How Chicago Became a Hotbed for COVID-19 Research
As researchers began to track the path of COVID-19 from China to the United States, a surprising discovery highlighted the potential of a new epicenter for virus diversity.
“Our models suggest that SARS-CoV-2 traveled both ways around the globe before meeting in the middle — in Chicago,” says Judd Hultquist, PhD, Medicine: Infectious Diseases. “This puts Chicago in a very unique position as a ‘melting pot’ of virus diversity and makes it an ideal location to do studies investigating the role of virus mutations in clinical outcomes of patients.”
Hultquist and a team of Northwestern Medicine investigators received two critical awards that funded the work, both supported by the Northwestern University Clinical and Translational Sciences (NUCATS) Institute.
A Dixon Translational Research grant was awarded to study the origins and epidemiology of the SARS-CoV-2 outbreak in Chicago, with an ultimate goal of understanding how viral mutations may influence disease spread and clinical outcomes. The Dixon Award allowed the team to begin immediately decoding the whole genome sequences of SARS-CoV-2 viruses isolated from patients at Northwestern Memorial Hospital. A supplement to the University of Chicago’s Institute for Translational Medicine, grant number UL1TR002389, is allowing the research team to engage in a larger, cross-institutional effort to map city-wide viral diversity.
“We found that Chicago is harboring at least three distinct families or ‘clades’ of viruses, each of which seems to have been introduced to Chicago independently,” says Hultquist, a NUCATS member. “One clade appears to be very similar to those that were circulating in the New York area while another appears very similar to those found in Washington state. The third clade of viruses is found relatively uniquely in Chicago and appears closely related to the original viruses sequenced in China at the beginning of the pandemic.”
The research team is now investigating how these different virus families might influence progression of the disease and/or the ability of the virus to spread.
“Strikingly, we found that patients infected with one of these virus families, the one that resembles viruses from New York, have higher viral loads in their noses than patients infected with the other virus families,” says Hultquist. “This suggests that this kind of virus might be able to spread more easily, though more research needs to be done to prove this.”
Early results of the team’s work have been published in MedRxiv, an open-access preprint repository.
Responding to the Virus
In the two months preceding Labor Day, nearly 1,500 COVID-19 cases were traced back to contact that took place with an infected individual at a bar or restaurant in Illinois.
That data point is the result of an arduous contact tracing process led by the Illinois Department of Public Health (IDPH) that involves hour-long interviews with anyone suspected of coming into contact with the disease. These conversations can be complicated and an entire day can be spent tracking a single case.
Jaline Gerardin, PhD, Preventive Medicine: Epidemiology, considers it paramount that the state better defines the requirements for contact tracing to contain the pandemic after reopening. She is also working to develop a capacity model for regional hospitals ahead of a potential second wave of COVID-19.
“Our contact tracing model will enable IDPH to prioritize resource deployment at the most important parts of intervention — the time from symptom onset to positive diagnosis, fraction of contacts found, and isolation success — and to develop target performance metrics for monitoring and evaluation,” says Gerardin, a NUCATS member. “We will also build a website to publicize status reports and modeling outputs for the general public.”
Gerardin received a highly competitive COVID-19 Rapid Response grant from the NUCATS Institute in July to begin the work. The team’s hospital capacity model will serve to guide decision-making on early warning indicators, expansion of hospital bed capacity, staffing needs, and acquisition of supplies during an increase in COVID cases.
A few drops of blood.
That’s all that it takes for Northwestern researchers to determine if an individual has anti-SARS-CoV-2 antibodies.
Working with a group of multidisciplinary investigators that includes Thomas McDade, Anthropology; Alexis Demonbreun, Pharmacology; Brian Mustanski, Medical Social Sciences; and Rich D’Aquila Medicine: Infections Diseases, Elizabeth McNally, MD, PhD, the Elizabeth J. Ward Professor of Genetic Medicine and director of the Center for Genetic Medicine, helped devise a dried blood spot test that people can take at home.
After an interested participant registers through the project website, they receive serology testing materials through the mail. Serology tests look for antibodies in blood. If antibodies are found, that means there has been a previous exposure to the virus. Once the required blood spots are collected, participants mail their sample card to the laboratory where a highly quantitative measure of anti-SARS-CoV-2 antibodies takes place.
“The funding we received as a supplement to the NUCATS grant will allow us to test more broadly in Chicago and surrounding suburbs,” says McNally, a NUCATS member. “We are also interested in learning more about disparate infection rates across Chicago and Illinois, including studying household spread. We are also inviting people who participated in Northwestern’s biobank NUgene.”
By including participant’s from the NUgene biobank, researchers hope to learn more about the genetics that lead to some people being protected while others remain susceptible.
NUCATS funding also served to establish the Northwestern Healthcare Worker SARS CoV-2 Serology Study led by John Wilkins, MD, MS, Medicine: Cardiology and Preventive Medicine: Epidemiology and Charlesnika Evans, PhD, MPH, Preventive Medicine: Epidemiology. Initial results led to a large philanthropic gift from the Northwestern Memorial Foundation.
“The NUCATS funding is central to keeping this cohort running,” says Wilkins. “This study will allow us to understand the prevalence and predictors of antibodies to SARS CoV-2 in healthcare workers.” The team also hopes to be able to determine if having antibodies to the virus affects the risk for developing COVID-19 in the future.
The team also hopes to be able to determine if having antibodies to the virus affects the risk for developing COVID-19 in the future.
Some of the research reported in this article was supported, in part, by the National Institutes of Health's National Center for Advancing Translational Sciences, Grant Number UL1TR001422. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Written by Roger Anderson