A Public Health Approach to Outbreak Investigations

Key points

  • Respiratory disease outbreaks are a common public health problem and can be challenging to investigate.
  • Determining which pathogen is the cause is critical to implementing appropriate control measures.
  • CDC developed resources for investigating unexplained respiratory disease outbreaks (URDO).

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CDC's approach

CDC uses a multidisciplinary team approach to help local, state, and international public health officials in URDO investigations.

Keep Reading: CDC's URDO Work Group

Outbreak investigation importance

Outbreaks of acute respiratory illness are common and can occur in many settings (e.g., communities, nursing homes, military barracks). The following may be needed to control outbreaks:

  • Specific therapies
  • Infection control practices
  • Other preventive measures

Consequently, investigation into the clinical and epidemiologic features, and the etiology of outbreaks is particularly important to public health.

Investigating severe unexplained respiratory outbreaks may be of particular importance to rule out emerging health threats.

Clinical respiratory syndromes

Predominant clinical respiratory syndromes include outbreaks of

  • Prolonged paroxysmal cough
  • Bronchitis
  • Pneumonia
  • Influenza-like illness
  • Acute respiratory distress syndrome or rapidly progressive pneumonia

Coordinate outbreak investigations

Despite continual efforts, the etiology of many acute respiratory illnesses may remain unexplained. Investigating unexplained respiratory outbreaks may identify infectious agents that require unique strategies for control and prevention. Examples of these infections include hantavirus pulmonary syndrome and avian influenza. However, outbreak investigations for previously identified etiologies are equally important.

This process can be enhanced through coordinated efforts that:

Alert clinicians: To identify and report cases and clusters of unexplained infectious diseases.

Prepare health departments: To investigate these clusters.

Guide laboratory scientists: To develop and apply both traditional and novel diagnostic approaches to define the organism-specific etiology of the outbreak.

Resources and tools

Data collection
Template for creating epi curves and tools for collecting data

Outbreak and case definitions
How to develop outbreak and case definitions, including examples