Urinary symptoms in adolescent females: STI or UTI?

To determine if urinary symptoms or urinary tract infections (UTI) were associated with sexually transmitted infections (STI) and which history, clinical, and laboratory findings could distinguish these infections in symptomatic women.

A cross-sectional sample of 296 sexually active females aged 14-22 years attending a hospital-based teen health center or emergency department were recruited. Genitourinary symptoms, medical and sexual history, and urinalysis results were recorded. STI was defined as a vaginal swab positive for Trichomonas vaginalis or urine nucleic acid amplification test positive for Neisseria gonorrheae or Chlamydia trachomatis. A urine culture with >10,000 colonies of a single pathogen was considered a positive UTI.

In the full sample, prevalence of UTI and STI were 17% and 33%, respectively. Neither urinary symptoms nor UTI was significantly associated with STI. Further analyses are reported for the 154 (51%) with urinary symptoms: Positive urine leukocytes, more than one partner in the last three months and history of STI predicted STI. Urinalysis results identified four groups: (1) Normal urinalysis-67% had no infection; (2) Positive nitrites or protein-55% had UTI; (3) Positive leukocytes or blood-62% had STI; and (4) Both nitrites/protein and leukocytes/blood positive-28% had STI and 65% had UTI. Those without a documented UTI were more likely to have trichomoniasis than those with a UTI, and 65% of those with sterile pyuria had STI, mainly trichomoniasis or gonorrhea.

Adolescent females with urinary symptoms should be tested for both UTI and STIs. Urinalysis results may be helpful to direct initial therapy.