Abstract

Brucellosis is a zoonotic infection with diverse clinical manifestations; however, thyroid involvement is exceedingly rare. Non-suppurative Brucella thyroiditis may clinically mimic subacute (De Quervain) thyroiditis, potentially leading to diagnostic delay. We report the case of a 50-year-old female livestock worker who presented with fatigue, sore throat, and right-sided cervical swelling. Laboratory evaluation revealed suppressed thyroid-stimulating hormone levels. Neck ultrasonography demonstrated thyroid nodules without evidence of lymphadenopathy. Brucella serology was positive, and Brucella spp. was isolated from blood culture, confirming microbiologically proven bacteremia. The patient was treated with streptomycin and doxycycline, followed by rifampicin and doxycycline, for a total treatment duration of 45 days, resulting in complete clinical recovery. In addition, a literature review identified six previously reported cases of non-suppurative Brucella thyroiditis. Most patients presented with painful thyroid swelling and transient thyrotoxicosis. Blood culture positivity was uncommon, whereas serological testing remained the primary diagnostic tool. All reported cases responded favorably to doxycycline-based combination therapy. In endemic regions, brucellosis should be considered in patients presenting with thyroid inflammation and biochemical thyrotoxicosis, particularly among individuals with occupational exposure to livestock. Early recognition and appropriate antimicrobial therapy can prevent misdiagnosis, unnecessary corticosteroid use, and invasive procedures.