Modelling process uncertainty

Example: Forecasts during the Ebola epidemic

The unknown

• Community/hospital/funeral transmission
• Spatial dynamics
• Changes in behaviour
• Changes in reporting
• Interventions
• Seasonality
• etc

The known

• Average incubation period (~9 days)
• Average infectious period (~11 days)
• Case-fatality rate (~70%)

WHO Ebola response team (2014)

Transmission intensity as a stochastic process

\(d\log(R_0(t)) = \sigma dW_t\)

Dureau (2013)

Particle MCMC

• Method for filtering trajectories consistent with data
• Highly parallelisable

Andrieu (2010), Murray (2013)

Example: Ebola outbreak in Lofa Country, Liberia

An attempt to tease out factors that controlled Ebola

An attempt to tease out factors that controlled Ebola

Example: age of infection in childhood infections