What are ‘superspreader’ events and how have they caused coronavirus outbreaks in US?
“Superspreader” events during the COVID-19 pandemic have led to a surge of cases across the country, which is why large gatherings might be the last thing to come back, media outlets reported.
“Superspreader” events are ones atiwhich a gathering of people leads to a large uptick in infections.
“It’s more of a colloquial term that epidemiologists and public health responders use to describe a situation where someone in a population or in a community seems to have spread the disease a lot more than most of the others,” Dr. Robert Amler, the dean of New York Medical College’s School of Health Sciences and Practice, told FOX Business. “Somebody who is just spreading contagion at a much greater rate than the average person who is infected.”
Such events have led to an increase in cases across the U.S.,authorities say.
One of the first superspreader events was In New Orleans, where more than a million party-goers packed the streets for Mardi Gras in February, The Washington Post reported. On March 9, 13 days later, Louisiana had its first COVID-19 case. Since then, all of the state’s 64 parishes have recorded cases, led by Orleans Parish with 6,608 cases and 453 deaths.
“We had people from all over the world. We also had the spread of this virus, and people did not realize it was spreading,” Rebekah Gee, a former state health secretary now on the faculty of Louisiana State University’s medical school told The Washington Post. “So people not only caught beads, but they caught COVID-19.”
On March 10, the Skagit Valley Chorale decide to hold their weekly rehearsal in Mount Vernon, Washington, according to The Los Angeles Times. Out of the 60 people who attended rehearsal, 45 were diagnosed with COVID-19 and two died.
More than half of the guests who attended a 40th birthday party on March 5 in Westport, Connecticut were infected with COVID-19, The New York Times reported.
Drug company Biogen held a corporate meeting on Feb. 26-27 in Boston, The New York Times reported. The event led to 99 people who were sickened with COVID-19, according to the Massachusetts Department of Public Health. The virus had also spread to Indiana, Tennessee, and North Carolina.
“In a newly introduced infection, a single superspreading event can do two (related) things: increase the number of cases by many-fold, moving ahead in the race for exponential spread, and also thereby make it more likely that at least some of those cases lead to many more cases rather than having all the local chains of transmission die out,” Mark Lipsitch, a Harvard epidemiologist, told Vox.
Lipsitch also said superspreading events are most significant at the beginning of the outbreak.
Puja Nambiar, an infectious disease professor at the Louisiana State University Health Sciences Center, said Mardi Gras had the “ingredients” for fast transmission: “high density, high contact, and exposure risk.”
In China, a patient who had abdominal symptoms and wasn’t thought to have COVID-19, infected at least 10 healthcare workers and around 4 patients, according to a Centers for Disease Control and Prevention report.
“Surveillance and focused response efforts should prioritize environments and settings at high risk for SSEs, including closed environments such as healthcare facilities, nursing homes, prisons, homeless shelters, schools, and sites of mass gatherings,” the authors of the CDC report wrote.
This story was originally published May 6, 2020 at 5:21 PM with the headline "What are ‘superspreader’ events and how have they caused coronavirus outbreaks in US?."