A Local Pandemic Expert on What Happens Next With COVID-19

Joshua Petrie, an epidemiologist at the University of Michigan’s School of Public Health, weighs in
COVID-19 pandemic photo: IStock

The COVID-19 pandemic crisis is so fast-moving and dramatic, it’s difficult to know what happens next. As of mid-March, Michigan joined most other states with its own coronavirus cases, the governor declared a state of emergency, and a cascade of widespread closures and cancellations of public gatherings disrupted normal life.

What’s next? It’s impossible to say, but pandemic expert and epidemiologist Joshua Petrie from the University of Michigan’s School of Public Health tried his best to answer.

Hour Detroit: As we speak, it’s mid-March. Where do you think this crisis will be a month from now? Is there anything predictable about any of this?

Joshua Petrie: By mid-April, I would say we’ll have increased the testing capacity in the U.S. dramatically. But we’re also going to see many, many more cases in the United States than we currently have right now.

The number of cases scares people, but I wonder if it really ought to reassure them in some way that somebody knows what’s going on? It seemed hard to believe that Michigan had no confirmed cases until March 10.

Oh, certainly. Knowing about the cases gives people a better chance to respond and for clinicians to treat people appropriately since they know exactly what they have. We’ll also know a lot more about the overall risk of the virus once we know how many cases are out there and what percent of those are severe.

What makes this situation different than Zika, Ebola, the H1N1 bird flu, or SARS?

It is comparable to SARS in that SARS was also a coronavirus, and even the bird flu was a similar sort of virus. But COVID-19 spreads more easily from person to person, and when that happens, it’s a lot harder to control. With SARS, we were able to basically stop that outbreak with public health measures before it really got out of control. We’re probably past that point with this virus, past the point where we’re going to control it and it’s just going to go away. It’s a virus that we’ll continue to see for a while.

So how does this go? What happens now?

It’s hard to say what happens next. It’s a new virus spreading widely and causing severe illness, and we’re trying to slow that down and spread that out over time so that our health systems are not overwhelmed and that people can get treatment when they need it. A lot of these measures like closing schools and that sort of thing are basically delays.

Is it an effective approach? I mean, if those people aren’t in class or on the subway or wherever, won’t they just be somewhere else?

It can be effective. There is enough public concern out there right now that if, say, school is canceled, people will stay home a bit more and try to avoid gathering in groups. Again, the goal is to flatten out the peak of the epidemic.

So we are not at a peak yet?

Probably not globally, probably not in the U.S. There’s been an ongoing outbreak in Seattle that’s been pretty widespread. Maybe they’re close to their peak, but the rest of the country is probably just getting started.

So for how long is this effort to limit social exposure supposed to go on?

Some of it will depend on how much this actually starts to affect health care systems and other systems, how much businesses can afford to have people work from home, that sort of thing, and also how much risk the public is willing to tolerate. A lot goes into those decisions.

Should the U.S. have been better prepared for this, and how would we have been better prepared?

A lot of preparedness efforts in the U.S. have traditionally gone toward the potential for an influenza pandemic. There are a lot of differences with this virus from influenza. I would have liked to have seen COVID-19 tests available earlier, but that’s easy to say in hindsight.

What is the nearest analog to this situation? SARS did this to China and parts of Asia but did not do this to the United States. What would you say is comparable, if anything, to this situation for us?

Maybe the closest comparison would be the 2009 influenza, the H1N1 pandemic. It caused a very large outbreak, but we did not see this level of disruption then.

Why not? Was it less contagious?

Oh, it was pretty contagious, but this virus may end up being a bit more severe in terms of the numbers of hospitalizations that it causes.

President Trump was mocked for suggesting that when the weather changes, the virus may disappear or diminish, but that really is what happened with SARS. Why does the season impact the spread of viruses?

It’s not totally understood, but at least for influenza, temperature and humidity play a role, as do social patterns. People stay inside and have closer contact with other people during the wintertime, school’s in session, that sort of thing.

Is the level of public fear out there right now warranted?

It’s a pretty individualized thing, how much risk you’re willing to take. In general, what we know so far is that for most people who are infected with COVID-19, it’s a fairly mild illness. It’s really been the older adults and people with high-risk conditions who have had the worst illnesses. For them, it’s warranted. Other people should limit their contact with large groups if not to protect themselves, then to prevent spreading it to those people who are more at risk.