Hongjie Liu presents data on the COVID-19 outbreak

“It is useful to compare the effects of different preventions in reducing disease burden—not to project a single number for how many people will get the disease,” says Dr. Hongjie Liu, chair of the Department of Epidemiology and Biostatistics.

May 12, 2020

This story was originally published by Maryland Today on May 13, 2020.

Opiaah Jeffers M.P.H. ’21 hadn’t even finished her first shift as a COVID-19 contact tracer for the Prince George’s County Health Department on Friday when the complexity of safely restarting public life in the state of Maryland hit her.

The job for which she and more than 20 other students in the University of Maryland School of Public Health recently volunteered is to call people diagnosed with the coronavirus and compile names of anyone they might have exposed to it. Next, they go down the list of people, asking each about symptoms and explaining the obligation to self-quarantine. Known as contact tracing, it’s a basic disease control measure that Gov. Larry Hogan last month identified as a core requirement for reopening businesses, schools, churches and other institutions.

Many people won’t pick up the phone, health department supervisors warned her. Others might be uncooperative, or be caught between a rock and a hard place—for instance, being told to report immediately back to work right after testing negative for the virus.  In cases like that, the evidence-based advice that Jeffers was trained to give was to quarantine slightly longer to rule out a false positive result. But not everyone complies.

“It can be hard, because people are going to do what they’re going to do,” Jeffers said. “We just have to provide the best information we can and hope it helps.”

She’s one of numerous students and faculty throughout the UMD School of Public Health playing an integral part in the state’s “Roadmap to Recovery.” Hogan in late April laid out a plan with four building blocks “that must be solidly in place” before statewide restrictions can be lifted: expanded testing capacity, increased capacity in hospitals, a larger supply of personal protective equipment and a robust contact tracing operation.

SPH students are providing boots on the ground for the contact tracing, while faculty experts are conducting modeling analyses to help state officials plan out next steps—like last week’s decision to relax outdoor recreation restrictions and allow elective medical procedures.

Since late March, SPH’s COVID-19 Projections Team has been providing the Maryland Department of Health, along with health departments from Prince George’s, Montgomery and Anne Arundel counties, regular assessments of the impact of various coronavirus intervention strategies. Using epidemiologic models and evidence from peer-reviewed literature, the team is analyzing a wide range of data to provide statewide projections for demand on hospital and intensive care beds, as well as ventilators, under different response scenarios ranging from tight—with lots of social distancing and mask use—to loose.

The flow of data helps the state as it weighs the readiness and risks of sending people back to work, students back to school or diners back into restaurants, said SPH Principal Associate Dean Dushanka Kleinman.

Department of Health Policy and Management Professor and Chair Luisa Franzini has been leading the SPH reports to the state, together with Assistant Professor Michel Boudreaux. The team has been using existing models to project COVID-related hospital use for each of Maryland's five hospital regions. They are currently working on integrating socio-demographic and mobility data into their epidemiologic and hospital demand models. 

“The state's team looks at these reports as input to the discussions with the governor and the overall team to make recommendations to what you've seen over the time period” of the pandemic, Kleinman said. “In some cases, they have resulted in enhanced recommendations, such as the extended closure of schools, malls and nonessential businesses, and the stay-at-home directive.”

The projections team has built epidemiological models for select Maryland counties, led by Professor Hongjie Liu, that project COVID infections over time and under different scenarios. These models help policymakers plan the public health response and gauge the potential impact of different policy options.

The modeling can’t give precise projections for how many people will contract or die of COVID-19, said Hongjie Liu, chair of the Department of Epidemiology and Biostatistics. Because of insufficient testing, officials don’t even know many people in the state have the virus now, and different responses will affect the number of future cases. Still, it’s a valuable gauge for action. 

“It is useful to compare the effects of different preventions in reducing disease burden—not to project a single number for how many people will get the disease,” Liu said.

The researchers have shown how stay-at-home orders, mask requirements and other strategies dramatically flattened the peak of a massive potential wave of disease that could have overwhelmed the state’s health care providers. The much smaller wave that resulted is something that for now, hospitals can cope with—although as Hogan has pointed out, flattening the curve also stretches the wave out over a longer time.

The team contacted surrounding counties in mid-March about sharing expertise on COVID-19, including Montgomery County, where chief epidemiologist Chunfu Liu (who is not related to UMD’s Hongjie Liu) frequently hosts SPH graduate student interns.

Combined with the county’s own extrapolations based on leading COVID-19 models, the results from UMD gave Montgomery County officials a solid basis for planning, Montgomery County’s Liu said.

“The predictive results Dr. Liu and UMD provided to us are pretty close to the extrapolation we did for Montgomery County” using a model developed at the University of Washington, he said. “Together they provide us very good confidence, because they’re not exactly the same, but they are close.”

SPH is seizing on an unfortunate moment both to do good for Maryland and its communities and to find educational opportunities for students, said Malachi Perez ’20, who’s preparing to graduate with a bachelor’s in behavioral and community health. A furloughed health aide with experience as a medical scribe, he’s already worked several shifts as a volunteer contact tracer since receiving training earlier this month.

“The school is staying on top of keeping students involved and informed on volunteering opportunities, training opportunities,” Perez said. “So even though I was laid off from my job in health care, I’m equipped with skills to help fight the virus, and I have an opportunity to do it.”

 

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Hongjie Liu, Dushanka V. Kleinman, Luisa Franzini, Michel Boudreaux