Pyelonephritis due to Brucella species: true clinical entity or ghost disease?

Brucellosis is a chronic granulomatous infection caused by intracellular Gram-negative bacteria belonging to Brucella species. While uncommon in the United States, northern Europe and Eastern Asia, it is common in the Middle East, southern Europe, and South America [1]. Human brucellosis is a potentially life-threatening multisystem disease which requires combined and prolonged treatment with antimicrobial agents. Genitourinary system involvement occurs in 2 to 20% of patients with brucellosis and includes prostatitis, epididymoorchitis, cystitis, pyelonephritis, interstitial nephritis, exudative glomerulonephritis and renal abscesses. Because of its nonspecific symptoms, infections of the urinary tract due to Brucella species often remain underdiagnosed and underreported [2]. Epididymis seems to be the most often affected organ of the genitalia and lower urinary tract. Epididymitis due to Brucella species may cause serious complications if left untreated, such as necrotizing orchitis, aspermia or oligospermia [3]. To our knowledge, genitourinary complications of brucellosis have rarely been reported in the medical literature, not to mention pyelonephritis due to Brucella species, which has barely been documented [4]. Specifically, only three cases of documented pyelonephritis due to Brucella species have been confirmed with a positive urine culture for Brucella species together with pyuria and/or urinary tract infection symptoms [4]. In the same study, which involved 390 patients with genitourinary brucellosis, pyelonephritis was diagnosed in another 30 female patients using extra laboratory tests, such as blood