THE FOX ON THE CAMERA, THE CHICKENS IN ARMOR: A COVID-19 analogy for workplace testing

As companies move to implement the new OSHA emergency temporary standard (ETS), it is worth noting that two COVID-19 misconceptions abound:

1.????Weekly SARS-CoV-2 testing is what keeps people safe

2.????Testing by PCR is more accurate than rapid antigen testing

The following analogy illustrates why both statements are false.

Imagine a henhouse full of chickens (a workplace with its employees). Outside the henhouse lurks a hungry fox (the SARS-CoV-2 virus).

Protecting the henhouse (COVID-19 mitigation for businesses)?

A prowling fox’s progress is blocked by henhouse defenses. One defense resides in the chickens themselves; some birds have encountered other foxes previously (prior infections). Fox-experienced chickens better duck and weave to avoid subsequent fox-induced injuries (prior experience with COVID-19 confers at least some degree of “natural immunity”).

Also good at ducking and weaving are fit, well-nourished chickens (healthy lifestyle providing bodily resilience). Conversely, chickens who eat poorly and who are sedentary fare less well in evading fox attacks (both unhealthful diet and inactivity increase COVID-19 risk).?

Younger chickens are relatively protected from foxes (COVID-19 risk increases with age). Likewise, thin chickens enjoy relative safety (obesity being a substantial COVID-19 risk factor). Older, bigger chickens are more enticing to foxes.

Chicken vigilance additionally provides protection. Any henhouse reports of fox activity (e.g., COVID-19 symptoms screens) help preserve safety for all. Furthermore, fox-deterrent systems (ventilation, filtration, disinfection) work to keep the predator at bay. Should a fox somehow succeed in entering the henhouse, extra impediments (masking, distancing, barriers) can stymie successful advance.

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Adding a security camera (SARS-CoV-2 testing)

As an additional layer of protection, the henhouse might install a security camera. The camera (SARS-CoV-2 testing) periodically surveils the surrounding grounds. One kind of camera (PCR testing) is very sensitive. The camera’s detection system is triggered by even the slightest fox-like activity. Indeed, the camera records almost any fox in its view. Unfortunately, not all foxes pose a threat.?

Helpfully, the camera detects almost all foxes actively hunting chickens (contagious SARS-CoV-2). Less helpfully, the camera also detects wounded, withdrawing foxes (immune-system de-activated SARS-CoV-2). In other words, the camera’s fox-detection system is not able to distinguish stalking predators from injured deserters. As a consequence, retreating foxes licking their wounds can look like advancing foxes licking their chops (false positives); the result could be unnecessary henhouse lock downs (i.e., avoidable workplace quarantines).

The other problem with the highly sensitive camera (PCR testing) is that it takes considerable time for images to develop. While fox activity might be recorded on one day, the images might not be available until several days later (lab-based PCR often taking multiple days to result). By the time images can be reviewed, it may be much too late to act; a hunting fox will have already done irrevocable henhouse damage.

A final problem with the high-sensitivity camera is its expense (PCR remains relatively pricey). The henhouse thinks it wants the maximum amount of fox detection. But undifferentiated any-fox images come at a high cost—especially when considering expenses resulting from unnecessary image delay. ?

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More helpful images (shifting from PCR testing to rapid antigen)

A solution to delayed and undifferentiated any-fox images is to replace the camera’s fox detection system. The detector should be triggered only by stealthy hunting foxes (contagious infections), not lumbering, maimed foxes (infections no longer infectious).?

A new detector (rapid antigen testing) gives better differentiation. It is more selective, showing only hunting foxes (live, transmissible, SARS-CoV-2). Greater selectivity allows for shorter processing times—minutes as opposed to days. Thus relevant fox images are available almost immediately (rapid antigen tests are rapid).?If there is a fox in an image (positive antigen test), it is a fox of concern (contagious virus)—and something can be done about it in real time.

Another benefit of the new detector is its lower cost (rapid antigen testing can be many times cheaper than PCR). If the henhouse shifts to the lower-cost detector, it actually gets higher quality, more actionable information, faster. The lesser detection actually results in greater accuracy (antigen testing is more accurate than PCR for population screening). More-selective detection is actually an upgrade (antigen testing is superior to PCR for what we want to know).

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The most important protection (what matters most for COVID-19)

Regardless of camera performance, however, a reasonable question is how much protection could possibly come from weekly camera use? (weekly SARS-CoV-2 testing)?Any surveillance camera, turned on for just a few minutes once every seven days, certainly could discover a prowling fox. But for every other minute—of every other day—foxes could come and go as they please.?Completely undetected!

In other words, weekly spot surveillance is by far the least—THE LEAST—important measure in fox protection (COVID-19 mitigation).?All other factors (“Protecting the Henhouse” above) are far more important.

Regardless, even more important than even all those factors is the single most protective henhouse measure—body armor!

Yes, placing chickens in armor (COVID-19 vaccination) is strong fox protection. No, armor is not perfect (“breakthrough” infections can occur). Indeed, some chickens’ parts protrude. But critical parts are covered. And serious—or fatal—wounds to exposed parts are rare (most infections in vaccinated individuals are mild).

Foxes far prefer easier meals (vulnerable, unvaccinated individuals). And foxes couldn’t care less if they get caught on camera. So maybe we should forget the cameras (testing). Maybe we should instead double down on providing armor (vaccination). That’s how we protect our henhouses (all of our businesses). That’s how we frustrate foxes (that’s how we return to normal).

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PLAIN-LANGUAGE BOTTOM LINES:

• For protecting employees (and employers from liability):

Vaccination = best; testing = not very good

• If <100% of employees are vaccinated (and employers are forced to test):

Rapid antigen = best; PCR = not very good