I had planned to write this month about the latest research in biologic therapy for allergic diseases—the theme of this year’s annual meeting of the American Academy of Allergy, Asthma and Immunology during March 13th-March 16th in Philadelphia. That plan changed at 4:10pm on Sunday March 8th when I received an e-mail announcing that the executive committee of the Academy cancelled the entire meeting. The train of cancellations for all of us hasn’t stopped since.
I thought that what I wrote at the end of February—hygienic measures by all of us and risk group awareness—would have avoided a ‘shelter-in-place’ governmental order here in Illinois and other states because the case-fatality ratio (i.e. death rate) from the novel coronavirus COVID-19 was not considered to be that of Ebola, MERS and SARS infections. But, federal and state government officials–including public health officials–saw what happened not only in China with a death rate of 4%, but also in Italy with a rising death rate that is 9.0% according to the WHO Situation Report of Sunday March 22nd. The USA case-fatality ratio is, by contrast, currently 1.25% (417 deaths in 33,276 confirmed cases); the Illinois statistic is 0.85% (9 deaths in 1,049 confirmed cases). They do not want to take the chance that hospitals here will be overwhelmed by cases due to a more contagious and more lethal virus than influenza virus—but still not as lethal as Ebola/MERS/SARS– when hospital beds, equipment and healthy workers are needed to treat the other typical urgent medical conditions.
Now that the attempts to prevent more cases of COVID-19 affect drastically our freedom of movement and our way of life, some more discussion of what we know about this particular virus–and viral infections in general—would be helpful to get through this.
COVID-19 affects both the young and the old:
In the USA, the CDC announced on March 18th that of the 12% of confirmed COVID-19 cases requiring hospitalization during February 12th-March 16th, 38% of these hospitalizations were between ages 20 and 54. And, here in Illinois, one of the new cases of COVID-19 announced on March 22nd was an infant.
The COVID-19 virus starts to replicate in the body by binding to a receptor on the cell’s surface called the ACE-2 receptor protein. Younger people have less (which doesn’t mean the same as none) of the ACE-2 receptor protein compared to older people. The virus is then less lethal in younger people, but that’s not the same thing as meaning no risk to becoming infected and carrying the virus.
Part of the reason for the higher mortality rate in Italy is probably due to a higher percentage—29.4% according to the 2017 UN World Population Ageing report—of their population being older than age 60 and consequently having more ACE-2 receptor protein expression. For comparison, China’s (minus Hong Kong) percentage is 16.2%; in the USA, that percentage is 21.5%. For those who know about the medical term ‘ACE’ because of blood pressure medications, the American College of Cardiology on March 17th advised patients on these medications not to stop them because there is no data to justify that.
Can I breathe the air and touch objects if they harbor COVID-19 virus?
A useful study to answer this was published in the March 19th issue of the New England Journal of Medicine. The researchers showed that:
- there is an exponential decay of the virus titer in the air over hours, with a median estimated half-life of 1.1-1.2 hours;
- on copper, no COVID-19 virus was detectable after 4 hours;
- on cardboard, the virus was not detectable after 24 hours;
- the half-life of the virus was 5.6 hours on stainless steel, with very low amounts–100.6 instead of 103.7–detected after 48 hours;
- the viral half-life was 6.8 hours on plastic, with very low amount–100.6 instead of 103.7—detected after 72 hours.
The conclusions are that the virus stays in aerosols for hours and stays on surfaces for up to days depending on the amount of virus initially present (and the type of surface). This should be encouraging news for those concerned about how transmissible the virus can be. As long as those who are infected wear gloves, surfaces are cleaned and others avoid the area where the infected person was for a few hours after the infected person left, then the risk is–for all practical purposes–avoided.
Can I become infected with COVID-19 from an asymptomatic carrier?
There are reports of asymptomatic transmission:
- A letter in JAMA published in the February 21st issue describes an asymptomatic Chinese woman from Wuhan who traveled to another area of China to visit family, and five of those family members became infected.
- The March 5th issue of the New England Journal of Medicine reports the scenario of a business meeting between an asymptomatic Chinese businesswoman from Shanghai and two German businessmen near Munich on January 21-22. The Chinese woman became symptomatic during her return flight to China on the 22nd and tested positive four days later. The German businessmen became symptomatic on January 24th and tested positive several days later.
There is some reassurance about this not continuously happening from the report of the first known USA person-to-person transmission of COVID-19, which happened in Chicago. In the March 14th online Lancet article describing this transmission, 43 contacts who became persons under investigation and 32 asymptomatic health-care personnel all tested negative.
Also on Tuesday evening March 17th, Dr. Anthony Fauci was interviewed on television about this question. He said: “If someone is asymptomatic but infected, and you walk into a room or just talk to them for a few minutes, that is a very low risk.” My opinion is that the chance of actually becoming another asymptomatic carrier is going to depend on many factors—among them the amount of viral load produced by the carrier, what was discussed above about from where the virus was outside the carrier’s body and the contact’s underlying health history.
How to treat it if I get it?
At present, mild cases (currently assessed as being ~80% of cases and either no pneumonia or mild pneumonia) are treated by isolation at home. Testing to confirm is still difficult to do as of this week because of the shortage of supplies. One of my patients with asthma developed fever and respiratory symptoms while in San Diego during March 6th-12th. Her test for influenza, after returning here, was normal. The point of deciding on international travel as a criterion for testing is really over now because we are in community-spread mode. Yet, the decision was made at the testing facility not to test for COVID-19.
When there is what is called a “non-test based strategy” to presumptively treat COVID-19, home isolation can end according to the CDC when:
– at least seven days have passed since symptoms first started and
-at least three days of both (a) no fever and no use of Tylenol, Motrin, etc. and (b) improvement in respiratory symptoms.
Treatment of severe to critical symptoms is currently what is called ‘supportive care.’ We’ve heard in the past couple of weeks about a drug used for malaria called Hydroxychloroquine–with or without using Zithromax. The basis for considering it includes its effect in vitro (i.e. test tube-like analysis) on the COVID-19 virus and a study in press of 36 infected patients in China who had a greater undetectability (70%) of the viral RNA on day 6 with using these drugs compared with those who received ‘supportive care’(12%). We are awaiting the analysis of the available data from this and other anecdotal reports by the expert virologists.
The antiviral drug at the moment that seems to be closest to a compassionate use in severe cases is Remdesivir because some benefit has been shown in animals infected with coronavirus. A different antiviral drug that has been used for HIV showed no difference of outcome in a clinical trial of 199 COVID-19 patients. As much as we’d like to think a vaccine is the answer to simply prevent it, a safe and effective one won’t be available for the general population this year and probably not even until mid-2021 at the earliest.
So, when will we go out again, dine out again, work out with people again?
We’d like to think that warmer weather will naturally cause COVID-19 to disappear because that’s what happens with influenza virus in temperate climates like the northern USA. The influenza virus is more stable in colder climates because the protective coat only melts at a warmer temperature inside the body.
The low mortality rate of 0.5% (2 deaths in 432 confirmed cases) from COVID-19 in tropical Singapore, which is just north of the equator with a relatively constant air temperature, would seem to support that as well. However, the Singapore infectious disease picture is more complicated. Singapore has experience from the 2003 SARS epidemic to implement containment and mitigation measures. Also, Singapore has two influenza seasons despite a consistent warm temperature range: April-July and November-January. The explanation there is an ill-defined relationship between absolute humidity and air temperature. And, I would prefer not to think about this, but the 1918 influenza pandemic began to a milder degree in the spring and then reappeared to a much more pervasive extent in September-October in the United States.
No one can predict with certainty what is going to happen biologically with COVID-19 virus. But, if we want to stop the deaths, the quarantines and the shut-downs of businesses before May, then the immediate answer is what we do over the next month. The government will need to strongly consider limiting the quarantine or self-isolation requirement to only the risk groups—those over 60 or 65 and those with certain chronic diseases—so that most businesses can reopen.
A health psychologist at University College London named Susan Michie referred to the hygienic measures to avoid infection as ‘the behavioral vaccine.’ If we
- wash our hands properly,
- don’t touch our eyes, nose and mouth,
- stand 6 feet away from others; and
- carry tissues to use for coughing and sneezing,
then we have a chance to accelerate the end of the governmental restrictions. Her comments and those of other experts about the COVID-19 outbreak can be heard on a BBC broadcast from this past weekend. https://www.bbc.co.uk/sounds/play/w3ct0hqz
I always enjoyed learning history in school and afterward because of the oft-quoted Santayana phrase that those who fail to learn from the mistakes of the past are condemned to repeat them. I think we all want to be better human beings. I’m fortunate to have had parents who enjoyed analyzing the present by remembering and discussing past political and socioeconomic events—no matter how controversial or unsettling. In last month’s blog about COVID-19, I referred to Franklin Roosevelt’s 1933 inauguration speech when he said “the only thing we have to fear is fear itself.” Eight days later, he gave his first ‘Fireside Chat’ radio address when he explained the banking system and inspired the nation to stop hoarding money—which he called “an exceedingly unfashionable pastime”—so that the banks could reopen successfully.
Roosevelt’s closing thoughts may be helpful for us in the coming weeks—and hopefully not for months. He said:
“After all, there is an element in the readjustment of our financial system—more important than currency, more important than gold. And that is the confidence of the people themselves. Confidence and courage are the essentials of success in carrying out our plan. Let us unite in banishing fear. It is your problem, my friends; your problem no less than it is mine. Together, we cannot fail.”