An outbreak or epidemic is the occurrence in a community or region of an illness(es) similar in nature, clearly in excess of normal expectancy and derived from a common or a propagated source (19 CSR 20-20.010).

The purpose of this Outbreak Investigation section is to provide general guidelines for local public health agencies (LPHAs) for the process of reporting, investigating, and documenting communicable disease outbreaks. A report of an outbreak may be received in a variety of ways (e.g., active or passive surveillance systems, concerned citizens, healthcare providers, media, law enforcement, etc.). All outbreaks or suspected outbreaks must be reported as soon as possible to the local health authority or the Missouri Department of Health and Senior Services (DHSS).

In Missouri, LPHAs hold the primary responsibility for conducting communicable disease investigations in their jurisdictions. The Bureau of Communicable Disease Control and Prevention (BCDCP) staff provide guidance, recommendations, and support to LPHAs as requested during investigations of communicable diseases. In addition, the BCDCP District Epidemiologists provide epidemiologic support for local investigations if the scope of the investigation exceeds the LPHA’s capacity to respond. When disease investigations span multiple local jurisdictions or states, the District Epidemiologists generally serve in a coordinating role to lead the investigation in coordination with other public health partners including, but not limited to, LPHAs and other state and federal partners. BCDCP support is made available to LPHAs, medical providers, and other public health partners 24 hours per day / 7 days per week, including weekends and holidays, through the DHSS Emergency Response Center by calling 800-392-0272.