300. Armed to the Teeth: Human Bite-Associated Septic Arthritis

BACKGROUND: Fight bite-related septic arthritis (FBSA) occurs when a joint is infected following a human bite injury. We aimed to describe the clinical features, treatment, and outcomes of FBSA and compare these with native joint septic arthritis of other causes. METHODS: Cases were obtained from a previously described retrospective cohort of adult native joint septic arthritis admitted to Middlemore Hospital, Auckland, New Zealand from January 1, 2009 and December 31, 2014. FBSA cases were compared with small-joint non-fight bite septic arthritis (SJNFBSA), and all NFBSA. P-values of ≤0.05 were considered significant. RESULTS: Sixty-seven FBSA and 476 NFBSA cases (including 183 SJNFBSA) were identified. Compared with SJNFBSA and all NFBSA, FBSA was associated with younger age (median 26 years vs. 49 and 52, respectively) and tobacco use, but lower rates of diabetes, osteoarthritis and renal failure. Osteomyelitis was more common and metastatic infection less common in FBSA (all P ≤ 0.05). FBSA was more likely to be polymicrobial (76% vs. 30% and 20%), and to be caused by oral flora, oral streptococci, HACEK organisms, and anaerobes. SJNFBSA was less likely to be caused by S. aureus than FBSA. FBSA was more commonly managed operatively than SJNFBSA and all NFBSA (93% vs. 79% and 81%) and received shorter antibiotic courses (median 2 weeks vs. 4 and 5 weeks), more commonly orally (84% oral vs. 6% and 32%). Hospital length of stay for FBSA was shorter (median 4.5 days vs. 6 and 9 days). Compared with all NFBSA, treatment failure was less common (7% vs. 19%, P = 0.0242) and there was a trend toward lower mortality (0% vs. 5%, P = 0.0604). CONCLUSION: FBSA represents a distinct subset of septic arthritis with differing morbidity and better outcomes than NFBSA. FBSA may be able to be safely managed with shorter, oral antibiotic regimens if adequate operative management is undertaken. Further studies are required to validate these findings. DISCLOSURES: All authors: No reported disclosures.