BackgroundSeptic arthritis is a rheumatologic emergency. Its delayed diagnosis and treatment cause joint morbidity and mortality.1 Cases involving antimicrobial-resistant bacteria have been reported.2,3ObjectivesTo determine the clinical manifestations and outcomes of septic arthritis, find the factors associated with mortality, and discover the incidence of drug-resistant organisms in our institutionMethodsA retrospective study was performed. Septic arthritis was defined as the presence of acute inflammatory arthritis indicated by a positive synovial fluid or synovial tissue culture for bacteria. A total of 116 septic arthritis patients, who visited Songklanagarind Hospital from January 2005 to December 2014, were reviewed.ResultsThe patient median age was 58 (IQR: 46, 72). Sixty-one patients (52%) were female. The median onset of symptoms and symptoms until diagnosis were 5 (IQR: 2, 7) and 6 (IQR: 3, 10) days, respectively. Eighty-eight cases (76.7%) had underlying diseases that might predispose to joint infection. Sixty-nine cases (59.5%) had pre-existing joint disease. Joint pain was the most common presenting symptom, and 58% of the cases had fever. The most common presentation was monoarthritis (87%), which was predominantly associated (78%) with knee joint involvement. The median synovial fluid leukocyte counts were 64,460 cells/μL (IQR: 30,300; 129,000). Blood cultures were positive in 53 patients (49.1%). Synovial fluid cultures commonly had Streptococcus spp. growth (41%). Seven cases (7%) involved drug-resistant organisms. All of them either were diagnosed with septic arthritis during hospitalization or had a history of previous surgery. Twenty-five percent of the cases obtained the empirical antibiotic, ceftriaxone, and 86 patients (80%) underwent arthrotomy drainage. The mortality rate was 12%, and its associated factors were cancer, liver disease and advanced age.Conclusions Streptococcus spp. is an emerging cause of septic arthritis in Southern Thai patients. Physicians should be aware of this in patients presenting with fever and acute monoarthritis, particularly those with comorbidities and underlying joint diseases. The proper empirical antibiotic of choice is ceftriaxone.References Garcia-Arias M, Balsa A, Mola EM. Septic arthritis. Best practice & research Clinical rheumatology. 2011;25(3):407–21.Frazee BW, Fee C, Lambert L. How common is MRSA in adult septic arthritis? Annals of emergency medicine. 2009;54(5):695–700.Chao CM, Lai CC, Hsueh PR. Bacteriology of septic arthritis at a regional hospital in Southern Taiwan. Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi. 2013;46(3):241–2. Disclosure of InterestNone declared