Global Infection Spread Simulator

An interactive website widget for exploring how a viral or bacterial infection could spread between countries under different transmissibility, travel, immunity, and intervention assumptions.

SEIR-style compartments Country population weighted Travel-network spread Intervention what-if mode

Origin

Country where infection starts

Area / city label

Initial active cases

Custom latitude

Custom longitude

Coordinates only move the origin marker. The country-level model still starts in the selected country.

Pathogen

Type

Name

Days to simulate

Base reproduction number R₀

Higher R₀ means faster transmission before interventions.

Incubation / exposed period

Infectious period

Pre-existing immunity / vaccination

Severe outcome proxy

Shown as a planning proxy only. It is not a clinical estimate.

Global movement

International mixing

Travel restrictions

Border screening / arrival testing

Interventions

Start day

Response speed

Contact reduction

Masking / hygiene effect

Testing, tracing, isolation

Treatment effectiveness

Treatment has more effect in bacterial scenarios; in viral scenarios it is treated as supportive reduction.

Trial variability

Random trial variability

Adds stochastic variation to local transmission, country susceptibility, and international seeding. Set to 0% for a fully deterministic classroom-style run.

Trial seed

Lock seed

Fast presets

Contained cluster

Moderate respiratory

High spread

Strict response

This is a simplified educational simulator, not a medical, public-health, or emergency forecast. Real-world spread depends on surveillance, behaviour, pathogen biology, transport data, climate, demographics, healthcare capacity, and stochastic events.

Active + exposed—Day 0

Cumulative infected—all countries shown

Affected countries—with ≥ 10 active/exposed

Estimated severe—planning proxy

Selected day: Day 0. Country bubbles are centroid markers, sized by active + exposed cases.

Exposed

Infectious

Recovered / removed

Day 0

Run a simulation to generate a scenario summary.

Highest burden at selected day

Day 0 · sorted by active + exposed cases

Country	Active	Share