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A funeral and a birthday party: CDC traces Chicago coronavirus outbreak to two family gatherings

Case study shows how a single person can set off a chain reaction of infections

People walk along Chicago's 53rd Street during the coronavirus outbreak. (Joshua Lott/Reuters)

In February, family members gathered for a Chicago-area funeral. A family friend who had been out of state attended and was just a bit sick with mild respiratory symptoms.

Before long, 16 people between the ages of 5 and 86 had been infected with the novel coronavirus (seven confirmed and nine probable), and three had died.

The case study, published Wednesday by the Centers for Disease Control and Prevention, is one of the most detailed looks at how covid-19 moves through communities and shows how a single person can set off a chain reaction of infections. The transmissions — traced to a funeral and birthday party held three days apart — took place before major social distancing policies were implemented and may have facilitated transmission of covid-19 to the broader Chicago community. (The CDC also previously investigated how those aboard the Diamond Princess cruise ship that had docked in Japan became infected.)

The CDC report begins the night before the funeral. The traveling friend — dubbed “Patient A1.1” as the first patient in the first transmission “generation” in the first cluster discovered — shared a takeout meal eaten from common serving dishes with two family members of the deceased at their home. The meal lasted about three hours.

At the funeral, Patient A1.1 hugged the friends who had been at the dinner and other family members to “express condolences.”

Two days later, one of the dinner hosts showed symptoms of the coronavirus. Two days after that, the other host got sick, too. A third family member who had hugged Patient A1.1 at the funeral also got sick.

Around the same time, Patient A1.1, who was then still experiencing mild respiratory symptoms, attended a birthday party with nine other people. They hugged and shared food at the three-hour party. Seven of the attendees soon became ill.

Within about a week of the onset of symptoms, the condition of the first dinner host deteriorated. The person was hospitalized, put on a ventilator and subsequently died.

Another family member visited the dinner host at the hospital and — without any personal protective equipment, according to the CDC — provided “personal care” and gave hugs. Three days later, that person developed a fever and cough, too.

Meanwhile, two of the birthday party attendees became critically ill and were put on ventilators. Both died. The five others experienced mild symptoms of cough and low-grade fever.

While one of the critically ill patients was hospitalized, a family member and a home-care professional who visited that person developed probable covid-19, the CDC said. The visiting family member, in turn, probably transmitted it to a household contact.

Three of the symptomatic birthday party attendees went to church six days after developing their first symptoms. Another church attendee who sat within one row for 90 minutes, talked to them and passed the offering plate with them also developed symptoms.

The CDC hypothesizes that these clusters may have facilitated transmission of covid-19 more broadly in Chicago and that they show why social distancing measures — and in particular, avoiding gatherings with multiple people — have been critical as the virus moved out of retirement communities, cruise ships and other more contained places. In New Orleans, local officials blamed another type of “super-spreading” event, Mardi Gras, for accelerating the transmission there. Outbreaks also have been traced to a French ski resort and an Italian soccer game.

“[T]hese findings highlight the importance of adhering to current social distancing recommendations, including guidance to avoid any gatherings with persons from multiple households and following state or local stay-at-home orders,” the CDC said.

Chicago Mayor Lori Lightfoot was alarmed April 6 at the racial disparities for blacks versus whites in deaths and coronavirus cases across the city. (Video: Reuters)

Read more:

Who gets a shot at life if hospitals run short of ventilators?

Medical ‘surge facilities’ are being set up on soccer fields, in state park cabins and converted convention centers.

Hospitals consider universal do-not-resuscitate orders for coronavirus patients

Coronavirus: What you need to know

Where do things stand? See the latest covid numbers in the U.S. and across the world. In the U.S., pandemic trends have shifted and now White people are more likely to die from covid than Black people.

The state of public health: Conservative and libertarian forces have defanged much of the nation’s public health system through legislation and litigation as the world staggers into the fourth year of covid.

Grief and the pandemic: A Washington Post reporter covered the coronavirus — and then endured the death of her mother from covid-19. She offers a window into grief and resilience.

Would we shut down again? What will the United States do the next time a deadly virus comes knocking on the door?

Vaccines: The CDC recommends that everyone age 5 and older get an updated covid booster shot. New federal data shows adults who received the updated shots cut their risk of being hospitalized with covid-19 by 50 percent. Here’s guidance on when you should get the omicron booster and how vaccine efficacy could be affected by your prior infections.

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