ten-steps.qmd

# Ten Steps of a Field Investigation  

The CDC Field Epidemiology Manual outlines 10 steps of a field investigation for an outbreak.

Source: [Field Epi Manual](https://www.cdc.gov/field-epi-manual/php/chapters/field-investigation.html)

**Step 1: Prepare for Field Work**  
Before beginning a field investigation, ensure all involved parties understand the purpose, roles, and responsibilities. 
Obtain necessary official approvals, including a formal invitation from an authorized official, and consult with laboratory colleagues about testing and safety protocols.

**Step 2: Confirm the Diagnosis**  
Verification of the diagnosis ensures that the issue is properly identified and not a misdiagnosis. 
This can be achieved through interviews, clinical exams, medical records, and laboratory tests, and specimens should be preserved for later analysis.

**Step 3: Determine the Existence of an Outbreak**  
Determine if an outbreak exists by comparing the number of cases to expected numbers, using historical data or surveillance records. 
This helps rule out pseudoepidemics caused by misdiagnosis or reporting issues.

**Step 4: Identify and Count Cases**  
Create a clear case definition and systematically search for all cases of the disease without including non-cases. 
This involves classifying cases based on symptoms, timing, and exposure settings and compiling the data into a structured format for analysis.

**Step 5: Tabulate and Orient the Data in Terms of Time, Place, and Person**  
Organize the collected data into an epidemiologic description that focuses on time, place, and person. 
This includes creating epidemic curves, spot maps, and comparing groups to form initial hypotheses about the outbreak’s cause and spread. 

**Step 6: Consider Whether Control Measures can be Implemented Now**  
Control measures can target either the source of the disease or susceptible individuals through interventions like treatment, isolation, vaccination, or prophylaxis. 
While typically implemented after confirming hypotheses, preliminary control measures can be initiated based on early information to prevent further spread.

**Step 7: Develop and Test Hypotheses**  
Develop hypotheses about the cause, source, and mode of transmission of the outbreak based on various sources, including descriptive epidemiology and interviews. 
Testing these hypotheses through analytic studies like cohort or case-control studies helps confirm risk factors and causal associations.

**Step 9: Implement and Evaluate Control and Prevention Measures**  
The goal of an investigation is to implement and evaluate effective control measures to prevent further morbidity or mortality. 
Ongoing evaluation, including active surveillance, helps assess the effectiveness of these measures and guides necessary adjustments.

**Step 10: Communicate Findings**  
Effective communication is essential throughout and after an outbreak investigation. 
Establishing a clear communications plan and a designated spokesperson ensures consistency in sharing findings with the public, stakeholders, and other relevant authorities, including through briefings and written reports.