US college campuses are Covid superspreaders: Study

College campuses are at risk of becoming Covid-19 superspreaders for the entire county, a new US study suggests. Looking at 30 campuses across the US with the highest amount of reported cases, researchers saw that over half of the institutions had spikes -- at their peak -- which were well above 1,000 coronavirus cases per 100,000 people per week within the first two weeks of classes.

"Our results confirm the widespread fear in early fall that colleges could become the new hot spots of Covid-19 transmission. But, at the same time, college administrators should be applauded for their rapid responses to successfully manage local outbreaks," said researcher Ellen Kuhl from Stanford University in the US. For the study, published in the journal Computer Methods in Biomechanics and Biomedical Engineering, the research team used advanced modelling, which assesses the real-time epidemiology of the Covid-19 outbreak using an SEIR (susceptible, exposed, infectious, and recovered) model to map how the disease spread across the campuses.

They drew Covid-19 case reports from 30 publicly available college dashboards across the US throughout the fall (autumn, September to December) of 2020. These institutions were either teaching in person, online or a hybrid of both. They selected colleges for which case numbers are reported on a daily basis and the total cumulative case number exceeded 100.

During this time window, the nationwide number of new cases had dropped below 50,000 per day. All reported campuses pursued regular surveillance testing, weekly or even twice per week, combined with aggressive test-trace-isolate strategies. "The majority of colleges and universities were able to rapidly manage their outbreaks and suppress campus-wide infections, while the neighbouring communities were less successful in controlling the spread of the virus," said Hannah Lu from the varsity.

"As a result, for most institutions, the outbreak dynamics remained manageable throughout the entire fall of 2020 with narrow spikes of less than 300 cases per day," Lu added. The team believes that this methodology, in combination with continuing online learning, is the best way to prevent college sites from becoming the major hub of the disease.