COVID – why terminology really, really matters

Source: Dr. Malcom Kendrick.

Had I written the headline for this commentary, I’d have gone with something cheeky: “How circumstances alter cases.” But that’s just me, and Dr. Kendrick’s title works well enough.

At issue is the technical meaning of the phrase Covid-19 case. To a practicing doctor (and to an honest statistician, I would add), a valid Covid-19 case is one in which symptoms of the disease are present. Definitionally, there is no such thing as an asymptomatic case of Covid-19.

On the surface this is merely common sense: If you have no symptoms, then you aren’t sick and you should not be counted among the ill in statistical reporting. Dr. Kendrick contends that patients who technically are not ill are being reported as Covid-19 cases, potentially scaring the bejeebus out of the public at large for no good reason.

11 thoughts on “COVID – why terminology really, really matters

  1. There are indeed many problems of definition and reporting about Covid-19. What is the actual cause of death of someone who has Covid-19 and other diseases. Are all the cases being identified. Especially when an elderly person passes away. How are these deaths reported and by whom? etc.

    The consensus among epidemiologists seems to be that these problems have lead to a significant under-reporting of the mortality impact of the virus. The reason for that is that this year there are hundreds of thousands of extra deaths above and beyond those attributed to Covid-19. “Extra” in the sense that they are more than are predicted based on modeling from previous year’s data. Leaving definitions and reporting problems aside, this virus is a disaster.

    I cannot agree with this sentiment . . . “scaring the bejeebus out of the public at large for no good reason.”
    There are very good reason to include the asymptomatic in the reporting. For my wife and I, who try to monitor the new cases in Chesapeake each day as indicator of the safety if going to the store, I am glad to have more testing rather than less. A person without symptoms may not be a “case” if someone wants to quibble, but since they can give it to me if I run into them, it is a distinction without a difference as far as being “scared” is concerned.

    Liked by 2 people

    1. RE: “There are very good reason [sic] to include the asymptomatic in the reporting.”

      Do you really mean to suggest that you and your wife prefer to be misled by the data you consult? If that’s true, what about your responsibility to others who prefer to make decisions based on accurate data?


      1. Asymptomatic carriers who are ignorant of their status are actually more of a hazard to public health than the sick people who generally are quarantined or hospitalized thereby reducing the spread of the virus.

        If a person is diagnosed with COVID and they are so sick that they need hospitalization is an obvious case. If he is pretty sick, but the fever is under 102º, they might not get admitted to a hospital. But, of course, they are still sick with COVID.

        We can go on down the line to lesser symptoms, but still positive all the way to asymptomatic. What you are professing sounds like some arbitrary cutoff of labeling someone as “sick” if a certain number of symptoms do not appear.

        Yet, the key issue is contagiousness, regardless of the severity of the disease in some people. Complicating this issue is that COVID can be asymptomatic for a week or longer even if the person eventually gets hospitalized. Seasonal flu’s aren’t contagious until the onset of the symptoms. That is a huge difference with regards to spreading the virus.

        Liked by 2 people

      2. RE: “What you are professing sounds like some arbitrary cutoff of labeling someone as ‘sick’ if a certain number of symptoms do not appear.”

        According to Dr. Kendrick, and to the Wikipedia article he cites, “symptoms are required by the definition of a case of any particular illness. This is also necessary for statistical reporting, as our own Nancy Naive has repeatedly pointed out, referencing Bayes Theorm as the explanation.

        You think the “key issue is contagiousness,” but if that is your concern, you should be quite satisfied by statistics reporting positive test results that do not mislabel them as cases. That would be a foolish way to think (for technical statistical reasons), but you are welcome to it. Just don’t expect the rest of us to take the foolishness seriously.


      3. Len answered your post very well above.

        The point is that knowing how many people around might cause me or my wife to sicken and die IS useful information. It is “accurate data.” For me or anyone else who wants to avoid the virus. Why you would accuse me of wanting to be mislead is a mystery but it is indicative you failing to understand the issues involved with testing and reporting.

        Liked by 1 person

      4. RE: “The point is that knowing how many people around might cause me or my wife to sicken and die IS useful information.”

        Maybe it is, maybe it isn’t. But the probability that an asympotomatic carrier will infect you or your wife is not the issue. The issue is calling asymptomatic patients cases of the disease.

        Dr. Kendrick argues that asymptomatic patients should not be cited as Covid cases, that doing so is a misrepresentation, a lie. I’m baffled to see both you and Mr. Rothman argue that the lie is the truth in some sense.


        1. …”asymptomatic patients should not be cited as Covid cases,”

          Yet how many cases are there that were caused by asymptomatic spread of the contagion? Seems to me that little piece is ignored to the benefit of making the argument that it ain’t as bad as it is being made out to be.


      5. I really do not care whether those who test positive for coronavirus are labeled “cases” or “carriers.” This seems to be an issue with some people because they follow a leader who thinks that there would be fewer cases if we did less testing.

        The tone of this forum has been discussed from time to time. I suggest you look at how you post and think about that issue.

        I politely responded to your original post, agreeing with some of it and stating an alternative view. You came back with . . .

        1. A claim that I preferred to be mislead.
        2. A charge that I was careless of the safety of others.
        3. You referred to Len’s careful and polite response as embracing foolishness.
        4. And now, that Len and I are proposing “the lie is the truth.”

        And all this because you think anyone or someone or you knows EXACTLY what a “case” is and what it is not. This is purely a matter of opinion. If I am exposed to a carrier and test positive for the presence of coronavirus in my body, I consider that I am dealing with a “case” and that is true no matter the severity of the symptoms that do or do not develop. And, for the reason given, I want to know how many such “cases” have occurred among the people I might interact with. No LIES anywhere.

        Liked by 1 person

  2. Technically. COVID-19 is the disease caused by SARS-CoV-2, so if we’re going to be picky, people who are symptomatic have COVID-19 but there are many others infected with and carrying SARS-CoV-2. Of course, some of those are really just pre-symptomatic and others have cardiomyopathy that is, for now, silent.

    It’s one of those cases where context matters, So, it’s COVID-19 patients and SARS-CoV-2 infections.

    Liked by 1 person

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