Pandemic Reemergence and Four Waves of Excess Mortality Coinciding With the 1918 Influenza Pandemic in Michigan: Insights for COVID-19

Abstract

The global influenza pandemic that emerged in 1918 has become the event of reference for a broad spectrum of policymakers seeking to learn from the past. This article sheds light on multiple waves of excess mortality that occurred in the US state of Michigan at the time with insights into how epidemics might evolve and propagate across space and time. We analyzed original monthly data on all-cause deaths by county for the 83 counties of Michigan and interpreted the results in the context of what is known about the pandemic. Counties in Michigan experienced up to four waves of excess mortality over a span of two years, including a severe one in early 1920. Some counties experienced two waves in late 1918 while others had only one. The 1920 wave propagated across the state in a different manner than the fall and winter 1918 waves. The twin waves in late 1918 were likely related to the timing of the statewide imposition of a three-week social distancing order. Michigan’s experience holds sobering lessons for those who wish to understand how immunologically naïve populations encounter novel viral pathogens.

(Re-)modelling of the disease and mortality burden of the 1918-1920 influenza pandemic in Zurich, Switzerland

“…On the one hand, in comparison with other Swiss cantons and cities, we confirm for Zurich the so-called Eastern Switzerland pandemic pattern already described earlier on the basis of mortality figures 19 , with a less pronounced first summer wave in 1918 compared to Western Switzerland, for example, but we broaden the Swiss horizon to include the obviously important 1920 wave, which has so far received too little attention 27 . On the other hand, we also confirm a handful of studies on other countries that have already pointed to the relevance of this later wave [48][49][50] . The exact reasons and possible explanations for this strong later wave still need to be clarified: There are initial signs that the virus has changed genetically during the pandemic 51 , and that reinfections and cross-protection between waves therefore play a role 52,53 .…”

Historically High Excess Mortality During the COVID-19 Pandemic in Switzerland, Sweden, and Spain

“…Other events also led to increased excess deaths between 1890 and 2020. For example, there were later waves immediately after the actual pandemic years (as seen in 1891 to 1894 and in 1920) ( 60 ). Seasonal influenza has also repeatedly led to noticeable peaks in all 3 countries ( 39 , 61 ).…”

Feasibility and utility of facemask sampling in the detection of SARS-CoV-2 during an ongoing pandemic

“…As the COVID-19 pandemic matures towards “the new normal” with anticipated repeated waves of infection [ 14 ], a cost-effective and reproducible method for SARS-CoV-2 testing, which allows for self-collection or rapid on-site collection for group screening, is becoming crucial for sustaining worldwide efforts in maintaining testing rigor even with rapid vaccine rollouts.…”