Urinalysis Findings in Gonorrhea and Chlamydia Infections
Yes, positive leukocyte esterase, negative nitrite, and pyuria on urinalysis are normal and expected findings in patients with untreated Chlamydia trachomatis or Neisseria gonorrhoeae infection. These urinalysis abnormalities reflect urethral inflammation (urethritis) rather than a urinary tract infection, and should not prompt treatment with typical UTI antibiotics 1, 2.
Why These Findings Occur
Positive leukocyte esterase and pyuria (≥10 WBCs per high-power field) are diagnostic criteria for urethritis and are expected when gonorrhea or chlamydia cause urethral inflammation 3, 1.
Negative nitrite is the expected finding because C. trachomatis and N. gonorrhoeae do not produce nitrate reductase enzymes that convert urinary nitrates to nitrites—this distinguishes STI-related urethritis from typical urinary tract infections caused by gram-negative enteric bacteria 3.
Sterile pyuria (pyuria with negative urine culture) occurs in 74% of women with confirmed STIs, demonstrating that pyuria in the setting of gonorrhea or chlamydia does not indicate a bacterial UTI 2.
Clinical Implications
Do not treat these patients with typical UTI antibiotics (such as nitrofurantoin or trimethoprim-sulfamethoxazole) based on the urinalysis findings alone, as this leads to substantial overtreatment—66% of patients with STIs who received UTI antibiotics had negative urine cultures 2.
The appropriate treatment is dual therapy for gonorrhea and chlamydia: ceftriaxone 250 mg IM single dose plus doxycycline 100 mg orally twice daily for 7 days 4, 5.
Leukocyte esterase testing on first-void urine has 100% sensitivity for detecting urethral infection with gonorrhea or chlamydia in asymptomatic males, making it a useful screening tool 6.
Diagnostic Approach
Obtain nucleic acid amplification tests (NAATs) for both N. gonorrhoeae and C. trachomatis on first-void urine or urethral swab, as these provide the highest sensitivity and specificity available 1.
A Gram stain showing ≥5 polymorphonuclear leukocytes per oil immersion field in urethral secretions confirms urethritis and provides immediate presumptive diagnosis if intracellular gram-negative diplococci are seen 4, 1.
The presence of nitrite-positive urine does not rule out STI—in fact, 59% of nitrite-positive urines in patients with confirmed STIs had negative urine cultures, indicating that nitrite positivity can be misleading in this population 2.
Common Pitfalls to Avoid
Do not assume pyuria equals UTI in sexually active patients—always consider STI-related urethritis, especially in younger patients with dysuria and urinary frequency 2.
Do not rely on the absolute number of leukocytes to distinguish UTI from STI—while culture-positive urines averaged 34 WBCs/hpf versus 24 WBCs/hpf for culture-negative urines, this 10-cell difference is not clinically useful for individual patient decision-making 2.
Recognize that asymptomatic infection is common—86% of adolescent males with pyuria and positive STI cultures in one study were asymptomatic, emphasizing the need for screening in high-risk populations 7.
Partner Management
All sexual partners within 60 days preceding symptom onset or diagnosis must be evaluated and treated empirically for both gonorrhea and chlamydia, regardless of their symptoms or test results 1, 5.
Patients should abstain from sexual intercourse for 7 days after initiating therapy and until all partners complete treatment to prevent reinfection 5.