I am attempting to make this post about 90% boring factual data and only 10% fun, exciting and insightful opinion.  There is a lot of valid but misleading and coincidentally, misunderstood information about what constitutes a COVID-19 “case” as it is generally reported by media and politicians.

Most people think that the number of cases reported and headlined are people sick and dying of the corona virus.  To be sure there are people being treated for and potentially dying because of COVID-19.  However, while the numbers of cases being treated may be included in the numbers being reported, they are not the same thing.

This post is not about people being treated for corona virus or the doctors and other healthcare professionals.

This is about Surveillance Cases.

The CDC definition of a case for reporting purpose is a “surveillance case”.

https://wwwn.cdc.gov/nndss/conditions/coronavirus-disease-2019-covid-19/case-definition/2020/

NOTE: A surveillance case definition is a set of uniform criteria used to define a disease for public health surveillance. Surveillance case definitions enable public health officials to classify and count cases consistently across reporting jurisdictions. Surveillance case definitions are not intended to be used by healthcare providers for making a clinical diagnosis or determining how to meet an individual patient’s health needs.

Remember the last sentence as we walk through the surveillance case reporting criteria taken directly from the CDC CSTE Position Statement(s).

“Clinical Criteria

At least two of the following symptoms: fever (measured or subjective), chills, rigors, myalgia, headache, sore throat, new olfactory and taste disorder(s)

OR

At least one of the following symptoms: cough, shortness of breath, or difficulty breathing

OR

Severe respiratory illness with at least one of the following:

    • Clinical or radiographic evidence of pneumonia, OR
    • Acute respiratory distress syndrome (ARDS).

AND

No alternative more likely diagnosis”

OPINION INSERTED:

If you have ever had a fever and sore throat, or headache and chills, or other combinations, according to the CDC, you could be presumed to be a COVID-19 surveillance case.

If you have ever had a cough, according to the CDC, you could be presumed to be a COVID-19 surveillance case.

If you have ever had pneumonia, according to the CDC, you could be presumed to be a COVID-19 surveillance case.

Not what you thought?  Me either.  To be fair, you probably would not be reported as a COVID surveillance case unless you went to the doctor or a clinic.  But the flu, heat stroke, a heart attack or pregnancy might get you there, right?

Back to the boring facts in the CDC CSTE Position Statement(s).

“Laboratory Criteria

Presumptive laboratory evidence:

    • Detection of specific antigen in a clinical specimen
    • Detection of specific antibody in serum, plasma, or whole blood indicative of a new or recent infection*

*Serologic methods for diagnosis are currently being defined.”

OPINION INSERTED:

The “specific antigen” is pretty much evidence that you are “sick” with the virus.  However, the “specific antibody” means that you had the virus at some point and presumably didn’t die and now have at least some degree of immunity.

That seems like the exact opposite of being sick with a treatable case.  In fact, they may collect your blood for use in developing a vaccine.  However, you will be recorded as a COVID surveillance case and included in the number of cases you read about in the morning paper.

I can hardly wait for serologic methods for diagnosis to be defined.  But, hey…how important could that be?

Back to the boring facts in the CDC CSTE Position Statement(s).

“Epidemiologic Linkage

One or more of the following exposures in the 14 days before onset of symptoms:

    • Close contact** with a confirmed or probable case of COVID-19 disease; OR
    • Close contact** with a person with:
      • clinically compatible illness AND
      • linkage to a confirmed case of COVID-19 disease.
    • Travel to or residence in an area with sustained, ongoing community transmission of SARS-CoV-2.
    • Member of a risk cohort as defined by public health authorities during an outbreak.

**Close contact is defined as being within 6 feet for at least a period of 10 minutes to 30 minutes or more depending upon the exposure. In healthcare settings, this may be defined as exposures of greater than a few minutes or more. Data are insufficient to precisely define the duration of exposure that constitutes prolonged exposure and thus a close contact.

OPINION INSERTED:

“Travel to or residence in an area with sustained, ongoing community transmission of SARS-CoV-2” would seem to mean at least New York and probably any major city at the top of the COVID-19 surveillance list.  So if you go there, you are automatically reported as a case which in turns adds to the number of cases.  Kind of a vicious circle, huh?

Member of a risk cohort in this outbreak would include anyone over the age of 65 and anyone with any life-threatening disease.  What do you know?  Vicious concentric circles.

Glad to see that they didn’t let insufficient data to define—well, any word in their definition—get in the way of defining how close is close, how long is prolonged and the duration of exposure depending upon the exposure.  (sarcasm font)

Back to the boring facts in the CDC CSTE Position Statement(s).

“Criteria to Distinguish a New Case from an Existing Case

Not applicable (N/A) until more virologic data are available.”

OPINION INSERTED:

Time-the-flock-out!  The CDC has no way to distinguish a new case from an existing case until more virologic data are available?  So…that would mean that every surveillance case must be reported as a new case.

Good thing nobody is using the number of new cases to determine reopening strategies affecting the lives millions of people and the economic future of the country.  Oh, wait—

Back to the boring facts in the CDC CSTE Position Statement(s).

“Case Classification

Probable

    • Meets clinical criteria AND epidemiologic evidence with no confirmatory laboratory testing performed for COVID-19.
    • Meets presumptive laboratory evidence AND either clinical criteria OR epidemiologic evidence.
    • Meets vital records criteria with no confirmatory laboratory testing performed for COVID-19.”

OPINION INSERTED:

As near as I can tell, if there is “no confirmatory laboratory testing performed for COVID-19” you are presumed to have a 92.678% probability of being reported as a probable COVID-19 surveillance case.

I just made up that percentage but, as far as making things up goes, I don’t appear to be alone.