From the Guidelines
The presence of pus cells in urine is a significant indicator of urinary tract infection (UTI), with the threshold for abnormal results varying between males and females due to anatomical differences, as noted in the 2024 European Association of Urology guidelines 1.
Significance of Pus Cells in Urine
The significance of pus cells in urine analyzed by sex (gender) is crucial for diagnosing and managing UTIs. In females, up to 5-10 pus cells per high power field (HPF) may be acceptable due to potential contamination from the vaginal area during collection, whereas in males, the presence of more than 2-5 pus cells per HPF is considered abnormal and suggests infection.
Anatomical Differences and Contamination
This difference exists because females have a shorter urethra and proximity of the urethral opening to vaginal and rectal areas, making contamination more likely, as discussed in the 2020 ACR Appropriateness Criteria for recurrent lower urinary tract infections in females 1. When elevated pus cells are found, a urine culture should be performed to identify any causative organisms.
Treatment and Management
Treatment typically involves antibiotics such as nitrofurantoin, trimethoprim-sulfamethoxazole, or fluoroquinolones for 3-7 days depending on the severity and type of infection, as suggested in the 2024 European Association of Urology guidelines 1. Proper collection technique using the clean-catch midstream method is crucial for accurate results, especially in females. Patients should also increase fluid intake, practice good hygiene, and complete the full course of antibiotics if prescribed.
Inflammation and Non-Infectious Causes
The presence of pus cells indicates inflammation, which is often due to bacterial infection but can also result from non-infectious causes like kidney stones or interstitial cystitis. According to the 2024 European Association of Urology guidelines, routine post-treatment urinalysis or urine cultures are not indicated for asymptomatic patients 1. However, for women whose symptoms do not resolve by the end of treatment, and for those whose symptoms resolve but recur within 2 weeks, a urine culture and antimicrobial susceptibility testing should be performed.
Key Considerations
- The threshold for abnormal pus cell results varies between males and females due to anatomical differences.
- Proper collection technique is crucial for accurate results.
- Antibiotic treatment should be guided by the spectrum and susceptibility patterns of the aetiological pathogens.
- Patients should increase fluid intake, practice good hygiene, and complete the full course of antibiotics if prescribed.
- The presence of pus cells indicates inflammation, which can be due to bacterial infection or non-infectious causes.
From the Research
Significance of Pus Cells in Urine
The presence of pus cells in urine is a significant indicator of a urinary tract infection (UTI) [ 2, 3 ]. Pus cells, also known as white blood cells (WBCs), are a type of immune cell that helps fight infections in the body.
Analysis by Sex (Gender)
- In women, the presence of pus cells in urine can be an indicator of a UTI, particularly if accompanied by other symptoms such as dysuria, urgency, and frequency [ 2 ].
- In men, the presence of pus cells in urine can also be an indicator of a UTI, although the symptoms may be less pronounced than in women [ 4 ].
- A study found that bacteriuria is more specific and sensitive than pyuria for detecting UTIs, even in older women and during pregnancy [ 2 ].
- Another study noted that pyuria is commonly found in the absence of infection, particularly in older adults with lower urinary tract symptoms such as incontinence [ 2 ].
Diagnostic Considerations
- Urine culture is the gold standard for detecting UTIs, but it can be time-consuming and costly [ 3 ].
- Dipstick urinalysis and microscopic urinalysis are commonly used screening tests for UTIs, but their results must be interpreted in the context of the patient's symptoms and pretest probability [ 2 ].
- Novel biomarkers such as leukocyte esterase, C-reactive protein, and procalcitonin are being researched as potential diagnostic tools for UTIs [ 3 ].