10  The investigation begins:

⬜ Developing Hypotheses
⬜ Sample Collection
🟩 Outbreak Investigation
⬜ Sequencing
⬜ Bioinformatics
⬜ Molecular Epidemiology
⬜ Public Health Implementation

The Molecular Epidemiologists were tasked with working alongside the Zoonotic Epidemiology Team and Local Health Epidemiologists to develop hypotheses about the origin and transmission of the mysterious flu-like illness. Their goal was to identify potential risk factors, exposure routes, and whether human-to-human or animal-to-human transmission was occurring. They also worked closely with the Bioinformaticians to ensure that genomic analyses were aligned with key epidemiological questions, including testing specific hypotheses about timing, contacts, and clusters based on sequence data.

To kick off the investigation, the Genomics team gathered to compare notes and summarize their current understanding of the outbreak. They began brainstorming what information was still missing and what kinds of questions they would need to ask to fill those gaps. Drawing from field epidemiology practices, the team developed a list of interview questions to guide their case investigations.

These questions aimed to capture details such as:

    - Symptoms and onset dates: used to define the case timeline
    - Travel history: especially visits to the Safari Zone or recent conferences
    - Occupational exposures: including contact with animals or other trainers
    - Household and social contacts: to explore possible transmission chains
    - Protective behaviors: such as masking, isolation, or vaccination
    - Animal contact history: including specific species or roles in the park
    - Prior illness in close contacts: to spot unrecognized early cases

Interviewing cases helped build exposure timelines and identify possible transmission links, forming the basis for contact tracing and deeper hypothesis testing. The Epidemiologists also used this information to generate exposure maps that helped visualize how people and animals were connected, and which links might explain the spread.

At this stage, the investigation was still full of unknowns. But each interview added a piece to the puzzle and helped guide both field-based response efforts and downstream genomic comparisons.

10.1 Discussion Five: Developing Questionnaires and Surveys for Case Interviews and Contact Tracing

Field epidemiology during outbreak investigations often relies on well-designed case interviews to uncover risk factors, transmission patterns, and possible sources of exposure.

What kinds of information would be most important to collect in this outbreak? And how would you word the questions to get that information clearly and respectfully from cases?

For example: If you want to know whether someone had contact with animals at the Safari Zone, how would you phrase that question in an interview setting?