Biosurveillance
Mass-Gathering Outbreak — Genomic Intelligence Under Pressure
An outbreak emerges during an international mass gathering of millions.
Duration
150 min
Injects
5
Audience
Mass-gathering health command, genomic surveillance, border health, international liaison
Situation
During an international mass gathering drawing millions of participants from 180+ countries, sentinel and wastewater surveillance detect a rising respiratory signal. Genomic sequencing identifies a variant of a known pathogen with possible immune-escape features. Participants will disperse globally within days, turning a local signal into a seeding event.
Exercise objectives
- Test real-time genomic and wastewater surveillance as an outbreak early-warning system at scale.
- Exercise the compression of the detect-to-decide window when participants disperse within days.
- Evaluate international data-sharing and coordinated notification.
- Rehearse decisions that balance the event, participant welfare and global seeding risk.
Capability stress
How hard this scenario tests each of the 10 benchmark dimensions (1–5).
Foresight lens
Getting ready for a threat that HAS a reference class — one that resembles something we have seen (COVID, influenza, known AMR). Plans, playbooks and drills work because the past is a guide.
TUNA profile
Assumptions this scenario windtunnelsfull register →
A1Surveillance will detect the next threat early enough to act on it.
Sensitivity: high · TUNA: N · U
A3Communities will comply with public-health measures as they did before.
Sensitivity: medium · TUNA: U · A
Scenario parameters
Illustrative planning figures for discussion — not operational data.
Population at risk
Millions of participants, 180+ countries of origin
Surveillance modalities
Sentinel clinics, wastewater sites, genomic sequencing
Pathogen
Variant of known respiratory pathogen, possible immune escape
Dispersal window
Days — global seeding on departure
Baseline genomic coverage
Partial — a core surveillance gap
Roles at the table
Mass-Gathering Health Commander
Owns event-level health decisions and escalation.
Genomic Surveillance Lead
Runs sequencing, variant characterisation and turnaround.
Wastewater/Environmental Lead
Interprets population-level signals ahead of clinical cases.
Border & Departure Health Lead
Manages measures for departing participants.
International Liaison
Coordinates notification and data-sharing with origin countries.
Inject timeline
- Hour 0Wastewater rise
Multiple wastewater sites show a sharp rise in a respiratory pathogen signal.
- Hour 12Clinical confirmation
Sentinel clinics confirm rising cases; samples sent for urgent sequencing.
- Hour 30Variant call
Sequencing identifies a variant with mutations of concern for immune escape.
- Hour 48Departure begins
Scheduled mass departures begin; global dispersal is now underway.
- Hour 60Origin-country query
Two origin countries request data and guidance for returning participants.
Decision points
D1With a genomic result and departures already starting, what measures do you take at departure — and are they proportionate?
- The narrow window between a variant call and mass dispersal.
- Proportionality, feasibility and participant welfare.
- What you can realistically operationalise in hours, not weeks.
D2How much do you share internationally, how fast, and through what channel?
- Speed and transparency vs. the risk of acting on preliminary data.
- Pre-agreed data-sharing agreements and formats.
- Reputational and economic sensitivities of the host and origin countries.
Response playbook
Early warning
- Integrate wastewater + sentinel + genomic signals
- Accelerate sequencing turnaround
- Pre-position sampling capacity
- Set variant escalation thresholds
Characterise & decide
- Confirm variant significance
- Assess dispersal risk
- Choose proportionate departure measures
- Brief international partners
Coordinate globally
- Notify origin countries
- Share sequences to public databases
- Support returning-participant guidance
- Sustain post-event surveillance
After-action questions
- Did your sequencing turnaround beat the departure clock? If not, what would close the gap?
- Which surveillance modality gave you the earliest usable signal?
- Were international data-sharing agreements ready, or negotiated mid-crisis?
National benchmark references
Real national strategies from the Global Pandemic Preparedness Benchmark that inform this scenario.