Outbreak Scenario S. marcescens

At a multi-disciplinary meeting on the surgical unit concerns are raised regarding a possible increase in wound infections and a suggestion that there may be more Serratia marcescens around than before??

5 minutes to consider your first actions: What further information would you require? How would you define / declare an outbreak?

What is a Cluster Outbreak Increased Incidence

How soon do you call an outbreak control group? Who should attend? Communications When to you put control measures in place?

The Communicable Disease Outbreak Plan HPA 18 th May 2012.

Case Definition 5 minutes to consider a case definition for the possible outbreak described in the first slide.

Case Definition Clinical Information Microbiology / culture information Location / ward / unit Time Characteristics of those affected

The importance of a case definition Ideally the case definition should be broad enough to include most cases, but not too broad such that the investigation becomes confused. –Confirmed cases –Probable –Possible

The Importance of a Case Definition Case Finding Ongoing monitoring Closure of an outbreak

Case Finding 5 minutes to discuss issues around case finding as related to this particular investigation Share any experiences you may have of case finding

10 minutes to discuss and describe what descriptive epidemiology tools you would use

Timelines

5 minutes to start developing hypotheses

Hypothesis Development Clinical evaluation –Signs and symptoms –Natural history –Diagnostics –Case Review Epidemiologic concepts –Transmission mechanisms –Transmission dynamics –Transmission containment Microbiology concepts –Organism’s natural history –Known sources –Antimicrobial susceptibility –Typing Infection control practices –Hand hygiene –Isolation precautions –Bloodborne pathogens –Environmental measures –Multi-drug resistant organisms Environmental Considerations –Air quality –Water quality –Food services –Sanitation services –Infectious waste disposal

Further Investigations Cohort Studies Case-Control Studies

Steps for Outbreak Investigation Establish the existence of an outbreak Define and Identify cases Descriptive epidemiology Hypothesis development Evaluation of Data Implementation of Control Measures / Prevention Consideration of further investigations