Introducing CDC’s Legionnaires’ Disease Outbreak Investigation Toolkit: Resources to Enhance Response Capacity Among Epidemiologists

Key Objectives:

• Introduce new Centers for Disease Control and Prevention (CDC) resources aimed at building state and local epidemiologic capacity to identify and control outbreaks of Legionnaires’ disease. 
• Provide a forum for state and local epidemiologists to suggest feedback on the toolkit contents and discuss remaining gaps in existing resources. 
• Discuss mechanisms for evaluating toolkit contents on an ongoing basis. 

Brief Summary:
Legionnaires’ disease is acquired by transmission of Legionella from environmental sources, and most recognized outbreaks are associated with complex building water systems that are not adequately managed. Although matching of case and environmental isolates using specialized typing techniques can definitively identify the source, epidemiological evidence is essential for the correct interpretation of laboratory results in the context of an outbreak and can point to a potential source in many situations, even if isolates are not available. Depending on the setting, controlling an outbreak often necessitates engagement with environmental health specialists, building owners and managers, engineers, consultants, contractors and other professionals. Furthermore, expectations around outbreak response have evolved since the advent of primary prevention guidance. An effective response often culminates in the implementation of a building-specific water management program. These programs identify preventive maintenance strategies that can interrupt the amplification, aerosolization, and transmission of Legionella, thereby reducing incidence of disease. Communicating risk to affected populations, the community, and additional stakeholders is also a challenge. Epidemiologists are often required to lead or coordinate these multidisciplinary activities, with varying degrees of experience and training. CDC is creating a suite of online tools aimed at building capacity among epidemiologists. This project is in direct response to requests from state and local epidemiologists for more guidance and recommendations around Legionnaires’ disease investigation and response activities. The new tools, downloadable from the CDC Legionella website, will include:

• Setting-specific template line lists
• Template notification letters targeting various audiences
• Chart abstraction forms
• Extended case interview forms 

CDC is also developing a checklist of questions epidemiologists can ask during investigations to better understand the nuanced environmental factors contributing to Legionella growth and transmission. We believe these tools will enable epidemiologists to investigate outbreaks more rapidly and implement control measures to protect at-risk populations. We would like to solicit input and feedback from state and local epidemiologists on the available tools, identify remaining gaps in outbreak response resources, and consider ways to address these gaps at the local, state and federal levels.