Predicting the Pandemic
UM center models the future course of COVID-19
By Erika Fredrickson
In 2006, Erin Landguth took a virology lecture class at the University of Montana that would prove prophetic. As a Ph.D. candidate in mathematical ecology through the Montana Ecology of Infectious Disease program, Landguth was somewhat new to the subject of viruses. And though the class informed her subsequent work on predicting the future course of infectious disease, some of it wouldn’t truly resonate until January 2020, more than a decade later, when the coronavirus pandemic hit.
“I vividly remember the professor, Mary Poss, saying, ‘We’re not far away from the next global pandemic. And it’s going to be a coronavirus,’” Landguth recalls. “But still, even in January this year when I started hearing about it, it was hard to believe. I kept thinking, ‘Is this really it?’”
Landguth is now an associate professor at UM and a researcher in the school’s new Center for Population Health Research (CPHR, pronounced “see-far”). She works on modeling factors that influence respiratory health, specifically in children. The center, whose goal is to foster multidisciplinary research success that can inform, develop and test strategies to improve rural population health, was funded by the National Institutes of Health as recently as March 2020.
But now the center has found itself facing questions it hadn’t anticipated — questions about how a worldwide pandemic will impact the state’s health and communities.
For Landguth and other CPHR researchers, COVID-19 has created an interesting shift in the work they do. The staff of experienced researchers is naturally positioned to provide an important lens on the pandemic issue — and already they’ve succeeded. Despite the chaos the virus has unleashed, the center has stepped up to both research and mitigation challenges, finding unexpected opportunities to bridge disciplines and departments across campus and support other UM initiatives with similar goals.
Still, it wasn’t clear in the beginning what role CPHR would play in Montana’s pandemic response. As COVID-19 began to spread in early 2020, everyone was talking about infectious disease modeling, but Landguth wasn’t sure she’d jump on board.
“It was daunting at first,” she says. “The whole world was modeling. It seemed like everyone was already on this problem.”
Landguth changed her tune when it became clear that Montana would need a different disease model than other places in the U.S. The landscape and infection rates across the country varied enough that a one-size model wasn’t going to suffice. So when Landguth and her colleagues realized it was time, they started factoring in the state’s COVID-19 data to build predictive models for the virus.
“Some of our center’s projects were already focused on communicable diseases, but the pandemic has necessitated adaptations,” says Curtis Noonan, an environmental epidemiologist at UM and the center director. “So myself and other colleagues in the public health program have been working on the COVID-19 response in a variety of different ways.”
Landguth, Noonan and other researchers meet with the state epidemiologist and others at the Montana Department of Public Health and Human Services regularly to discuss how to best develop models for COVID-19.
“We look at how to best deal with the difficulties of informing and parameterizing models like this for a rural state like Montana, where the data are really sparse,” Noonan says.
The work requires some flexibility because being in a pandemic while trying to research the pandemic comes with a lot of pressure.
They developed “susceptible, infected and recovered” (SIR) models that first match Montana’s COVID-19 case data and then project COVID-19 numbers based on dynamically changing transmission scenarios. The models and scenarios have evolved throughout the project in an effort to respond to changing events unique to Montana’s experience. For example, one scenario projects what happens if the shelter-in-place order Gov. Steve Bullock had implemented in late March was continued. It’s a baseline scenario that shows a stable, low level of infections.
Another scenario is the current trajectory that assumes transmission trends will reflect Montanans adherence to, or noncompliance with, infection prevention practices. The CPHR model updates data on a rolling 14-day time interval and predicts future infections. It is a dynamic model that can adapt quickly and account for wildcard factors like cluster outbreaks.
“This scenario can change rapidly, reflecting Montanans’ behavior,” Landguth says. “For example, Montana’s transmission dynamics shot way up in early June to about July 6, then we leveled off through the rest of the summer, and we are hovering just below the point of explosion.”
That was last summer, of course. Since then, new surges have struck Montana.
The models are organized by clickable tabs that are broken down by county and also into five health regions, so it’s easier to see projections for variation across the state. The models predict number of people infected with, hospitalized for and killed by the virus.
“That last one — projected deaths — was the last thing I added,” Landguth says. “That’s a dreary number I never really wanted to add.”
Landguth says she wasn’t always sure who else was using the models. However, after temporarily shutting down the site to make some updates to the models, Landguth got a glimpse of their value to the outside community.
“I started getting emails and calls from hospitals,” Landguth says. “St. Patrick Hospital called me, and their emergency planner wanted to know what was going on.”
She learned that hospitals, doctors and local health departments were all checking it on a regular basis.
There is a lot more that can be done with these pandemic models, and the center is tapping into an array of possibilities. But modeling requires a balance between simplicity and complexity.
“This is a very complex problem,” Landguth says. “But when you approach modeling, you really want to come at these complex problems simply to be able to understand them. An SIR model is a pretty simple model, but you can always make it more complex. So we are beginning to add more compartments and modules as the Montana experience unfolds. It gives us more robust answers.”
No single model is the correct model, but more models can paint a more comprehensive truth. Scott Whittenburg, UM vice president for research and creative scholarship, has a background in modeling molecules and biomolecules.
“When the national models for COVID-19 began to receive criticism for not accurately predicting the number of cases and deaths, I wondered if I could use my background in computer simulation to devise a better model,” he says.
With some time to spare during the stay-at-home order in March, Whittenburg developed a SIR-UM model using Google Mobility data. Hearing about other people working on models across campus has helped fortify the research. Whittenburg now often meets with Montana DPHHS and the center to discuss their findings.
“I have an increased appreciation of the difficulty in modeling COVID,” Whittenburg says. “The laws of physics didn’t change in my modeling of molecules. When you model the spread of a virus, external factors — such as mask-wearing and quarantines — have a large impact on the simulation. This makes predicting the spread of the virus quite challenging.”
The Center for Population Health Research recently published a study that looked at the delayed effects of wildfires on the subsequent influenza season. Epic fire seasons, like those in 2012 and 2017, had corresponding influenza seasons that were three or five times the usual caseload, Landguth says. They expected to see short-term accumulation of fine particulate matter (PM2.5) — the bad kind of particulate that embeds in your lungs — and an association with adverse health effects, but instead they found that there was a long-term lag. That meant that bad fire seasons and accumulation of fine particulate matter during that wildfire season time could make us more vulnerable to influenza. No matter what modeling they threw at it, there was a long-term health cost.
“There is a lot that we do know,” Landguth says. “Air pollution wreaks havoc on our lungs, but how is that all going to intersect with COVID? That’s the unknown.”
Like with the pandemic modeling, modeling around wildfire will entail collecting data that eventually should start painting a broader picture of not just where flu and COVID intersect with hospitalization numbers, but how policy decisions and social interactions might play a role in respiratory outcomes.
Landguth’s investigations into factors associated with children’s risk of respiratory infections provides some clear linkages to COVID-19, too. For instance, how will social distancing and mask-wearing during the pandemic impact children’s transmission of other, non-COVID-19 respiratory infections?
Erin Semmens, associate professor of epidemiology at UM, leads a CPHR project studying the impact of wildfire exposures on birth and development in children. She now can take into account how the virus and air pollution interact to affect health in early childhood.
“We have seen in the U.S. and around the world that higher air pollution exposures are linked to increased vulnerability to COVID,” Semmens says. “Air pollution can compromise our immune systems, making us more susceptible to COVID infection and more severe illness. In addition, air pollution particles may actually help the virus stick around longer in the air. At the same time, decades of research have shown that elevated air pollution exposure is associated with lower birth weight, higher risk of preterm birth and, more recently, with adverse developmental and behavioral effects. But the interplay between COVID and air pollution exposures is just a big unknown when it comes to kids.”
Semmens adds: “It is not just the smoke, and it is not only the virus. Increased barriers to health care, including prenatal care visits, stress and social isolation all may interact to compound the effects of COVID and air pollution. It is important from a public health perspective to evaluate these interactions not just to see what makes us most vulnerable but also what makes us resilient.”
Another area of research at the center could end up setting the stage for investigating how rural Montana communities will respond to a COVID-19 vaccine. Sophia Newcomer is working on a project that seeks to identify barriers to early childhood vaccinations in the state. She is leading a comprehensive analysis of immunization records in Montana focused on children less than 2 years old.
“Specifically we’re analyzing immunization data to try to identify if, first of all, kids are getting vaccines on time,” Newcomer says. “And if they’re not getting vaccines on time, why not?”
One major reason kids fall behind in their vaccines is because of structural barriers. Some people don’t have easy access to a medical provider, and the only option is to drive a long distance, which can be a deterrent for families without time or reliable transportation.
Another major barrier is vaccine hesitancy. Some parents who are concerned about vaccines are choosing to either delay or not get one or more recommended vaccines for their children.
“My project seeks to understand how common each of those types of barriers are in Montana,” Newcomer says. “And we’re doing that through data analysis and also through a survey of medical providers.”
How COVID-19 plays into these barriers has created an interesting dimension to Newcomer’s work. The CDC reported a decline in vaccinations, particularly during March and April, when stay-at-home orders were coming out of governors’ offices. That drop in 2020 vaccinations leads to questions for the future health of children. Will there be undervaccinated children who are now more susceptible to preventable diseases like mumps and measles? Might that lead to hot spots of mumps, measles and other diseases, and how might a rebound of those diseases affect people’s perception of vaccines in the future?
“I think there is now a need to pivot and to look at the effects of the pandemic,” Newcomer says. “For this center project, we’re looking at data before the pandemic, but in many ways it can serve as a baseline for what barriers to vaccinations in Montana looked like before the pandemic. What I’m hoping we can do is see what happens over the next few months. We can then identify whether there were any changes to vaccine access as a result of COVID-19.”
Research is the bread and butter of the center, but the nature of the pandemic as an unfolding drama of unknowns, has created unique non-research opportunities. For instance, Noonan has collaborated with Lily Apedaile, the Western Montana Area Health Education coordinator, to develop Griz Health, a COVID-19 resource for students, faculty and staff that will serve to mitigate COVID issues and provide preventative messaging to the campus.
Griz Health students have been trained on contact tracing, using curriculum developed through the Montana Department of Public Health and Human Services and the center.
Semmens also stepped up to head the Epidemiologic Situation Unit for the Missoula City-County Health Department’s COVID-19 response. She and other center researchers provide weekly epidemiological analysis and reporting of COVID-19 transmission in Missoula County. And Newcomer advised the University on COVID-19 response and re-opening, including working closely with on-campus housing administration to develop a quarantine and isolation plan.
Tony Ward, deputy director of CPHR and chair of UM’s School of Public and Community Health Sciences, is working on training and professional development opportunities in collaboration with the state health department. Many of these trainings have focused on supporting public health professionals throughout the state in dealing with COVID-19.
Supported by UMOnline, one such training relates to contact tracing for county and tribal public health personnel in Montana. On campus, he’s a co-leader of UM’s Health Advisory Group’s mitigation team, which, early on, developed safety and health guidelines that would help bring people back to campus while reducing risk. With input from CPHR researchers, Ward says it was amazing to see staff and faculty from across campus come together to inform the health and safety protocols for students, staff and faculty that we saw on campus in fall 2020.
“It’s really been interesting for me to see how these folks have used their training and their expertise and applying it toward keeping the staff, faculty and students at the University of Montana as safe as possible,” Ward says. “We are lucky to have such a dedicated group of colleagues here.”
The Center for Population Health Research’s ability to respond and collaborate with campus groups during a crisis reveals the important intersection between health research, public health practice and community outreach — especially during an event that was predicted by epidemiologists for years and yet is so hard to truly be ready for.
“When we first started to develop the center more than two years ago, we could not have anticipated that we would be launching during a pandemic,” Noonan says. “But we were all able to pivot and explore modifications to our research and outreach to better understand and mitigate the pandemic’s effects in our communities.
“Our timing was fortunate in allowing us to help with the public health response in Montana.” •
