[WBB fan]

I started this thread because I have questions that don't fit elsewhere. There are what may seem minor matters, but then again, maybe not -- just how to conduct and protect myself and others, not answered in all the info that's I'm seeing. So, for starters . . . 

1) I blow my nose (I have allergies) using a tissue. Should that used tissue go in 1) landfill, 2) recycle, 3) Compost. My husband was putting it in compost. I'm thinking landfill. But I suspect none of them are good. Burning would probably be best, but that's not an option

2) I go to the grocery store -- use my own bags. Some are cloth, some are plastic coated. Does it matter which ones I use? And if so, does the virus potentially attach to the plastic coated ones? If so, should I sanitize them on getting home?

     And along these line, if I get the plastic bag option at the grocery store, are those bags a place for the virus to rest and come home with me?

3) I go to the grocery store, get produce, put it in a plastic produce bag. Are those bags safe at home, or should I at once throw them away? (I generally save and re-use them)

4) At the grocery store, I bought veggies in a plastic container. Should I clean that plastic container when I get it home.

And so on. I suspect that many of us have similar questions -- seemingly minor, but maybe important in fact.

[WBB fan]

I started this thread because I have questions that don't fit elsewhere. There are what may seem minor matters, but then again, maybe not -- just how to conduct and protect myself and others, not answered in all the info that's I'm seeing. So, for starters . . . 

1) I blow my nose (I have allergies) using a tissue. Should that used tissue go in 1) landfill, 2) recycle, 3) Compost. My husband was putting it in compost. I'm thinking landfill. But I suspect none of them are good. Burning would probably be best, but that's not an option

2) I go to the grocery store -- use my own bags. Some are cloth, some are plastic coated. Does it matter which ones I use? And if so, does the virus potentially attach to the plastic coated ones? If so, should I sanitize them on getting home?

     And along these line, if I get the plastic bag option at the grocery store, are those bags a place for the virus to rest and come home with me?

3) I go to the grocery store, get produce, put it in a plastic produce bag. Are those bags safe at home, or should I at once throw them away? (I generally save and re-use them)

4) At the grocery store, I bought veggies in a plastic container. Should I clean that plastic container when I get it home.

And so on. I suspect that many of us have similar questions -- seemingly minor, but maybe important in fact.

[magnus]

I started this thread because I have questions that don't fit elsewhere. There are what may seem minor matters, but then again, maybe not -- just how to conduct and protect myself and others, not answered in all the info that's I'm seeing. So, for starters . . . 

1) I blow my nose (I have allergies) using a tissue. Should that used tissue go in 1) landfill, 2) recycle, 3) Compost. My husband was putting it in compost. I'm thinking landfill. But I suspect none of them are good. Burning would probably be best, but that's not an option

2) I go to the grocery store -- use my own bags. Some are cloth, some are plastic coated. Does it matter which ones I use? And if so, does the virus potentially attach to the plastic coated ones? If so, should I sanitize them on getting home?

     And along these line, if I get the plastic bag option at the grocery store, are those bags a place for the virus to rest and come home with me?

3) I go to the grocery store, get produce, put it in a plastic produce bag. Are those bags safe at home, or should I at once throw them away? (I generally save and re-use them)

4) At the grocery store, I bought veggies in a plastic container. Should I clean that plastic container when I get it home.

And so on. I suspect that many of us have similar questions -- seemingly minor, but maybe important in fact.

Not claiming to be an expert.  Have read a bit, but don't quote me. =)
1) is this question for environment or spread concern?  My wife thinks the specially treated tissues should be put in the garbage and not compost figuring there are chemicals in there that aren't compost friendly.  As for spread...i don't think it matters. the virus should die soon enough right?

2) regarding plastic bags to take home...CDC and others are saying that the virus can stay in the air for a while.  So I'd imagine it's _possible_ that someone coughed nearby and had the virus settle onto the plastic bags.

3) If you leave them alone for a few days, would the virus then be neutralized?

4) again, it's _possible_ there's virus on there.

I think many of these questions depend on your tolerance to risk.

The more concerned are leaving their mail/packages untouched for days to let the virus deactivate.  And they wash _everything_ they bring into the house from the grocery store. Shoes left outside.  Cell phones, wallets, and keys thrown into a basket and sprayed down upon return home.  And other things with a careful eye towards any potential entry points for the virus.

[magnus]

I started this thread because I have questions that don't fit elsewhere. There are what may seem minor matters, but then again, maybe not -- just how to conduct and protect myself and others, not answered in all the info that's I'm seeing. So, for starters . . . 

1) I blow my nose (I have allergies) using a tissue. Should that used tissue go in 1) landfill, 2) recycle, 3) Compost. My husband was putting it in compost. I'm thinking landfill. But I suspect none of them are good. Burning would probably be best, but that's not an option

2) I go to the grocery store -- use my own bags. Some are cloth, some are plastic coated. Does it matter which ones I use? And if so, does the virus potentially attach to the plastic coated ones? If so, should I sanitize them on getting home?

     And along these line, if I get the plastic bag option at the grocery store, are those bags a place for the virus to rest and come home with me?

3) I go to the grocery store, get produce, put it in a plastic produce bag. Are those bags safe at home, or should I at once throw them away? (I generally save and re-use them)

4) At the grocery store, I bought veggies in a plastic container. Should I clean that plastic container when I get it home.

And so on. I suspect that many of us have similar questions -- seemingly minor, but maybe important in fact.

Not claiming to be an expert.  Have read a bit, but don't quote me. =)
1) is this question for environment or spread concern?  My wife thinks the specially treated tissues should be put in the garbage and not compost figuring there are chemicals in there that aren't compost friendly.  As for spread...i don't think it matters. the virus should die soon enough right?

2) regarding plastic bags to take home...CDC and others are saying that the virus can stay in the air for a while.  So I'd imagine it's _possible_ that someone coughed nearby and had the virus settle onto the plastic bags.

3) If you leave them alone for a few days, would the virus then be neutralized?

4) again, it's _possible_ there's virus on there.

I think many of these questions depend on your tolerance to risk.

The more concerned are leaving their mail/packages untouched for days to let the virus deactivate.  And they wash _everything_ they bring into the house from the grocery store. Shoes left outside.  Cell phones, wallets, and keys thrown into a basket and sprayed down upon return home.  And other things with a careful eye towards any potential entry points for the virus.

[2006alum]

I have been operating on the assumption anything that comes into contact with the outside world could have the virus on it when it comes into my house. For that reason, I have done the following:

I shop with my own plastic coated bags. I put everything in 1-2 while I shop, then when self-checkout is available, transfer immediately into 1-2 more on the other side. Nothing touches the checkout. And I wear gloves the entire time. For produce, I bag what is necessary in plastic.

I load grocery bags into the floor of the car. Take off the gloves inside out and stash in a small plastic bag in the car (to dispose of when I get home). 

Once home, new set of gloves, bags out of the car. In the entryway, place a towel on the entryway table, use Lysol wipes to sanitize every item I plan to use in the next week. Place those items on the towel to dry. Anything that I won't be using in the next week stays in one bag in the trunk of the car. (The virus degrades on plastic and paper within a week.) Still wearing the gloves, Lysol wipe the plastic coated bags all over - sides, handles, insides, inside bottom and outside bottom. leave those in the entryway to dry. 

Once everything's dried, stash the groceries and fold the bags to be stored in our standard pile of grocery bags. 

For produce, specifically, when I bring them into the house I empty them into a very large fruit bowl and toss the produce bags. Then I use wash on all the produce and let it soak for a few minutes in water and produce wash. Then let it dry, etc. 

(FWIW, I have not been eating fresh produce just in case, but I think those procedures should do the trick in the event you do.)

Oh, and I always restock on the tin foil for my tin foil hats. ;)

Hope this helps. I am sure I am on the extreme end, but then again, my extreme end two weeks ago is now the legally mandated minimum for all of the Bay Area, so YMMV...

[2006alum]

I have been operating on the assumption anything that comes into contact with the outside world could have the virus on it when it comes into my house. For that reason, I have done the following:

I shop with my own plastic coated bags. I put everything in 1-2 while I shop, then when self-checkout is available, transfer immediately into 1-2 more on the other side. Nothing touches the checkout. And I wear gloves the entire time. For produce, I bag what is necessary in plastic.

I load grocery bags into the floor of the car. Take off the gloves inside out and stash in a small plastic bag in the car (to dispose of when I get home). 

Once home, new set of gloves, bags out of the car. In the entryway, place a towel on the entryway table, use Lysol wipes to sanitize every item I plan to use in the next week. Place those items on the towel to dry. Anything that I won't be using in the next week stays in one bag in the trunk of the car. (The virus degrades on plastic and paper within a week.) Still wearing the gloves, Lysol wipe the plastic coated bags all over - sides, handles, insides, inside bottom and outside bottom. leave those in the entryway to dry. 

Once everything's dried, stash the groceries and fold the bags to be stored in our standard pile of grocery bags. 

For produce, specifically, when I bring them into the house I empty them into a very large fruit bowl and toss the produce bags. Then I use wash on all the produce and let it soak for a few minutes in water and produce wash. Then let it dry, etc. 

(FWIW, I have not been eating fresh produce just in case, but I think those procedures should do the trick in the event you do.)

Oh, and I always restock on the tin foil for my tin foil hats. ;)

Hope this helps. I am sure I am on the extreme end, but then again, my extreme end two weeks ago is now the legally mandated minimum for all of the Bay Area, so YMMV...

[BostonCard]

A new paper was just published in the New England Journal of Medicine:

https://www.nejm.org/doi/full/10.1056/NE...3?query=RP

Bottom line:

Our results indicate that aerosol and fomite (surface) transmission of SARS-CoV-2 is plausible, since the virus can remain viable and infectious in aerosols for hours and on surfaces up to days (depending on the inoculum shed). These findings echo those with SARS-CoV-1, in which these forms of transmission were associated with nosocomial (ED: spread within hospitals) spread and super-spreading events,5 and they provide information for pandemic mitigation efforts.

With regards to which material to use, the shortest half-life was for copper

SARS-CoV-2 was more stable on plastic and stainless steel than on copper and cardboard, and viable virus was detected up to 72 hours after application to these surfaces (Figure 1A), although the virus titer was greatly reduced (from 103.7 to 100.6 TCID50 per milliliter of medium after 72 hours on plastic and from 103.7 to 100.6 TCID50 per milliliter after 48 hours on stainless steel). ... On copper, no viable SARS-CoV-2 was measured after 4 hours and no viable SARS-CoV-1 was measured after 8 hours. On cardboard, no viable SARS-CoV-2 was measured after 24 hours and no viable SARS-CoV-1 was measured after 8 hours (Figure 1A).

BC

[BostonCard]

A new paper was just published in the New England Journal of Medicine:

https://www.nejm.org/doi/full/10.1056/NE...3?query=RP

Bottom line:

Our results indicate that aerosol and fomite (surface) transmission of SARS-CoV-2 is plausible, since the virus can remain viable and infectious in aerosols for hours and on surfaces up to days (depending on the inoculum shed). These findings echo those with SARS-CoV-1, in which these forms of transmission were associated with nosocomial (ED: spread within hospitals) spread and super-spreading events,5 and they provide information for pandemic mitigation efforts.

With regards to which material to use, the shortest half-life was for copper

SARS-CoV-2 was more stable on plastic and stainless steel than on copper and cardboard, and viable virus was detected up to 72 hours after application to these surfaces (Figure 1A), although the virus titer was greatly reduced (from 103.7 to 100.6 TCID50 per milliliter of medium after 72 hours on plastic and from 103.7 to 100.6 TCID50 per milliliter after 48 hours on stainless steel). ... On copper, no viable SARS-CoV-2 was measured after 4 hours and no viable SARS-CoV-1 was measured after 8 hours. On cardboard, no viable SARS-CoV-2 was measured after 24 hours and no viable SARS-CoV-1 was measured after 8 hours (Figure 1A).

BC

[cardcrimson]

Don't think that's right. The virus has been here for well over two weeks and is showing no signs of slowing down.

On cardboard, no viable SARS-CoV-2 was measured after 24 hours and no viable SARS-CoV-1 was measured after 8 hours (Figure 1A).

BC
[/quote]

[cardcrimson]

Don't think that's right. The virus has been here for well over two weeks and is showing no signs of slowing down.

On cardboard, no viable SARS-CoV-2 was measured after 24 hours and no viable SARS-CoV-1 was measured after 8 hours (Figure 1A).

BC
[/quote]

[magnus]

Not saying 2006alum's method is wrong,  but the difficulty with 2006's methods is that you run out of supplies fast.  Supplies that are hard to come by at the moment and maybe for the foreseeable future.

[magnus]

Not saying 2006alum's method is wrong,  but the difficulty with 2006's methods is that you run out of supplies fast.  Supplies that are hard to come by at the moment and maybe for the foreseeable future.

[BostonCard]

Don't think that's right. The virus has been here for well over two weeks and is showing no signs of slowing down.

On cardboard, no viable SARS-CoV-2 was measured after 24 hours and no viable SARS-CoV-1 was measured after 8 hours (Figure 1A).

BC

[/quote]

Touché.

Incidentally, I find my cats very soothing in these stressful times.

BC

[BostonCard]

Don't think that's right. The virus has been here for well over two weeks and is showing no signs of slowing down.

On cardboard, no viable SARS-CoV-2 was measured after 24 hours and no viable SARS-CoV-1 was measured after 8 hours (Figure 1A).

BC

[/quote]

Touché.

Incidentally, I find my cats very soothing in these stressful times.

BC

[2006alum]

Not saying 2006alum's method is wrong,  but the difficulty with 2006's methods is that you run out of supplies fast.  Supplies that are hard to come by at the moment and maybe for the foreseeable future.

FWIW, I find the whole operation takes 4 gloves and about 6-8 lysol wipes for two full bags of groceries, so because I bought a lot of both several weeks ago, this procedure would last me several months assuming I am grocery shopping 1-2 times a week. And it's also why I separate what I'm going to use right away from what I don't plan to use until the virus will die off first. Any non-perishable dry goods, cleaning supplies, etc., can all be segregated out of breathing and touching range for longer term use.

[2006alum]

Not saying 2006alum's method is wrong,  but the difficulty with 2006's methods is that you run out of supplies fast.  Supplies that are hard to come by at the moment and maybe for the foreseeable future.

FWIW, I find the whole operation takes 4 gloves and about 6-8 lysol wipes for two full bags of groceries, so because I bought a lot of both several weeks ago, this procedure would last me several months assuming I am grocery shopping 1-2 times a week. And it's also why I separate what I'm going to use right away from what I don't plan to use until the virus will die off first. Any non-perishable dry goods, cleaning supplies, etc., can all be segregated out of breathing and touching range for longer term use.

[Snorlax94]

My follow-up question is: will we get information on how the transmissions are occurring? Even with privacy issues, could people who are sick volunteer information about what they've been doing?

For example, if someone like me got sick, pretty much all I do is work from home, stay at home and occasionally get groceries/supplies from Target and Costco. If a lot of people like me got sick, that could indicate stores like that are a major source of transmission and we could focusing on delivery, shorter lines, sanitizing shops, etc.

In France, reportedly, a surprising share of those hospitalized are younger, but it was also reported that until Friday, people were still going out and cafes and bars were still crowded, so there, the lockdown on social activities sounds especially helpful.

My guess is that the odds of transmission from a shopping or packaging are low. Many of the bags like vegetable bags are packed tightly so they aren't exposed until you grab one. I try to reduce my # of trips, I try to get in and out as quickly as possible (and go at less crowded times),  after unpacking I toss the reusable bag in a closet and try not to re-use it for a week, and now when I shop I plan to use my limited supply of masks (from the wildfires, not purchased recently) and gloves. My guess is that shopping (and packaging) would be relatively low-risk, the worst part being standing in line to get in or get out, but how can we know without any data being made public?

[Snorlax94]

My follow-up question is: will we get information on how the transmissions are occurring? Even with privacy issues, could people who are sick volunteer information about what they've been doing?

For example, if someone like me got sick, pretty much all I do is work from home, stay at home and occasionally get groceries/supplies from Target and Costco. If a lot of people like me got sick, that could indicate stores like that are a major source of transmission and we could focusing on delivery, shorter lines, sanitizing shops, etc.

In France, reportedly, a surprising share of those hospitalized are younger, but it was also reported that until Friday, people were still going out and cafes and bars were still crowded, so there, the lockdown on social activities sounds especially helpful.

My guess is that the odds of transmission from a shopping or packaging are low. Many of the bags like vegetable bags are packed tightly so they aren't exposed until you grab one. I try to reduce my # of trips, I try to get in and out as quickly as possible (and go at less crowded times),  after unpacking I toss the reusable bag in a closet and try not to re-use it for a week, and now when I shop I plan to use my limited supply of masks (from the wildfires, not purchased recently) and gloves. My guess is that shopping (and packaging) would be relatively low-risk, the worst part being standing in line to get in or get out, but how can we know without any data being made public?

[stupac2]

I would put tissues (and all other paper products) into the compost. For instance Oakland's website specifically mentions paper products, and I believe most municipal composting could handle it.

If you're doing a worm bin or whatever then you'd want to look into that, but tissue break down easily, I would think they could handle it. Any chemicals on there will be organic (in the chemistry sense) and I have to think would be fine.

[stupac2]

I would put tissues (and all other paper products) into the compost. For instance Oakland's website specifically mentions paper products, and I believe most municipal composting could handle it.

If you're doing a worm bin or whatever then you'd want to look into that, but tissue break down easily, I would think they could handle it. Any chemicals on there will be organic (in the chemistry sense) and I have to think would be fine.

[BostonCard]

One thing to keep in mind is that the probability of infection is related to the number of viable viral particles that are transmitted to an infectable surface (I assume a mucous membrane) and how direct the transmission is.  A seriously ill patient who coughs directly on a healthcare provider is different than someone who is minimally symptomatic and touched a can that you then bring home.  That's not to discourage anyone from taking whatever risk mitigation measures they think are necessary.  But it is worth noting that the estimated R0 for the virus is somewhere in the 2 to 3, so the average person with the disease is "only" infecting 2 or 3 others, which means that most likely these infections are not occurring through fomites in a grocery store but rather with direct contact.  That being said, there will be some superspreaders, such as the guy who infected 70+ at a Biogen meeting in Boston.

BC

---

Apropos my last post...

https://www.wsj.com/articles/what-are-th...1584462015

Experts say the main risk from ordering food and groceries is that you could catch the virus from an infected delivery person, if he sneezes or coughs on you. That’s because the virus spreads mostly by person-to-person contact.

It is less likely, although still possible, to get the virus from touching contaminated packaging. There may also be a small risk from touching raw food that has the virus on it and then touching your face. But there appears to be no risk of contracting the virus by eating it in cooked food, experts say.'

BC

[BostonCard]

One thing to keep in mind is that the probability of infection is related to the number of viable viral particles that are transmitted to an infectable surface (I assume a mucous membrane) and how direct the transmission is.  A seriously ill patient who coughs directly on a healthcare provider is different than someone who is minimally symptomatic and touched a can that you then bring home.  That's not to discourage anyone from taking whatever risk mitigation measures they think are necessary.  But it is worth noting that the estimated R0 for the virus is somewhere in the 2 to 3, so the average person with the disease is "only" infecting 2 or 3 others, which means that most likely these infections are not occurring through fomites in a grocery store but rather with direct contact.  That being said, there will be some superspreaders, such as the guy who infected 70+ at a Biogen meeting in Boston.

BC

---

Apropos my last post...

https://www.wsj.com/articles/what-are-th...1584462015

Experts say the main risk from ordering food and groceries is that you could catch the virus from an infected delivery person, if he sneezes or coughs on you. That’s because the virus spreads mostly by person-to-person contact.

It is less likely, although still possible, to get the virus from touching contaminated packaging. There may also be a small risk from touching raw food that has the virus on it and then touching your face. But there appears to be no risk of contracting the virus by eating it in cooked food, experts say.'

BC

[ChicagoCard]

One thing to keep in mind is that the probability of infection is related to the number of viable viral particles that are transmitted to an infectable surface (I assume a mucous membrane) and how direct the transmission is.  A seriously ill patient who coughs directly on a healthcare provider is different than someone who is minimally symptomatic and touched a can that you then bring home.  That's not to discourage anyone from taking whatever risk mitigation measures they think are necessary.  But it is worth noting that the estimated R0 for the virus is somewhere in the 2 to 3, so the average person with the disease is "only" infecting 2 or 3 others, which means that most likely these infections are not occurring through fomites in a grocery store but rather with direct contact.  That being said, there will be some superspreaders, such as the guy who infected 70+ at a Biogen meeting in Boston.
BC

I'm glad you posted this, very interesting. Thanks.

[ChicagoCard]

One thing to keep in mind is that the probability of infection is related to the number of viable viral particles that are transmitted to an infectable surface (I assume a mucous membrane) and how direct the transmission is.  A seriously ill patient who coughs directly on a healthcare provider is different than someone who is minimally symptomatic and touched a can that you then bring home.  That's not to discourage anyone from taking whatever risk mitigation measures they think are necessary.  But it is worth noting that the estimated R0 for the virus is somewhere in the 2 to 3, so the average person with the disease is "only" infecting 2 or 3 others, which means that most likely these infections are not occurring through fomites in a grocery store but rather with direct contact.  That being said, there will be some superspreaders, such as the guy who infected 70+ at a Biogen meeting in Boston.
BC

I'm glad you posted this, very interesting. Thanks.

[M T]

One thing to keep in mind is that the probability of infection is related to the number of viable viral particles that are transmitted to an infectable surface (I assume a mucous membrane) and how direct the transmission is.

A number of misunderstandings there, based on the medical articles I'm reading. 

Main mode of transmission is by inhaling droplets from the infected person's breathing.   Coughing/Sneezing is not needed (as aKidDoc said earlier).
In 2003's SARS-COV-1 days, at least one study in healthcare situations indicated failure to wear a mask resulted in more illnesses than failure to wear gloves.

There is no need for a very sick person to do the breathing.  The seemingly healthy guy at your door dropping off groceries can give you a dose.  The virus shedding is maximal early in the disease.   The evidence has been that a person is infections between 2 to 3 days before the first symptom.

There are cases where person A infects person B, and person B gets the symptoms well before person A.
The serial interval (time that B shows symptoms relative to A) is in the 4-5 day range, which is shorter than the incubation period.

---- details

In this Mar 13 preprint on serial interval (time between a series of infections),

Notably, 59 of the 468 reports indicate that the infectee developed symptoms earlier than the infector. Thus, pre-symptomatic transmission may be occurring, i.e., infected persons may be infectious before their symptoms appear.

the serial interval was as low as -11 days to as high as 20 days, with a mean of 4 days and a standard deviation of 4.75 days.

Wow!  I had seen indications of very short serial intervals (the Mar. 6 report that lead this particular thread had serial interval as low as 2+ days (ie, 2 days after infection of person A, person A infected person B))   Apparently, the variability in onset of symptoms (incubation) is large enough to allow B's symptoms to show up before A's symptoms.  


By the way, links to a number of papers can be found here.

China's 1099 patient study, the 291 for which documented exposure existed, had a mean incubation 4 days, with 25 percentile at 2 days or less, 75 percentile at 7 days.  At hospital admission (all positive tests in China were admitted), only 43% had fever, only 67% had a cough.  (How did they detect them so early?  Aggressive tracking & testing of contacts.)    As with ALL these studies (China and other countries), "The uncertainty of the exact dates (recall bias) might have inevitably affected our assessment.'

Compare this to the report about the pre-symptomatic spread.  The incubation period minus the serial interval (interval between successive cases) was 2.5 days and 4.8 days, which, as I understand it, would be about how quickly someone becomes infectious after exposure.

[M T]

One thing to keep in mind is that the probability of infection is related to the number of viable viral particles that are transmitted to an infectable surface (I assume a mucous membrane) and how direct the transmission is.

A number of misunderstandings there, based on the medical articles I'm reading. 

Main mode of transmission is by inhaling droplets from the infected person's breathing.   Coughing/Sneezing is not needed (as aKidDoc said earlier).
In 2003's SARS-COV-1 days, at least one study in healthcare situations indicated failure to wear a mask resulted in more illnesses than failure to wear gloves.

There is no need for a very sick person to do the breathing.  The seemingly healthy guy at your door dropping off groceries can give you a dose.  The virus shedding is maximal early in the disease.   The evidence has been that a person is infections between 2 to 3 days before the first symptom.

There are cases where person A infects person B, and person B gets the symptoms well before person A.
The serial interval (time that B shows symptoms relative to A) is in the 4-5 day range, which is shorter than the incubation period.

---- details

In this Mar 13 preprint on serial interval (time between a series of infections),

Notably, 59 of the 468 reports indicate that the infectee developed symptoms earlier than the infector. Thus, pre-symptomatic transmission may be occurring, i.e., infected persons may be infectious before their symptoms appear.

the serial interval was as low as -11 days to as high as 20 days, with a mean of 4 days and a standard deviation of 4.75 days.

Wow!  I had seen indications of very short serial intervals (the Mar. 6 report that lead this particular thread had serial interval as low as 2+ days (ie, 2 days after infection of person A, person A infected person B))   Apparently, the variability in onset of symptoms (incubation) is large enough to allow B's symptoms to show up before A's symptoms.  


By the way, links to a number of papers can be found here.

China's 1099 patient study, the 291 for which documented exposure existed, had a mean incubation 4 days, with 25 percentile at 2 days or less, 75 percentile at 7 days.  At hospital admission (all positive tests in China were admitted), only 43% had fever, only 67% had a cough.  (How did they detect them so early?  Aggressive tracking & testing of contacts.)    As with ALL these studies (China and other countries), "The uncertainty of the exact dates (recall bias) might have inevitably affected our assessment.'

Compare this to the report about the pre-symptomatic spread.  The incubation period minus the serial interval (interval between successive cases) was 2.5 days and 4.8 days, which, as I understand it, would be about how quickly someone becomes infectious after exposure.

[82 Card]

According to the most recent notice from our county recycling program:

As we all use more disinfecting products and wipes, please remember that these items are not recyclable, and should not be flushed down your toilet. All wipes and disinfecting products, including paper towels that have been sprayed with chemicals and “flushable” wipes should go in your black landfill cart (or gray bin).

[corrected] Although I had been putting tissue in green cart, I just found that the January newsletter said to put tissue in the landfill cart as well. Oops.

[82 Card]

According to the most recent notice from our county recycling program:

As we all use more disinfecting products and wipes, please remember that these items are not recyclable, and should not be flushed down your toilet. All wipes and disinfecting products, including paper towels that have been sprayed with chemicals and “flushable” wipes should go in your black landfill cart (or gray bin).

[corrected] Although I had been putting tissue in green cart, I just found that the January newsletter said to put tissue in the landfill cart as well. Oops.

[BostonCard]

From this study in Singapore:

https://jamanetwork.com/journals/jama/fu...le/2762688

In this study, viral load in nasopharyngeal samples from patients with COVID-19 peaked within the first few days after symptom onset before declining.

I think one thing to take into account is that people with symptoms are (hopefully) more likely to self-quarantine and not go to work so they may be more likely to transmit the virus, but I think we will generally find that patients with symptoms shed more virus than patients who are infected but pre-symptomatic.

The way I look at it, the probability of a transmission (between infected and healthy) is proportional to the probability of an interaction between them, the intensity of the interaction between them, and the quantity of virus being shed.  The first two factors are likely to be higher for asymptomatic infected people than patients with symptoms; the third one is likely to be higher for a patient with symptoms than someone who is asymptomatic.

BC

[BostonCard]

From this study in Singapore:

https://jamanetwork.com/journals/jama/fu...le/2762688

In this study, viral load in nasopharyngeal samples from patients with COVID-19 peaked within the first few days after symptom onset before declining.

I think one thing to take into account is that people with symptoms are (hopefully) more likely to self-quarantine and not go to work so they may be more likely to transmit the virus, but I think we will generally find that patients with symptoms shed more virus than patients who are infected but pre-symptomatic.

The way I look at it, the probability of a transmission (between infected and healthy) is proportional to the probability of an interaction between them, the intensity of the interaction between them, and the quantity of virus being shed.  The first two factors are likely to be higher for asymptomatic infected people than patients with symptoms; the third one is likely to be higher for a patient with symptoms than someone who is asymptomatic.

BC

[WBB fan]

According to the most recent notice from our county recycling program:

As we all use more disinfecting products and wipes, please remember that these items are not recyclable, and should not be flushed down your toilet. All wipes and disinfecting products, including paper towels that have been sprayed with chemicals and “flushable” wipes should go in your black landfill cart (or gray bin).

[corrected] Although I had been putting tissue in green cart, I just found that the January newsletter said to put tissue in the landfill cart as well. Oops.

Thanks for this. I think a lot of people are confused on this, and today, we tend to resist putting things in the landfill cart, hoping they belong in compost or recycle. But it's important to get this one right.  Actually, my original question / concern was about putting tissues that might have viral load on them in compost. Hadn't thought about the chemicals -- and that's certainly necessary to take into account.

[WBB fan]

According to the most recent notice from our county recycling program:

As we all use more disinfecting products and wipes, please remember that these items are not recyclable, and should not be flushed down your toilet. All wipes and disinfecting products, including paper towels that have been sprayed with chemicals and “flushable” wipes should go in your black landfill cart (or gray bin).

[corrected] Although I had been putting tissue in green cart, I just found that the January newsletter said to put tissue in the landfill cart as well. Oops.

Thanks for this. I think a lot of people are confused on this, and today, we tend to resist putting things in the landfill cart, hoping they belong in compost or recycle. But it's important to get this one right.  Actually, my original question / concern was about putting tissues that might have viral load on them in compost. Hadn't thought about the chemicals -- and that's certainly necessary to take into account.

[Snorlax94]

That being said, there will be some superspreaders, such as the guy who infected 70+ at a Biogen meeting

Yes, thank you for this.
Do we know how superspreaders super spread? Like did the guy at the Biogen meeting shake everyone’s hand? Did he cough on a buffet? Did he stand close to and breathe on a lot of people? Is there any pattern to the superspreaders? Were they symptomatic?

[Snorlax94]

That being said, there will be some superspreaders, such as the guy who infected 70+ at a Biogen meeting

Yes, thank you for this.
Do we know how superspreaders super spread? Like did the guy at the Biogen meeting shake everyone’s hand? Did he cough on a buffet? Did he stand close to and breathe on a lot of people? Is there any pattern to the superspreaders? Were they symptomatic?

[ChicagoCard]

This may be a dumb comment but having spent a couple years in Europe I appreciated the way in which people kissed each other in the cheeks liberally. Can that cultural practice made Italians even more vulnerable...

[ChicagoCard]

This may be a dumb comment but having spent a couple years in Europe I appreciated the way in which people kissed each other in the cheeks liberally. Can that cultural practice made Italians even more vulnerable...

[Mick]

This may be a dumb comment but having spent a couple years in Europe I appreciated the way in which people kissed each other in the cheeks liberally. Can that cultural practice made Italians even more vulnerable...

I've actually read that same concept in a few articles.  Sounds as if's true, and Italy's contagion and mortality statistics are through the roof.

[Mick]

This may be a dumb comment but having spent a couple years in Europe I appreciated the way in which people kissed each other in the cheeks liberally. Can that cultural practice made Italians even more vulnerable...

I've actually read that same concept in a few articles.  Sounds as if's true, and Italy's contagion and mortality statistics are through the roof.

[magnus]

This may be a dumb comment but having spent a couple years in Europe I appreciated the way in which people kissed each other in the cheeks liberally. Can that cultural practice made Italians even more vulnerable...

I've actually read that same concept in a few articles.  Sounds as if's true, and Italy's contagion and mortality statistics are through the roof.

Don't look look now but I think we're gaining on Italy fast.   Previously we were 10 to 14 days behind.   I think i read late last night that we were now only 4 days behind.   I hope that was just a nightmare.

[magnus]

This may be a dumb comment but having spent a couple years in Europe I appreciated the way in which people kissed each other in the cheeks liberally. Can that cultural practice made Italians even more vulnerable...

I've actually read that same concept in a few articles.  Sounds as if's true, and Italy's contagion and mortality statistics are through the roof.

Don't look look now but I think we're gaining on Italy fast.   Previously we were 10 to 14 days behind.   I think i read late last night that we were now only 4 days behind.   I hope that was just a nightmare.