As many states take the first steps to reopen, future coronavirus hot spots will likely be the places we’re most eager to return to, according to a University of Massachusetts — Dartmouth immunologist.
Dr. Erin Bromage, who specializes in evolutionary immunology, warns that reopening now would risk doubling the pandemic death toll — now at more than 78,000 — “over the next six weeks,” he claims.
“It seems many people are breathing some relief, and I’m not sure why,” Bromage writes in a blog. “As states reopen, and we give the virus more fuel, all bets are off.
“I understand the reasons for reopening the economy,” he adds, “but I’ve said before, if you don’t solve the biology, the economy won’t recover.”
He points out that “very few states” have seen a bona fide decline in new COVID-19 infections. “When you take out the data from New York and just look at the rest of the USA, daily case numbers are increasing,” he adds.
Nevertheless, the show will go on and already has in states such as Georgia, Alabama, South Carolina, Indiana and Nevada. Even in New York, which leads among states hit hardest by the disease, Gov. Andrew Cuomo promised that some regions of the Empire State could reopen as soon as the end of this week. Meanwhile, Mayor Bill de Blasio of NYC, now the global epicenter of the virus, projects a June reopening date.
It’s a tricky business considering scientists are still unsure of all the ways it’s possible to contract COVID-19. It only takes about 1,000 viral particles to make someone sick and breathing alone can release 50 to 5,000 respiratory droplets with each exhale, which may contain millions of viral particles. Nevertheless, the risk of transmission through breath alone is low compared to a cough, which may expel 3,000 droplets at a rate of 50 mph. Worst of all is a sneeze, which can send 30,000 droplets “easily across the room” at 200 mph, according to Bromage.
Contact tracing has shown that most infections stem from the home, where “sustained contact” between members of the household facilitates the spread, according to Bromage. On the other hand, only a marginal percentage of cases have been traced back to supermarkets, parks and other outdoor settings. He calls attention in particular to cruise ships, which “don’t even land in the top 50 outbreaks to date,” he writes.
It’s good news for cruise-goers, who helped Carnival soar to a 600% surge in bookings following an announcement that its routes would resume Aug. 1. The staggering uptick is a shock to those who have been horrified by the many reports of stranded passengers and crew being sick or quarantined to their closet-sized quarters aboard the ship for weeks.
Rather, Bromage is advising citizens in states with relaxed stay-at-home orders to be especially aware of the five environments — home, workplace, public transport, social gatherings and restaurants — for which “90% of all transmission events” can be blamed, and points to these indicative, real-life examples.
“All these infection events were indoors, with people closely spaced, with lots of talking, singing or yelling,” he adds.
Restaurants and bars
Bromage refers to a real-life epidemiologic model, based on a known restaurant outbreak in China, that demonstrates how quickly a virus can spread in the restaurant setting.
“During this [hypothetical] meal, the asymptomatic carrier released low-levels of virus into the air from their breathing” via dining room airflow vents, resulting in half of the people at their table becoming infected, plus another 75% of guests at an “adjacent downwind” table. Thanks to common “turbulent airflow,” another two people at an upwind table also become infected.
In the end, 10 of 31 people in the restaurant during a 90-minute period become infected.
Offices and other workplaces
In another Chinese case study, it took just one infected person to infect 43.5%, or 94 colleagues (two of which became asymptomatic carriers of the illness), out of 216 in just a week.
“While exact number of people infected by respiratory droplets / respiratory exposure versus fomite transmission (door handles, shared water coolers, elevator buttons etc) is unknown,” writes Bromage, “it serves to highlight that being in an enclosed space, sharing the same air for a prolonged period increases your chances of exposure and infection.”
A church choir from Mount Vernon, Washington, made headlines in March when 45 of its 60-member choral group fell ill with the coronavirus, two of whom died from the disease. All this, despite the fact that the organization had taken many steps to reduce contact between singers.
“A single asymptomatic carrier infected most of the people in attendance,” says Bromage. “The choir sang for 2½ hours, inside an enclosed church which was roughly the size of a volleyball court.”
Compared with talking, singing is an even more effective vehicle for the virus by causing respiratory droplets to “aerosolize,” or become a fine mist that travels through the air.
In Canada, a recent curling tournament in Alberta resulted in 24 new cases of the coronavirus out of the 72 people in attendance at the two-day event.
“Curling brings contestants and teammates in close contact in a cool indoor environment, with heavy breathing for an extended period,” Bromage notes.
Parties and other social gatherings
Bromage notes that 10% of all “early spreading events” originated at parties, weddings and funerals.
He points to one clinical report, published by the Centers for Disease Control and Prevention, which traces the transmission pattern of Chicago-based patient zero (who is not identified).
In just a few days, the not-yet symptomatic patient infected two family members with whom he shared a meal, another relative who he hugged at a funeral the next day and seven more people at a birthday party later.
Within a few more days, the patient had fallen ill and died. Meanwhile, three of the people he’d infected at the party had taken the virus to their church, where they, in turn, caused six more cases. In all, patient zero was directly responsible for 16 other patients, three of whom also died.
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