How the virus spreads and doesn't spread (or: "Stop worrying about the wrong things")

[Kokeshi123]

www.bloomberg.com/opinion/articles/2020-05-15/will-i-get-coronavirus-at-the-grocery-store-unlikely

TLDR: We need to spend less time worrying about picking up the virus in open air spaces or even in shops, and more time thinking about how to smash transmission chains in households, workplaces etc.

The virus is fanned out into the population mainly through super-spreading events: "In the real world, most people transmit the disease to nobody, or one person, and a minority infect many others in so-called super-spreading events. It's those we must learn how to avoid."

"The disease is apparently very infectious but only for a short window, and perhaps only in some cases. "

"Sharing a home or office does make transmission more likely, since length of exposure matters as much as distance from other people. People passing by you in a supermarket are unlikely to infect you. Outdoor environments appear much safer as well. In one study, which followed hundreds of cases, all but one transmission occurred indoors.

“I’d like people to stop wasting mental energy on the wrong things,” Bromage says. “To stop worrying about outdoors and bike riders since it’s such a low risk.”"

www.usatoday.com/story/news/health/2020/05/20/coronavirus-does-not-spread-easily-surfaces-objects-cdc/5232748002/

The CDC in the US has now updated its statements on surface transmission. Surface transmission appears to be difficult and rather unusual. We absolutely should wash our hands very thoroughly in any case, but it doesn't prevent many infections. Stopping droplets being breathed onto uninfected people is the really big game-changer here. This suggests ways to open up things like restaurants and businesses---moving operations outside when possible, spacing people out, and ventilating spaces well, may be enough.

I don't think most ppl could reasonably not spread out within their own households, esp if they have young kids.

Even with nearly two months of lockdown, distancing and current restrictions there are thousands of news cases every single day. Unless these are all within care homes or hospitals then it is still spreading somewhere.

Tracing and tracing every case is really the only way to stop the spread imo.

*"Not spread it"

Interesting article.

good article.

It's also not clear in article whether they assume all trips to supermarkets are "brief, for 5 minutes" as they first state. I spend about an hour on my weekly shop due to adhering to distancing!

Unless these are all within care homes or hospitals then it is still spreading somewhere. A high % will be in care homes and hospitals---but most of the rest are probably within workplaces and people's own family homes.

Tracing and tracing every case is really the only way to stop the spread imo. I couldn't agree more! The lockdown should have been used as the opportunity to get this nailed.

This has been the problem in recent weeks - after being lambasted for not counting care home deaths in the statistics, the government is now including them in the figures for new cases and R value, which distorts the picture. Most new cases are now in care homes and hospitals, community transmission is low. And the majority of the evidence now suggests that risk of transmission in the open air, even in a place where many people are crowded together in the open air, is very low.

Thanks for sharing this. It is very helpful.

Maybe this is why we haven't had a surge after VE day

Maybe this is why we haven't had a surge after VE day

Or after the Easter weekend
Or after all the other shiny days with multiple families having picnics in parks

Now people have started complaining about crowds at beaches but I am personally not sure it is going to make any difference.

However it is worth remembering that not all outdoor activities are entirely safe. As soon as people get together and start shouting or singing for an extended period of time, this creates ideal environment for C19 transmissions. One of the most famous super spreading events (carnival in Gangelt, Germany) took place outdoors.

Gangelt will have involved a lot of crowding onto public transport and packed bars though too, won’t it? One of my abiding memories of the German Karneval I have been to is the drunk people on the trams!

TheCountessofFitzdotterel

I have seen an article in what I thought was a reliable source that one of Gangelt super spreaders did not spend any time indoors but, unfortunately, I cannot find the link. I was also wondering whether the transmissions might have happened in bars / restaurants but the paper suggested it was not the case.

That’s interesting, thanks. I suppose it’s because the crowds will have been very dense, whereas normally people outdoors tend to be more spread out.

What I have wondered all along is... if it’s as virulent as we’ve been led to believe... Why aren’t all the following either dead or struck down in critical proportions:

Dentists
Physios/chiropractors
Podiatrists
Beauticians/masseuses
GPs
Nail techs
Nursery workers
Teachers
Pilots
Cabin crew
Supermarket workers
Sex workers...

There will be hundreds more jobs where people work in close proximity with the bodies of strangers, or breathe in shared air with many strangers at once.

And yes I am sure there have been many people in each profession who have had it, but what I mean why has it not reached crisis point with these people if it’s so easy to catch we’ve all to stay 2m away from each other, wear masks and disinfect our shopping?

So aerosol transmission is a major transmission route just as I suspected. Droplets have to land in the mucosa do there's an element of chance. Aerosols merely need to be inhaled.

Germany scientists knew that it was very difficult to spread with "smears" at least a month ago. It's been a hard week and I haven't got the energy to reference it. But it was widely reported in the German press, not some closely guarded secret so I am surprised it wasn't reported here.

I think it's too early to say about VE Day.

As to whether things like VE could cause an increase, it really depends what people were doing. If people were out and about but mostly sticking to their own family groups rather than joining crowds, it will have little impact. That said, crowded outdoor events definitely can spread the virus, like Mardi Gras. People end up close up against people for minutes at a time in crowds, there is singing and shouting which causes droplets to get sprayed about, and then spectators are yelling to be heard over the noise, which means more droplets. I think banning these kinds of events is absolutely justified.

I just wish we could all stop with the panicky meltdowns about families picnicking on beaches and parks and river banks, people eating a sandwich on a bench, children and their parents getting horrible comments from strangers because a toddler wanders close to another person for a whole 2 seconds, people bitching neighbors walking their dog for a second time that day etc and even posting photos/reporting people. Don't even get me started on the stories of single parents being harassed for taking their children into a supermarket to buy food, because they might touch something and then everyone will die etc.

This kind of stuff is not spreading the virus. It's distracting everyone from the things that really DO spread the virus (we might have made faster progress on breaking up transmission chains in workplaces, hospitals and households if we had not spent weeks being encouraged to hyperfocus on parks and shops). And it's dangerously divisive and has fueled frustration and a backlash.

There have been cases of people getting the disease while shopping in the supermarket, eg the very sad case of the man whose young baby was seriously ill in hospital, and the only time anyone in the family had left the house for weeks was him going to do the weekly shop at Tesco.

Likewise, while the risk is lower at outdoor events it's certainly not zero either.

I think if we are to quash this disease we want to be reducing all risks, not just ignoring some.

I note in a separate point, that nearly half of comments on coronavirus on social media were recently found to be posted by foreign disinformation bots.

Which I thought was interesting.

I always read all posts suggesting we lower our defences with interest, and wonder who would benefit if we followed their advice.

I think your certainty about this is misleading. Your Bloomberg link is to a journalist quoting that Eric bloke and if you read his actual blog, he's very much been challenged.

CDC says it's possible to contract it from packaging, just that it's not the main path of transmission.

It doesn't have to be the main way to kill you ‍

P2P is obviously the fastest/strongest path of transmission and indoors is obviously the worst. Fabulous so many are being sent back to work

Social Distancing, even outside, is vitally important, but there are many instances of it not happening.

ONS released a statistic today to say the rates of infection of frontline keyworkers and the rest of the population is no different. This blows the 'it only spreads in care homes and hospitals" well and truly out the water.

I always read all posts suggesting we lower our defences with interest, and wonder who would benefit if we followed their advice.

See, I would actually not define myself as thinking this at all. There are a lot of areas where I think we should be raising our defenses. We need to put a lot more emphasis on ventilating indoor spaces, on masks, on moving things outdoors, and on testing and identifying mild/asymptomatic cases quickly, so that we can get them out of homes and workplaces where they will infect others.

I do however think that people don't need to disinfect food packaging, and that spending time outdoors should be OK as long as we are avoiding any kind of crowding.

Regarding "outdoor events"-I would be surprised if anyone on here was advocating outdoor events, to be honest-festivals, fireworks, concerts, street events etc. These are indeed risky and need to be avoided for quite a while yet. But being outdoors in a way which does not create crowds should be fine, and is very important for physical and mental health esp children.

Re keyworkers---totally agree, and we need to be improving safety for working environments too, through masks, ventilation, reducing operations and spacing people out, making use of outdoor spaces as well. Workplaces are definitely places where the virus can easily spread.

@Sadie789

Presumably lockdown stopped the work of most of these people... And I believe some of them do feature more highly in stats of risky professions.

@Kokeshi123

This fits in with what I’ve been thinking. With R being 2-3 prior to social distancing, and some people spreading to dozens, it follows that some spread to no-one, either because they happen not to be very infectious (ie children), or they just haven’t been especially socially interactive. I wouldn’t be surprised if the median R0 was zero!

This also helps explain Sweden... and how we don’t need to practice extreme social distancing for there to be a dramatic impact on spread. It also explains how it could have been here for a month or so before we identified it.... If say 5% of people do 95% of the transmitting, then it’s quite possible for it to have spread slowly at first... but as soon as you get to the point of large numbers having it, the mean R0 becomes the overriding factor and there’s exponential growth at a population level.

I was also very interested to see the statistics from ONS about infection rates looking similar throughout the population. It is as if the virus has been with us longer than we thought?

Well said, Kokeshi.

Re this:
‘I note in a separate point, that nearly half of comments on coronavirus on social media were recently found to be posted by foreign disinformation bots.’

Really? Which social media? Found by who? I don’t believe this for a second.