review urinary catheter necessity daily.
    • Record the reason for keeping catheter in situ each day.
    • Remove the catheter promptly when no longer needed.

    4.2. The review can be supported by reminders/stop orders for removal, nurse empowerment, and patient/family communication about the need for catheterization.

    4.3. Institutional culture and power dynamics will influence implementation of this element.

  • Aseptic Technique for Catheter Insertion (10 min)

    Watch the following video for an in-depth look at the aseptic procedure for catheter insertion. After watching the video, answer the comprehension questions.

    1Arrange the steps of preparing for an aseptic procedure:

    2After the clinical waste bag is attached to the trolley, what should you do?

    3When cleaning the genitalia of a female patient, which is true?

    4In male patients, when applying lidocaine lubricant gel how long should you hold the penis to allow the anaesthetic to take effect?

    5Arrange the steps of disposal after the insertion procedure is complete:

  • Specimen Collection and Urine Testing (10 min)

    As you have learnt in the previous module, disrupting the closed drainage system of an indwelling urinary catheter creates an opportunity for infection-causing microorganisms to enter the patient’s body. Because of this, collecting routine urine samples for culture is not recommended. The sampling port should be used only when it is actually necessary to obtain urine samples—e.g., when the patient has possible or probable CAUTI. The sample must be collected through the sampling port using aseptic technique (with the key moments for hand hygiene—moments 2 and 3) as follows:3

    1. Disinfect the port by wiping with a 70% alcohol swab. Allow it to dry.
      • Do not disconnect the closed drainage bag.
      • Do not obtain the sample from the drainage bag or send catheter tips for culture.
    2. If the sampling port is not available, the sample can be drawn from the connecting tube, using a sterile small-bore needle/syringe, and transferred into a sterile container. This is not considered a best practice.
    3. Transport to the lab for culture and sensitivity within two hours or refrigerate the specimen. If the specimen cannot be taken to the lab on time, or a refrigeration method is not available, boric acid can be used to maintain the sample. When using boric acid,
      • measure accurate concentrations, since boric may affect the viability of the bacteria—and, therefore, the bacteriology culture result;
      • use a marked bottle to achieve 1% w/v or 0.1 g/10 mL; and
      • send the sample to the laboratory within four hours, or store in the refrigerator until transport to the laboratory is available.
    4. On the microbiology form, record that it is a catheter specimen of urine, and note any antibiotics the patient is receiving.

    Urine Testing

    After obtaining the urine sample using aseptic technique, the sample must be sent to a laboratory in a sterile container within two hours of collection. If a delay is anticipated, the sample must be put into a designated refrigerator or ice box. An ice box can be used to transport the sample to prevent overgrowth of bacteria.

    Urine Test Strip (Dipstick Test)

    Urine dipstick tests are a valuable screening tool for guiding empirical treatment of UTIs. Nevertheless, results should be interpreted using microscopy and clinical information. Test strips and dipstick tests may detect nitrites (metabolic product of typical pathogens in the urinary tract) and leukocyte esterase from white blood cells/neutrophils.

    Nitrites:

    • are produced by most common bacteria that cause UTIs, especially Gram-negative (and some Gram-positive) bacteria; and
    • can give false-negative results due to shortened bladder incubation time (< 4 hours), pH < 6.0, presence of nitrate reductase-negative organisms, urobilinogen or urinary vitamin C.

    Leukocyte esterase:

    • relies on reaction of leukocyte esterase produced by neutrophils;
    • can give a positive result, suggesting pyuria associated with UTI;
    • can be hindered, since leukocytes may disintegrate in transit;
    • can give false-positive results due to contamination with vaginal discharge; and
    • can result in reduced sensitivity due to elevated urine glucose (e.g., diabetes).
    Advantages Disadvantages
    • Convenient
    • Easy to interpret
    • Cost-effective
    • Short turn-around time
    • Performed at point of care
    • Results are time- and storage-sensitive
      • Specified time between specimen collection and test reading
      • False-positive/negative results
    • Qualitative

    The use of urine dipstick results must be interpreted with caution. In the presence of a urinary catheter, bacteria will be present and trauma caused by the catheter may give a reading of positive white blood cells in urine. Despite these limitations, the results, when coupled with other criteria, can be useful.

    Treating CAUTI with Antibiotics

    Antibiotics are indicated only if there is evidence of clinical or symptomatic infection. Routine use of antibiotic prophylaxis while a catheter is in situ to prevent CAUTI is not recommended. For patients with infections related to long-term use of urinary catheters, treatment may be difficult because of biofilm formation. In these cases, consider replacing the catheter if it has been in place for more than seven days before giving the patient the appropriate antibiotic. Treatment of asymptomatic catheter-associated bacteriuria or candiduria is usually not indicated; bacteriuria and candiduria frequently resolve following removal of the catheter. Type and duration of treatment depend on causative pathogen(s), severity of clinical symptoms and local guidelines.

  • Knowledge Check (10 min)

    1Which of the surveillance definitions for CAUTI requires positive microbiological cultures from a laboratory to be obtained before a diagnosis is made?

    2Is the presence of bacteria in urine an indicator of an infection?

    3Which of the following is/are suggested recommendations for catheter maintenance? Select all that apply.

    4A specimen must be transported to a laboratory within…

  • A Multimodal Approach to CAUTI Prevention (10 min)

    Click or tap the tabs below to learn more about how each element of the multimodal strategy can help you implement the necessary measures that we have learnt about to prevent CAUTI in your facility.

    System Change

    CAUTI prevention begins with the right infrastructure, and access to the necessary resources and equipment. These two elements support CAUTI prevention interventions. The key question to ask is: What infrastructure, equipment and supplies are needed to prevent CAUTI?

    As you consider changes to make in your facility, ensure that the facility has the necessary equipment and resources available, such as:

    • pre-prepared CAUTI insertion kits;
    • personal protective equipment; and
    • hand hygiene supplies.

    Consider these additional questions:

    • Can necessary supplies be procured easily, affordably and when needed?
    • Is the infrastructure supportive of CAUTI prevention? For example: Can hand hygiene be performed at the point of care? Is there adequate lighting? Can patient privacy and dignity needs be met?
    • Are enough catheters available to ensure single use?
    • Are there enough jugs to ensure decontamination between catheterization?
    Training and education

    Practical training and education methods aligned with the recommendations for CAUTI prevention are essential for facility staff that care for patients who have indwelling catheters. The key questions to ask are: Who needs training? What type? How frequently? It is important to bridge the gap of insufficient or inaccurate knowledge of the importance and risk of CAUTI, and recommendations about prevention. Here is a list of training approaches you may suggest at your facility:

    • onsite courses
    • simulations and videos
    • group discussions
    • bedside training
    • training support materials (handouts, case studies, e-learning modules, etc.)

    Consider these questions when determining a training and education plan for CAUTI prevention:

    • Is clinical staff aware of risks associated with urinary catheter use?
    • Is everyone who catheterizes trained on the four key principles and practices described in the section above?
    • How is competency assured?
    • Are regular refresher courses/seminars/grand rounds provided?
    • Are policies/guidelines/protocols available/accessible and consistent with current evidence?
    • Are patients/families taught about measures they can take to prevent CAUTI?
    Evaluation and feedback

    Choosing a tool or method to document compliance with best practices recommended for insertion and ongoing management of urinary catheters keeps staff accountable. Evaluating appropriateness of procedures regularly and reporting results in a timely manner will ensure that everyone is being consistent when interacting with urinary catheters. A key question to ask is: How can you identify gaps to prioritize actions, track progress and provide feedback to drive change?

    Consider these tools when designing monitoring and feedback approaches for your staff:

    • checklists
    • algorithms
    • monitoring forms (WHO hand hygiene observation tools)
    • CAUTI surveillance systems
    • stop orders

    Consider these questions when determining an evaluation and feedback plan for CAUTI prevention:

    • Are existing monitoring and feedback (audit) tools (e.g., WHO hand hygiene observational audit tools) available and accessible?
    • Have monitoring and feedback tools been developed at your facility?
    • Are checklists available?
    • Are CAUTI surveillance systems in place?
    • Is someone with data analysis skills available to analyse and interpret the data to ensure effective feedback is provided to the right people?
    Reminders and communications

    This element encourages health professionals to recognize the importance of CAUTI prevention practices through visual methods and effective communication. These reminders encourage health professionals to communicate with patients and their visitors. Talk to senior leaders and decision-makers about what CAUTI prevention strategies should be considered. A key question to ask is: How do you promote and reinforce the appropriate messages? Consider the following methods when designing approaches to “sell” CAUTI prevention:

    • posters
    • brochures
    • organizational charts
    • infographics
    • sample letters
    • advocacy messages

    Consider these questions when exploring appropriate CAUTI prevention communications and reminders for your facility:

    • Are posters (either commercially produced or developed in-house) available to act as reminders or calls to action—e.g., to remind about timely removal?
    • Is technology (e.g., text messages) available to support reminders in the workplace?
    • Are bundles used to promote the right practices?
    • Do team meetings/ward rounds routinely address patients with indwelling urinary catheters?

    An implementation tool aiming to improve the care process and patient outcomes in a structured manner. It comprises a small, straightforward set of evidence-based practices (generally 3 to 5) that have been proven to improve patient outcomes when performed collectively and reliably.

    Culture change

    Create an environment that facilitates awareness of prevention at all levels. Nurture a climate that understands and prioritizes safety. The culture of your facility influences how teams collaborate. This sense of teamwork affects both how valued people feel and their daily performance in the workplace. You can influence staff perceptions of their ability to make a change. Key questions to ask: Do senior managers support the intervention? Are others willing to be champions? Consider these strategies as you develop culture changes in your facility:

    • motivated, empowered, multidisciplinary teams
    • champions
    • role models
    • leadership
    • morbidity and mortality rounds (learning from past outcomes)
    • advocacy messages
    • patient and family engagement

    Consider these questions when promoting a culture of safety in your facility:

    • Are there champions on wards who are informed about the four principles and practices and actively promote them, thus providing the message “we take CAUTI seriously here”?
    • Do staff feel empowered to challenge suboptimal practices in a safe way?
    • Do senior clinicians and nurses support and promote the other four parts of the multimodal strategy, for example, by releasing staff to attend training?
    • Are patients involved and engaged in prevention measures?
  • Multimodal Strategy at The Udaipur Central Health Centre (10 min)

    At their second IPC meeting of the month, the IPC team are ready to present their findings to facility management. They propose using a multimodal strategy to combat CAUTI. Based on their observations, the team have listed the following challenges:

    • Nurses in the maternity ward have complained that there aren’t enough catheter kits available when they need them.
    • It has become clear that some HCWs are unaware of when it is inappropriate to use indwelling catheters; insertion has become part of the ward routine all women post-labour.
    • Concerns have been brought up that CAUTI surveillance data is not being analysed and acted upon to support improvements.
    • CAUTI prevention is not routinely discussed among staff, despite being a big problem at this facility.
    • Documentation is poor, with catheter insertion and removal often not recorded accurately.

    Match their proposed solutions to the appropriate multimodal strategy element:

    The complete absence of a supply.

  • Summary (5 min)

    In this section of the module, you have learnt about the most common definitions used to describe CAUTI. It is important that a facility agrees on which definition they will use, so that all data collected are as consistent and accurate as possible in measuring CAUTI rates. There are inherent challenges to recognizing CAUTI. Patients with long-term catheters will often have bacteria in their urine; this is not necessarily indicative of an infection. You can now explain the four key principles of CAUTI prevention interventions. In general, these principles are to (1) avoid catheters when possible, (2) use an aseptic technique when inserting a urinary catheter, (3) maintain the catheter according to best-practice guidelines, and (4) review the urinary catheter daily to determine when to remove it.

    In this section, you also learnt the proper procedure for catheter preparation and insertion. You can now describe the aseptic technique for both male and female patients. In addition, you learnt how to safely obtain and preserve a urine sample for testing. As you know, interrupting the closed bag system of a urinary catheter can allow intraluminal entry of microbes that cause infection. Obtain a urine sample from a catheter only if it is absolutely necessary.

  • References
    1. National Healthcare Safety Network (NHSN) patient safety component manual. Atlanta, GA: Centers for Disease Control and Prevention; 2018 (https://www.cdc.gov/nhsn/training/patient-safety-component/index.html).
    2. Point prevalence survey of healthcare-associated infections and antimicrobial use in European acute care hospitals; 2012 (http://www.ecdc.europa.eu/en/publications/Publications/0512-TED-PPS-HAI-antimicrobial-use-protocol.pdf).
    3. Rockville, MD: Agency for Healthcare Research and Quality; 2017 (https://www.ahrq.gov/professionals/quality-patient-safety/qualityresources/tools/cauti-ltc/modules/implementaion/education-bundles/urineculturing/whento-order/cultures-slides.html).
    4. Manojlovich M, Saint S, Meddings J, Ratz D, Havey R, Bickmann J, et al. Indwelling urinary catheter insertion practices in the emergency department: an observational study. Infect Control Hosp Epidemiol. 2016;37(1):117–9.