Answering Your Questions About Virus Transmission

KCBS Radio is answering your questions about all things coronavirus every weekday at 9:20 am

As we continue to navigate these unprecedented times, KCBS Radio is getting the answers to your questions about the coronavirus pandemic. Every morning at 9:20 a.m. Monday-Friday we're doing an "Ask An Expert" segment with a focus on a different aspect of this situation each day.

Today we're focusing on coronavirus trends, the latest data and any worries that you might have with Dr. Peter Chin-Hong, UCSF infectious disease specialist.

I did want to get your take real quickly on this paper out of King's College London, where they looked at about 1,600 patients who were logging their symptoms into a tracker app and have decided there are sort of six clusters of symptoms around COVID-19. Have you had a chance to look at that yet?

I haven't seen the King's College paper although of course, King's College was in the headlines for another reason, which is about antibody levels. But I definitely have a good sense about symptoms and the patients that we're seeing in general.

It sounds like what makes this disease tricky is it seems to be many diseases in one. You get a flu-like with no fever, flu-like with fever, gastrointestinal, severe level one fatigue, severe level two confusion where you literally are having mental issues and an abdominal and respiratory severe level three, and the list of symptoms on that one seems to cover every symptom known to man. And you must have seen all of these, I guess.

Definitely. I think this kind of work could be confusing to the community because it seems like anything you have could be COVID, which leads me to think about two main points. Which is, first of all testing should be free and widely available to anybody, anytime they want. In that case, we wouldn't have the fuss and hemming and hawing and worrying whether or not this might be COVID, maybe that might be COVID and exposing potentially close family members in the household.

And the second point: I would say that of all these different shades of disease symptoms, they're probably some that are still very core, the ones that we thought about at the beginning of the epidemic. Which is, wake up in the morning, check to see if you have a fever and you smell your coffee. If you don't have a fever and you can still smell your coffee, I think you're kind of good to go. And then the rest of it, you can talk to your advice nurse or your primary care physician about it.

And for those who don't drink coffee, maybe make some toast.

Yeah (laughs).

Okay, let's get to the questions and again, is the email inbox. First question: given the increasing evidence on airborne/aerosol transmission, what do you recommend in terms of masks or face coverings, particularly for exercisers such as cyclists, who are traveling quite quickly, may not be able to distance sufficiently from other unmasked exercisers due to narrow bike lanes, et cetera?

Yes, my response to that is that although there has been a lot of hoopla around aerosol transmission it still probably isn't the biggest way that COVID gets around in the community. For the example of the cyclists, you're moving fast, you're outdoors and there's a lot of air turbulence. It will be extremely unlikely to transmit infection that way, unless the cyclist is going around you in circles and then shouting and screaming at you the whole time while doing that.

Let me ask you personally, then, because there's a lot of consternation around this. Should these local mask orders be more specific and exclude the scenario we just talked about: two people out riding bikes quickly on the road?

I think when you give a lot of exceptions to public guidance, it gets confusing to people. But yes, I think if you say a simple message like, "we really want masks," which is what I think we're still trying to do, and then maybe you can have some nuance around it that might be okay. But I'm worried that if I give like 10 exclusions to masks, that people might be a little bit confused as to what they should or shouldn't do.

Is there any reason why, practically speaking, the United States cannot repurpose factories and materials and make N95 masks for every man, woman and child, and then insists that people wear them?

I love the idea of repurposing local factories to do protection for the community. We did that in wartimes, and they've been doing that actually for face shields. For a while we were short of face shields in the healthcare field and we talked about 3D printing, and all that got a lot of attention. But what happened was a very interesting thing. A lot of plastics companies that make water bottles and so on, diverted their production lines to making face shields for health care providers. And that was a remarkable sort of intervention because it was cheap, it was high quality because they were used to doing quality control.

And I just haven't seen the same with face masks. I would love it if that happened. I know there was a lot of talk initially, about 3M making millions for the people but then that sort of died down. And I think ultimately what we need is the national distribution of masks that are free for everyone. Like in Toronto, they give out masks on public transit, in Taiwan every single person gets a face mask for free from the government. So I think that kind of public benefit that's free and widely available will increase people's use of this intervention that's so cheap and so easy in terms of protecting each other.

I have a friend who says she will not return back to cutting hair due to her belief that COVID-19 spreads like glitter. She believes the virus is potentially in everyone's hair, which she is cutting, and is exposing herself, salon floor and everywhere else, creating a concern for cleaning. Is this a valid concern as long as both hair cutter and client are wearing masks? Can she catch COVID-19 from cutting hair and/or touching the skin on the head, back of the neck? Is this virus, like glitter, all over one's hair, skin and clothes? Would it be safer to cut hair outdoors, minimizing the risk?

That's a great question. I would bring that question back to the basics of how we protect ourselves and like I mentioned in the last time we talked, it boils down to the three W's. You Wear a mask, Wash your hands and Watch your distance.

Of course in the hair cutting environment you can't really watch your distance, but wearing the mask is the most important thing and then washing your hands. And then you don't worry about surfaces, because the surface could be bad and full of virus, but if you wash your hands - your hands are like the Muni, that transfers the virus from a surface to your nose or your mouth, where the virus is trying to get to. So if you wash your hands often, it doesn't matter how many services are contaminated.

I come back to that really cool example in Missouri when these two hairstylists had COVID-19 - like full blown COVID, they were actually symptomatic - everyone was wearing a mask and out of 139 people who were exposed to these hairstylist, you know how many of them got COVID?

I do know the answer to this one, and it is stunning. At first it sounded anecdotal, and it made the local news but this has been run down, it's in a peer-reviewed paper and the answer is zero, right?

Zero. It's not just the hairstylist example, there are numerous other examples of environments; when people wear masks, there doesn't seem to be a lot of transmission. So the surface and fomite stuff, it's definitely great to add additional protection. But again, the virus is just trying to jump from somebody's nose and mouth to somebody else's nose and mouth. So if you wear a face covering, it really gives you the most protection. And if you wash your hands, it just adds that protection up a little bit. But the face covering is definitely the most important thing.

Next question. I've heard rumors that hospitals get paid 3-4 times more for COVID-19 deaths than other deaths, thus COVID deaths are inflated. Is this true?

Not that I know of. I actually think it's the opposite. We probably underestimated COVID deaths, and the reason comes back to that first question you asked me. There's a wide range of symptoms that people have, and the more we go along in this pandemic, the more we're understanding that it's quite diverse. And a lot of people die at home - and particularly early on in the surge cities, like in the tri-state area - they didn't know they had COVID and nobody knew they had COVID and those deaths weren't counted.

The second thing is, of course, we had a delay in diagnostic testing in the United States. So a lot of people probably had COVID, because we knew it was circulating in the community before we actually had the test, the diagnosis. We still have a shortage of tests, so I think it's actually the opposite and it probably doesn't have to do as much with payments as it does the lack of diagnostic testing and lack of appreciation of the wide range of symptoms that people may have while having COVID.

How long should we wait for the air to be safe in an average one story home when there have been people - residents or visitors - without masks for a day, or house cleaners who may not have been wearing masks while working. Can we just open lots of windows for a couple of hours? 

It depends on a bunch of different factors. One interesting factor with indoor situations is the amount of air exchanges you have. So in the hospital setting, for example, there's really good air exchanges because the hospitals were made with that in mind. But there's a wide range in the community. So if your particular room is crammed, there's not a lot of ventilation, the air exchanges are not that frequent, then you probably need to wait a little bit longer. Like half a day or a few hours, to be conservative. One day is okay, in terms of going into an Airbnb that somebody else has stayed in before. But if the air exchange is good, if there's good ventilation, you open the windows and again, clean the surfaces (but if you wash your hands, again, you don't have to go crazy) it would be okay.

Would your guest please comment on the presence of enanthem? I think we're talking about cavity lesions in the mouth as an early clue to diagnosis of COVID.

Not a very prominent indication. But again, I'm completely humbled by this disease. So again, as we learn more, we will understand the role of rashes and COVID-19. The biggest signal for rashes are not the enanthems, it's more of the potential exanthems, which are the stuff you see on the outside skin, particularly the rashes around the toes that people talked about. And even with that, they haven't found evidence of COVID in all of these examples of the sort of "COVID toes" that we've been talking about. So I think the answer is it's not a big, prominent sign, probably more prominent with other diseases. So I'd worry about other infections, like hand foot and mouth disease, other kinds of diseases before COVID. But again, I'm completely humbled by COVID every single time. So "open mind" is the axiom that I take with me.

Let's say that one sibling or child who lives without physical contact in another state gets COVID, moderate to severe. Does that mean it's much more likely one will get a similar moderate-to-bad reaction if oneself is infected? That is, what is the heritability of poor reactions to COVID, such as the genetic component in one's response?

That's a great, great question. We don't have a lot of information about genetics right now. We think it's still old fashioned; regardless of genetics, it jumps from somebody's nose and mouth to the other nose and mouth. It's kind of an equal opportunity virus. But there's some intriguing evidence that there is some genetics and even gender might play a role.

In terms of the genetics, the information comes from blood type and COVID. Blood type O has fewer proteins on the surface of the cells, so your body is kind of less reactive to it. Those people tend to have more protection, when you look at large studies. And on the other side, blood type A has a little bit more protein that stimulates the immune system. As you know, it's the inflammatory response that makes people feel bad and get more severe disease. So those people tend to have a little bit more severe disease. It's really debatable how blood type O and A differ. It's seen in other infections, not just COVID, so there must be something going on there.

As to the effect, it's probably not that huge, but it is something to make you think that there might be some small genetic contribution. But I think overall, if I had to pick one thing, it would be more environmental rather than genetic.

Major League Baseball's Florida Marlins had a COVID-19 outbreak, we've been reporting on that this morning. It's difficult to have mask wearing and social distancing with consistently 50-plus players and support staff together. That would appear to be not all that different from a group of classrooms physically near each other in a school. The question is, can we learn anything from the Marlins situation about, should we, or how should we open schools?

Totally. I think the Marlins situation is extremely instructive, not just for other sports to come. And the MLB has been extremely meticulous about playing this out. I mean they have had reams and reams of guidance, and they have done really innovative things like using saliva tests, doing frequent testing every couple of days. I think it's a really good example of how to do stuff, but nevertheless, you're going to be at the mercy of the virus in the community. So first of all, the Marlins is based in Florida, Florida has a big surge. So if it was a team in Hawaii, for example, probably going to be less of an issue.

But it is a good example of what will happen in schools. So even if you keep kids in pods, when one person is infected, the whole pod is going to be. The bottom line is, if somebody's infected in a pod - and a team is like a pod, we think about having pods in schools of students and small cohorts - but what will happen is that the entire pod or group gets affected, even if you have no symptoms or aren't infected, because from public health guidance you have to stay isolated for two weeks. In schools, what will that mean? It means that even if you plan in person activities, all of a sudden you'd have to be flexible because that class or that group will be at home so you may have to convert quickly to online.

I now have nine workers who've tested positive on my construction site over the past four weeks. Some of them had to wait up to 10 days for results, during which time multiple people could have been exposed. At what point does the delay render the testing worthless? Seven days, 14 days?

Yeah, that's a great question and something that is completely frustrating. As one of my colleagues said, the test becomes theater if you wait more than 7-14 days, because that's the time when you isolate or quarantine anyways. So you would develop symptoms of disease after incubation in that period of time so it just becomes theatrics when you wait 7-14 days for a test. But I would still do it. I think people are trying to make these test delays less prominent by doing a bunch of different things like pooling tests, by running different, more convenient sites. But we need to do better in the U.S. with testing.

If a baseball player tests positive, won't the entire team have to go into quarantine for 14 days?

Yes, the entire team should go into quarantine, that's why I think it's a domino effect. And also the teams that have interacted with that team before, even if they have no symptoms. So it affects more people than the people who are infected. But I think what's happening in MLB is that they've developed this alternate list of people who can play, so they just go down the list. But at some point, the list might run dry. And I'm really crossing my fingers that that doesn't happen.

I'm over 65, undergoing chemotherapy for cancer and previously received a solid organ transplant. Will it be safe for me to get the SARS-CoV-2 vaccine as soon as it is available?

Yes. I think that most of the vaccine candidates being tested are safe in people with compromised immune systems on. And personally, I think that immunocompromised patients and elderly patients should be one of the first groups to get the vaccine because of all the reasons that we know about: increased mortality, more vulnerable. So I think I would prioritize that group to get vaccinated.

Being inside since early March, I've been ordering food online from Amazon, et cetera. How is eating the processed packaged tuna, chicken, crackers, canned foods, et cetera and trying to make sure they have nutrients and are not junk without going out to get fresh fruit, veggies and dairy affecting me? I'm in my late 70's, in good health, with glaucoma. Really afraid to go out and even to have stuff delivered from grocery stores. I even let my Amazon order sit for a few days before opening.

I would say that it's completely understandable to feel worried about, but I would say that the cases I've seen coming into the hospital usually have a very defined risk, like being exposed in close quarters, not wearing a mask, all of those things. So I would say go for the biggest bang for your buck which is to wear your mask, go at a period of time when a lot of people are not out. I know a lot of grocery stores are reserving the first hour for people like the questioner, where it's less crowded, there's not going to be other people allowed in.

Also, you can have fresh vegetables delivered to your place as well, but I wouldn't necessarily wipe down the vegetables. Coming back to one of the same questions we had earlier: the biggest bang for your buck is washing your hands and not worrying too much about ingesting the virus.

Could secondhand smoke transmit the coronavirus?

That's a great question. It probably wouldn't transmit the virus, but if somebody's blowing smoke, you can imagine the virus can travel a little bit further. But every time it travels further, the concentration of virus drops off. Smoke is also interesting because it's like pollution, and it may not necessarily increase your chances of getting it, but may increase the chances that it will progress because it kind of stimulates your immune system a little bit more, like particulate matter and pollution.

This interview has been edited for clarity.