A Rare Pathogen of Bones and Joints: A Systematic Review of Osteoarticular Infections Caused by Gemella morbillorum

Osteoarticular infections (OAIs) caused by Gemella morbillorum (G. morbillorum) are a rare clinical entity. This study aimed to review all published cases of OAI due to G. morbillorum. A systematic review of PubMed, Scopus, and Cochrane Library was conducted to report the demographic and clinical characteristics, microbiological data, management, and outcome of OAIs caused by G. morbillorum in the adult population. A total of 16 studies reporting on 16 patients were included in this review. Eight patients had arthritis and eight patients had osteomyelitis/discitis. The most reported risk factors were immunosuppression, poor dental hygiene/dental infections, and recent gastrointestinal (GI) endoscopy. Five cases of arthritis occurred in a native joint while three patients had prostheses. The potential source of G. morbillorum infection was documented in more than half of the cases (56%) (most commonly odontogenic and GI sources (25% and 18%, respectively). The knee and hip joints were the most frequently affected joints in patients with arthritis, while the thoracic vertebrae were the most common sites for osteomyelitis/discitis. The blood cultures were positive in three patients with arthritis (37.5%) and five patients with osteomyelitis/discitis (62.5%). Associated endovascular infection was found in five patients with bacteremia. Contiguous spread (adjacent mediastinitis) was documented in two patients with sternal osteomyelitis and thoracic vertebral osteomyelitis. Surgical interventions were performed for 12 patients (75%). Most strains of G. morbillorum were susceptible to penicillin and cephalosporins. All patients with reported outcomes had achieved complete recovery. G. morbillorum is an emerging pathogen for OAIs in certain susceptible populations with specific risk factors. This review reported the demographic, clinical, and microbiological features of OAIs caused by G. morbillorum. A careful evaluation of an underlying infectious focus is warranted to control the source. When G. morbillorum bacteremia is present, it is also necessary to have a high index of suspicion to rule out an associated endovascular infection.