Aerosolized alpha-hemolytic Streptococcus as a cause of knee sepsis after intra-articular injection: predisposing factors.

Joint sepsis from an aerosol source of any organism during knee injection has never been reported and the standard of care for joint injection does not include facial masking. This case collection suggests that simple talking or teaching during injection procedures near an open hub needle may create a significant aerosol contamination risk with viridans group alpha-hemolytic strep. In addition, it suggests that the pathogenicity of alpha-hemolytic Streptococcus may be facilitated by the combination of dextrose and methylprednisolone. This finding has potential implications for the use of protective masking and/or avoidance of verbal communication (teaching or patient explanations) during the process of knee injection, especially of patients who are in an immunocompromised state. Potential parallels with the literature on aerosol-transmitted postdural meningitis with alpha hemolytic strep are explored.