An outbreak of group B Streptococcus following a total hip replacement is most likely to have which common source?

• A. Patients
• B. Visitors
• C. Community
• D. Staff

Answer: (D)

In a hospital setting, outbreaks of infections after surgery are most often traced to people who interact with many patients. Healthcare workers who may be colonized with group B Streptococcus can transfer the organism during wound care or procedures if aseptic technique or hand hygiene isn’t perfect. Visitors and the community are less likely to produce a coordinated cluster limited to postoperative patients, and while patients can be reservoirs, the pattern of transmission across multiple postoperative cases points to staff as the common source.