Category: Summer 2020

Active cases update

As of 9/8/20, the latest date for which the numbers are available, the Maine CDC reported a total of 4734 Mainers who have had COVID-19 since testing began over 180 days ago.  Among those cases, 4135 have recovered (87%), and 134 have died (2.8%).  Active cases totaled 465 (9.8%).   Also since testing began 999 health care workers (21%) in Maine have been infected with COVID-19, 933 of whom have recovered.  This means there are likely 66 active cases among health care workers. As of the end of July there had been no deaths among health workers, but I don’t think that information has been updated since.  And, take a moment to consider that “recovered” simply means the infection is over.  It does not mean the person is well.  We have seen many cases with what appears to be permanent lung damage, or other ravages left by the virus.  It is serious.

As of yesterday, a total of 429 people had been hospitalized with COVID-19 in Maine since the start of testing.  The number of hospitalizations is not just Mainers, but all hospitalizations of COVID-19 within the state.  If we add an estimated 200 out of state cases to the overall total the percent of cases hospitalized in the state is 8.7%.  In Maine on 9/8/20 6 Mainers were in critical care, and 2 on ventilators with COVID-19.

So, what does this tell us?  If we look at the graphic for this post (view on the website if you cannot see by email), the number of active cases is down from the peak of 714 (May 24), but is unfortunately trending up currently.  This is for the most part due to a series of widely reported preventable outbreaks.  We just had Labor Day, and hopefully will not see a spike following holiday gatherings. 

We are not done with COVID-19 yet, and we need to be careful because fall is approaching, and with it, cold and flu season as people head back indoors. Please continue physical distancing, hand washing, covering coughs and sneezes.  Please use good sense and wear a mask or facial covering.  If you can’t do that, stay home.  Wearing a facial covering limits the spread of droplets which contain the virus that causes COVID-19.   To those of you who complain about wearing a mask when you go out, imagine those of us who wear one all day, every day.  We like it even less, but we do it for a good reason.  We still do not know who the asymptomatic carriers are.

Please don’t argue with health professionals about whether you can accompany a loved one to a doctor’s visit.  There are criteria in place meant to help everyone, including us, to limit the spread of COVID-19.   Yet, doctors, nurses, and office screeners at the front door have to deal with very difficult people about this topic daily.  It helps no one, and creates additional risk.

Also, if you can take one, get a flu vaccine as soon as you can.  If you are eligible for the pneumonia vaccine, please get it.  COVID-19 can be hard enough to fight by itself.   

That’s it.  I hope you are healthy in body, mind, and spirit.  

More on active cases

Nine days back I wrote about active cases of COVID-19 in Maine.  Recall that the active infections we are tracking are among Maine residents who have either had a positive test, “confirmed” cases, or are “probable” (close contact with a confirmed case and meeting certain clinical criteria as defined by the CDC).  These cases have not recovered or died, and are thus actively ill. As of yesterday there had been 424 probable cases and 3287 confirmed since testing began 131 days back.   These numbers do not reflect those who were ill but never tested, and likely do not reflect the majority asymptomatic carriers, who for the most part have not been tested.  The numbers also do not reflect out of state visitors who test positive in Maine.   

In the July 11 post I discussed the bump in cases seen after Father’s day, and expressed concern about the possibility of the same following July 4.  We have now passed two weeks since that holiday, and numbers of cases among Maine residents have been shared by the Maine CDC, as outlined in the above graphic (view the article on the website if you cannot see that).   What the numbers tell us now is that we did fairly well for most of that two weeks.  The number of active cases dropped to 385 on July 14, which was the lowest level we have seen since April.   However, those numbers have since been slowly climbing, and the current number of active cases is 435.  Recall that in Maine the peak of active cases so far was 714 on May 24.  The current 7 day average is 22 cases per day (up from 15 on July 11).  So far, 117 Mainers have died from COVID-19. 

On Friday of last week Maine was one of three states in our country whose numbers were going down.  My concern is that it appears our numbers might be starting to go up again.  And, though it appears to me the number of out-of-state visitors is lower than normal, there are still many here.  The concern expressed by many of my patients and their family members is that visitors tend to have a false sense of security when they visit here, saying to Mainers that there are practically no cases here, or that they don’t need to worry when they come here because the risk is so low. It seems lost on them that they are a risk to Mainers. Many are also not wearing masks, and don’t appear to be quarantining.  This is how the virus is spread.  Remember, a significant number of people will be asymptomatic carriers of this disease.   

We are not doing a good job dealing with this virus in our country.   The CDC found in late June that antibody tests in six different states showed viral exposure at a much higher magnitude than prior testing had revealed. After reviewing thousands of blood tests in each state, CDC estimated the differences between reported case counts and actual was as follows:  western Washington State (11x higher than reported positive tests), New York metro area (12x), southern Florida (11x), Missouri (24x), Utah (11x), Connecticut (6x).   But this is nowhere near the levels of infection we would need to see to have herd immunity, which would require somewhere north of 50% of the population immune (more likely over 70%). 

As of today there have been 14,608,517 cases of COVID-19 across the globe, with 3,808,104 in the U.S. (26% of cases though we have just 4% of the world’s population).  Our case numbers are now 11 times that of Mexico, 15 times that of Italy, 19 times that of Germany, 34 times that of Canada, and 45 times that reported by China-who hosts 36% of the world’s population.   We have had several days with over 60,000 new cases of COVID-19 in the U.S. lately and the trend is going up.  Over 137,000 Americans have already died from COVID-19, and the CDC estimates the overall case fatality rate of COVID-19 to be 2.3%.  That means for each day that we have 60,000 new infections, we can expect close to 1,400 additional deaths. 

We are seeing more young people around the country with COVID-19. The problem with this is that although they are still at risk of serious illness or death, they are also more likely to have a minor illness or be an asymptomatic carrier.  We need people to take this seriously. 

It seems to me that although everyone knows about the virus, they are getting information from a lot of suspect sources.  The CDC is a good source but I don’t think everyone is listening.  There should be PSAs in all kinds of media about COVID-19 telling people how to avoid catching or spreading disease, how to wear a face cover or mask, how to do their part. 

Some good news about a promising COVID-19 vaccine

In April I wrote about vaccine development  for COVID-19.  That article outlines some of the background information you might want to read if you are not familiar with this topic.  At the time the frontrunner, the Moderna messenger ribonucleic acid (mRNA) vaccine, had been in trials for about a month.  This week the New England Journal of Medicine (NEJM) published an article outlining the phase I trial of the Moderna vaccine against COVID-19. 

The vaccine was given to 45 healthy adults ranging from 18 to 55 years of age, as two injections given 28 days apart, with mRNA-1273.   The vaccine was developed by researchers at the National Institute of Allergy and Infectious Diseases (NIAID, the trial sponsor) and at Moderna (Cambridge, MA). Participants were enrolled at Kaiser Permanente in Seattle, Washington, and Emery University in Atlanta, Georgia.

Researchers measured blood levels of antibody responses in the participants. Recall that antibodies are the tiny molecules our immune system produces to protect us from reinfection by an invader such as a virus at some point in the future.  Think of them as a sort of weapon the body uses.

In this study, following the second injection “serum-neutralizing activity was detected.”  In other words, antibodies that would neutralize SARS-CoV-2 were seen in all participants.  Side effects including fatigue, chills, headache, muscle aches, and pain at the injection site were reported in more than half, though none significant enough to limit the trial were detected.  

Researchers found that a type of so-called binding antibody called IgG against the viral spike protein increased rapidly after the first vaccination in all participants by day 15.  After the second vaccine all participants likewise produced a volume of antibody similar to that seen in patients who produce convalescent serum. That implies a good immune response, what you need to stop an infection.   For more on that topic, see this MPDN article.  And, in case you are wondering, the participants were also tested for antibodies prior to vaccination, and all found to have no detectable antibodies, indicating antibody formation was all but certainly due to vaccine exposure.

Finally, a type of immune cell in the blood called the CD4 T-cell was activated by the vaccine, again indicating a robust immune response.

A large phase III efficacy trial is starting at the end of July to determine if the vaccine is effective.

To listen to a 7/17/20 podcast (or read the transcript) of Drs. Anthony Fauci, Abraham Verghese, and Eric Topol discussing this and other topics on Medicine and the Machine, please click here. 

COVID-19 update in and out of Maine

On Tuesday of this week Dr. Nirav Shaw of the Maine CDC reported that since testing began in our state there had been 111 positive tests among non-residents.   Dr. Shaw took care to note that “many” of these cases are from people who live in New Hampshire but get their healthcare in Maine.   Further, he noted that among the total of 374 people who have so far been hospitalized with COVID-19 in Maine, some of the cases were out-of-staters, though the number was not given.  As of today, he notes that there are 13 people hospitalized in Maine with COVID-19, 11 of whom are in ICUs, and 4 of whom are on ventilators. 

Today the total number of cases given (posted as of midnight last night) was 3598 cases among Maine residents since testing began (391 probable cases).  Subtracting 3094 recoveries, and 114 deaths, we are left with a total of only 390 active cases.  The current 7-day average of new cases is 15 per day.  Overall, numbers are falling in Maine.  

The total number of healthcare workers who have been infected in our state since testing began is 844.   As always, if you cannot see the graphic in the email of this post, please view the post on the website.

Maine is doing so much better than many other parts of the country. But those problems can come here. A surge of cases in another state can for example deplete resources such as PPE or testing materials needed everywhere. Speaking of that, it has been a strange week in our country for COVID-19.  Every week of this pandemic has been for that matter, but a few points really stand out. 

  • On Tuesday of this week there were 64,000 new cases in the U.S., and the Trump Administration unilaterally removed the ability of the leading public health agency -the CDC – to collect hospitalization data on COVID-19-requiring hospitals to report elsewhere.  That information will now be given to a central database in Washington, in part run by a private company.  Health experts around the country are calling this an alarming and unprecedented move because public health data is being taken from the experts who need it.  There is also concern the information will be suppressed, spun or politicized. 
  • The White House and Trump have made disparaging remarks about the country’s leading infectious disease specialist, Dr. Anthony Fauci. We are no longer hearing from Fauci via the the White House. America needs to hear from an expert. I have a feeling that most of America trusts Fauci.
  • Georgia’s governor Brian Kemp has sued Atlanta  over a mask mandate, even as cases there climb. And, Kemp banned cities in Georgia from ordering people to wear face masks.  There have been 127,834 cases of COVID-19 in Georgia (almost 24,000 in the last seven days).
  • Nearly a third of the 54,022 children tested for COVID-19 in Florida have been positive (16,797 kids).  Four of the children have died, and 213 have been hospitalized.  The Trump administration is demanding that schools reopen in the fall. 

There are other concerns, lots of them.  Where are the checks and balances in our government? Where is the leadership? Where are we going with the out-of-control exponential growth down south and the failure of politicians to recognize it is an emergency?

Note, the links are current as of the time of posting, and are subject to change.

Active cases

Let’s talk about active cases of COVID-19 in Maine.  By this, I mean people here in the state who are currently sick with COVID-19.   It sounds simple enough, but it is not a number that we have, because while we are shown a count of infections among state residents, we in the public sector do not know the number of infections among visiting non-residents.  Those that have tested positive in our state are counted in their home states (and the same is true for out-of-state Mainers, another number we don’t have).  I think these numbers should be public, because if people are ill in Maine (or anywhere for that matter), they impact healthcare and could influence decisions about opening businesses, and influence Mainers as to calculating their own risk.   So what do the numbers of active cases mean, and how can we count them?

Because the state is posting totals at midnight,   we will reference data as of July 10, 2020.  To calculate how many Maine residents have an active infection we take the total number of cases since testing began (3,520), subtract recoveries (2,971) and deaths (112), to arrive at 437 active infections (Maine CDC lists these as “other” cases).  The peak of active cases so far in Maine occurred on May 24, 2020 at 714.  The number declined steadily following that peak until June 23, (two days after Father’s Day), with 393 active cases.  The average time for symptoms to show after infection is 5 days, and testing of people with COVID-19 is usually a few days after that.  Since this virus spreads when people congregate, we could expect a “bump” in active cases a week or two after Father’s Day (if people were congregating, especially indoors). By July 3 (12 days later) we reached 529 active cases (a 35% increase), which was not simply a function of increased testing.  Numbers of hospitalized patients did not fall during this time. 

I was on call July 4th weekend, and drove to the hospital a few times.  I saw a lot of people in town, a lot of shopping, crowding, gathering, and a lot of out-of-state tags.  The one hopeful issue about July 4 is that most gatherings were likely outside, where chance of infection is lower. And, in the six days of data available following July 4, active cases trended down. The current 7-day average of new cases has dropped from 33 to 19. While those declines might sound very hopeful, they might also represent the other side of the Father’s Day “bump.”  However, we might be about to see another bump. We are now 7 days out from July 4.  Let’s hope that over the next week we do not see an increase. 

We are also seeing the ongoing opening up of Maine and the tourism industry. New York, New Jersey, Connecticut, Vermont, and New Hampshire residents are not being asked to quarantine, and we are seeing a lot of visitors from those states.  According to the CDC in Atlanta,  in the last week new cases in each of those states has totaled the following:  New York (4,476), New Jersey (1,914), Connecticut (563), Vermont (45), and New Hampshire (151).   Maine has seen 131 new cases in the past week.  Since our states have different population sizes, we can look instead at the number of cases per 100,000 of population to get a sense of how widespread infection is in those states compared with our own: New York state excluding NYC (1,628), New Jersey (1,956), Connecticut (1,321), Vermont (203), and New Hampshire (440), and Maine (261).  We are not even close to the numbers being seen in New York, New Jersey, or Connecticut.  And, we are all seeing a lot of Massachusetts tags, though they are asked to quarantine or show a negative COVID-19 test if they want to visit Maine. Massachusetts has had 1,559 cases in the last week, and the case count per 100,000 is 1,606.  

While we hope that visitors are being tested before coming here, the problem is that in traveling itself we all visit the same rest stops, gas stations, and so on.  The virus spreads where people congregate.  And, asymptomatic carriers likely represent a high percentage of spread.   People may come here thinking they are well, but still spread virus.  For reasons that are still not completely clear, some people have no symptoms, or only mild symptoms, but they may give someone else a fatal infection.  

Cases in New England are improving overall, but case trends around the country are not looking good.  Texas is experiencing a huge increase in cases, currently counting over 114,000 active cases (from over 230,000 since testing began), and having suffered over 3000 deaths due to COVID-19.  In the last seven days Texas has seen 54,369 new cases.  I trained at the Texas Medical Center in Houston, which was the world’s largest, with over 50,000 employees and multiple huge hospitals, including the DeBakey VA Hospital (one of the largest federal buildings in the country), the Ben Taub County Hospital, huge Methodist and Presbyterian hospitals, and the MD Anderson Cancer Center Hospital.  Recently, Texas Children’s Hospital (also in the TMC) had to start housing adult patients with COVID-19 because space had run out elsewhere. Florida has seen over 63,000 new cases in the last week.

Here in Maine tourists and summer home owners are arriving, and the number is not trivial.   The Maine Office of Tourism reported 33 million people visited Maine in 2015.  During just the summer of 2018 11 million overnight visitors came to Maine.  

To that point, when I last posted on this topic I noted that there was some confusion (at least in my mind) regarding the numbers being stated at Maine CDC briefings when compared with the data given on the same agency’s website.   I want to take a moment here to say I truly appreciate what the Maine CDC and Dr. Shaw have been doing.  The numbers were confusing nonetheless, and I want to follow-up on that.  As discussed in that last post, the case trend numbers given during briefings did not match the data shared in the website table  “All Reported COVID-19 Tests in Maine,” which has consistently shown a higher number than the total cases in the state. I called the Maine CDC and asked for clarification. In order to get this information, I became one of the Maine CDC’s “consultations.”  What I learned was that the number given in briefings is basically a headcount of positive and probable cases among Maine residents; whereas the “All Reported” table includes only lab test results, and does indeed include non-residents who have tested positive while visiting Maine.  That table includes all positive results, even if they belong to the same person.  Put another way, if a person has had more than one positive test – for example, a hospitalized patient who needs a negative test prior to discharge, they are counted.  A breakdown of those numbers explaining how many of each category was not given.  However, we do know that the table does not include “probable tests,” which currently stand at about 400 of the 3520 cases.  Thus, 3120 Mainers have tested positive.  We can use these numbers in a simple calculation and say that 4652 total positive tests minus 3120 individual Mainers leaves 1532 additional positive tests, some out-of-staters, some duplicates. It should be obvious that we are doing better than many other states. And, it should be obvious that raising our summer population by millions is a risky proposition during a pandemic.

So, please don’t let down your guard. Remember, health resources are also limited.  This includes people.  Since testing began 831 health care workers have tested positive in Maine (24% of reported cases), and this number grew by 100 new cases in just three weeks.  Around the country about 700 health care workers have died from COVID-19.   

The way to avoid COVID-19 is to practice physical distancing. If the virus can’t get to another host, it can’t spread. Stay at least 6 feet away from others not in your household.  Stay as far as possible from people who do not wear masks in public and avoid sharing indoor spaces with these people.  It would seem very likely that people who don’t wear masks are more likely to carry the virus that causes COVID-19 than those who do.  Of course, stay away from people with COVID-19, and if you are ill, stay home.  

If you are healthy and are around others in public, wear a cloth face cover or a mask.  Remember that the mask does not mean you are free to stand closer. It is a simple barrier which helps, but does not guarantee safety.   Also, wear a mask the right way.  Studies by the Center for Infectious Disease Research and Policy (CIDRAP) have reported that in review of news footage an average of 25% of Americans are not wearing their mask correctly.  Many do not cover the nose, for example.  A mask should cover both the mouth and the nose at all times.  There is also a great deal of inappropriate handling of masks.  You should only touch the mask with clean hands, handle the mask by the drawstrings, and do not touch the part through which you breath.  If you touch your mask, remember that it is a filter for the virus that causes COVID-19. You could be contaminating your fingers. Wash your hands.   A mask should not be moved under the chin, put in a pocket, or otherwise handled carelessly.   A wet or damaged mask is not helpful.

Finally, the U.S. has seen over 3 million cases of COVID-19 and over 132,000 people have died from this preventable viral infection.  Please do your part.  It is not a political issue, wear a mask and do all that you can to avoid contributing to this pandemic.  

COVID-19 update June 27, and some confusion…

Yesterday, Friday, June 26, 2020, at the Maine CDC briefing Dr. Nirav Shaw reported that as of that morning the new cumulative number of cases of COVID-19 among Maine residents had reached 3,102, with 32 new cases.  This number was made up of 2758 confirmed (with either PCR or antibody testing), and 344 probable (symptomatic people with close contact to a confirmed case).  Dr. Shaw noted that in that 24 hour period alone the state conducted 2,225 PCR tests, among them 39 positive.  As there were 32 new cases among Mainers for that time period, one could reasonably conclude this meant 7 cases were among non-Mainers – more on that below.

However, and here is where a little confusion begins, I would note the numbers given in the Friday press briefing matched the data listed on the Maine CDC website for Thursday. Perhaps that morning’s data was not updated yet? Or, perhaps the data was not concluded. In the past, the data given during the briefing exactly matched the data on the website. Perhaps that has changed?  I would also note though that the numbers given at the press briefings Monday, June 22, and the Wednesday, June 24 also did not match what was posted on the Maine CDC website for those dates (and he numbers did not represent the prior day values).  I am using the website data for calculations in this article because it is integrated into CDC tabulations.

To that end, the data posted indicates Friday there were 3154 total cases (52 new cases), 2564 recoveries, 104 deaths among Maine residents.  And, as of the time of writing this post on Saturday, June 27 the data indicates no new cases overnight.  I would question that number as the prior week’s daily average number of new cases was 33 per day.   Because of that question I have not included today’s numbers in the graphic at the top of this article.  As always, if you cannot see the graphic in email form, please view this post on the website.

The number of active cases among Maine residents as of Friday was 486. This number reached a peak of 712 on May 26, and had dropped to 393 on June 23. Active cases are represented by the green line in the graphic above. Note that line is starting to trend up.

The state has started giving information about total testing on the CDC website, noting that among the 96,295 tests run to date, 3,787 were positive.  If we subtract the total number of reported and probable cases as above (3,154) from this number we are left with 633 cases.  This again could reasonably suggest 633 non-residents have tested positive in our state.   This is especially relevant as we see more visitors and part-time residents returning with the good weather.  I would think knowing how many out-of-staters have tested, and are currently testing positive in the state would be good information to help business owners, and all Mainers for that matter, calculate their own risk.  Considered another way, if the actual number of positive tests to date is 3,787, then 633 unaccounted for people, presumably non-residents, is about 17% of the total.  That is 1 in 6 positive tests, a lot of visitors.    

Among the total number of cases reported at yesterday’s briefing 787 were among health care workers-25% of total cases reported. For the first time since reporting began Dr. Shaw gave information about recoveries among that group: 680.  This leaves a total of 107 active (or possibly deceased-data not disclosed) cases among health care workers.  There were 28 people hospitalized with COVID-19 in our state, 9 in ICUs, and 6 on ventilators-presumably on Thursday. 

Finally, though there are executive orders, and compliance with physical distancing and facial covering is high, there are still some businesses around the state that do not require their employees to wear a mask. I encountered this twice yesterday when shopping for groceries and other necessities. I would suggest that if you encounter this situation you do as I did in both cases: leave. Do not shop with those businesses. This will protect your own health, and will send a message that you expect everyone to do their best to stop this pandemic. As I have discussed several times here, wearing a mask protects you and others from spread of COVID-19. Choosing not to wear a mask places others at risk.

COVID-19 update by the numbers, June 21, 2020

As of today, June 21, 2020, there have been 2957 cases of COVID-19 among Maine residents reported by the Maine CDC.  There have been 328 cases in the “probable” category (known close contacts of confirmed cases with symptomatic disease as previously discussed).  Reportedly, 2391 people have recovered from COVID-19 in Maine.   In the last two weeks we have accumulated four new deaths due to COVID-19, bringing that unfortunate total to 102 Maine residents.  The only good news about that accounting is that the rate of deaths has been falling.   In the just over two weeks since I last reported on the numbers, the number of new cases per day has averaged 28, dropping from a prior two week average of 36 cases per day.  The number of current active cases has fallen to 464, a number which has been declining since a peak of 712 on May 26, 2020. In the attached graphic active cases are represented by a green line, which also shows a downward trend.  Note, if you cannot see the graphic, please view this article on the website.   The current seven day average number of active cases has been 478, down from 628 two weeks back. 

The number of health care workers that had been infected since testing began was 743 as of Friday, June 19 (the last day for which the data is available).  This represented 26% of cases reported in the state on that date.  Testing for health care workers has been symptom-based for the most part, in some cases related to direct exposure, and included in universal testing at congregate care facilities.  In short, the vast majority of health care workers in the state have not been tested. 

These numbers are a snapshot, a look at the available data, not a picture of every COVID-19 infection, and no clear measure of asymptomatic carriers in the state.  Still, numbers are trending down.  On the other hand, we are “opening up” and our summer population is growing.   It is possible that we could see another wave of infections soon, even more likely in the fall if there is not a vaccine or some other intervention.  Physical distancing, wearing a mask, and hand washing are still excellent tools to limit the spread of COVID-19.  Please help to keep the numbers down. 

More on asymptomatic carriers and bad modeling by the POTUS

In a recent MPDN post about asymptomatic carriers  of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes COVID-19 I noted that these people can be infected and infect others without ever knowing they are ill.  This is particularly concerning because we have not had enough testing in the state (or the country for that matter) to know the incidence of these cases.   It is also concerning because we are opening up businesses and many people do not take the most basic precautions to protect themselves and others, such as wearing a mask in public or practicing physical distancing.  We are also seeing an influx of tourists in our state and have no way of knowing who has actually been tested or quarantined.  Finally, there have been a variety of gatherings around the state and the country, such as the heavily televised campaign rally for the POTUS yesterday, in which masks were worn by very few, voices were loud, and people were crowded at an indoor location; conditions near ideal for spread from asymptomatic carriers. 

This past week a scientific letter published in Nature Medicine about asymptomatic carriers raised more concerns about COVID-19 that have a lot of bearing on all of this.  The cases were detected by the Chinese Wanzhou District Centers for Disease Control and Prevention (CDC), which conducted RT–PCR tests on 2,088 “close contacts under quarantine.” None of these people had symptoms in the two weeks prior to testing.  This is especially relevant because in the U.S. the standard is to have people who have had a close contact with a sick person go into isolation for two weeks.  If they develop no symptoms, they come out of isolation.  In this study, a positive test was detected in 178 patients.  All 178 were hospitalized and a variety of tests were conducted.  All patients were followed for several weeks.  Among these 178 cases, 37 (20.8%) remained asymptomatic.  Within the 37 asymptomatic cases, the average age was 41 years, and 22 were female. 

A younger average age is an interesting feature that might speak to the fact that younger people seem to do better with the virus if exposed.  However, that might also lead people to a false sense of security.  First, not all young people do so well.  Many younger people (including children) with COVID-19 in our country have died or suffered a variety of serious illnesses. Second, these people might spread disease, even if they are not so sick.  If one person infects two other people, and those two people infect two other people, it doesn’t take long for infection to grow to huge numbers.  For another example of exponential growth, see this post.

It is important to understand a little about how the testing was done to understand a couple other concerns.  Recall that polymerase chain reaction (PCR) is a test for genetic material.  PCR looks for the genetic material of the organism when the COVID-19 test is done, and in that case the only way for one to have a positive test is if the organism is present (an infection).  In this study, the amount of genetic material found in the 37 asymptomatic cases was compared against symptomatic cases and found to be the same. Similar to the prior post on asymptomatic cases, this tells us that viral shedding, or the amount of virus being emitted is probably about the same between symptomatic an asymptomatic people.  (footnote)

The authors also reported that asymptomatic carriers were found to shed virus for a period of time longer than people with symptomatic disease.  The average duration of viral shedding among these “silent spreaders” was 19 days, with a range of 15-26 days (versus an average of 14 days among symptomatic patients).  This longer duration may be related to another finding in the study, that asymptomatic carriers in this report had a less robust immune response than people with symptomatic disease.  This concept fits with the idea that much of the damage done to the body with severe cases is thought to be caused by an infected person’s own immune response. In other words, a person with a strong immune response to the virus might wind up severely ill, and if they survive, stop shedding virus faster than a person with a weaker immune response and fewer neutralizing antibodies.  Also, asymptomatic people in the report had  lower levels of pro- and anti-inflammatory cytokines.  The so-called “cytokine storm” is implicated in progression to severe disease in symptomatic cases. 

However, the longer duration of positive testing could have another meaning.  Again, a positive PCR test means genetic material is present, but does not necessarily imply viral infectivity is still possible.  It could be that after one has stopped being infectious a test could remain positive for a few days due to viral debris.  It is known in many other viral infections that the immune system can neutralize viruses by damaging the outer envelope or aggregating virus particles.  These acts prevent infection but do not destroy the nucleic acid, which degrades slowly over time.  One example is measles virus RNA, which can be detected for up to 8 weeks after the clearance of infectious virus.  As an analogy, if you thought there was a nest of hornets in your attic, and you had a test that picked up hornets, it might not distinguish between live hornets and the ones left behind after fogging the attic with hornet spray.  It would take a while for the hornets to disintegrate. 

Whatever the case, asymptomatic carriers reproduce and spread virus.  Being in the presence of someone who is slowly emitting virus by talking or breathing is much less risky if that person is wearing a mask.  It is also less risky if the encounter is kept brief, if you are wearing a mask also, and if are physically distanced at least 6 feet.  Indoor environments are less dangerous if air is being circulated away from you to the outside (windows open, air exchangers, or negative pressure rooms). 

So let’s close with a few words from the president yesterday.  To paraphrase, he stated he had asked for COVID-19 is a “flu,” that testing to be slowed down in this country, because if you test, you find cases.  He made a point that some cases are mild and should not have been counted.  He stated that he had probably saved hundreds of thousands of lives by acting as quickly as he did.   He was wrong on all counts, and several more I haven’t mentioned. What he said about COVID-19 so clearly illuminated his indifference to science and experts, failure to read daily briefings, inability to grasp or accept simple medical facts, and failure to lead in a health crisis.  What he had to say, and the very fact that he brought so many people from all over the country together for an indoor rally where masks were not required, and where people who had to sign a waver stating they would not hold him liable if they caught COVID-19, was dangerous, and sent a very bad message about public health and his lack of concern for the wellbeing of even his own supporters.  This came even after the deaths over 120,000 Americans during this pandemic, a number which is still growing.   

We need a lot more testing to understand the incidence of asymptomatic cases, for contact tracing, isolation, and public health.  We need leaders who, if they don’t understand what is going on, at least listen to experts, take their recommendations, and model the behavior in those recommendations. This comment is not about politics. It is about common sense and public health. 

Until we have a vaccine or some reasonable intervention comes along we need to wear masks, practice physical distancing, wash our hands, stop touching our faces (unless the hands and the face are clean).  Stay well, and follow the advice of the Maine CDC.

FOOTNOTE:  We should note of course that coughing and sneezing emit huge numbers compared with talking or simple breathing.  Still, the point is important, asymptomatic people can shed a lot of viral particles, and infect others.