Northern Arizona Disease Model Cautions Against Returning To ‘Business As Usual’ Too Soon

May 11, 2020

Scientists at Northern Arizona University have designed new models for the spread of the coronavirus disease, tailored to rural counties in Northern Arizona. One goal of the project is to offer information to public health officials and decision-makers about the outcomes of different scenarios for easing restrictions. KNAU’s Melissa Sevigny spoke with epidemiologist Joe Mihaljevic  about the research, which is funded by a $200,000 grant from the National Science Foundation.

Joe Mihaljevic
Credit NAU


Tell me about this model that you created to track disease spread in Northern Arizona.

We were contacted by Flagstaff Medical Center and Coconino County epidemiologists who were looking to make projections for how COVID-19 might impact the hospital system and the general community of Northern Arizona…. So we’re building models that are similar to models used across the country and across the world to understand how this virus is spreading, but we’re trying to fine tune them to our region and to the populations we have here… We look at our the population density and the number of folks that are in different regions are spread across space so we can understand how movement of individuals and any public health interventions that alter movement like stay-at- home orders might impact the regional spread of the virus.

What have you found out about how, for example, the stay-at-home orders are affecting the spread of this disease?

I’ll just say they’re a lot of caveats for models. We’re building models as fast as we can with the limited information we have about this novel pathogen… We know that early on in the spread once we started to have community transmission, we had did exponential growth of the pathogen, meaning it was spreading really rapidly in our communities. But then once interventions were put into place, we were able to slow down the spread…. We don’t yet see the virus declining in our communities. We still seeing increases of cases every day. But the good news is that our interventions have slowed the spread of the virus. Then we can use our models to try to understand, okay, as we start easing restrictions and going back to some sort of normalcy or business as usual, how might that affect the spread of the pathogen?... We know that because this virus does spread easily between people, we could get a situation that if we go back to business as usual too soon, we’d get a second wave of outbreak that could be potentially worse than the first wave.

So right now the stay at home is planned to lift on May 15; that of course may change. Does that seem like it’s too soon based on the data you have right now?

I understand all of the complexities that our public leaders are faced with in terms of balancing public health and the economy. I understand that these are really tough decisions… But given the data we have and how quickly this virus can spread in our communities, we do think if we go back to just business as usual without any sort of preventative measures on May 15, that we will get another wave of spread. I think a second wave of spread is inevitable until we follow the original CDC orders which is having 14 days in a row of no cases. There are very few places across the world that have been able to meet those criteria. That means the pathogen is still in our communities, and as soon as we start increasing our human to human contact rates the pathogen will spread again. I think going back to business as usual is too soon right now. But I think that we can put other interventions in place, like social and physical distancing, wearing masks, contact tracing to try to isolate people exposed, which requires an increase in testing. All of these things have been advised by the CDC, and we don’t fully understand right now, or at least my group, how well we are prepared we are to implement some of those strategies as we start opening up.

Joe Mihaljevic, thanks so much for speaking with me.

Thanks, Melissa, I appreciate your time.