Researchers from Stanford University in the United States conducted a study that showed that college campuses have an extremely high incidence of coronavirus disease in 2019 (COVID-19) and that their reopening could initiate superspreciation in neighboring communities.
Team modeling of COVID-19 outbreak dynamics in 30 campuses and their home counties revealed a large number of epidemics on campus during the first two weeks of classes. These attacks usually spread to neighboring communities.
Of the 30 institutions surveyed, 14 recorded a sharp increase in infections, with the highest seven-day incidence, which was an order of magnitude larger than the state peaks that occurred during the first and second pandemic waves.
Many institutions failed to control the spread of the virus off-campus and within just two weeks, 17 epidemics caused the peak of infections in home counties.
However, most campuses quickly managed attacks and rapidly reduced the number of new infections.
We expect strict search-quarantine strategies, a flexible transition to online instructions and – most importantly – compliance with local regulations to be crucial to ensure the safe opening of the campus after the winter break, ”writes Ellen Kuhl and colleagues.
A pre-print version is available on the server medRxiv *, while the article was reviewed.
The question of whether to reopen is a topic of constant debate
The question of whether colleges and universities should reopen while the COVID-19 pandemic is still ongoing remains a topic of constant debate and a major concern.
Many institutions that reopened in the fall experienced massive waves of infection, and colleges were quickly declared the new foci of the pandemic.
Given that the mandate is over and we have a long winter break ahead of us, it is necessary to comprehensively review the fall and carefully assess the risks of reopening the campus, the researchers say.
What did the researchers do?
The team analyzed the dynamics of COVID-19 outbreaks in 30 campuses and their home counties across the United States using the Sensitive-Exposed-Infectious Recovery Section (SEIR) model. A method called Bayesian inference was used to estimate the effective reproductive number (number of secondary infections resulting from a single infection) based on daily institute reports for COVID-19 during the fall of 2020.
By comparing campus outbreak features with COVID-19 case reports for home counties, the team could assess whether campus reopening is related to local community attacks.
The first two weeks of classes were a period of high risk
Of the 30 institutions surveyed, the number of infections increased in 14 campuses in the first two weeks of classes.
The maximum seven-day incidence per 100,000 in these institutions was well above 1,000 – an order of magnitude larger than the state peaks seen during the first and second pandemic waves (70 and 150, respectively).
Policymakers often consider the seven-day frequency of 50,000 cases to be a threshold for high-risk counties, states, or states. All 30 institutions included in the study had a maximum incidence that exceeded this value by two or even three orders of magnitude.
The highest maximum incidence (3,083) was recorded at the University of Notre Dame, followed by the University of Arizona (2,700) and Clemson University (2,685).
Many institutes failed to control SARS-CoV-2 transmission off-campus and within just two weeks, 17 epidemics caused the peak of infections in neighboring communities.
Our results are a quantitative confirmation of the usual fear at the beginning of autumn that the faculties could become new hotspots for the transmission of COVID-19 “, the team writes.
Successful reopening relies on control measures
However, most campuses responded well to epidemics and were able to quickly reduce the number of reproductions to well below one within two to three weeks.
At most campuses, outbreak dynamics continued to be manageable throughout the fall, with narrow jumps of less than 300 cases per day. Neighboring communities were less successful in curbing the spread of the virus.
“Our findings suggest that college campuses pose a risk of triggering events that predominate, but, at the same time, they should be welcomed for quick responses to successfully manage local epidemics,” Kuhl and team say.
“Successful reopening is based on limiting the introduction of the virus during the initial weeks of the mandate, regular testing and a quick search, and a collective understanding of the importance of quarantine and isolation,” they advise.