Detection of undiagnosed STIs in patients with suspected UTI using pooled urine PCR screening

Abstract

Introduction: Sexually transmitted infections (STIs) remain a major global public health concern, with a high proportion of asymptomatic cases. Undiagnosed infections may lead to significant clinical, economic, and epidemiological consequences. Patients with sterile pyuria and suspected urinary tract infection (UTI) represent a relevant target population for STI screening.

Methods: We evaluated the real-world performance of a targeted STI screening strategy based on urine sample pooling in patients with suspected UTI, genitourinary symptoms, leukocyturia, and negative urine culture.

Results: Over a 15-month period, 2019 urine samples were analysed using pooled PCR testing, identifying 212 STI-positive patients (10.5%). Chlamydia trachomatis was the most prevalent pathogen, followed by Trichomonas vaginalis, Mycoplasma genitalium, and Neisseria gonorrhoeae. Pooling did not compromise analytical sensitivity, with comparable cycle threshold values between pooled and individual samples.

Conclusions: Pooled PCR screening reduced testing volume while preserving diagnostic yield, supporting its use as an efficient and potentially cost-effective strategy for STI-screening.

Keywords: Cribado de ITS; Estrategia de pooling; Infección de transmisión sexual; Infección del tracto urinario; Leucocituria; Leukocyturia; Pooling strategy; STI screening; Sexually transmitted infections; Urinary tract infection.