Clinical characteristics of patients with polymicrobial septic arthritis.

Little is known about the incidence, risk factors, clinical characteristics, and outcomes of patients with polymicrobial SA (PMSA). We aimed to determine the unique characteristics of patients with PMSA by comparing them to patients with monomicrobial SA (MMSA). We conducted a retrospective cohort study of patients 18 years and older admitted to a single tertiary care medical center, between 1998 and 2015, with surgically treated culture-positive SA affecting one or more joints. Patients were separated into two groups by the presence of one (MMSA) or more organisms (PMSA). A total of 441 patients with MMSA and 47 with PMSA were identified. Prior history of SA was more common among the PMSA group (31.9% vs. 18.6%; p = 0.03) as well as higher rates of prosthetic joint involvement (48.9% vs. 36.1%; p = 0.06). Patients with PMSA were sicker with higher rates of shock at presentation (14.9% vs. 5.5%; p = 0.02), intensive care unit admissions (39.1% vs. 18%; p < 0.001), and longer mean length of stay (16.1 vs. 10.9 days; p < 0.001). The most prevalent pathogens in the PMSA group were coagulase-negative Staphylococcus (31%), followed by methicillin-sensitive Staphylococcus aureus (29%), and Enterococcus (24%). To our knowledge, this is the first study to determine the clinical and microbiologic profiles of patients with PMSA. Important differences were noted such as more frequent involvement of atypical and prosthetic joints in PMSA. PMSA should be suspected in patients with these clinical features, and broad-spectrum antibiotics should be considered as these patients appear to be sicker and have worse outcomes.

Clinical features of patients with septic arthritis and echocardiographic findings of infective endocarditis.

PURPOSE: Patients with septic arthritis (SA) often undergo echocardiographic evaluation to identify concomitant infective endocarditis (IE). The purpose of this study is to identify distinguishing features of patients with SA and IE by comparing them to patients with SA alone. METHODS: We conducted a retrospective study of all patients 18 and older admitted to a single tertiary hospital between 1998 and 2015 with culture-positive SA. Patients were stratified by echocardiogram status and the presence of vegetations: those who had echocardiographic evaluation with no evidence of infective endocarditis (ECHO + IE-) or with a vegetation present (ECHO + IE+) and those who had no echocardiographic evaluation (ECHO-). Demographic data, clinical characteristics, microbiology data, treatment strategies, and patient outcomes were recorded and compared. RESULTS: We identified 513 patients with SA. Transthoracic echocardiogram and/or transesophageal echocardiogram were performed in 263 patients (51.2%) and demonstrated evidence for IE in 19 patients (3.7%). While most demographic features, comorbidities, and clinical characteristics did not differ significantly between those with and without IE, those with IE had higher rates of sepsis and septic shock. In addition, patients with SA and IE had higher rates of positive blood cultures and Methicillin-sensitive staphylococcus aureus (MSSA) infection when compared to those with SA without IE. Patients with IE had higher rates of intensive care unit admission and increased 30-day mortality. CONCLUSIONS: IE is uncommon among patients with SA. Echocardiography may be overutilized and may be more useful among patients presenting with sepsis, shock, or positive blood cultures, especially when MSSA is isolated.