Figure 2.

The spectrum of healthcare capacity strain. Random variation and semi-predictable variations can exist in well-resourced settings or on top of a baseline of static strain in resource-limited settings. Acute surge events are defined by a dramatic increase in care demands and/or decrease in care resources that trigger deviations from normal care delivery processes, reliance on contingencies and external resources, and, in the most extreme cases, nonroutine decisions about resource allocation. Etiologies of acute surge events include epidemics and pandemics from emerging pathogens, natural disasters, attacks on the public, and primary infrastructure loss.