Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Disease outbreaks are a common public health problem and investigating them can be challenging because many pathogens can cause them. Implementing appropriate control measures depends on finding a cause (etiology). However, diagnostic test results are often missing or difficult to interpret, or an appropriate diagnostic test may be unavailable locally.

This website provides information and resources to help public health professionals and partners investigate unexplained respiratory disease outbreaks (URDO).

Investigate an Outbreak
Initial steps, line lists, epidemiology curve template, case questionnaire, sample data collection forms…

Generate a Differential Diagnosis
Tools to create a list of the most likely infectious causes or etiologies of an outbreak…

Specimen Collection and Handling
Guidelines and forms for specimen collection, handling, storage, and shipping…

Detect and Characterize the Pathogen
Summary of diagnostic methods to identify pathogens…

Prevent Disease Transmission
Guidelines on infection control measures, respiratory hygiene…

Request CDC Assistance
Instructions, description of how CDC can help in URDO investigations, directory of tests, specimen submission requirements…

Publications and Resources
Publications, information on select respiratory diseases, national, state, and local resources…

URDO fact sheet

Unexplained Respiratory Disease Outbreaks Work Group Factsheet
Did you know CDC can provide support if you have a respiratory disease outbreak of unknown etiology? Learn more about how you can get CDC’s help to investigate your outbreak.

TOP