COVID19 update, June 7, 2020: Do-it-yourself COVID-19 tests found to be more accurate as well as comfortable; Israeli study confirms protective effect of smoking?!; “half of colleges may close in the next 5-10 years”

(1) Via Instapundit, a popular writeup of a study that found samples acquired by the patients themselves were more accurate than the usual deep nasal and pharyngeal swabs, and not just more comfortable. Besides, they are less likely to expose healthcare personnel, as deep sampling often causes sneezing, coughing, and gagging.

I should perhaps clarify here that the accuracy-limiting factor of RT-PCR testing, at this point, is not the testing apparatus at all (with lab-prepared samples, accuracy approaches 100%) but the sampling technique.

 

The original scientific article about the study was published in the New England Journal of Medicine: http://doi.org/10.1056/NEJMc2016321

Here is an animation of how, once the sample has been acquired, RT-PCR testing works in the lab.

 

(2) There were several reports that, counterintuitively, smokers were underrepresented among COVID19 positive cases. Now in https://www.medrxiv.org/content/10.1101/2020.06.01.20118877v2.full.pdf is an intriguing large-sample study from doctors associated with Clalit Health Services, the largest HMO in Israel which has about 3 million patients in its central database. [Full disclosure: we are insured through a competitor. All four authorized HMOs operate such databases—unlike with Surgiscape, I have every reason to believe these data are kosher.]

As of the cutoff date (May 16), over 145,000 adults insured with Clalit underwent RT-PCR testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2),  3.3% of which tested positive. After discarding cases aged under 18 and over 95, as well as those where it was unknown whether they smoked or not, the authors were left with 4,235 positive tests and 124,192 negative. Out of the latter, they randomly selected a control sample of 20,755 patients (5x as many) that matched statistical make-up of the positive sample in terms of gender, age distribution, and ethnosocial group — Jewish Orthodox, Arab, General(mostly Jewish non-Orthodox).

Guess what: Statistically, 9.8% of the  COVID19 positive cases smoke currently, one-half the percentage in the control group 18.2%. Because of the large sample size, p<0.001, i.e., the probability that this result could have arisen from “the luck of the draw” is less than 0.1%. There was no significant difference for past smokers (11.6 vs. 12.9%) — it’s definitely got something to do with current smokers (nicotine or some other component of tobacco smoke).

Of the COVID19-positive tests, 1.8% deceased, 2.0% hospitalized in severe condition, 4.0% in moderate condition, 15.0% in mild condition, the remaining 77.2% did not require hospitalization. There was no significant correlation between the degree of severity and the patient’s smoking status.

Changeux et al11, relying on similar observations, propose a crucial role for the nicotinic acetylcholine receptor (nAChR) in COVID-19 pathology. According to their neurotropic hypothesis, SARS-CoV-2 invades the central nervous system through the nAChR receptor, present in neurons of the olfactory system, as reflected by the frequent occurrence of neurologic symptoms, such as loss of smell or taste, or intense fatigue in patients affected by COVID-19. Other mechanisms may also affect SARS-CoV-2 infection potential in smokers. It is widely accepted that the angiotensin converting enzyme 2 (ACE2) represents the main receptor molecule for SARS-CoV-2, and smoking has been shown to differentially affect ACE2 expression in tissues12–14. Other putative explanations could involve altered cytokine expression such as IL-6, for which increased levels are associated with unfavorable disease outcome14,15.

 

 

(3) Business school professor admits that as many as half of tier-2 colleges will be gone in the next 5-10 years. This was a bubble waiting to burst anyway: the COVID-19 crisis and the attendant shift to online learning is just precipitating the burst, the way Amazon and online shopping more generally were the downfall of many a brick-and-mortar store.

(4) This is the sort of behavior that makes me cringe in embarrassment for my profession. True scientists follow the facts wherever they lead, and seek the truth wherever it may be found. Political hacks exist in every profession — but they are especially grating in ours. And when the public loses all faith in us because of such politicized hacks, it will be blamed on “anti-science” and anti-intellectualism.

 

2 thoughts on “COVID19 update, June 7, 2020: Do-it-yourself COVID-19 tests found to be more accurate as well as comfortable; Israeli study confirms protective effect of smoking?!; “half of colleges may close in the next 5-10 years”

  1. #4-
    science can predict what is likely to happen. It can’t say if it’s worth it or not.
    (Even with 90% accuracy, you’re still wrong one in ten. It is amazing how much flipping that formatting around can change the look of a situation.)

    *********

    On smoking– doesn’t smoking give the rush it does in part because it increases the blood flow in your lungs?

    Maybe that does something to prevent blood clots from making trouble, which makes someone less likely to get sick bad enough to be tested?

    It’s an odd result, for sure!

    (The snark in me says “Sure, because nobody wants to be that close to a smoker!” Is just snark, though.)

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