Answering Your Questions About COVID-19

Stan Bunger
June 25, 2020 - 2:23 pm

    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, sponsored by Sierra Pacific Financial Advisors.

    Today we continue to explore how the virus transmits in the community and why we're seeing a rise in cases again with Dr. Bob Wachter, chair of the Department of Medicine at UCSF.

    Here's a headline. I'll just pull one out of a whole batch of them: the three most populous states are breaking coronavirus records leading to fears of "apocalyptic surges". What's going on here?

    Well, I think we let our guard down a little too quickly. If you look at the national statistics, you see an uptick in cases and it looks it's worse than it looks because New York, New Jersey, the Northeast have gotten so much better. So if you extract those from the mix, you see many, many states going up with cases and California is one of them right now. It's worse in Southern California than in Northern California, but we're beginning to see some worrisome signs that may indicate that we're going to see an uptick here as well.

    And is there anything we can peg this to? Everybody wants to know, well, was it the protests? For awhile it was the Memorial Day weekend. Is there some nexus or series of nexuses we can talk about?

    Well, it's interesting because we're in the first wave, that has to be clear. There was never a dip to say, this is a second wave. So we're still in the first wave, but it really is a second phase of the first wave. The first phase was, virus was introduced to a whole variety of places before we even knew it. We didn't have testing. And it was stealthily marching along in various places and then hammered certain places worse than others. This time is worse in a way because we could have prevented it. We now know what the steps that we need to take to tamp the virus down.

    So what has basically happened is that areas that have gone back to normal too soon, or where people are either choosing not to wear masks or health directors and politicians are telling them they don't need to wear masks, or they don't believe masks or distancing are important, those areas are seeing big surges. And when you look at which states had surges, it's almost the mirror image of which states had it the first time. So if you got hammered the first time through in March and April, you're generally doing quite well. And that's probably a combination of you now see what this looks like. You can't say there's no such thing, or it's a hoax or it's like the flu when you see a refrigerated morgues outside of hospitals and you see your friends and family get sick and sometimes die. So those states are now doing quite well.

    And the states, particularly in the Southeast, but also in the South, some in the Southwest and as I say in Southern California are seeing upticks. And I think it mostly has to do with behavior. People getting too close people not wearing masks, people not taking the precautions they need to take. The protests don't seem to have played an important role. That was a worry, but the best studies now that are coming out of the protests, don't see any significant uptick. There certainly were people infected during the protests, but the fact that most people were outside, many people were wearing masks, the protests don't seem to be it. This is just general behavior. That is now saying what I've said all along, which is there's really nothing about the virus that has changed. And we have no way to prevent it yet, other than people doing the things that they need to do to prevent spread.

    We have a lot of questions that have come in from our listeners to askus@kcbsradio.com. First one says, this came up in a conversation I was having with someone who says he heard that it's not necessary to wear your mask over your nose because the real concern is droplets spraying from the mouth when talking, singing, et cetera. Is that true? Do we know what the viral outflow would be for people who exhale through their noses and is just general exhalation likely to admit virus or is it the talking singing, et cetera?

    Yeah, it's a great question. I actually looked up whether anyone has studied this issue of mask over just mouth or mask over mouth and nose. I can't find a good research study on it. So I'll answer based on theory and the way we understand the virus. The virus likes what's called the respiratory epithelium, which is in the back of your nose, the back of your throat and then if things go badly, down into your lungs. And so there's plenty of virus in the back of your nose. The way we know that is when we test you for virus, we take a swab and we stick it in the back of your nose. So there's virus there. We know that when you exhale, even in normal breathing, there is some virus that comes out. The amount of spread that's due to that is a little bit up in the air.

    Certainly the riskiest thing is if someone coughs on you or sneezes on you, but there clearly have been cases of transmission where someone is just breathing normally. And so there's no good reason to think that breathing out of your nose versus breathing out of your mouth are all that different. And so my guess is - it's not a guess, I'm sure covering just your mouth is better than nothing, but for the maximum protection, both for you and for others you should cover both. And I say for you, because early on we said, "Oh, the masks are really just to protect other people," but that's not true. The mask also protects you. And so if you get if you get virus up your nose that is a good way of becoming infected. So I would wear it over both.

    What is California's R number and why does Britain treated like it's very important, but we seem not to?

    So I think in part, because it's a little confusing and people have just become familiar with the R number. So the R is the average number of people that a person with the coronavirus will infect. If you don't do anything, just live your normal life, it's somewhere around three. And you want to get it to below one because below one means every person who's infected will spread it to fewer than one other person. And if you do the math, eventually the virus will die out.

    California now is a little bit above one. I think 1.05 was the last time I looked, which is a little worse than we were a few weeks ago. And so it's demonstrating that as we open up, there was an expected increase in R. This is tricky because it's not irrational for us to be trying to get back toward normal in terms of the economy and people going stir crazy. But the key is, can we continue to open up while maintaining distance and while having universal masking? If we do that, the best evidence is you can open up a fair amount and still keep your R below one. We're in the wrong direction, and R is a little bit above one. The states that are seeing massive surges like Texas and Arizona have R's more in the order of 1.3, 1.5. It's not up to where we were in March when nobody knew anything. But it is getting into an area where you're going to start seeing exponential growth. And that's what they're seeing in certain parts of Texas, Arizona, Alabama, places like that. And I'm afraid we could see in California if we're not careful.

    Does UCSF have a protocol for patients once they receive a positive virus test? Our primary care MD retired, we don't yet have a replacement physician, just a nurse practitioner for routine issues. Do we contact an infectious disease specialist? Are we evaluated in person? Where would we go if we're positive for COVID for an assessment? Is there a special outpatient area at UCSF for positive patients to be examined? This goes on.

    That's a lot of questions (laughs). Let me just take that sort of as a general matter. First of all, we're happy to see new patients. We have what's called a respiratory screening clinic, which is designed just for this. The first visit is likely going to be a tele-visit, and you can go onto the website and just look up "UCSF respiratory screening clinic" and find your way in.

    A new diagnosis doesn't need an infectious disease specialist, this is now so common that all of our primary care doctors are comfortable with it. There is no therapy of any proven benefit for patients that are feeling okay, or even patients that feel a little bit crummy like they have a fever and some aches and a mild cough, but nothing else. And so the recommendation is going to be, if all that you have is that you have tested positive and you aren't short of breath, you're otherwise feeling okay. Even if you have a low grade fever or muscle aches, the recommendation is going to be to isolate yourself, to stay away from others and to take Tylenol or Advil or non-steroidals like that for fever and aches. But that really is, at this point, all we can do.

    There are a couple of therapies that have been proven to be beneficial. They are all for patients that are sick enough to be in the hospital requiring oxygen. So the two that have been studied one came out a month ago, remdesivir, it's an intravenous antiviral therapy. The other is dexamethasone, it's an intravenous or oral steroid therapy. And one of my fears is that because dexamethasone, or corticosteroids are common - you may have prednisone in your medicine cabinet, cause you got it for poison oak or something - people may start taking it. That's a bad, bad mistake because the only groups that benefited from it are people that were sick enough to be in the hospital and requiring oxygen. And the reason is that you do not want to suppress your immune system if you have been diagnosed with the virus. You want your immune system to be doing everything it can to beat the virus down. But what we have found is that people that get very sick and sick enough to be in the hospital and even sick enough to be in the intensive care unit on a ventilator, some of the damage to them is their immune system has overreacted. And it's the immune system's effect on the lungs that may ultimately kill them. So for those patients, the study that just came out this past week has shown that taking that that form of cortisone called dexamethasone does decrease the mortality rate. It's a good thing to do, but do not extrapolate that to taking it any earlier. And the evidence from the study was fairly clear that it will not only not help you, but very likely harm you.

    And this person wanted to know what devices should they have at home? They proposed a thermometer, a blood oximeter. I imagine those are pretty good things to have.

    I think the thermometer is fine obviously, although there really is no fever. If fever is all you have, that wouldn't make me so worried that you need to be in the hospital just for a fever. If you have a fever of 102, take Tylenol, take Advil or Motrin or something like that and get it down, drink plenty of fluids. That's all you need to do, the fever itself is not particularly worrisome. The oxygen level is a worrisome sign. And one of the funky things about this virus that now has become sort of well known is this kind of odd thing where sometimes people don't feel that badly, but their oxygen level has gone down. If the oxygen level goes down significantly from the normal oxygen saturation, which is 97%, down below about 92, then you need to be seen, you need to go to an ER and be seen, cause that can be a worrisome sign. So if it were me, I certainly would be taking my temperature. But I think having an oximeter at home, some of the home ones are not super reliable, so I'd try to get a decent oximeter. And having that and monitoring that, that's probably the main thing if that were going in the wrong direction, that would make me worried enough to go into the hospital.

    Next question, there's actually a personal note to you first. Thanks so much for putting Grand Rounds on YouTube. I got to tell you it's geeky viewing, but boy, there's a lot of great information there.

    Great. I'll tell you this afternoon, or in a couple of hours I'm going to interview John Barry, who wrote the book, "The Great Influenza" about the 1918 pandemic. And it's an incredibly interesting book and there just all sorts of eerie lessons for today and we'll post that on YouTube.

    Good deal. Yeah it's been fascinating stuff. Anyway, the question goes on: with all the reopening I don't see any advice tailored to elders. For while it seems safe to see my grandchild (all involved had been sheltering in place, zero outside contacts), now with kids returning to preschool, the number of outside contacts increases tenfold. I'm healthy, 72, can do without most things for two more years, but hard not to see my family. What are epidemiologists with grandkids doing?

    Yeah. Oh, it's such a hard question. You know, a lot of it depends on the prevalence of the virus in your community and at least in San Francisco and the Bay Area, it's still relatively low. As I said, I'm a little bit worried cause we're seeing some early signs that it may be on its way up. There is no way, unfortunately, to make a contact with anyone zero risk. If it were me - I'm not quite 70, but I'm 62 - and if it were a matter of seeing my grandkids, I would be wearing a mask. I would be careful in terms of super close contact, but I understand, you know, how hard that is not to do it. As I've mentioned before, my parents are 90 and 84 and they're in Florida and they're pretty much staying inside. The state is wide open, but now the cases in Florida are spiking through the roof. And so you know, in San Francisco, the risk that any person who is asymptomatic - a person who feels fine, including kids - has the virus is about one in 200. That's our experience at UCSF when we test asymptomatic people. So it's not zero, but it's not very high. If you went to Houston today or Phoenix today it would be significantly higher than that, might be five or more percent. So a lot of it depends on where you are and whether you're willing to take take a small, but non-zero risk.

    There's an increase of COVID-19 in California, but doesn't that help move us toward herd immunity, the ultimate goal, as long as we keep half of intensive care beds free, aren't we moving in a reasonable direction? By the way, could we get a better name than herd immunity?

    Yeah, I have nothing to do with the name and I think it's probably not going to go away. It's been around for a hundred years. So the concept of herd immunity is that enough people have been infected and have antibodies and that the antibodies work and protect you against another infection, that the virus begins dying out because it can't find enough victims that can take the virus and continue to allow the virus to multiply. The virus has only one purpose in life, which is to make copies of itself inside us. The problem is, to get to herd immunity the estimates for the coronavirus are, we have to get to about 60% of the population infected. 60% of the U S population being infected would be 200 million people. If the mortality rate is 1% (maybe it's a smidgen less than that) that's 2 million deaths. We're up to 120,000 now. So it is not anybody's idea of a good goal for us to have.

    The goal is to tamp this thing down as much as, and as long as possible. Just in the past three months by virtue of having done that in the Bay Area, not only have we prevented thousands of deaths, but if you were to get sick, now we have testing, we have contact tracing. We do have hospital beds and ICU beds available. We have a couple of treatments that have been shown to lower the mortality rate of patients who got very sick. And so the chances of you dying, if you got so sick that you needed to be on a ventilator have gone down from 50%, probably to closer to 20% - still pretty terrible. So the goal here is to keep this thing tamped down for another nine, 12 months, whatever it takes until a vaccine comes out or more treatments come out that lower the mortality rate. Getting to herd immunity is a nightmare and should not be any of our goals.

    Now in New York, where about 20% of people have antibodies they're nowhere near herd immunity, but that number is high enough that you actually are going to start seeing it influence the number of infections. Cause if someone has the virus and is near a person on the subway, there's a one in five chance that person can't be infected, assuming the antibodies work. But to get there, New York had to have 22,000 people die. In all of San Francisco we've had 48 people die. So I don't want to get to two, three, five, 10,000 people dying in order to achieve this benefit. We got to keep it tamped down and then continue to work therapies and on a vaccine.

    How long after possible exposure is the nasal swab test effective? I imagine testing too soon will give false confidence. For example, if I'm at the farmer's market Saturday, do I get a test Tuesday or wait until Thursday or Friday?

    Yeah, that's about right. It's somewhere in the three to five day range. And so if you have a test Tuesday, there is a chance of a false negative. If you go out to a week out, the chances go down considerably. Not to zero but yeah, it's in the order of four to six days.

    We would like to know if a person has asthma, is it okay to wear a mask? If not, please state the reason?

    Yeah, it's fine to wear a mask. First of all, the cloth masks or surgical masks allow a fair amount of air to come in and out. That's why they're a little bit less effective in blocking virus than the N95 that we sometimes will use in a hospital, but they still block the big droplets from going through. So for someone with asthma, by and large, they're going to be able to get more than enough air to to get through in order to be okay. I mean, if they have severe, severe asthma then it's one thing, but the kind of person who has asthma and is walking around using their inhaler, not needing to be in the hospital they're fine. And in fact if we have people with asthma who are sick enough to be in the hospital and they have also have a bad infection, let's say the flu, we put a mask on them and they're okay. So I wouldn't worry about that.

    My parents are over 65 and we don't live together. I'm going to drop items off to them and plan to bring my dog along. I understand the need to socially distance. What are your feelings of my dog getting close to them?

    The dogs are fine. I mean, there have been a few cases of people who have tested dogs for the virus. And apparently if a dog is like really, really close to someone who has the infection themselves, there have been cases where the dogs have tested positive. I don't believe there has been a documented case of dogs being a route of transmission. So I'm not worried about the dogs at all.

    For months we've been told a mask doesn't protect the wearer, especially the cloth ones most people wear. That never made sense to me, if it blocks/reduces the flow of particles out, why not block them in? Now, we're hearing wearing a mask does protect the wearer. People are questioning who to believe. So does wearing a mask protect the wearer and if not, why not?

    The answer is it does. The messaging on masks has been just terrible. I heard a clip from even Tony Fauci saying in early March, you don't need to wear one outside. It was basically because they wanted to preserve the masks for healthcare workers, which was reasonable. We now have enough masks in our hospitals.

    There is no question, the evidence is crystal clear that the masks may very well be the most important thing we could all do. As I mentioned earlier, they definitely protect others, in part because if you cough or sneeze or sing or breathe deeply out they will block the droplets, the particles. If you sneeze and you see big droplets going in the air, that's the biggest risk and the mask blocks that from coming out from the wearer. On the other hand, they also do protect the wearer. Probably less than they protect others, but still significantly, there's no question about it. So the best possible circumstance is we're all wearing masks, you're protecting others and you're also protecting yourself. And they're not perfect because as I said with the asthma question, they do let some small amounts of air go through. But they will block the big droplets from coming in and touching your mouth or touching your nose. And those are the two main places that the virus gets into us.

    Should restaurant servers and bartenders be wearing medical grade PPE as they're face to face with unmasked guests? It seems only healthcare workers face a similar exposure risk.

    It doesn't seem like it. First of all, there is not enough medical grade PPE to go around. We kind of barely have enough in our hospital. And so I don't think that's going to be a feasible thing to do in the short term. But even so I think the best evidence would say that if the restaurants are screening their workers for symptoms and you don't have people coming in who are coughing or sneezing, and they have them wear a surgical or even good cloth masks and the servers are being careful so that they're trying to stay two or three feet away from you and not getting right up in your face, that is safe. And we've seen cases - there was a case report of hairdressers in I forgot where it was, who had the virus as it turned out, were wearing masks and none of 200-300 people that got their haircut became infected. And that's not with medical grade masks, that's with regular old masks.

    So I think keeping a distance, making sure that folks who come into work are not sick and wearing regular masks is going to be good enough. That said, if you were in an at-risk group, and someone who's over 60 or has diabetes or obesity or a significant heart or lung disease, personally I think it's prudent to not go to an indoor restaurant for a while, until we have a better handle on this thing. Outdoors seems to be fine. If I were going to go indoors, I would be absolutely sure that all the servers were wearing masks and trying to keep a distance.