Finally starting to get some numbers on minimum-infectious-dose for SARS-CoV-2 ... alas the news is deeply worrisome:

[url=https://www.medrxiv.org/content/10.1101/2020.07.27.20162362v2]Exposure to a COVID-19 carrier: transmission trends in respiratory tract and estimation of infectious dose[/url] | medRxiv. Serious work on droplet size and transmission. At the conclusion of the Discussion:
[quote]Now to derive an estimate of infectious dose, consider the March 2020 Skagit Valley Chorale superspreading incident inthe United States, where an infected person transmitted the disease to 52 other individuals in a 61-member choir group. Exposure time there was reported to be 2.5 hours; consequently, for an average RNA load (assuming that the carrier had mild-to-moderate symptoms), the number of virions depositing at a closely-positioned susceptible individual’s nasopharynx over that duration approximates to (11/5) x 2.5 x 60 ≈ 330. So, 300 can be considered a conservative upper estimate for the COVID-19 infective dose, the order agreeing with preliminary estimates from replication rates of the virus. That the number of virions needed to establish the infection is, at most, O(10^2) is indeed remarkable! The scale clearly manifests how communicable this disease is, especially if discerned in the perspective of infectious doses for other airborne transmissions, e.g. the infective dose for influenza A virus, when administered through aerosols to human subjects lacking serum neutralizing antibodies, ranges between 1950 – 3000 virions. The discovery of infectious dose, together with this study’s detection of droplet sizes that target the infection-prone nasopharynx, could provide a useful resource in mitigating the COVID-19 pandemic and in the mechanistic design of topical anti-viral therapeutics and targeted intra-nasal vaccines that can induce prophylaxis through mucosal and systemic immune responses.[/quote]
So: wear a mask whenever you leave the house, pull it up over mouth & nose whenever close proximity to others is likely, or unavoidable. Wash hads & face first thing on returning home, before you have a chance to unconsciously touch your now-maskless face. I also continue to snort my 35%-alcohol homemade saline solution after coming insde and handwashing (dip a latex-gloved fingertip in the stuff, stick up nostril, snort, repeat several times on each side) - having been forced to use cheap vodka in place of rubbing alcohol for several months early in the pandemic, I can say it's a little less nasty-smelling than isopropyl. My own crude version of a targeted intra-nasal vaccine, as it were.

[QUOTE=ewmayer;552871]Finally starting to get some numbers on minimum-infectious-dose for SARS-CoV-2 ... alas the news is deeply worrisome:


So: wear a mask whenever you leave the house, pull it up over mouth & nose whenever close proximity to others is likely, or unavoidable. Wash hads & face first thing on returning home, before you have a chance to unconsciously touch your now-maskless face. I also continue to snort my 35%-alcohol homemade saline solution after coming insde and handwashing (dip a latex-gloved fingertip in the stuff, stick up nostril, snort, repeat several times on each side) - having been forced to use cheap vodka in place of rubbing alcohol for several months early in the pandemic, I can say it's a little less nasty-smelling than isopropyl. My own crude version of a targeted intra-nasal vaccine, as it were.[/QUOTE]

ISOPROPYL ?!?!?!?

Dear Mr Hughes,
Are you aware this is poisonous? Especially when exposed to mucous membranes which will get it into your bloodstream much quicker than drinking.
You are better off with the cheap vodka.

[QUOTE=tServo;552904]ISOPROPYL ?!?!?!?

Dear Mr Hughes,
Are you aware this is poisonous? Especially when exposed to mucous membranes which will get it into your bloodstream much quicker than drinking.
You are better off with the cheap vodka.[/QUOTE]Ethanol is also poisonous, though not quite as much as are the propanols.

In my opinion, the major problem with 2-propanol[SUP]*[/SUP], is that it gives a much nastier hangover and not so pleasant an intoxication.

* based entirely on a study of the literature, of course...

I have pointed out before in this thread that these posts should be removed. They are highly irresponsible. I just heard on the news that 4 people have died and a few more gone blind for drinking hand sanitizers. Many are recalled for containing wood alcohol. And if you think rubbing alcohol is necessarily safe, see this story from way before Covid-19:
[url]https://technology.inquirer.net/47069/rubbing-alcohol-brand-recalled/amp[/url]

These posts are reachable by billions of people with differing levels of intelligence and will linger on various internet caches for centuries if not longer.
Alas the mods on this board are in a class of their own to put it politely.

[QUOTE=tServo;552904]ISOPROPYL ?!?!?!?

Dear Mr Hughes,
Are you aware this is poisonous? Especially when exposed to mucous membranes which will get it into your bloodstream much quicker than drinking.
You are better off with the cheap vodka.[/QUOTE]

Looks like I picked the wrong week to quit sniffing glue.

[QUOTE=a1call;552921]I have pointed out before in this thread that these posts should be removed. They are highly irresponsible. I just heard on the news that 4 people have died and a few more gone blind for drinking hand sanitizers. Many are recalled for containing wood alcohol. And if you think rubbing alcohol is necessarily safe, see this story from way before Covid-19:
[url]https://technology.inquirer.net/47069/rubbing-alcohol-brand-recalled/amp[/url]

These posts are reachable by billions of people with differing levels of intelligence and will linger on various internet caches for centuries if not longer.
Alas the mods on this board are in a class of their own to put it politely.[/QUOTE]The differently-clued will reach their own conclusions regardless of what we contribute. The amount of input from MF to their thought processes is way down in the noise even assuming that they read it. Such an assumption is questionable in my opinion..

I love your usage of the quaint term "board". You are showing your age, as am I in being able to recognize it instantly without having to look it up.

[QUOTE=xilman;552942]The differently-clued will reach their own conclusions regardless of what we contribute. The amount of input from MF to their thought processes is way down in the noise even assuming that they read it. Such an assumption is questionable in my opinion..

I love your usage of the quaint term "board". You are showing your age, as am I in being able to recognize it instantly without having to look it up.[/QUOTE]

Well you are not the 1st person to have noticed my dictation excellence.
You are correct in that it is age related but probably not for the correct mechanics,
I use Phone's google keybored (Swipe feature) to communicate on this board and proof reading with aged vision is not foolproof. Of course, if i were to actually spell everything myself it would come across as gibberish as I could not spell anything properly at any age.:smile:

ETA I just noticed that I proofread Bulletin=Bored wrong again. My apologies. It's difficult to be funny on purpose when you are old.

[QUOTE=a1call;552921]I have pointed out before in this thread that these posts should be removed. They are highly irresponsible. I just heard on the news that 4 people have died and a few more gone blind for drinking hand sanitizers.[/QUOTE]

Fewer than 5 drops of diluted-to-35% alcohol up one's nose != equate to drinking multi-ounce servings of hand sanitizers. 5 average-sized drops ~= 0.25 ml, thus we're talking < 0.1g of alcohol. If someone posts credible data comparing the toxicity of that amount of isopropyl alcohol to drinking straight ethanol showing that it's more toxic than, say, 50g of the latter, I'll be happy to add a loud "IF YOU TRY THIS, USE ETHANOL ONLY" warning to my above posts.

Oh, [url=https://www.healthline.com/health/isopropyl-alcohol]lookee here[/url] - isopropanol is absorbed readily not just through mucus membranes, but through skin, so make sure to sue your doctor next time he or she uses a standard rubbing-wipe on your skin prior to giving you a shot:
[quote]Your body can handle small amounts of IPA. In fact, your kidneys remove approximately 20 to 50 percent of IPA from your body. The rest is broken down into acetone by enzymes known as alcohol dehydrogenases. This acetone is filtered out of your body through your lungs or kidneys.

However, when you ingest more IPA than your body can manage (which occurs around 200 milliliters for an adult), poisoning can occur.[/quote]
Got that last bit? *Hundreds* of ml, on the order of 1000 times the amount I may have used.

So, yes, as with all non-FDA-approved self-dosage regimens caution is warranted, but as with all health-related matters, [b]cautions should be grounded in reality[/b]. Telling people mask-wearing (and doing so properly) is not a must, as many health experts did in the early months of the pandemic, *that* is highly irresponsible, based simply on the precautionary principle.

You want irresponsible? Here's an example from early February, someone citing their nation's health minister making evidence-free claims about lack of asymptomatic transmission and doing a bit of national-pride chest-thumping to boot:
[QUOTE=a1call;536533]Canadian Health Minister States that asymptomatic people do not transmit the virus.

[url]https://globalnews.ca/video/rd/e17a62ee-449f-11ea-aa37-0242ac110003/?jwsource=em[/url]

Makes you kind of proud to be a Canadian and not to give in to unjustified panic like most of the rest of the world.:smile:[/QUOTE]

[QUOTE=xilman;552942]I love your usage of the quaint term "board". You are showing your age, as am I in being able to recognize it instantly without having to look it up.[/QUOTE]
All together now: ATDT...

[QUOTE=Nick;552965]All together now: ATDT...[/QUOTE][SPOILER]Hayes modem commands![/SPOILER]

:mike:

[QUOTE=Nick;552965]All together now: ATDT...[/QUOTE]

Many times did I ATDT my favorite 300 baud BBS: The Sanctuary in Oklahoma City.

EDIT: Even had a 2nd phone line installed in my house for it!