COVID19 update, March 27, 2020: (1) how long does the virus survive on surfaces? (2) more anecdata about remdesivir

You have all seen the reports that the virus “survives” for three hours on copper, 1 day on cardboard, 3 days on stainless steel, and whatnot— but what does this really mean?

First of all, “survival” of the virus on a fomite (the epidemiological term for an object that can hold a pathogen and pass it on to another person using the object) is not a binary state. It’s not like if somebody touched your stainless steel doorknob, say, 2d23h ago you will get infected from it, but at 3d exactly you’d be OK. Empirically, “survival” of such pathogens roughly follows an exponential decay curve (like radioactivity), and the meaningfully measurable parameter is the “half-life”, i.e., how much time does it take for the titer (virus “count”) to be halved.

Here is a recent research article in the New England Journal of Medicine where they empirically studied the question for both SARS-CoV-1 (the 2002-3 SARS virus) and the current SARS-CoV-2.
It seems that the various “survival” times being bandied about in the popular press correspond to either drops by four orders of magnitude in titer (that’s a bit more than 13 half-lives), or to the point where the pathogen concentration fell below the detection limit.

Excerpt from Figure 1 of the paper, showing uncertainty intervals.

The other item I want to highlight for today: I’ve mentioned the proprietary drug remdesivir (originally developed by Gilead Scientific for ebola) and anecdotal evidence of its effectivity against COVID-19 when used as a “Hail Mary Pass” on a critically ill patient in Washington.
Now (hat tip: Mrs. Arbel) there is more such evidence from Israel (link to Haaretz, which is a far-left newspaper but tends to have fairly reliable science reporting, as so many of its limited readership are in academia):

As for coronavirus patients in serious condition, the ministry proposed – in addition to treating respiratory failure and supportive treatment – using the drug Remdesivir, which was used in the case of Patient 16. The 38-year-old bus driver from East Jerusalem was in serious condition and the drug improved his situation dramatically, so much so that he was in good condition after the treatment.

For background, “Patient 16” who was treated at the Poriah Hospital in Tiberias, had been driving around a group of pilgrims from Greece to Christian sites in Israel, the Palestinian Authority, and Egypt in a tour bus. Upon their return to Greece, 21 of the pilgrims tested positive. It is not clear where they originally got infected.

As I mentioned earlier, “remdesivir is a so-called “nucleotide analog”. In plain English, it pretends to be a nucleic acid (i.e., a letter in the genetic code), but when the “imposter” is being incorporated in a piece of RNA instead of the real nucleotide, it has no place to attach the next one, and copying stops. Thus, the virus cannot reproduce.”

To be updated. Stay healthy, stay safe, and stay calm.

UPDATE 1: Roger Seheult, MD’s medical tutoring channel “MedCram” on YouTube with a video on antibody testing in general, and its specifics in the case of COVID-19

UPDATE 2: The Tagesspiegel (in German) has a very detailed report on “The Taiwanese anomaly”: why the island nation, despite many visitors to and from mainland China, appears to have largely dodged the bullet, without resorting to lockdowns. The article refers to an English-language report in the Journal of the American Medical Association.
TL;DR version: Like in South Korea, an early clampdown, aggressive testing and tracking, and “big data” analytics were the key. Taiwan acted almost immediately following the initial (as we now know, scandalously delayed) December 31 report. While South Korea got its “dress rehearsal” during the limited 2015 MERS outbreak, Taiwan got it during the 2003 SARS outbreak.

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