A Boston hotel that was linked to a coronavirus outbreak after it hosted a local biotech company’s conference earlier this year likely led to about twenty thousand cases, according to a new study. 

The superspreading event occurred in late February at the Boston Marriott Long Wharf, where roughly two hundred people attended the conference.  

“Ultimately, more than ninety cases were diagnosed in people associated with this conference or their contacts, raising suspicion that a superspreading event had occurred there,” the researchers wrote in their study, which has not yet been peer-reviewed but was posted on medRxiv. 

In settling on their conclusions, the researchers, who are from the Broad Institute of MIT and Harvard in Cambridge and other institutions, tapped into genetic analyses of coronavirus specimen samples in Massachusetts.

They were able to sequence and analyze 772 complete genomes of the virus and eventually discovered eighty introductions of the virus, most likely from elsewhere in the United States and Europe, into the Boston area.  

The researchers noted that since this particular event occurred early in the pandemic—before lockdowns, mask mandates, and social-distancing measures—the contagion had an easier avenue to spread quickly and widely.  

The researchers did not identify the conference in their study, but The Boston Globe reported that it was an international meeting of leaders from the biotechnology company Biogen.

On Tuesday, Massachusetts Governor Charlie Baker said during a news conference that February’s Biogen conference was a “seminal event” in the coronavirus pandemic for the region.  

“I was criticized actually for saying a few months ago that the Biogen event was a seminal event with respect to corona here in the commonwealth and I couldn’t put a number on it at that point in time,” he said. 

“This is no offense to anybody, but at that point in time, nobody was wearing masks, nobody was social distancing, nobody was even behaving with concern about the presence of the virus at all. I mean all rules of the game with respect to that have changed. It speaks to the power of that virus to move from one person to another to another.”  

The study also examined the high infection rates of the coronavirus in other settings in the Boston area, such as a skilled nursing facility and a homeless shelter.  

“Our findings repeatedly highlight the close relationships between seemingly disconnected groups and populations: viruses from international business travel seeded major outbreaks among individuals experiencing homelessness, spread throughout the Boston area, and were exported to other domestic and international sites,” the researchers wrote.  

There are now more than 23.9 million confirmed cases of coronavirus worldwide, including at least 820,000 deaths, according to the latest data from Johns Hopkins University.  

The United States has the most cases, with nearly 5.8 million confirmed infections and more than 178,000 deaths.

Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV. Follow or contact him on LinkedIn.

Reuters