From the Guidelines
Urinary tract infection (UTI) symptoms with a negative urinalysis (UA) should be evaluated for other conditions that mimic UTI, and empiric antibiotic treatment may be considered if symptoms are severe and typical of UTI, despite the negative UA, as suggested by the most recent study 1.
Considerations for UTI Symptoms with Negative UA
- Conditions that mimic UTI, such as interstitial cystitis, overactive bladder, pelvic floor dysfunction, or sexually transmitted infections, should be considered.
- For immediate relief, phenazopyridine (AZO) 100-200mg three times daily for 2-3 days can help with urinary pain, though it will turn urine orange.
- Increased water intake and avoiding bladder irritants like caffeine, alcohol, and spicy foods may also help.
Further Testing and Evaluation
- If symptoms persist, further testing may be needed, including a urine culture (which can detect infections missed by UA), STI screening, or evaluation for interstitial cystitis.
- Sometimes, empiric antibiotic treatment with nitrofurantoin 100mg twice daily for 5 days or trimethoprim-sulfamethoxazole twice daily for 3 days might be considered if symptoms are severe and typical of UTI, despite the negative UA.
- The most recent study 1 suggests that antibiotics should be prescribed if there are symptoms such as frequency, incontinence, urgency, unless urinalysis shows negative nitrite and negative leukocyte esterase.
Specialized Evaluation
- If symptoms don't improve within 48-72 hours of treatment, or if they recur frequently, consultation with a urologist or urogynecologist is recommended for more specialized evaluation, as suggested by 1.
- The evaluation should include a thorough medical history, physical examination, and laboratory tests to determine the underlying cause of the symptoms.
Key Points
- UTI symptoms with a negative UA require a thorough evaluation to determine the underlying cause.
- Empiric antibiotic treatment may be considered if symptoms are severe and typical of UTI, despite the negative UA.
- Further testing and specialized evaluation may be needed to determine the underlying cause of the symptoms and to provide appropriate treatment.
From the Research
UTI Symptoms with Negative Urine Analysis (UA)
- UTI symptoms can still be present even with a negative UA, as the test may not always detect the infection 2, 3.
- A negative nitrite test with a positive leucocyte-esterase (LE) test can still indicate a UTI, with a high positive predictive value (PPV) of 79% and sensitivity of 82% 2.
- Approximately 50% of samples with negative nitrite and LE tests can still be culture positive, indicating a UTI 2.
- In patients with a high probability of UTI based on symptoms, a negative dipstick urinalysis does not rule out UTI 3.
- Nitrites are more sensitive and specific than other dipstick components for UTI, particularly in the elderly 3.
Diagnostic Approaches
- Urine culture and susceptibility testing should be reserved for women with recurrent infection, treatment failure, history of resistant isolates, or atypical presentation to make a definitive diagnosis and guide antibiotic selection 4.
- Urine culture is the gold standard for detection of UTI, but asymptomatic bacteriuria is common, particularly in older women, and should not be treated with antibiotics 3.
- Microscopic urinalysis is comparable to dipstick urinalysis as a screening test, and bacteriuria is more specific and sensitive than pyuria for detecting UTI 3.
Treatment Options
- First-line antibiotics for uncomplicated UTI include nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole (when resistance levels are <20%) 5, 4, 3, 6.
- Immediate antimicrobial therapy is recommended rather than delayed treatment or symptom management with ibuprofen alone 6.
- Individualized assessment of risk factors for resistance and regimen tolerability is needed to choose the optimum empirical regimen 6.