Published: Nov. 30, 2020 By

In March, , Professor of Applied Mathematics in the CU Boulder College of Engineering, was invited to join the State of Colorado’s COVID-19 modeling team. Since then, he has contributed his expertise in mathematical modeling in biology as the team helps to predict theA portrait of Dr. David Bortz smiling. He has brown short hair, is wearing thin wire glasses, and is wearing a red button up shirt. He is sitting in front of a blue background. impact of local and state governments’ responses to the COVID-19 pandemic.

According to Dr. Bortz, “understanding the infection drivers for this pandemic and preparedness for future ones on the scale of society is both a huge challenge and opportunity for applied mathematicians. Fully synthesizing different aspects of this research - identifying infection vectors, predicting hospitalization needs, estimating non-pharmaceutical intervention effectiveness, etc... would be a huge achievement that will serve us well now and in the future.” In September, Dr. Bortz sat down to talk with us at the Colorado Engineer Magazine to discuss the efforts of the COVID modeling team to address the healthcare needs of the State.

During our interview with Dr. Bortz, we discussed the accuracy of the models used by the government, “In a large part because of the high quality hospitalization data we get from the State, we have been able to fit the data and our ‘two week in the future’ forecasts has always been over- or under-predicting by no more than 40 patients.” Dr. Bortz went on to discuss how the infection rate is continuously changing due to personal behavioral choices as well as public health orders. For example, over the July 4th weekend the data clearly shows an increase in transmission, resulting in a hospitalization peak about two weeks later.

We also raised the issue of non-compliance with public health orders. Dr. Bortz replied, “It’s simply a fact that mask usage reduces transmission of airborne diseases. We’ve known this for over a century; during the 1918 flu pandemic, everyone wore masks. Moreover, the science of epidemiology has made huge advances over the last hundred years, and model predictions are more akin to hurricane forecasts. When this information is synthesized to create public health orders, these are fundamentally life saving recommendations based on the best-available data and forecasts. In the absence of a vaccine, masks remain one of the best ways to reduce transmission.”

Professor Bortz also developed a model specific to CU and the student population. He further explained that the low infection rates at CU are due to the rapid testing and isolation protocols put in place by the University. In most cases, the time between positive test and isolation was less than 24 hours. The capability to rapidly identify and isolate infectious students is the core of what allowed CU to maintain an in-person classroom experience for most of the fall semester.

Since the onset of the COVID-19 pandemic, governments and organizations have made enormous efforts to manage the spread of the disease. The Colorado COVID modeling team is just one example of some of the efforts being employed to inform policymakers on the best ways to protect people from contracting a potentially fatal disease. Prof. Bortz is honored to serve on this world-class team as they work to make this model a more robust and accurate resource, ultimately preserving and protecting the lives of Coloradans.

Photo courtesy of David Bortz.