Situation critical

Led by Chris Dibble, we recently published a paper in JRS Interface that asked the question, “As R0 increases through 1, how long until a disease outbreak?”. Many systems have slowly increasing parasite fitness whether it’s through parasite evolution, demographic susceptible recruitment, or abandonment of vaccination (sweep rate). Susceptible populations are also regularly challenged with infectious individuals that have the potential to ‘spark’ an outbreak (spark rate). We integrated these two rates with epidemiology models and survivorship theory (which characterizes time to an event) to establish the waiting time to infectious disease emergence. We demonstrated that this time is influenced by factors such as infectious period, meaning that different infectious disease systems can cause outbreaks sooner after R0 exceeds 1, than others.