Diamond Princess outbreak analyzed

[caribill]

The New York Times has published an article analyzing the outbreak of Covid-19 on the Diamond Princess and aerosols transmission.

 

Very interesting reading.

 

https://www.nytimes.com/2020/07/30/health/diamond-princess-coronavirus-aerosol.html

[ElkGroveCruiser]

Too bad it's behind a subscription firewall.

[pcur]

6 minutes ago, ElkGroveCruiser said:

Too bad it's behind a subscription firewall.

 

I had to use my apple ID, and then was able to read the article.  Google and Facebook sign-in will work, too.

 

We are also in Elk Grove!  Southwest area off Denali.  

[pcur]

The article reinforces that masks are needed on cruise ships, even with good air circulation.  Another reason why waiting for a vaccine is a good idea.  

[caribill]

24 minutes ago, ElkGroveCruiser said:

Too bad it's behind a subscription firewall.

The NYT is supposed to have no firewall around Covid-19 articles.

[dickinson]

I had no problem and don't have a subscription.

[voljeep]

23 minutes ago, dickinson said:

I had no problem and don't have a subscription.

#metoo

[bluesea321]

2 hours ago, caribill said:

The New York Times has published an article analyzing the outbreak of Covid-19 on the Diamond Princess and aerosols transmission.

Very interesting reading.

https://www.nytimes.com/2020/07/30/health/diamond-princess-coronavirus-aerosol.html

 

Very interesting reading indeed however I have a minor quibble.  The article states that "But good ventilation is not enough; the Diamond Princess was well ventilated and the air did not recirculate, the researchers noted." (emphasis added).

 

That is not true.   The air in the cabins is indeed recirculated but only within the individual cabins but more important, the air in the common areas, hallways, atrium, clubs, restaurants, theater, etc. is indeed recirculated with a mixture of fresh AND recycled air.  So if COVID particles stay in the air for a while like the study suggests, common areas were a likely factor in transmission prior to the cabin quarantine and a likely factor among the crew afterwards.

Edited July 30, 2020 by bluesea321

[Thrak]

2 hours ago, ElkGroveCruiser said:

Too bad it's behind a subscription firewall.

 

I didn't have to log in at all. Weird.

[ontheweb]

https://www.nytimes.com/2020/07/30/health/diamond-princess-coronavirus-aerosol.html

 

Although NY Times articles are usually behind a firewall, their Covid 19 articles are not.

[clo]

Just now, ontheweb said:

https://www.nytimes.com/2020/07/30/health/diamond-princess-coronavirus-aerosol.html

 

Although NY Times articles are usually behind a firewall, their Covid 19 articles are not.

That's good to know. I used to subscribe but switched to WaPo after the election.

[ontheweb]

12 minutes ago, clo said:

That's good to know. I used to subscribe but switched to WaPo after the election.

I believe most new sources who have a pay firewall are making an exception for Covid 19 articles. And that includes the Washington Post.

[lenquixote66]

28 minutes ago, clo said:

That's good to know. I used to subscribe but switched to WaPo after the election.

I have not read a US newspaper on a regular basis since 1970.

[bluesea321]

Ironically there is a second article on the NYT today regarding aerosol transmission which also talks about the Diamond Princess.  Don't know if this is behind the paywall, I have a subscription.

 

https://www.nytimes.com/2020/07/30/opinion/coronavirus-aerosols.html?action=click&module=Opinion&pgtype=Homepage

[caribill]

12 minutes ago, bluesea321 said:

Ironically there is a second article on the NYT today regarding aerosol transmission which also talks about the Diamond Princess.  Don't know if this is behind the paywall, I have a subscription.

 

https://www.nytimes.com/2020/07/30/opinion/coronavirus-aerosols.html?action=click&module=Opinion&pgtype=Homepage

 

On a recent dentist visit, they did not use a cavitron as it would put small particles into the air that could stay there for an extended period of time.

[pcur]

2 hours ago, ontheweb said:

https://www.nytimes.com/2020/07/30/health/diamond-princess-coronavirus-aerosol.html

 

Although NY Times articles are usually behind a firewall, their Covid 19 articles are not.

 

The issue I had was the article required me to be logged into either Google, or Apple, or Facebook, not necessarily be a NYT subscriber.  I don't like to be logged into Google or FB all the time, because they track your activity and I consider that to be invasive.  I have to be logged into Apple to use my iphone.

[chengkp75]

On 7/30/2020 at 4:28 PM, bluesea321 said:

 

Very interesting reading indeed however I have a minor quibble.  The article states that "But good ventilation is not enough; the Diamond Princess was well ventilated and the air did not recirculate, the researchers noted." (emphasis added).

 

That is not true.   The air in the cabins is indeed recirculated but only within the individual cabins but more important, the air in the common areas, hallways, atrium, clubs, restaurants, theater, etc. is indeed recirculated with a mixture of fresh AND recycled air.  So if COVID particles stay in the air for a while like the study suggests, common areas were a likely factor in transmission prior to the cabin quarantine and a likely factor among the crew afterwards.

Yes, the common areas were a source of contamination, but not as I believe you are thinking about it.  The air that is recirculated would not carry the virus all the way through the HVAC ducting, and return it to the space in a viable form.  The problem with recirculated air is that only about 20% per minute is exchanged (20% is extracted to the outside, and 20% is added as fresh air).  With less or no recirculation, the amount of air that is extracted is higher, so more air already containing aerosolized virus is removed from the space.  The optimum would be 100% fresh air, but this leads to much higher cooling costs, and even with 100% fresh air, it is the airflow pattern in the space (from the cooled air supply vents to the exhaust vents) that will cause the aerosolized virus to spread further.  I am not sure, but I believe that once the ship was in quarantine, that the common space ventilation was changed over to as much fresh air, and as little recirculation air, as possible.

[npcl]

1 hour ago, chengkp75 said:

Yes, the common areas were a source of contamination, but not as I believe you are thinking about it.  The air that is recirculated would not carry the virus all the way through the HVAC ducting, and return it to the space in a viable form.  The problem with recirculated air is that only about 20% per minute is exchanged (20% is extracted to the outside, and 20% is added as fresh air).  With less or no recirculation, the amount of air that is extracted is higher, so more air already containing aerosolized virus is removed from the space.  The optimum would be 100% fresh air, but this leads to much higher cooling costs, and even with 100% fresh air, it is the airflow pattern in the space (from the cooled air supply vents to the exhaust vents) that will cause the aerosolized virus to spread further.  I am not sure, but I believe that once the ship was in quarantine, that the common space ventilation was changed over to as much fresh air, and as little recirculation air, as possible.

AS I read the article and other reports on the Diamond, even with 100% fresh air the problem would have still existed because it take time to do full exchange so some air is removed and some injected.  Depending upon the concentration of the virus is different areas of the room the rate at which fresh air is injected would impact the rate at which the concentration density is lowered and its rate of movement around the room.  That is the problem with any indoor space.  Virus remains more concentrated and takes longer to drop below infection levels.

 

 

Edited July 31, 2020 by npcl

[Hlitner]

I read the study and it seems to be more "educated speculation" then real science.   The study needs to be peer reviewed and findings should ultimately be proven or disproven by real scientific verification.  Unless I have missed something, it is more of the same.  Ever since the Diamond Princess mess it has been theorized that COVID was "aerosolized" which was a major cause of the spread.  However, I have not found any study that proves that aerosolization was the primary (or even secondary) reason for the spread of COVID.   One can be sure that there will be additional studies that attempt to prove whether (or not) COVID can actually spread via aerosolization.

 

By the way, we did something in that study which was very interesting and confirms what has been posted here on CC by ChungKP...who is a marine chief engineer.  The study confirmed that the HVAC system on the Diamond does not "recirculate" air.  As a long time cruiser I find this quite interesting (and almost unbelievable) since recirculating air (some or all) is more efficient.  Just think about your car which likely has a "recirculate mode on its A/C and is often the default setting with automatic systems.   ChungKP has long told us that there is no sharing of air between cabins on the Diamond or other modern cruise ships.

 

My own reaction to the study is that, if valid. would lead to a finding that the safest place to avoid COVID is outdoors where the normal air currents would naturally disperse the virus and UV would aid in its destruction.  On the other hand, the most dangerous place would be indoors which is just where most of the politicians told us we should stay!  It may well turn out that sitting on a beach (where there is always air flow) is one of the safest of all activities and yet authorities in many places insisted on closing beaches!  Go figure.

 

Hank

[npcl]

2 hours ago, Hlitner said:

I read the study and it seems to be more "educated speculation" then real science.   The study needs to be peer reviewed and findings should ultimately be proven or disproven by real scientific verification.  Unless I have missed something, it is more of the same.  Ever since the Diamond Princess mess it has been theorized that COVID was "aerosolized" which was a major cause of the spread.  However, I have not found any study that proves that aerosolization was the primary (or even secondary) reason for the spread of COVID.   One can be sure that there will be additional studies that attempt to prove whether (or not) COVID can actually spread via aerosolization.

 

By the way, we did something in that study which was very interesting and confirms what has been posted here on CC by ChungKP...who is a marine chief engineer.  The study confirmed that the HVAC system on the Diamond does not "recirculate" air.  As a long time cruiser I find this quite interesting (and almost unbelievable) since recirculating air (some or all) is more efficient.  Just think about your car which likely has a "recirculate mode on its A/C and is often the default setting with automatic systems.   ChungKP has long told us that there is no sharing of air between cabins on the Diamond or other modern cruise ships.

 

My own reaction to the study is that, if valid. would lead to a finding that the safest place to avoid COVID is outdoors where the normal air currents would naturally disperse the virus and UV would aid in its destruction.  On the other hand, the most dangerous place would be indoors which is just where most of the politicians told us we should stay!  It may well turn out that sitting on a beach (where there is always air flow) is one of the safest of all activities and yet authorities in many places insisted on closing beaches!  Go figure.

 

Hank

people socially distant in their own home, not in contact with others, is pretty safe.

 

while being outdoors is safer, there are numerous cases of transfer taking place outdoors, due to people not keeping distant. the beaches were closed mostly because large groups filled them, ignoring social distance requirements.

 

indoor areas with different people in relatively close proximity is certainly worst.

[Hlitner]

4 minutes ago, npcl said:

people socially distant in their own home, not in contact with others, is pretty safe.

 

while being outdoors is safer, there are numerous cases of transfer taking place outdoors, due to people not keeping distant. the beaches were closed mostly because large groups filled them, ignoring social distance requirements.

 

indoor areas with different people in relatively close proximity is certainly worst.

There is so much anecdotal speculation without any real backup from contact tracing.  But I did smile when we happened to watch one of Governor Andrew Cuomo's press conferences when he seemed to surprise himself:

https://www.cnbc.com/2020/05/06/ny-gov-cuomo-says-its-shocking-most-new-coronavirus-hospitalizations-are-people-staying-home.html

 

Hank

[npcl]

4 hours ago, Hlitner said:

There is so much anecdotal speculation without any real backup from contact tracing.  But I did smile when we happened to watch one of Governor Andrew Cuomo's press conferences when he seemed to surprise himself:

https://www.cnbc.com/2020/05/06/ny-gov-cuomo-says-its-shocking-most-new-coronavirus-hospitalizations-are-people-staying-home.html

 

Hank

I am a volunteer doing contact tracing in the county where I live.  Far more than anecdotal speculation.

 

You might try it.  It provides value and it makes a number of things pretty clear.

[Hlitner]

21 minutes ago, npcl said:

I am a volunteer doing contact tracing in the county where I live.  Far more than anecdotal speculation.

 

You might try it.  It provides value and it makes a number of things pretty clear.

Bless you for volunteering for that work.  Having spent over 35 years in the government healthcare industry and also having previously worked as a Paramedic (one of the first in our part of the country) I now leave the work to others :).  Contact tracing is really an important job (often minimized in the press) and provides invaluable information that feeds into future policy.   In our State I believe that contact tracing is being run by the PA Dept of Health who has been hiring paid folks ($17 - $20 per hour) for that job.  Follow up investigation will apparently be done by Community Health Nurses.

 

Personally I would like to see more public disclosure of the contact tracing results.  For example, in New York Governor Cuomo's revelation that about 2/3 of their hospitalized cases came from folks who had been sheltering at home was a very interesting announcement (which did not get a lot of play in the national press since it likely does not fit the usual press agenda).   I would like to know just how much risk we take if we simply go to a restaurant that is following all the prescribed procedures.  Giving the public more real information (as opposed to speculation) on risk-benefit would be helpful to many folks.

 

Hank

[npcl]

1 hour ago, Hlitner said:

Bless you for volunteering for that work.  Having spent over 35 years in the government healthcare industry and also having previously worked as a Paramedic (one of the first in our part of the country) I now leave the work to others :).  Contact tracing is really an important job (often minimized in the press) and provides invaluable information that feeds into future policy.   In our State I believe that contact tracing is being run by the PA Dept of Health who has been hiring paid folks ($17 - $20 per hour) for that job.  Follow up investigation will apparently be done by Community Health Nurses.

 

Personally I would like to see more public disclosure of the contact tracing results.  For example, in New York Governor Cuomo's revelation that about 2/3 of their hospitalized cases came from folks who had been sheltering at home was a very interesting announcement (which did not get a lot of play in the national press since it likely does not fit the usual press agenda).   I would like to know just how much risk we take if we simply go to a restaurant that is following all the prescribed procedures.  Giving the public more real information (as opposed to speculation) on risk-benefit would be helpful to many folks.

 

Hank

Unfortunately the privacy laws are very strict.  You cannot even tell someone you are contacting who the infected point of contact was.

 

I got involved because of my FDA and pharmaceutical background.

 

I can say that here sheltering in place worked.  Like with most things it can often come down to definitions to what one means by sheltering in place.  Our definition of sheltering in places is where the entire household is sheltering and no external contact.  Limited movement from home only for essentials (food, doctors appointments, etc.). 

 

To many people it means not going to work, but where family members might still visit or one member of the household might still work.  We have seen cases where one family member has gotten infected outside and then brought it home to other  family members sheltering in place.

 

The biggest problem we have is recreational travel. Family members of friends traveling from areas with higher infection rates to visit friends or family often in a non-social distanced setting.  Very bad during graduation times in June.

 

Personally I would like to see a system where a lot more information is made public, including summary data on the categories of transfers (airplane, social gathering, recreational travel, work, unknown source).  It would provide good information to the public on what is or is not working, but would also show when contact tracing is getting overwhelmed.

 

I live in an area that has had it pretty easy so far, but our cases are growing faster.  Here in Southern Oregon we are seeing a lot of people from higher infection rate areas such as California, Arizona and Washington decide that since they cannot travel any other way they are going to do a car or RV trip to Oregon. Unfortunately they seem to be bringing more infection with them, and in many ways deciding that since Oregon is a lower case count area they can drop their guard and neglect to properly social distance.  Was over at Crater Lake NP and the number of people standing shoulder to shoulder, many without masks, most from other states, was a bit disconcerting.

Edited August 1, 2020 by npcl