Superspreaders: Could You Unknowingly Infect Hundreds — or Thousands — of People With the Coronavirus?

Without proper precautions, 'superspreaders' can pass COVID-19 to many people while not having a single symptom. Here's why it’s crucial to avoid becoming one.

Even people who feel fine may have COVID-19 and infect others.iStock

Imagine going to a choir practice, a church, or even a funeral and later learning that you were responsible for dozens of people getting seriously sick. Some people don’t have to imagine, because they now know they unwittingly spread the novel coronavirus far and wide, simply by attending a gathering like so many of us did, before the social-distancing rules began.

Who Are Superspreaders, and Why Are They So Dangerous?

The fear of superspreaders is one reason experts are so worried about people who continue to congregate in large groups despite the recommendations to stop doing so, whether at a church service in Houston, on one of the many beaches that recently reopened in Georgia, or at social events in a retirement community in Florida.

Scientists call people who infect a large number of others superspreaders. And the dangerous thing is that anyone can become one.

As far as the experts know, no one is immune from getting COVID-19, and no one is immune from passing it to others, including potentially a lot of others, says Raagini Jawa, MD, MPH, an infectious-disease physician in Boston.

The possibility you could turn into a superspreader, giving the disease to dozens, hundreds, or, as those people go on to infect others, even thousands, is one reason it is critical that you follow current guidance for minimizing coronavirus infection transmission.

You May Transmit Coronavirus Before You Know You Have It

One of the most vexing problems with trying to contain COVID-19 is that people can have the virus multiplying in their body before they feel a single cough or other symptom.

“A person could be ‘viremic’ — meaning the virus is circulating in their body, for days before they even have a symptom, and theoretically they could be shedding the virus during this time,” Dr. Jawa says.

Even more vexing, experts are now finding that some people can have the virus and never experience any sign of it.

Scientists say that each person who has the coronavirus infects an average of one to three people, but that is merely an average. One person may infect no one else, while another could sicken dozens or more.

“If for your job or social network you are around many people, you may be able to spread it to more people,” Jawa says.

Learn From These Known COVID-19 Superspreading Events

Scientists only discover a superspreader in hindsight, when they trace an outbreak back to the person who started it. Someone could be generating a superspreading event right now, such as on a crowded beach or church service, but they won’t be identified for a while.

Nonetheless, we already know some superspreading events that have occurred with this pandemic. A report published by the Centers for Disease Control and Prevention (CDC) in March states that, “Although we still have limited information on the epidemiology of 2019 novel coronavirus disease (COVID-19), there have been multiple reports of superspreading events.”

Experts suspect a superspreader was behind these coronavirus outbreaks:

·         A 40th birthday party in Westport, Connecticut Days after someone with hidden symptoms joined 50 other guests at a woman’s home to celebrate her birthday, more than a dozen people came down with the disease. Within that time, those people went to work, stores, and other parties, and their kids went to school (before schools were shuttered). Westport quickly became an infection hot spot, and the county the town is in now has hundreds of cases.

·         Two funerals in Albany, Georgia When a large family gathered in this rural town to say goodbye to their deceased brother, they came from Atlanta, Louisiana, Washington, DC, Hawaii, and beyond. One of the funeral goers was apparently viremic, because soon after the burial many people started coming down with COVID-19. Then another large funeral was held the following weekend, and someone spread the virus there. Now many people in Albany have the disease.

·         An Episcopal church service in Washington, DC A priest who presided over a service, and afterward shook hands with hundreds of worshippers, was diagnosed with COVID-19. Other members of the church soon developed the telltale cough and fever. In the interim, like the priest, those people potentially infected others before they knew they had it.

Superspreaders Are Behind Many Past Tragedies

The classic superspreader in history is Typhoid Mary, whose real name was Mary Mallon. Mary was a cook in the early 20th century who had no symptoms of the disease but was later documented to have given typhoid fever to 50 other people.

During the 2003 SARS epidemic in Beijing, China, the CDC report notes, one person was behind a transmission to 76 others. When MERS circulated in South Korea, a single individual infected 28 others, who subsequently gave it to more than a hundred more.

Superspreaders have also been responsible for measles outbreaks in the United States, the report says.

How to Keep Yourself From Spreading COVID-19

The two most important ways to keep yourself from spreading the coronavirus are to avoid getting the disease in the first place and, if you do get sick, to keep from contaminating others.

The CDC recommends that everyone wash hands regularly and properly, avoid touching your face, wear a cloth face cover when in public with others (leave medical grade masks for healthcare workers), and stay home except when necessary. When you must go out, maintain a physical distance of six feet from other people.

“By staying home and engaging in social distancing, you minimize the risk of spreading the disease,” Jawa says.

Because so few Americans have been tested, and because you can have and spread COVID-19 well before you experience symptoms, Jawa says, “the way I think about it is that everyone should assume they have it, and do all they can to minimize the risk of transmitting it to others.”