Air conditioning spread the coronavirus to 9 people sitting near an infected person in a restaurant,

[IronLionZion]

Last edited Wed Apr 22, 2020, 09:23 AM - Edit history (1)

Air conditioning spread the coronavirus to 9 people sitting near an infected person in a restaurant, researchers say. It has huge implications for the service industry.

https://www.businessinsider.com/air-conditioning-spread-coronavirus-restaurant-can-service-industry-open-again-2020-4

In an early-release research letter in the journal Emerging Infectious Diseases, researchers said they found that 9 people who were sitting near one another at a restaurant in China in January got COVID-19, the illness caused by the coronavirus, and that it likely spread because of the restaurant's air conditioner.

The authors advised restaurants to increase the distance between tables and improve ventilation.

As restaurants look forward to reopening, experts say they will need to take extra safety measures, like reducing capacity, having employees wear masks, and capping how long diners can stay there.

Three seemingly healthy families were struck by COVID-19 after dining at neighboring tables in a windowless restaurant in Guangzhou, China, in January.

Researchers studying the case think that the restaurant's air conditioner blew the viral droplets of one person who was asymptomatic farther than they might have normally gone. Nine other people across the three families later got sick.

The researchers described their findings in an early-release research letter published in the journal Emerging Infectious Diseases earlier this month.

It's a frightening prospect for people who are trying to keep a healthy distance from others. However, in a potentially hopeful finding for the locked-down restaurant industry, none of the 73 other diners and eight employees in the restaurant at the time got sick, the researchers said.

Sounds like a recipe for a second wave this summer as weather gets warmer and people want to go out in the states that open up.

The photos in the article have jack to do with the text so I didn't include them here. The research letter is there at the CDC link with some useful diagrams that I recommend looking at for those who are into this sort of thing.

[Laffy Kat]

1. Oh shit. nt

[TheBlackAdder]

26. Getting flashbacks of the initial Legionnaire's Disease contamination from a dirty AC unit.

[bullwinkle428]

2. I was JUST about to post this story. Definitely worth the read.

[uponit7771]

3. People will have to eat with masks on / sarc

[Blue_true]

22. ..

[lunasun]

4. You didn't want to sit next to the kitchen before the virus . Now it's not near the air vents

[Blue_true]

21. Actually.

If the air is not recirculated, the safest place is as near the AC vent as possible, with no one between you and it.

[PoindexterOglethorpe]

5. Windowless restaurant.

That says a lot.

Some years ago I heard a report on NPR, and a doctor who'd done a lot of work in places like Africa, pointed out that in third world countries the hospitals had windows that opened, and they opened those windows. In the first world, even if there were windows, the windows didn't open. He'd noticed how pathogens were contained and spread in the windowless environments, and often didn't get a foothold in the places with windows.

I've never forgotten that.

While it has nothing to do with keeping pathogens from building up inside my home, I have windows and doors open as often as I can.

[IronLionZion]

7. The virus spreads quickly on planes and ships for similar reasons

For third world countries, buildings in general tend to have windows that open due to logistical reasons from before air conditioning was widespread. They also have problems like power outages or reusing equipment that would be considered unthinkable in the US.

[SeattleVet]

27. Actually, the way commercial aircraft cabin air systems are set up is pretty safe.

Except when on the ground and on auxiliary power, the air is a mixture of outside air (-65 degrees) or engine bypass air (200-500 degrees) mixed with some recirculated cabin air (at about a 50/50 mix), which is all run through hospital-grade HEPA filters (99.9+% particulate capture - and, contrary to intuition, as these filters get dirtier they become better at filtering) on a multi-branched and segmented system. Depending on the aircraft model you are really only 'sharing' air with somewhere between 3 and 7 rows, with the air coming in from the top and exiting through floor and sidewall grills. Generally, cabin air changes are about 20x per hour, vs. about 12 per hour in the typical office building.

The greatest danger for contamination and picking up something is from surfaces - tray tables, armrests, lavatory doors, and (probably the dirtiest of all) inside the seatback pockets.

Best practices in a commercial aircraft environment would seem to be to keep your air vent turned on and your hands away from the commonly contaminated surfaces, and wipe down the tray table and armrests.

Here's a 3-year old article that has a pretty decent (and very basic) explanation of how aircraft cabin air circulates:
https://www.travelandleisure.com/travel-tips/turning-ac-on-during-flight

And this is one from last month with additional information about cabin air management:
https://www.tripsavvy.com/air-quality-during-your-flight-54164

(There are some technologies used in newer aircraft that are even more efficient at removing contaminants from the air, and also raising the humidity in the cabin. It's usually the low humidity that makes people feel like crap after a long flight.)

[IronLionZion]

31. That's good to know about the air systems

but people get sick from traveling all the time. Probably because of being around lots of people in the airport waiting rooms or touching contaminated surfaces or something.

[JustABozoOnThisBus]

45. All that, plus, the air in the plane may be ok, but surfaces are Petri dishes.

The seats, headrests, cabinet covers, magazines, arm rests, who knows how often they're disinfected. The air and the toilets are probably the cleanest parts of the airplane.

[IronLionZion]

46. Here's a woman licking a plane toilet seat

Link to tweet

Coronavirus challenge

[JustABozoOnThisBus]

47. At least she didn't light herself on fire, another stupid online challenge.

I hope she scrubbed the seat with Clorox wipes before her stupid video.

And, I just remembered, there are rules about setting yourself on fire in an airplane's lavatory.

[IronLionZion]

49. Yeah people are insane

in this case, she later admitted to using nuclear level disinfectant on the toilet first and it was her sugar daddy's private plane

[Midnightwalk]

50. She's still a toilet licker.

Put it on her tombstone and or obituary.

Greatest accomplishment: she was a prominent toilet licker during the covid-19 pandemic.

[IronLionZion]

51. Whatever you are, be a good one

[Blue_true]

20. No, restaurant that has AC.

Windowless has nothing to do with it. The big factors are the AC conditions (great for covid19) and the positioning of AC release points. If the release points are low, that likely enhances the spread.

[ProfessorGAC]

6. A Lot Of Supposition There

I'd say it's close to a coin flip as to whether they've proven this or not.
I find these "OMG, There's No Place Safe" stories very unhelpful and creating more stress where people are already stretched thin.
Especially like this one, where they have really no proof that those 9 people weren't exposed elsewhere, days before.
"These people say they know they weren't around any other asymptomatic carriers until they knew an asymptomatic carrier sat near an air conditioner.". (Not a real quote. Thought bubbling the premise for the conclusion)
Really? That's definitive enough to publish?

[wnylib]

16. I had similar thoughts when I read it.

Those people could have been exposed to the virus somewhere else. Or, the wait staff could have transmitted the virus from one person to another.

[Hortensis]

30. Nevertheless, I don't think we should assume it was

ignorant supposition. It's the conclusion of infectious disease researchers, who tracked sick people back to one point and presumably bring a lot more to the job than the typical ability to make stupid guesses.

And this report was published by the CDC's Emerging Infectious Diseases journal, probably also not put out by irresponsible idiots.

[ProfessorGAC]

34. Taking The Opposing View, H

I think this a ridiculous logical leap & don't trust the detective skills of these folks.
Yes, they may be experts in viral transmission but that doesn't mean they have world class problem solving skills.
If, if, if, is proof of nothing.

[Hortensis]

37. :) Too many unsupported suppositions.

[obamanut2012]

48. Yup, totally unscientific supposition here

ZERO evidence of this as of now.

[Snake Plissken]

8. If you think air condition is bad, those hand drying in bathrooms

blast all the germs in those public bathrooms all over every surface and every person in the room.

[dalton99a]

11. +1. Those stupid things should be outlawed

Some of them are as loud as a leaf blower

[Aussie105]

9. It's how the virus spread on cruise ships.

Pack the ships with workers from different countries, with unknown medical histories and poor health checks, pack the ships with rich old people who like to have food cooked for them and be waited upon, crank up the cooling and ventilation systems in warmer waters, and you have a recipe for infection spreading. And not just this one, either.

Meh. It's a holiday, an expensive holiday. What could possibly go wrong? Nobody gets hurt or dies enjoying a holiday, right?

[yellowdogintexas]

18. I caught a vicious cold when we went on our cruise

Fortunately it did not really hit me until we were on the way home from Galveston.

[dalton99a]

10. Kick

Sketch showing arrangement of restaurant tables and air conditioning airflow at site of outbreak of 2019 novel coronavirus disease, Guangzhou, China, 2020. Red circles indicate seating of future case-patients; yellow-filled red circle indicates index case-patient.

[Blue_true]

23. C1 and C2 seem strange. All the others make lots of sense to me.

I wonder where the restroom is situated relative to C1 and C2? C1 and C2 nominally were positioned in a way that their exposure from A1 should have been minimal, unless A1 was in the area of their table. The AC conditions should allow the virus to survive for days on chairbacks, which seldom are wiped down, and even on tables if they are not wiped down and certainly on condiments containers (salt, pepper, sauces, ect).

[Takket]

38. What kind of units are those?

If they are just units recircing the air over and over again there is no fresh air. If they are vents that return to a central air handling system then there is some fresh air mixed in. My guess is these are just recircing room air.

[Midnightwalk]

12. Here's a link to the cdc early release article

https://wwwnc.cdc.gov/eid/article/26/7/20-0764_article#tnF1]

I guess it’s about 6 pages long so I won’t bother to excerpt anything since it’s an easy read if you want more details. It admits that there are limitations but it’s not just conjecture. Btw the figures in the cdc article do match but you have to click on the word figure in the caption to see the details.

Many restaurants in Arizona are open for takeout including alcohol. Walking I’ve seen cars waiting for someone to bring orders out. I wonder whether letting people in would increase or decrease business.

The human risk of opening is more important. That risk and decision needs to be driven by science and a solid plan.

[Hortensis]

32. "I wonder whether letting people in would increase or decrease business."

Boy, that's a question!

Opening of course would increase the risk to everyone involved, service employees forced back to work and idiots demanding it. And drive-throughers. And in the three southern states supposedly "reopening" service businesses, air conditioning is pretty critical in summer.

With an almost-80-year-old husband, I've gotten myself exactly one hamburger on a rare shopping in the past couple of months, and I wouldn't be getting drive-through from "opened" restaurants at all.

Thanks for wondering.

[Bayard]

13. Someone should shove this article up tRump's nose

As well as the governors that refuse to issue stay at home orders, and close businesses.

[Midnight Writer]

14. Oh, come on! No one could have anticipated a virus would spread through an air circulation system.

[Blue_true]

19. It is just not circulation, the temperature and humidity conditions are

perfect for covid19 to survive a long time. So even tables and other things a person can touch becomes hazardous.

[Tumbulu]

24. Who did not know that it could be spread this way- anyone could have figured this out

This paper simply proves the obvious. Why do you think it spread all over NYC? Buildings with large common air handling systems.

Cruise ships, air planes, building complexes that have air recirculating.

[IronLionZion]

15. I'm sure Trump misses his big rallies and fancy dinner parties

[Blue_true]

17. I wrote about this earlier today (yesterday now).

The only air conditioning systems that are close to safe are the ones where the cool air releases from the ceiling. Even in those cases, there will be dead zones where virus can linger and infect a person.

Air conditioning produces excellent conditions for covid19 to survive, cool, dry air.

In Florida, the vast majority of AC systems are upper wall release, or torso release, or near floor release AC systems, they all produce the most disastrous possibilities for spreading this virus rapidly among people.

Those of you in states that are opening up, avoid sitin eating places. Even if you go to takeout wear a mask, have you AC set to maximum blast as you come to the window, open only the driver side window a tad to hand out cash, honestly, tell the person to keep the change if it is a few bucks. When the food comes, wait until the person has extended it out, wait for 3 seconds, open your window, take it in fast then put your window back up. Once you leave the window, turn your AC flow back down. The whole concept with the car AC flow and window management is to keep a positive pressure flowing from your car outward, the takeout person normally is higher than you, the low burst of air out of your car should not endanger that person.

[Tumbulu]

25. Good suggestions!

Thanks!

[AdamGG]

28. That's one thing I've wondered about when they talk about seasonality of virus

In 1918, the pandemic let up in the summer and then hit in the fall with a 2nd surge that was bigger than in the spring. But. in 1918 there was no air conditioning. Since people spend most of their time in climate controlled indoor spaces, maybe season won't matter so much.

[Luz]

29. It was summer, the virus was quiet, so they all went out

to picnics and parades. That's what caused the terrible second wave. Just like we're doing now.

[IronLionZion]

33. The fall also has schools to deal with

kids might spread it to parents and grandparents

[Hortensis]

36. I've looked briefly a couple of times and not found discussion

of the effects of HVAC on seasonality. Same wonder.

However, depending on the disease, seasonality apparently isn't always what we think it is. I read that another coronavirus had been found to continue spread during the hot period, but that was hidden because relatively few people were showing symptoms of infection. The virus itself was far from dormant.

[DFW]

35. Even if we make it to the States this summer

It looks like of all the great places to eat on Cape Cod, we will get to exactly one of them--our kitchen.

[IronLionZion]

39. Yum, I get wonderful coffee, excellent cocktails, and perfectly cooked dishes

from my kitchen. Prepared exactly the way I want because I prepared it.

[DFW]

42. I usually do without the coffee and cocktails

I am a tea drinker, myself, and I don't do alcohol at all. On the other hand, my wife is a gourmet chef, and never misses, so I just have to make sure her creative energy doesn't go wild, or she'll make up some fabulous 7 course meal with enough leftovers to feed the Chinese army for a week.

[LAS14]

40. Has anyone read the original report? Does it give the ages of all the people...

... at the three tables? I'd be very interested to know if age played a factor in CATCHING the disease. I don't have it in me to plow through an original scientific report.

Also, are there any explanations as to why the AC, which was blowing right to left, allowed the people on the right-hand table to get infected. No one in the whole rest of the restaurant got infected.

EDIT - The MidnightWalk in reply #12 kindly alerted that the report was easy to read, so I did. It doesn't talk about age. I wish it did.

tia
las

[LAS14]

41. What's 1% of 9????????

" Of note, patient B3 was afebrile and 1% of the patients in this outbreak were asymptomatic, "

This is from the original article. Am I reading something wrong?

[IronLionZion]

43. Sounds like 1% of the total outbreak of positives, not just the 9 from the restaurant

and I had to look up "afebrile" - no fever

I know the way it was worded is very confusing, probably translated from Chinese.

[LAS14]

44. Makes sense. Thanks. Interesting, though, as...

... some other stories (note especially Pine Street Inn in Boston) show a way, way higher percentage of asymptomatic infected people.