Today’s confusion about COVID-19 is understandable due to the sheer volume of information often expressed in different ways and often mixed with misinformation. For instance, COVID-19 is just one name for the new Coronavirus officially known as SARS-CoV-2. Many people, including experts, use these three names interchangeably.
At Truesdale Health we want to share with you what we believe are some excellent sites for reliable information about COVID-19, as well as address three important things you've probably been hearing a lot about that cause can confusion:
- The death rate of COVID-19
- The expression ”flattening the curve”
- Why there will not be a vaccine available in a matter of months
The COVID-19 (Coronavirus) Death Rate
You likely have heard widely divergent numbers regarding the death rate for COVID-19, and think that no one knows what they are talking about. The reality is that there is not any one mortality rate for the disease.
- U.S. health authorities report a rate under 1% (although 2% is seeming more likely)
- The World Health Organization reports about 3.4%
- China publishes 2.3%
Why the discrepancy? Well, they are talking about different populations and some are blended numbers. Confused? Let us explain.
Epidemiologists determine the mortality rate (often referred to as the crude case-fatality rate [CFR]) with a simple calculation:
The number of fatal cases divided by the number of cases = mortality rate.
However, the result can be very misleading. Arranging Chinese data by different groups of people, we see that people older than 80 had a CFR of 14.8%. Those 70-79 years old had a CFR of 8%. Those who were infected with a critical case of COVID-19 (under 5% of the infected) had a CFR of 49%! All of these numbers are accurate -- but specific to the population group being looked at. The problem is that health experts don’t always clarify what group they are talking about.
Currently, America has about 22.6 million in the 70-79 age group and 12.6 million aged 80-plus. Infected people older than 60 and especially those with co-existing diseases are at a higher risk of having a severe to critical case. That is one reason why we are concerned about a disease in which “80% have a mild case.” If you’re young and healthy that applies to you, but not to the 33 million Americans who are in the higher risk group.
You can see that the calculation of an accurate case fatality rate is completely dependent on knowing how many cases there are within the population, both diagnosed and undiagnosed. With the current lack of surveillance (identifying how many cases there are in the population versus how many are sick enough to meet the present criterion for testing), we really don’t know how many people are or have been infected. Without this knowledge, we can’t take the needed steps to limit the spread, because we don’t know how widespread it really is. A good analogy is that we are asking a color-blind person to tell us how many redheads there are in the room!
Flattening The Curve
Epidemiologists look at disease curves to guide our interventions and understanding of a disease. The curve is a simple graph that shows the number of cases over time. Experts warn us that our healthcare system (including hospitals, ICU beds, equipment such as respirators, etc.) could easily be overwhelmed as the number of cases rise (especially if the rise is sudden and large. This is the situation in Italy where difficult decisions regarding whom to treat and not treat are being made. If we take measures to slow down the spread such as social distancing (cancelling large gatherings, working from home, avoiding crowded areas, closing schools…) as well as common-sense measures such as staying home when sick, hand washing and frequent cleaning of surfaces in public areas, we can decrease the number of cases over a given time, thus “flattening the curve.”
Slowing the spread of the virus helps to prevent the healthcare system from being overwhelmed. A slower flow of susceptible and high-risk people enables providers to manage their treatment more effectively. The whole concept was well illustrated in a March 11 article by Helen Branswell in Statnews.com (see the accompanying graph above).
No Quick Vaccine
A vaccine will likely not be available even in nine months. This is because there is a critical process that must take place once a suitable vaccine candidate is found.
- It must first be demonstrated to be safe and effective in preventing the disease from developing (typically via animal testing in a mammal whose immune system is similar to ours)
- A small group of people get the vaccine and are observed for side effects or major adverse reactions and followed over a period of time to identify late effects
- A larger group gets the vaccine and is observed
- A larger group that more closely mimics the general population is vaccinated and observed
If all phases show no major issues, then adequate doses of the vaccine are produced. Bottom line: Producing a safe and effective vaccine for the public is neither easy nor quick.
Where to get up-to-date and accurate, information about COVID-19
- MA Department of Public Health
- Johns Hopkins Center for Health Security
- CDC Coronavirus info page
- CDC Travelers Coronavirus info page
- NIH Coronavirus info page
- American Academy of Family Physicians Coronavirus webpage
For those interested in real-time mapping and seeing where the cases are:
As always, if you have questions or concerns, your healthcare provider at Truesdale Health is there for you. Should you need to be seen for any acute symptoms, please call your provider.