Clinical and microbiological characteristics of acute epididymitis in Japan: A multicenter study by the Japanese...

This study aimed to investigate the clinical and microbiological characteristics of acute epididymitis (AE) in Japan using multicenter real-world data and to evaluate factors associated with hospitalization.

This multicenter retrospective study was conducted by the Japanese Research Group for Urinary Tract Infection. A total of 110 patients clinically diagnosed with AE at 13 hospitals between January and December 2017 were analyzed. Clinical findings, microbiological results, antimicrobial therapy, and outcomes were compared between hospitalized patients and outpatients.

Among 110 patients, 31 were hospitalized and 79 were managed as outpatients. The median age was 67 years (range, 9-95 years). In univariate analysis, fever, epididymal induration, dysuria, elevated white blood cell count, elevated C-reactive protein level, positive urine culture, systemic inflammatory response syndrome (SIRS), epididymal abscess, urinary retention, and recent urethral catheterization were significantly associated with hospitalization. In multivariate analysis, SIRS was independently associated with hospitalization. Escherichia coli was the most frequently isolated pathogen. Among E. coli isolates, fluoroquinolone-resistant and extended-spectrum beta-lactamase-producing strains accounted for 45.0% and 25.0%, respectively. These microbiological findings did not differ significantly between hospitalized patients and outpatients. Only two cases of Chlamydia trachomatis infection and no gonococcal infections were identified.

In this Japanese multicenter study, AE predominantly affected older adults and was frequently associated with urinary tract-related or healthcare-associated backgrounds. Hospitalization was primarily associated with systemic inflammatory response. Fluoroquinolone-resistant and ESBL-producing E. coli require attention in both hospitalized patients or outpatients.