Covid Coronavirus Transmission

Dagne

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There are a number of interesting researches dealing with transmission of coronavirus.
One Chinese study
Indoor transmission of SARS-CoV-2 https://www.medrxiv.org/content/10.1101/2020.04.04.20053058v1.full.pdf+html
says that

“among our 7,324 identified cases in China with sufficient descriptions, only one outdoor outbreak involving two cases occurred.”

Methods: "We collected descriptions of each confirmed case from the local Municipal HealthCommission website of 320 prefectural cities in mainland China, not including Hubei province. Each local Municipal Health Commission announced a description of the confirmed cases each day. The case descriptions generally included age, sex, venue of infection, symptoms, date of symptom onset, hospitalisation, and confirmation and history overxposure. Many described cases also included the individual trajectory and relationship with other confirmed cases, and quite often clusters had already been identified. We consulted the websites nationwide except for those of cities in Hubei province and collected all available data up to 11 February 2020. Data from a few major cities – Beijing, Shanghai, andGuangzhou – were not included in our analysis due to insufficient case descriptions. Case descriptions from Hong Kong, Macao, and Taiwan were collected from their health authorities. We input the data into a database in a unified format and conducted cross validation to ensure data reliability. A total of 7324 cases with the minimum required descriptions (i.e., the information listed above) were found; these accounted for 66.7% of the 10,980 confirmed non-Hubei cases inChina by 11 February 2020. "


The findings are very significant, it means that practically there is little change of getting infected while being outside. Surface cleaning and hand washing, too, might not be the way to stop the transmission, it is more about being together in a closed badly ventilated place.

On the other hand, the findings may reflect transmission routes under lockdown conditions, because China started lockdown outside of Hubei province from the 2nd or 3rd of February, and conditions where such that transmission could mostly happen in at home among related persons.

Having said that I think it is still true that transmission happens in-doors, if it is home or work environment. The latest cluster of infections in Lithuania is among sewing workshop workers which worked in the same closed space, and it did happen in spite of general precautionary measures. Staying within in-door space for a longer time with at least one infected person is enough to start a large cluster.
 
The paper was posted in the other thread.

As I mentioned there, the caveat is that the largest cluster in Germany was the result of outdoor festivities for Carnival.

So, not sure how significant it is.

See also from that thread...

"One recent study showed that the 1.5m social distance advised in Belgium may not be enough to protect against the cloud of droplets ejected by the force of a cough or sneeze – droplets which carry the virus and can travel up to 8m.
Now, a study from the National Institutes of Health demonstrates that the same droplets are expelled – albeit with much less force – when simply speaking.
The test subjects, all healthy volunteers, were asked to say the words “stay healthy” in a normal speaking voice, into a box. The droplets then passed through a film of laser light, and were photographed and measured.
The research found that the simple statement produced “numerous droplets” measuring between 20 and 500 micrometres – one micrometre is one-thousandth of a millimetre. Speaking more loudly produced more droplets, and the “th” sound in the word “healthy” produced the most.
The droplets themselves were smaller than those produced by a sneeze, but about the size which some studies have shown are produced by a cough. Because of the way the experiment was set up, it was not possible to measure the distance travelled by the droplets.
The most important result of the experiment, apart from demonstrating the existence of droplets produced during normal speech, was the effectiveness of a face mask.
Many if not most people think the face mask they wear when they go outside is to protect them from infection by the virus, despite the fact that it can enter through the eyes.
Medical professionals know, and have stressed since the beginning, that a mask is more effective in protecting others, and this study supports that view.


https://www.brusselstimes.com/all-ne...eads-droplets/



Takeaways from CV study in Bavaria: Children rarely transmit the virus; virus in feces appears non-infectious, merely touching surfaces doesn't transmit virus unless they're freshly/intensely infected; fresh air disperses CV, sunlight's UV kills it.

If we took that as incontrovertible fact, we should forget about being so manic about disinfecting surfaces, open all the windows and keep them open, keep teens, not toddlers away from grandparents, stay away from our elderly parents ourselves, and wear masks all the time, as it seems it's airborne. Being outside is safer, but packed venues outside may still spread it.

My other take homes: stay away from ships. It will also be a long time before I go to a movie theater, mask or not.
 
some things are becoming clear

a doorknob would not be able to transmit the virus unless someone infected coughs on it just before you touch it
in normal circumstances 1,5 meter distance is enough, but cyclists who ride 30 km/h are advised to keep 5-10 meter distance behind

I'm sure one can think of special coincidences by which the virus still transmits, but the most important message is : zero-risk does not exist, unless you force the whole population to stay in the basement untill they perish from hunger and thirst
 
"One recent study showed that the 1.5m social distance advised in Belgium may not be enough to protect against the cloud of droplets ejected by the force of a cough or sneeze – droplets which carry the virus and can travel up to 8m.
Now, a study from the National Institutes of Health demonstrates that the same droplets are expelled – albeit with much less force – when simply speaking.
The test subjects, all healthy volunteers, were asked to say the words “stay healthy” in a normal speaking voice, into a box. The droplets then passed through a film of laser light, and were photographed and measured.
The research found that the simple statement produced “numerous droplets” measuring between 20 and 500 micrometres – one micrometre is one-thousandth of a millimetre. Speaking more loudly produced more droplets, and the “th” sound in the word “healthy” produced the most.
The droplets themselves were smaller than those produced by a sneeze, but about the size which some studies have shown are produced by a cough. Because of the way the experiment was set up, it was not possible to measure the distance travelled by the droplets.
The most important result of the experiment, apart from demonstrating the existence of droplets produced during normal speech, was the effectiveness of a face mask.
Many if not most people think the face mask they wear when they go outside is to protect them from infection by the virus, despite the fact that it can enter through the eyes.
Medical professionals know, and have stressed since the beginning, that a mask is more effective in protecting others, and this study supports that view.

I very much agree about it, however it should be taken into consideration that the study you referred to https://jamanetwork.com/journals/jama/fullarticle/2763852 relates to indoor environment - so to say, viruses disperse while being outside with natural air movements, while inside, infections follow airflow imposed by ventilation or climate control systems and, if it is not specially filtered (which is done only within special negative pressure rooms) all the infections stays within the system, which is the problem.
This is from the article you mentioned:

"Droplets that settle along the trajectory can contaminate surfaces, while the rest remain trapped and clustered in the moving cloud. Eventually the cloud and its droplet payload lose momentum and coherence, and the remaining droplets within the cloud evaporate, producing residues or droplet nuclei that may stay suspended in the air for hours, following airflow patterns imposed by ventilation or climate-control systems".
 
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Regarding festivities of the Carnival - it may mean many thinks not necessarily that people got infected while being outside. As I imagine Carnival in Bavaria, people would sit somewhere nice and cozy, drink and socialise... which is exactly what is needed for the virus to spread.
 
Regarding festivities of the Carnival - it may mean many thinks not necessarily that people got infected while being outside. As I imagine Carnival in Bavaria, people would sit somewhere nice and cozy, drink and socialise... which is exactly what is needed for the virus to spread.

Still wouldn't want to be standing here when someone with Covid 19 is coughing next to me.
41343828_303.jpg
 
:) That's true, where did you get the picture, is it this year's Karneval in Köln? It is a dense crowd, really ...
I think of Carnival in term of Balls in Theatre Halls
WF.jpg


I've never been to Bavaria, but I suppose it was still rather cold in February, so in addition to outside parades, there must have been many activities in doors too. At least that's how it in my local tradition.
 
:) That's true, where did you get the picture, is it this year's Karneval in Köln? It is a dense crowd, really ...
I think of Carnival in term of Balls in Theatre Halls
WF.jpg


I've never been to Bavaria, but I suppose it was still rather cold in February, so in addition to outside parades, there must have been many activities in doors too. At least that's how it in my local tradition.

I don't know about Germany. In the U.S. and in the areas near me in Italy it's a lot about the parades.

In New Orleans the celebrations were credited with spreading the virus. I only went to Mardis Gras once, and it was an accident because there was a raging storm in New York so our plane from the Caribbean was diverted there for two days. I'm not a fan. It's about the parades, as I said, but also about a lot of public drunkenness and lewd behavior, i.e. women walking around bare breasted. Not my scene. I almost decked one moron who vomited all over my Bruno Magli shoes.

There are balls and dinner parties, but that's for the locals, not the tourists or the young.


In Viareggio it's again mostly about parades and floats either for the young or satirical ones about celebrities or with a decidedly political turn, and there's a lot of children around. No drunkenness, which is a blessing, and the floats are fabulous, but I really don't love standing around in brisk weather watching floats. I guess I'm just not a parade person, especially when packed in like sardines. It makes me a bit claustrophobic. If you start at about 9 minutes in you can see what it's like, and one of the younger themed floats.
https://www.youtube.com/watch?v=Ke6Kku1O_Wc

In Venezia, again, parties and balls for the locals, but parades, and for the rest you just concentrate on creating the most beautiful costume conceivable and parading around being gorgeous. :) Now that I could definitely get into...

https://www.youtube.com/watch?v=BLRQzlu2Goo

The Veneto wasn't hit very badly at all; I doubt any virus made it outside those masks. :)

In Lombardia the big superspreader event was probably the Atalanta/Valencia match. I bet all that shouting and singing was a great conduit for the virus.
 
There is a lot of drinking in New Orleans both inside and outside. Same thing in Miami/Ft Lauderdale and Cleawater FL during spring break. But most of the clusters in Florida were probably a result of New Yorkers escaping from New York and not outdoor spring breakers. There are a lot of clubs in Miami Beach that those spring breakers went after hours.

I believe that if you're at the beach with a nice little breeze blowing, if you catch coronavirus you are a very unlucky person. On the other hand if you are at a restaurant indoors and you are getting served by a waiter/waitress that went to an overcrowded club the night before, you are sure to get it.
 
There is a lot of drinking in New Orleans both inside and outside. Same thing in Miami/Ft Lauderdale and Cleawater FL during spring break. But most of the clusters in Florida were probably a result of New Yorkers escaping from New York and not outdoor spring breakers. There are a lot of clubs in Miami Beach that those spring breakers went after hours.

I believe that if you're at the beach with a nice little breeze blowing, if you catch coronavirus you are a very unlucky person. On the other hand if you are at a restaurant indoors and you are getting served by a waiter/waitress that went to an overcrowded club the night before, you are sure to get it.

Coronavirus is detected in water even after wastewater treatment, a precedure that can last according the quantities, sh..load, BOD, from 1 day, usually 2-4 days, (in case of high quantities chemicals added (high cost) and its min 12 hrs), PLUS the time in shewers and transportation.
considering that areas at sea lvl, are swampy,
and corona can infect pets, I have a 'feeling' that some pods may be infection source,
or close to wastewater exit to sea,

Just suspicious,

BTW,
my dog is angry, cause I don't let him smell other dog's pissing corners,
I am afraid for him. or I just turn to psycho
 
A test of 200 volunteers in Chelsea, Massachusetts showed that 32% had been exposed to the virus instead of the 2% that had been tested in Chelsea. Now this was just a sample it was not totally random sample but it is an indication. None of the 200 people were symptomatic. Take it for what it's worth:

https://www.yahoo.com/news/test-200-people-just-outside-144732703.html
 
Coronavirus is detected in water even after wastewater treatment, a precedure that can last according the quantities, sh..load, BOD, from 1 day, usually 2-4 days, (in case of high quantities chemicals added (high cost) and its min 12 hrs), PLUS the time in shewers and transportation.
considering that areas at sea lvl, are swampy,
and corona can infect pets, I have a 'feeling' that some pods may be infection source,
or close to wastewater exit to sea,

Just suspicious,

BTW,
my dog is angry, cause I don't let him smell other dog's pissing corners,
I am afraid for him. or I just turn to psycho

Well, it is difficult to say how the novel coronavirus does in water environment. I think it is always worse when it is in-doors. In Lithuania there was a cluster when a man returned from Denmark and went with his two sons to water spa park. After several days he discovered that his friend whom he travel with from Denmark had COVID. So he tested himself and he had it too (without symptoms).
The bad twist is that at the same spa, but on a different place, in a restaurant, which is apart from water spa facilities, there was a party organised, where a couple celebrate their 40th wedding anniversary. Some 13 quests got ill, and one man - of 61 who did not had any health problems before - died. The party happened before the quarantine started in Lithuania, and Denmark was not among the list of countries where people had to quarantine themselves after returning from.
The 40th wedding anniversary party, too, believed they were safe as they did not travel anywhere and did not want to postpone the celebration as many quests were invited from different locations throughout Lithuania, the restaurant was booked...

BTW
And about the dog - let him sniff wherever he wants - I think ticks are much more dangerous for dogs than COVID. I read a story that perhaps cats (tigers) can get it but for dogs it is nothing and they won't pass it to human in any case (dogs are too small and the virus cannot multiply in them well so it is OK)
Anyway, I let my dog be as always :)
 
Well, about the cluster in water park spa - actually, the people who attended the wedding party anniversary stayed overnight, and also used spa, which means they went to variety of pools and saunas (closed small space, dry or humid air). Besides, the man who died was very heavy built, he was a business person, and such men according to Lithuanian statistics are very prone to cardio vascular problems, as they tend to eat a lot of meat, animal fats, get high blood pressure already in forties, but they tend not to go to doctors until it is critical. So it was written in the news article that this person was healthy according to his family members, which most probably mean that he was not complaining, but it is unclear if his actual physical condition was good. He most probably was among the risk group because of coronary artery problems.
 
A test of 200 volunteers in Chelsea, Massachusetts showed that 32% had been exposed to the virus instead of the 2% that had been tested in Chelsea. Now this was just a sample it was not totally random sample but it is an indication. None of the 200 people were symptomatic. Take it for what it's worth:

https://www.yahoo.com/news/test-200-people-just-outside-144732703.html

Yes, I posted about the paper on the original thread. As I said at the time, I have no idea what the results would show for Boston, but randomized control studies are the only ones that will give accurate information, not studies made up of "volunteers" who perhaps have reason to think they've been exposed, and whether people are actually "asymptomatic" is time dependent. There's no way of knowing whether they're truly asymptomatic unless they're seen and examined at least fourteen days later.

The only randomized trials I recall having been done are the ones in the hard hit area in Germany and in Lombardia, both of which showed a 15% infection rate.

So, I think you're right to be cautious. Some of these papers may be worth very little in the long run.
 
I very much agree about it, however it should be taken into consideration that the study you referred to https://jamanetwork.com/journals/jama/fullarticle/2763852 relates to indoor environment - so to say, viruses disperse while being outside with natural air movements, while inside, infections follow airflow imposed by ventilation or climate control systems and, if it is not specially filtered (which is done only within special negative pressure rooms) all the infections stays within the system, which is the problem.
This is from the article you mentioned:

"Droplets that settle along the trajectory can contaminate surfaces, while the rest remain trapped and clustered in the moving cloud. Eventually the cloud and its droplet payload lose momentum and coherence, and the remaining droplets within the cloud evaporate, producing residues or droplet nuclei that may stay suspended in the air for hours, following airflow patterns imposed by ventilation or climate-control systems".

Yes, I get it.

If you're indoors it hangs around in a cloud for some period of time. If you're outdoors it's dispersed. So, if you're outside you'd have to be standing rather close to the person expelling the droplets while the person is sneezing, coughing, or even shouting or singing, for example. If you're in a packed square you could inhale them from a person close to you. Indoors you could inhale them even from people not so close.

Illustration: How people can be infected by a current of air propelled by flows of air from air conditioning. (My mother was right once again; air conditioning isn't good for you.:) She wasn't just a saint, she was a "sensitive"; she was right about so many things. Fool that I am I didn't always listen.)

It makes me wonder how much of the transmission on ships is due to this sort of thing.

See:
https://wwwnc.cdc.gov/eid/article/26/7/20-0764_article

I've already read how despite the lifting of lockdowns people are not returning to restaurant eating in any great numbers in South Korea. This could turn into a lasting disaster for that industry and for all the poor people employed in it.
 
Coronavirus is detected in water even after wastewater treatment, a precedure that can last according the quantities, sh..load, BOD, from 1 day, usually 2-4 days, (in case of high quantities chemicals added (high cost) and its min 12 hrs), PLUS the time in shewers and transportation.
considering that areas at sea lvl, are swampy,
and corona can infect pets, I have a 'feeling' that some pods may be infection source,
or close to wastewater exit to sea,

Just suspicious,

BTW,
my dog is angry, cause I don't let him smell other dog's pissing corners,
I am afraid for him. or I just turn to psycho

The question is whether those snippets are still contagious. The same goes for the "fomites" which remain on plastic or metal surfaces even after 24 hours.

Those are things which they have to test. Until they do and say they're no longer virulent, I'm still wiping off my groceries, although not as manically as before. :)

As for my dog and cat, it's more likely they'd get it from one of us. My cat, especially, never goes outside.
 
Yes, I get it.

If you're indoors it hangs around in a cloud for some period of time. If you're outdoors it's dispersed. So, if you're outside you'd have to be standing rather close to the person expelling the droplets while the person is sneezing, coughing, or even shouting or singing, for example. If you're in a packed square you could inhale them from a person close to you. Indoors you could inhale them even from people not so close.

Illustration: How people can be infected by a current of air propelled by flows of air from air conditioning. (My mother was right once again; air conditioning isn't good for you.:) She wasn't just a saint, she was a "sensitive"; she was right about so many things. Fool that I am I didn't always listen.)

It makes me wonder how much of the transmission on ships is due to this sort of thing.

Our Mothers are always right ;)
I also wonder about the transmission in ships due to air conditioning systems. It was so unfair to all those people in the Diamond Princess being told that virus can be passed only by droplets, and they should not be afraid of air conditioning systems, which is not the case as we can see now. The good thing is that, apparently, the seriousness of COVID-19 depends on the amount of virus load one was exposed to, and in case of viruses being passed by air ventilation systems - if it is not in hospital environment packet with patients, the virus load passed by the air ventilation system should not be too bad. This is the statistics of the Diamond Princess

Diamond Princess 712 infected13 deaths644 recovered55 active cases7 serious


I think if the passengers were kept on board longer, both the number of infected people and the fatalities/serious cases were worse due to the fact that more sick passengers were using the same air which was passed throughout the ship to everyone.

To tell the truth, I absolutely dislike air conditioning as I often get allergy from it - start coughing and crying from the dust particles it carries within.
 
In North Italy, also in Slovenia, main carnival event is house-to-house visits, you can check the video below. Regularly there is also community gathering – in bigger cities now usually the main event of custom. It really seems a perfect opportunity for virus spread.

http://isn3.zrc-sazu.si/etnofolk/Priloge/Video/2012/ISN_2012_561.mp4

Off topic a bit, but I had to tell you I just love that! I don't remember it for Carnevale, I'll have to ask my aunts and cousins, but in rural areas they still do it in Italy in early May. We call it Cantamaggio, or Sing May. It has disappeared from our cities. Lucky you if they still do broadly it in Slovenia.

Apennines of Parma

La Spezia, Liguria
https://www.youtube.com/watch?v=zeWrm6E-v7Q

As you say, great spreader event singing loudly into each other's faces like this.
 
Our Mothers are always right ;)
I also wonder about the transmission in ships due to air conditioning systems. It was so unfair to all those people in the Diamond Princess being told that virus can be passed only by droplets, and they should not be afraid of air conditioning systems, which is not the case as we can see now. The good thing is that, apparently, the seriousness of COVID-19 depends on the amount of virus load one was exposed to, and in case of viruses being passed by air ventilation systems - if it is not in hospital environment packet with patients, the virus load passed by the air ventilation system should not be too bad. This is the statistics of the Diamond Princess

Diamond Princess 712 infected13 deaths644 recovered55 active cases7 serious


I think if the passengers were kept on board longer, both the number of infected people and the fatalities/serious cases were worse due to the fact that more sick passengers were using the same air which was passed throughout the ship to everyone.

To tell the truth, I absolutely dislike air conditioning as I often get allergy from it - start coughing and crying from the dust particles it carries within.

Take a look at this from the paper's authors:
b5Pr9tT.png


I guess the moral of the story is never sit where the air conditioning is blowing on you.
 

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