Learning from Outbreaks

When a group of people becomes ill at the same time, local or state health departments may

• Investigate to understand what caused the outbreak
• Take steps to control the outbreak and prevent additional illnesses
• Learn how to prevent similar outbreaks from happening in the future

Following an investigation, health departments report outbreak summary data to CDC. The information includes the number of outbreak-associated illnesses, hospitalizations, and deaths; agents; implicated types of water; water systems; and water settings.

CDC disease detectives (epidemiologists) review the reported outbreak data and follow up with health departments to verify it and to gather more information as needed. CDC researchers analyze the reported outbreak data periodically and summarize outbreak characteristics and trends in waterborne disease outbreak surveillance reports.

Public health agencies, policy makers, and the public can access waterborne disease outbreak surveillance reports and use the findings to guide health communication, policy, and prevention efforts to reduce the future spread and occurrence of waterborne disease.