Psoas abscess caused by non-typhoid Salmonella in a man with human immunodeficiency virus (HIV): A rare case report

Non-typhoidal Salmonella (NTS) typically causes self-limiting gastroenteritis but can rarely present with severe extraintestinal manifestations, especially in immunocompromised individuals. We report a case of a 32-year-old HIV-positive man on antiretroviral therapy, with a history of pulmonary Mycobacterium riyadhense infection, who presented with progressive hip pain, flank swelling, and intermittent low-grade fevers. Imaging revealed a large multiloculated left iliopsoas abscess with secondary extension, and cultures from surgical drainage grew NTS. Despite initial incision and drainage, the patient required repeat open debridement and prolonged antimicrobial therapy with ertapenem and azithromycin, alongside antiretroviral and antimycobacterial regimens. He showed significant clinical and radiological improvement after eight weeks of therapy. This case highlights the necessity of a multidisciplinary approach, given the complexities of treating infections in HIV patients who may have drug-drug interactions and may need prolonged courses of treatment.