Imperial College modelers published a new analysis looking at #COVID19 transmission scenarios for the entire globe (202 countries). imperial.ac.uk/media/imperial…
Looking at global infection rates and health impacts of COVID19 under different mitigation scenarios, authors find in a “no mitigation” scenario, 7 billion (range 6.4-7.2 billion) infections and 40 million (range: 35-42 million) deaths could occur this year globally. 
Under different mitigation scenarios, this number can be substantially reduced, with greater reductions in infections and mortality the more complete and lengthy the social distancing measures imposed.
In the most extreme scenario (“suppression”), social distancing of 75% is imposed when deaths per population cross a certain threshold and sustained until deaths fall below the threshold.
If this suppression strategy is implemented early (at 0.2 deaths per 100,000 per week), 38.7 million lives could be saved… if initiated at 1.6 deaths per 100,000 per week, then 30.7 million lives could be saved, the authors state.
More moderate mitigation scenarios (~30-45% effective social distancing measures that are sustained) also have a large effect and save many lives -- a range of reduction in mortality between 19%-55%.
However, regardless of income category and mitigation scenario, demand for critical care is still predicted to vastly exceed capacity at peak demand in all countries.
Still, impacts will vary across low-, middle-, and high-income countries. Older age structures in high-income countries mean greater risk of mortality, but weaker health system capacity in low-income countries (LICs) also means greater mortality in those countries.
Authors expect lower incidence of severe disease, hospitalization & deaths in LICs. But, in LICs peak demand for critical care outstrips supply by a factor of 25.4, whereas in HIC, this factor is 7.0 (LMIC and UMIC factors over-demand = 16.4 and 10.86 respectively).
“The only approaches that can avert health system failure in the coming months are likely to be the intensive social distancing measures currently being implemented in many of the most affected countries, preferably combined with high levels of testing.”
Authors say this analysis highlights challenging decisions faced by all governments in the coming weeks and months, and demonstrates the extent to which rapid, decisive and collective action can prevent billions of infections and save millions of lives globally.
