FAQs: Urinary Tract Infection (UTI) Events

Catheter-Associated Urinary Tract Infection [CAUTI] and Non-Catheter-Associated Urinary Tract Infection [UTI] and Other Urinary System Infection [USI]

Spinal cord injury, heavily sedated, or ventilated patients

Surveillance criteria may not be equally sensitive for all patient populations.  Patient populations in which the UTI criteria may not be as sensitive include spinal cord injury patients, those with brain injuries, and heavily sedated patients. NHSN constructed its Surveillance definitions to balance sensitivity and specificity along with feasibility. A set of criteria that covered every subpopulation with high specificity and sensitivity would be too complicated to employ consistently across different facilities.  Simply follow the criteria as written in locations in which you are performing CAUTI surveillance.

Mechanical ventilation or sedation does not always mean that patients will not be able to verbalize pain.  Facilities should always perform physical examination and assess patients for non-verbal communication of pain or tenderness.

100,000 CFU/ml included in more than 1 laboratory category

My lab offers culture counts that are:

  • 75k-100,000 CFU/ml
  •  >100,000 CFU/ml

You must check with your laboratory to determine if they can identify whether at least 100,000 CFU/ml are identified in the urine culture, and if so to report it as ≥ 100,000 CFU/ml.  Some laboratories have been able to clarify this.

If the laboratory cannot clarify the culture count and cannot say for certain that a culture has at least 100,000 CFU/ml because the lab reported it as 75,000-100,000 CFU/ml, do not use that culture for NHSN UTI surveillance.

Mixed flora

No, this urine culture is not eligible for use in an NHSN UTI determination.  The medical definition of flora is a group of organisms.  Any type of mixed flora makes a positive urine culture ineligible for use to meet NHSN UTI criteria, because “mixed flora”* implies that at least 2 organisms are present in addition to the identified organism.  The urine culture does not meet the criteria for a positive urine culture with 2 organisms or less and cannot be used to meet the NHSN UTI criteria.  * The same is true for perineal flora, normal flora, and vaginal flora.

Morphology determining what equates to > 2 organisms

  • E. coli #1 > 100,000 CFU/ml
  • E. coli #2 > 10,000 CFU/ml
  • Staph Aureus > 100,000 CFU/ml

No. NHSN surveillance identification of an organism to the genus level or the species level, for example Escherichia (genus) coli (species) or Staphylococcus species is as far as you can get for reporting purposes. The E. coli #1 and #2 is considered one organism, and then S. aureus would be considered the second organism. Antimicrobial susceptibility results and colony morphology difference do not equate to a report of separate organisms. This urine culture result is not > 2 organisms, and therefore, is an eligible specimen.

Multiple colony counts for the same organism

I have a final lab result for a patient in my possible CAUTI report:

  1. 50,000 colonies/mL Pseudomonas aeruginosa #1
  2. 50,000 colonies/mL Pseudomonas aeruginosa #2
  3. 10,000 colonies/mL Pseudomonas aeruginosa #3

Yes. When an organisms found in urine are identified to the same genus and species level but there is an indication of different colony morphology or a different antibiogram (indicated by strain 1 or strain 2, colony A , colony B, for example), for purposes of NHSN UTI surveillance the organisms should be considered the same and if the sum total of the colony counts is ≥ 100,000 CFU/ml the culture result is eligible for use in meeting a UTI definition.  If antibiograms are available and the sensitivities differ for the same organisms, always report the more resistant panel.  Colony morphology, biotype, and drug sensitivity comparisons should not be used to differentiate organisms because laboratory testing capabilities and protocols vary between facilities.

Number of organisms in cultures

Do not add multiple cultures together.   More than 2 organisms in a single urine culture suggests the possibility of contamination of the specimen. The same is not true for separate urine cultures with less than 3 organisms in each.

In this example the first culture would be eligible for a UTI. If no UTI was associated with that urine culture, then the second urine culture could be considered for a UTI, since no previous UTI RIT was set and there were not more than 2 organisms in that urine culture.

Identifying single vs multiple UTIs

Yes.  This time period is called the Repeat Infection Timeframe (RIT). Please see the information on RIT found in Chapter 2 “Identifying Healthcare-associated Infections” in the NHSN manual. Identifying Healthcare-associated Infections [PDF – 1 MB]

  • 40,000 – 50,000 CFU/ml Klebsiella oxytoca
  • >100,000 CFU/ml Pseudomonas aeruginosa
  • <10,000 CFU/ml Candida, not albicans

No, the urine culture would be ineligible for use to meet NHSN UTI criteria, because there would be a total of three organisms present, including the candida (which is an excluded UTI organism).  An excluded organism, such as candida, can be in a positive urine culture, however, there can only be one other organism present that has > 100K CFU/ml to be an eligible urine culture.

Patient reported fever

If the patient reports a fever > 38.0°C (or over 100.40 F), during the POA timeframe and within the IWP of a positive urine culture, this can be used to determine if the definition of a POA infection is met.  A general report of “fever” by the patient, without an accompanying temperature measurement, may not be used.

UTI Symptom: dysuria

Urinary retention is not the same as dysuria and cannot be used to meet the UTI definition.  Dysuria is defined as painful or uncomfortable urination.

UTI Symptoms: urinary urgency, urinary frequency, and dysuria

No, “with no other recognized cause” does not apply to these symptoms. In the presence of a positive urine culture which may have been collected as a differential diagnosis for suspicion of UTI, it would be very rare that there is another associated cause for urinary urgency, urinary frequency and dysuria which are hallmark UTI symptoms.

Yes. If the patient’s urinary urgency, urinary frequency, or dysuria occurred when the indwelling urinary catheter was not in place at the time the patient experienced the urinary urgency, urinary frequency, or dysuria, then the urinary urgency, urinary frequency, or dysuria can be used as an element even on a day when the indwelling urinary catheter was in place for part of the day.

Costovertebral angle (CVA) pain or tenderness

Generalized “low back pain” in the medical record is not interpreted as CVA pain or tenderness, as there can be many causes of low back pain. Left, right, or bilateral low back or flank pain is acceptable to describe costovertebral pain.

Suprapubic tenderness

There are many causes of abdominal pain and abdominal pain is too generalized to meet the localized UTI symptom of suprapubic tenderness. Low abdominal pain, (left/right or bilateral) or bladder or pelvic pain or discomfort are acceptable documentation to meet NHSN’s UTI symptom of suprapubic tenderness.

“With no other recognized cause”

General guidance: UTI signs/symptoms within the IWP of a positive urine culture would seem to indicate the symptom is a UTI symptom related to the positive urine culture, which may have been collected based on suspicion of UTI. To exclude using “with no other recognized cause,” it should be clear the symptom relates to that cause and is clearly differentiated from a UTI symptom.

Ideally, clinical decisions about “with no other recognized cause” for the UTI signs/symptoms of suprapubic tenderness or costovertebral angle pain or tenderness should be made by a physician and/or their designee in your organization who has access to the entire medical record and clinical picture.  The other recognized cause must occur during the current admission.

Clinical judgment determination needs to be defended and backed up by physician documentation and there should be clear rationale in the event the case is validated.

Leg bags/attaching urometers

Yes. Both practices may increase the risk of UTI, and these patients should be included in CAUTI surveillance.


Only catheter-associated UTI data (both ABUTI and SUTI) are shared with CMS. Keep in mind that ABUTI may occur in patients with or without an indwelling urinary catheter. Therefore, if a patient in one of these locations has an ABUTI and an indwelling urinary catheter within the timeframe to meet the device-associated rule, this is a CAUTI and is reportable to CMS if CAUTI reporting in the location is included in your monthly reporting plan.

Device attribution

NHSN surveillance is aimed at identifying risk to the patient that is the result of device use in general, not risk from a specific device. NHSN does not allow for attribution to a specific device when entering a UTI event. You should attribute the UTI to the inpatient location where the patient was assigned on the DOE.

Patients with colovesical fistula

No. Patients with colovesical, enterovesical, or rectovesical fistulae are not excluded from meeting the NHSN UTI definition. NHSN surveillance for infection is aimed at identifying risk to the patient that is the result of device use in general, not aimed at a specific device. An indwelling urinary catheter in place puts the patient at risk and, therefore, is included in CAUTI surveillance.

The purpose of submitting a urine specimen for culture is to determine infection. The NHSN definitions currently account for contamination of urine specimens. NSHN excludes specimens with culture results of more than two organisms (polymicrobial) for use in meeting UTI definitions.

Neobladders and CAUTIs

Yes.  Patients who have neobladders are not excluded from CAUTI surveillance. NHSN surveillance definitions account for contamination.  Urine cultures that result with > 2 eligible organisms, are not eligible for use to meet NHSN UTI criteria.

Urine specimen source

No. Any urine specimen submitted for culture is eligible for review to see if that urine specimen meets NHSN UTI criteria.

Secondary BSI and associated urine colony count

No.  Only the E. coli has a colony count eligible for use in meeting a UTI criteria.  Scenario 1 of the Secondary BSI guide (Appendix B of the BSI protocol –  https://www.cdc.gov/nhsn/pdfs/pscmanual/4psc_clabscurrent.pdf [PDF – 900 KB]) states: At least one organism from the blood specimen must match an organism identified from the site-specific infection, in this case the urine, that is used as an element to meet the NHSN site-specific infection criterion.  The 50,000 CFU/ml MRSA is not used as an element in the UTI definition. In this example the BSI with MRSA only cannot be attributed as secondary to the UTI event. Additionally, the blood specimen must have a collection date within the UTI secondary BSI attribution period.

What information is needed to assist with UTI determination?

  • Date of Admission
  • Date(s) of indwelling urinary catheter insertion/removal if applicable
  • Collection date(s) and results of urine cultures including colony count
  • Collection date(s) and results of any positive blood cultures

NOTE: Please do not send Personal Identifiable Information through the NHSN email system.