Diagnostic criteria include clinical and laboratory symptoms:
Two or more clinical symptoms:
Fever > 38ºC
Urinary urgency or frequency
Acute dysuria
Hypogastric pain
Costovertebral angle tenderness
One or more laboratory finding:
Bacteriuria (> 100,000 CFUs/mL)
Pyuria (>10 WBCs/HPF)
Investigations
Urinalysis
Leukocyte esterase
Nitrite, positive for organisms that convert nitrate to nitrite such as the Gram-negative bacteria
High negative predictive value if both LE and nitrite are negative
Urine microscopy
Pyuria indicated by 5-10 cells per HPF
References
^Dimitri M. Drekonja, Barbara Trautner, Carla Amundson, Michael Kuskowski, James R. Johnson. Effect of 7 vs 14 Days of Antibiotic Therapy on Resolution of Symptoms Among Afebrile Men With Urinary Tract Infection. JAMA. 2021;326(4):324. doi:10.1001/jama.2021.9899.