Association between post-craniotomy Propionibacterium acnes infection and dural implants: a case-control study.

Area of Science:

• Medical Microbiology
• Infectious Disease Epidemiology
• Surgical Site Infections

Background:

• An outbreak of deep-seated Propionibacterium acnes infections occurred in patients post-craniotomy in a UK hospital in 2011.
• This necessitated an investigation to identify the source and risk factors.

Purpose of the Study:

• To describe the Propionibacterium acnes outbreak following craniotomies.
• To identify the source, risk factors, and inform control measures for the infection.

Main Methods:

• Case-control study involving 15 patients with P. acnes surgical site infection (SSI) and 65 controls.
• Analysis of clinical records, surgical variables, and infection prevention procedures.
• Environmental assessment of theatre ventilation and disinfectant use.

Main Results:

• Dural implant insertion (aOR: 14.6) and use of an alcohol/Betadine/chlorhexidine disinfectant mix (aOR: 7.9) were associated with increased odds of P. acnes infection.
• Theatre ventilation systems were found to deliver air exchange rates below recommended standards.

Conclusions:

• A significant association exists between dural implants and P. acnes infection.
• Inefficient skin disinfectant use and environmental factors, such as inadequate ventilation, likely contributed to the outbreak.
• Recommendations include enhanced surveillance, use of chlorhexidine disinfectant, and improved theatre environmental controls.