Top Ten Myths Regarding the Diagnosis and Treatment of Urinary
    Tract Infections
    by Lucas Schulz, PHARMD; Robert J. Hoffman, MD; Jeffrey Pothof, MD; Barry Fox, MD
    from J Emerg Med. 2016;51(1):25-30.  The Journal of Emergency Medicine
    - Click to link:    . It is worthwhile to read!

    Background: Urinary tract infections (UTI) are the most common type of infection in the United States. A
    Centers for Disease Control and Prevention report in March 2014 regarding antibiotic use in hospitals
    reported "UTI" treatment was avoidable at least 39% of the time. The accurate diagnosis and treatment of
    UTI plays an important role in cost-effective medical care and appropriate antimicrobial utilization.

    Objective: We summarize the most common misperceptions of UTI that result in extraneous testing and
    excessive antimicrobial treatment. We present 10 myths associated with the diagnosis and treatment of
    UTI and succinctly review the literature pertaining to each myth. We explore the myths associated with
    pyuria, asymptomatic bacteriuria, candiduria, and the elderly and catheterized patients. We attempt to give
    guidance for clinicians facing these clinical scenarios.

    Discussion: From our ambulatory, emergency department, and hospital experiences, patients often have
    urine cultures ordered without an appropriate indication, or receive unnecessary antibiotic therapy due to
    over-interpretation of the urinalysis.

    Conclusions: Asymptomatic bacteriuria is common in all age groups and is frequently over-treated. A UTI
    diagnosis should be based on a combination of clinical symptoms with supportive laboratory information.

    This review will assist providers in navigating common pitfalls in the diagnosis of UTI.

    Urinary tract infections (UTI) are the most common type of infection in the United States. Emergency
    medicine providers are frequently faced with making this common diagnosis. A Centers for Disease
    Control and Prevention (CDC) report in March 2014 regarding antibiotic use in hospitals reported "UTI"
    treatment was avoidable at least 39% of the time.[1] How is it that something that seems so simple is so
    often misdiagnosed and treated in emergency departments (EDs)? The 10 myths outlined below address
    the common fallacies as they pertain to the diagnosis of UTI, and reveals the evidence behind the myth.

    Myth 1: The Urine is Cloudy and Smells Bad. My Patient has a UTI

    Truth 1: Urine color and clarity or odor should not be used alone to diagnose or start antibiotic therapy in
    any patient population.

        Visual inspection of urine clarity is not helpful in diagnosing UTI in women.[2] One hundred female
    patients at a university hospital had their urine tested by reading newsprint through the sample. The
    sensitivity, specificity, and positive and negative predictive values were 13.3%, 96.5%, 40.0%, and 86.3%,

        Foul-smelling urine is an unreliable indicator of infection in catheterized patients, and is usually
    dependent on patients' hydration status and concentration of urea in the urine.[3,4]
    Myth 2: The Urine has Bacteria Present. My Patient has a UTI. Also See Myth 8

    Truth 2: The presence of bacteria in the urine on microscopic examination or by positive culture without UTI
    symptoms is NOT an indication of a UTI due to the possibility of contamination and asymptomatic

        UTI is not a laboratory-defined diagnosis. Diagnosis should be based on clinical symptoms whenever
    possible, and confirmed by positive urine microscopy and culture.

        Quantitative colony counts should not be used to guide therapy in asymptomatic patients.[6] In
    symptomatic females, colony counts of >102 cfu/mL are usually clinically meaningful. In symptomatic
    males, colony counts >102 cfu/mL are usually clinically relevant for diagnosis of UTI or prostatitis.
    Myth 3: My Patient's Urine Sample has >5 Squamous Epithelial Cells per Low-Power Field
    and the Culture is Positive. Because the Culture is Positive, I can Disregard the Epithelial
    Cell Count and Treat the UTI

    Truth 3: A good specimen has fewer than five epithelial cells per low-power field on urinalysis.[7]
    Contaminated specimens should be considered for recollection or straight catheterization should be
    Myth 4: The Urine has Positive Leukocyte Esterase. My Patient Should Have a Urine
    Culture Performed, has a UTI, and Needs Antibiotics

    Truth 4: A urinalysis with positive leukocyte esterase should not be used alone to support a diagnosis of
    UTI or start antimicrobial therapy in any patient population. Medical systems with reflex urine cultures for >5
    white blood cells (WBC)/high-power field should be re-evaluated for their utility in the absence of patient

        A dipstick leukocyte esterase test has high sensitivity and specificity for the presence of quantitative
    pyuria, 80–90% and 95–98%, respectively; however, a positive leukocyte esterase alone is NOT
    recommended for diagnosis of UTI.[7,11] As in myth #2, symptoms are usually required for the diagnosis
    of UTI; pyuria or bacteriuria alone is not an indication for antimicrobial therapy and can result in an
    overtreatment rate of up to 47%.[4,12]

       On rare occasions, a negative leukocyte esterase in the presence of UTI symptoms may still prompt a
    urine culture if clinically suspected.[7,11] More appropriately, this situation should prompt a search for
    urethritis, vaginitis, or sexually transmitted infection.
    Myth 5: My Patient has Pyuria. They Must Have a UTI

    Truth 5: A urinalysis with quantitative urine WBC counts should not be used alone to support a diagnosis of
    UTI or start antimicrobial therapy in any patient population.

       In neutropenic or leukopenic patients, the WBC count may be artificially low. In systems with reflex culture
    (the algorithm-based performance of culture based on laboratory values), reflex culturing may not occur.
    The microbiology laboratory should be contacted and a specific order for a urine culture made if urinary
    symptoms are present and urinary source of infection is suspected.

       Borderline WBC counts of 6–10 cells/mL may reflect the patient's state of hydration. For example,
    patients with oliguria or anuria (dialysis) usually have some degree of pyuria. If a UTI is defined solely by
    WBCs more than 3 per high-power field, then overtreatment can be as high as 44%.[12] WBCs may also
    be seen in the presence of moderate hematuria.

        Noninfectious conditions, such as acute renal failure, sexually transmitted infections, or noninfectious
    cystitis from the presence of a bladder catheter may result in pyuria.
    Myth 6: The Urine has Nitrates Present. My Patient has a UTI

    Truth 6: Urine nitrates should not be used alone to diagnosis or start antimicrobial therapy in any patient

        Urine nitrate has a high true-positive rate for bacteriuria, but bacteriuria, as noted above in Myth 2, does
    not define a clinically significant UTI. Diagnosis of UTI should be considered in a patient with elevated
    urine nitrate in the presence of clinical signs and symptoms of UTI.[5]

        A negative leukocyte esterase AND a negative urine nitrate largely rule out infection in pregnant women,
    elderly patients, family medicine, and urology patients.[13] Alternative diagnosis should be thoroughly
    investigated in this scenario. The combination of a negative leukocyte esterase and negative nitrite test
    demonstrated a UTI negative predictive value of 88% (95% confidence interval [CI] 84–92%).[13]

        Even if both leukocyte esterase AND nitrite analyses are positive, the sensitivity for bacteriuria was only
    48% (95% CI 41–55%), and specificity was 93% (95% CI 90–95%) among elderly nursing home residents,
    indicating the need to correlate with clinical symptoms that suggest a UTI (see Myth 2).[14]
    Myth 7: All Findings of Bacteria in a Catheterized Urine Sample Should be Diagnosed as a

    Truth 7: Virtually 100% of patients with an indwelling Foley catheter are colonized within 2 weeks of
    placement with 2–5 organisms.[15] Catheter colony counts define bacteriuria but must be taken in a
    clinical context for diagnosis of UTI.

       Ninety-eight percent of chronically catheterized patients had bacteriuria and 77% were polymicrobial. The
    mean interval between episodes of bacteriuria with new organisms was 1.8 weeks.[16]

       Bacteriuria and pyuria in chronically catheterized patients should be treated only in the presence of signs
    and symptoms of infection when assessable (e.g., fever, leukocytosis, suprapubic pain, and tenderness.
    Dysuria is obviously not assessable). Pyuria or bacteriuria alone is not an indication for antimicrobial

       Although antibiotics may delay the onset of bacteriuria in catheterized patients, this strategy ultimately
    selects for resistant microorganisms.[17] Prophylactic anti-infectives are not recommended for patients
    with chronic catheters, but may be considered for short-term (usually no more than 2 weeks) use by
    urology specialists to delay the onset of bacteriuria in selected cases where benefits of prophylaxis may
    outweigh the risk.
    Myth 8: Patients With Bacteriuria Will Progress to a UTI and Should Therefore be Treated

    Truth 8: Bacteriuria does NOT establish a diagnosis of a UTI. Antimicrobial therapy should not be initiated
    in asymptomatic patients.

       The prevalence of bacteriuria in elderly institutionalized patients without indwelling catheters varies from
    25–50% for women and 15–49% for men, and increases with age.[18] Bacteriuria and pyuria in the elderly
    is, to a large degree, an expected finding.

       Symptomatic UTI is substantially less common than asymptomatic bacteriuria.[19]

       Asymptomatic bacteriuria has not been associated with long-term negative outcomes such as
    pyelonephritis, sepsis, renal failure, or hypertension.[19]

       The overuse of antibiotics leads to antibiotic resistance and potential side effects.[20]

       Pyuria, leukocyte esterase, or nitrate, individually, accompanying asymptomatic bacteriuria are NOT
    necessarily an indication for antimicrobial treatment in the general population.[3] Some exceptions include:
    pregnancy and any urologic procedure with bleeding, such as urinary tract stenting.[21,22]

       Recent evidence suggests that in younger women with true recurrent UTI, that bacteriuria may be
    "protective" for future UTI with more pathogenic organisms.[23]
    Myth 9: Falls and Acute Altered Mental Status Changes in the Elderly Patient are Usually Caused by UTI

    Truth 9: Altered mental status and falls in the elderly are caused by many factors. Evidence of systemic
    infection (fever, leukocytosis) or other signs and symptoms of UTI, especially dysuria (when able to
    assess), should be present to make the diagnosis of UTI in noncatheterized patients. Symptoms of active
    infection in a catheterized patient are obviously more difficult to assess.[24]

       Elderly patients with acute mental status changes accompanied by bacteriuria and pyuria, without
    clinical instability or other signs or symptoms of UTI, can reasonably be observed for resolution of
    confusion for 24–48 h without antibiotics, while searching for other causes of confusion.[25,26]

           In all elderly patients, acute mental status change and functional decline are nonspecific clinical
    manifestations of several circumstances, including, but not limited to dehydration, hypoxia, and poly-
    pharmacy adverse reactions. Diagnosis of UTI should be correlated with others signs of systemic

       In the noncatheterized patient, acute changes in mental status was associated with bacteriuria plus
    pyuria in patients with clinically suspected UTI.[27] However, these two findings are also frequently
    demonstrated in elderly patients with asymptomatic bacteriuria. Attribution of altered mental status to
    bacteriuria can result in failure to identify the true cause.[24,25]

       Falls without localizing urinary symptoms were not associated with bacteriuria or pyuria.[28,29]

       Elderly patients, especially those with dementia or indwelling Foley catheters, have high rates of
    bacteriuria.[18] Diagnosis of infection/sepsis of a urinary source with asymptomatic bacteriuria is not
    recommended unless other infectious sources have been excluded and patients meet urine criteria
    suspicious for infection. Diagnosis of UTI in the catheterized patient should always be a diagnosis of
    exclusion by investigating other causes for altered mental status in the absence of localized urinary tract
    Myth 10: The Presence of Yeast or Candida in the Urine, Especially in Patients With Indwelling Urinary
    Catheters, Indicates a Candida UTI and Needs to be Treated

    Truth 10: The occurrence of candiduria in the catheterized patient is common, especially in the intensive
    care unit, and most often reflects colonization or asymptomatic infection.[30] Treatment of candida in the
    urine should occur only in rare situations, such as clear signs and symptoms of infection and no
    alternative source of infection.

       Treatment of asymptomatic candiduria in nonneutropenic catheterized patients has usually not been
    shown to be valuable.[30]

    The UTI Myths
    Health care providers have, over the years, adhered to dogma surrounding the diagnosis of UTI that is
    incorrect. This information has been perpetuated, and has caused significant overtreatment of
    asymptomatic bacteriuria. Common misconceptions such as color or smell have no predictive value as it
    pertains to the diagnosis of UTI, but are commonly utilized as "tests" to increase the posttest probability
    that a patient has a UTI. There also exists wide variation in the interpretation of a urinalysis between
    different providers. Our review demonstrates how no one test value can reliably make the diagnosis of UTI.
    Especially common in emergency medicine is using the diagnosis of UTI to account for an elderly patient's
    altered mental status. Not only is this uncommon, but this type of anchoring hinders the clinician from
    diagnosing the real cause of the patient's altered mental status.

    Overtreatment of Asymptomatic Bacteriuria
    Frequent overdiagnosis of UTI and subsequent treatment is a common problem that is perpetuated by
    many myths surrounding the diagnosis of UTI. This leads to unknowingly using antibiotics that have no
    benefit, but do carry risks. The CDC reports that nearly 40% of all antibiotics prescribed for presumed UTI
    could have been avoided.[1] Unfortunately, the practice of overprescribing antibiotics has generated
    antibiotic resistance among organisms that continue to challenge our health care systems and harm
    patients.[31] In addition, inappropriate antibiotic utilization increases health care costs. The National Health
    Expenditure Accounts Team estimates that in 2014 the United States spent $9523 per person, or 17.5% of
    our gross domestic product, on health care.[32]

    Recommendations for Improved Accuracy When Diagnosing UTI
    EDs that have implemented reflexive urine cultures based on urinalysis values should carefully evaluate
    whether this practice increases their treatment rate of asymptomatic bacteriuria. We believe increased
    education aimed at physicians, advanced practice providers, and nurses could go a long way toward
    disproving the common myths that frequently guide providers to make the wrong decision. There is also a
    role for clinical decision support built into our electronic medical records that could provide real-time
    assistance to providers such that it is easier to use evidence-based guidelines, and as a result, improved
    accuracy of the diagnosis of UTI could be ensured.Continue Reading

    Emergency medicine providers frequently evaluate patients for urinary tract infections. There are many
    myths that have been perpetuated on the interpretation of patient symptoms and laboratory results that
    lead to overtreatment of asymptomatic bacteriuria. By using clinical history and laboratory data in addition
    to understanding the evidence behind these common myths, emergency medicine providers will be better
    able to make an accurate diagnosis. This will result in increased patient safety and decreased health care

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