In a male patient in his late 80s presenting with dysuria and hematuria, a urine dipstick negative for leukocyte esterase and a culture showing only mixed normal flora, does this indicate a urinary tract infection?

Does This Presentation Indicate a UTI?

No, this presentation does not indicate a urinary tract infection and should not be treated with antibiotics. The combination of negative leukocyte esterase, negative culture, and mixed normal flora strongly suggests specimen contamination rather than true infection, even in the presence of dysuria and hematuria. 1, 2

---

Why This Is Not a UTI

Diagnostic Criteria Are Not Met

Both pyuria AND acute urinary symptoms are required to diagnose and treat a UTI. 1, 2 This patient fails the pyuria requirement:

• Negative leukocyte esterase effectively rules out bacterial UTI with a negative predictive value of 82–91%, regardless of symptoms present 2
• The absence of pyuria (≥10 WBCs/HPF or positive leukocyte esterase) makes bacterial infection extremely unlikely 1, 2
• In elderly hospitalized patients with bacteremic UTI, dipstick urinalysis demonstrates 96.9% sensitivity—meaning a negative result is highly reliable for excluding infection 3

Culture Results Indicate Contamination

• Mixed normal flora with a negative culture is highly suggestive of contamination, not infection 2
• A negative urine culture essentially rules out significant bacterial UTI with >95% specificity 2
• The presence of mixed bacterial flora (gram-positive and gram-negative bacilli) without growth on culture almost always represents peri-urethral or skin contamination 2
• True polymicrobial UTIs are rare (3–11% of cases) and occur only in high-risk settings such as structural urinary abnormalities, neurogenic bladder, or chronic indwelling catheters 2

---

Alternative Explanations for Symptoms

Dysuria Without Infection

The burning with urination in this elderly male patient likely represents:

• Mechanical or chemical irritation rather than bacterial infection, particularly if symptoms improve with hydration 2
• Prostate-related issues such as benign prostatic hyperplasia (BPH), which creates both static obstruction and dynamic smooth-muscle tone changes that can cause dysuria without infection 1
• Non-infectious urethritis or bladder irritation 2

Hematuria Considerations

• Trace blood alone does not indicate infection when pyuria is absent 2, 4
• In elderly males, hematuria may be related to prostatic enlargement, urolithiasis, or other structural causes 1
• Persistent hematuria beyond 6 weeks after symptom resolution warrants urologic evaluation (CT urography, cystoscopy) to exclude malignancy or stones 2

---

Critical Pitfalls to Avoid

Do Not Treat Based on Symptoms Alone

• Never prescribe antibiotics based solely on dysuria without confirming pyuria 1, 2
• In elderly patients, urine dipstick specificity ranges from only 20–70%, but a negative result for both nitrite and leukocyte esterase reliably excludes infection with 90.5% negative predictive value 1, 2, 5
• Non-specific symptoms like confusion or functional decline alone should not trigger UTI treatment without specific urinary symptoms AND pyuria 1, 2

Do Not Treat Contaminated Cultures

• Discontinue any antibiotics started for contaminated cultures immediately to avoid unnecessary harm, cost, and antimicrobial resistance 2
• Treating contaminated cultures or asymptomatic bacteriuria provides no clinical benefit and increases adverse outcomes including C. difficile infection 2
• Asymptomatic bacteriuria occurs in 15–50% of elderly patients and should never be treated 1, 2

---

Recommended Management Algorithm

Immediate Actions

1. Stop any antibiotics if already started 2
2. Do not order repeat urine cultures unless new specific urinary symptoms develop 2
3. Evaluate for alternative causes of dysuria and hematuria 1, 2

If Symptoms Persist or Worsen

• Assess for prostatic enlargement by measuring post-void residual urine volume, as incomplete bladder emptying increases risk of recurrent symptoms 1
• Consider non-infectious causes: urolithiasis, interstitial cystitis, structural abnormalities 2
• Refer to urology if recurrent symptoms despite appropriate evaluation, or if hematuria persists beyond 6 weeks 1, 2

When to Reconsider UTI Diagnosis

Only pursue infection workup if the patient develops:

• Recent-onset dysuria PLUS at least one of: urinary frequency, urgency, new incontinence, fever >37.8°C, or costovertebral angle tenderness 1
• Systemic signs such as fever, rigors, hypotension, or acute delirium 1

If these criteria are met, obtain a properly collected specimen (midstream clean-catch after thorough cleansing) and repeat urinalysis looking for ≥10 WBCs/HPF before proceeding to culture 1, 2

---

Special Considerations in Elderly Males

• All UTIs in men are classified as complicated and require minimum 7 days of therapy when truly present 1, 2
• Prostatic enlargement impairs antibiotic delivery to prostatic tissue and reduces bacterial clearance, increasing treatment failure risk 1
• Post-void residual measurement is essential in elderly males with urinary symptoms to assess for incomplete emptying 1
• Patients with recurrent symptoms despite appropriate management should be referred to urology for further evaluation 1

---

Quality of Life and Antimicrobial Stewardship

• Unnecessary antibiotic treatment causes harm including increased antimicrobial resistance, adverse drug effects (including tendon rupture, C. difficile infection, and drug interactions), and increased healthcare costs without clinical benefit 1, 2
• Educational interventions on proper diagnostic protocols achieve a 33% absolute risk reduction in inappropriate antimicrobial initiation 2
• Treating asymptomatic bacteriuria promotes reinfection with more resistant organisms, further limiting future therapeutic options 1, 2