As the front line of the American health care system’s defense against the novel coronavirus SARS-CoV-2 and the associated coronavirus disease 2019 (COVID-19), emergency departments (EDs) have borne the brunt of the initial onslaught since the global pandemic reached the United States last winter. The very novelty of COVID-19, in multiple senses—immunologic novelty for a population lacking herd immunity, clinical novelty in its diversity of presentations, and sociocultural novelty in that it has appeared amid nationwide tumult and institutional distrust—makes it a perfect storm. It has caught much of the United States unprepared. Yet despite the many uncertainties about COVID-19, emergency physicians have gained critical practical knowledge. When the second wave strikes, it is imperative to apply what they have learned from recent experience and from epidemiologic history.
The concept of a second wave is a matter for debate because much of the country is by no means past the first one. (The “wave” metaphor itself can be misleading, said epidemiologist Marc Lipsitch, DPhil, of Harvard’s T. H. Chan School of Public Health in a New Yorker
interview, because of its implication that case and mortality figures ebb and flow naturally and symmetrically, rather than as consequences of policies, interventions, and behavioral decisions. The image of a forest fire, prone to sudden instability when sparks meet tinder, struck Dr. Lipsitch as more appropriate.
At this writing, the national epicenter of COVID-19, the New York City metropolitan area, has succeeded in flattening its new-case
curves since their spring peaks through lockdowns, social distancing, masking, and first-responder resilience. Concern that businesses and activities may be reopening too quickly drives predictions that the fall and winter will see deadly resurgences.
“I do think a second wave is coming; it’s just a matter of when, and how big is that wave going to be,” said Nancy Conroy, MD, associate chief of service in the ED at New York University Langone Hospital–Brooklyn and clinical associate professor at New York University Grossman School of Medicine.
A focus on the epicenter alone can be misleading. “Most of the country did not have the experience that New York, Chicago, Detroit, New Orleans, [and] even Seattle had,” observed Donald M. Yealy, MD, chair of the Department of Emergency Medicine at the University of Pittsburgh School of Medicine. “Much of the country looks more like western Pennsylvania, where there was an increase in activity, but it was accommodated within the health care system.”
In some locations, however, that slower-breaking first wave, combined with uneven test availability, may have contributed to a false sense of security: areas where the populace has adopted preventive practices less rigorously have seen new cases begin to soar. The Johns Hopkins Coronavirus Research Center’s daily case report
indicates the sharpest rises in Arizona, Texas, and Florida at this writing, with several other Sunbelt states’ data also looking alarming. By publication, other locations may be the hottest of this disease’s diverse hot zones.
Dr. Yealy provides historical perspective. “The timing of the peak, the intensity and height of the peak, and then how long that stayed really vary,” he noted. “That’s been true of viral pandemics since the beginning of time. They do not enter every geographic location at the same time with the same intensity, and they respond differently for reasons that we don’t really understand.”