Public health emergencies can be caused by events which impact on public health or events that can potentially overwhelm the health-system.
For example, a highly infectious disease spreading through the community, health impacts arising from emergencies (for example smoke from a major fire or waterborne diseases during a flood), and any mass casualty situations or weather-related events such as thunderstorm asthma.
Examples of significant public health emergencies include the Victoria’s thunderstorm asthma event of 21–22 November 2016, and the current worldwide COVID-19 pandemic.