On Mon, 28 Mar 2022 14:18:20 +0100, Recliner
<recliner.usenet@gmail.com> wrote:

>On Mon, 28 Mar 2022 03:08:15 +0100, Charles Ellson <charlesellson@btinternet.com> wrote:
>
>>On Sun, 27 Mar 2022 23:23:32 -0000 (UTC), Recliner
>><recliner.usenet@gmail.com> wrote:
>>
>>>Charles Ellson <charlesellson@btinternet.com> wrote:
>>>> On Sun, 27 Mar 2022 22:15:19 -0000 (UTC), Recliner
>>>> <recliner.usenet@gmail.com> wrote:
>>>>
>>>>> Charles Ellson <charlesellson@btinternet.com> wrote:
>>>>>> On Sun, 27 Mar 2022 21:54:54 -0000 (UTC), Recliner
>>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>>
>>>>>>> Charles Ellson <charlesellson@btinternet.com> wrote:
>>>>>>>> On Sun, 27 Mar 2022 20:46:35 -0000 (UTC), Recliner
>>>>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>>>>
>>>>>>>>> Charles Ellson <charlesellson@btinternet.com> wrote:
>>>>>>>>>> On Sun, 27 Mar 2022 15:53:01 +0100, Recliner
>>>>>>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>>>>>>
>>>>>>>>>>> On Sun, 27 Mar 2022 15:15:43 +0100, Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> In message <t1o8bo$p0d$1@dont-email.me>, at 23:41:44 on Sat, 26 Mar
>>>>>>>>>>>> 2022, Recliner <recliner.usenet@gmail.com> remarked:
>>>>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>>>>> In message <atoe0djbfzse$.dlg@example1357.net>, at 19:37:01 on Thu, 24
>>>>>>>>>>>>>> Mar 2022, mechanic <mechanic@example.net> remarked:
>>>>>>>>>>>>>>> On Thu, 24 Mar 2022 11:06:55 +0000, Roland Perry wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> I first saw them at scale in a pub which had just reopened with
>>>>>>>>>>>>>>>> stringent Covid precautions. Tables separated, pre-booked only, one-way
>>>>>>>>>>>>>>>> system, one person in toilets at a time, table service only etc. It was
>>>>>>>>>>>>>>>> not at all clear what protection they gave either the waitresses or
>>>>>>>>>>>>>>>> customers.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> That was when we were fed the 'droplets' theory, science is now
>>>>>>>>>>>>>>> reluctantly moving to the aerosol idea where earlier instructions to
>>>>>>>>>>>>>>> clean surfaces and wash hands have given way to more emphasis on
>>>>>>>>>>>>>>> ventilation and effective masks.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I suppose I always did think it was mainly transmitted by the smaller
>>>>>>>>>>>>>> droplets know trendily known as aerosols, rather than spit and sneeze.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Still wouldn't want a Covid person to spit in my face though.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Breathing in your direction might be worse.
>>>>>>>>>>>>
>>>>>>>>>>>> 2metres, 30 seconds, and both masked, shouldn't be an issue.
>>>>>>>>>>>
>>>>>>>>>>> No, probably not, but nor would spitting in those circumstances.
>>>>>>>>>>>
>>>>>>>>>> Saliva is generally a far better carrier of infection if it lands on
>>>>>>>>>> targer.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Are you sure that's true of Covid? It's an airborne virus.
>>>>>>>>>
>>>>>>>> It isn't just airborne. The virus is present in saliva, mucous and
>>>>>>>> other bodily secretions. The difference with saliva (in original form)
>>>>>>>> is the practical need for more direct transmission from infection
>>>>>>>> source to entry route (e.g. snogging, spitting on target etc.) than is
>>>>>>>> needed with aerosols which generally require a relatively longer
>>>>>>>> presence to enable infection.
>>>>>>>>
>>>>>>>
>>>>>>> Would virus particles present in saliva get into a potential victim's
>>>>>>> airway?
>>>>>>>
>>>>>> Your airway starts at your nose and mouth. Coughing and sneezing can
>>>>>> cause a heavier and more concentrated stream of saliva than you get
>>>>>> with an aerosol.
>>>>>>
>>>>>> "The virus can spread from an infected person?s mouth or nose in small
>>>>>> liquid particles when they cough, sneeze, speak, sing or breathe.
>>>>>> Another person can then contract the virus when infectious particles
>>>>>> that pass through the air are inhaled at short range (this is often
>>>>>> called short-range aerosol or short-range airborne transmission) or if
>>>>>> infectious particles come into direct contact with the eyes, nose, or
>>>>>> mouth (droplet transmission)."
>>>>>> https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/coronavirus-disease-covid-19-how-is-it-transmitted
>>>>>>
>>>>>
>>>>> A mask wearer is presumably reasonably well protected against droplets
>>>>> landing on their mouth or nostrils and then breathing in the particles. Is
>>>>> there any evidence that the virus can be transmitted via the eyes?
>>>>>
>>>> Your eyes drain internally to your nose via the nasolacrimal duct;
>>>> infection via the eye itself is less common. Eye protection is
>>>> standard kit for ambulance and first aid personnel dealing with
>>>> potential COVID patients.
>>>>
>>>
>>>Is that precaution based on actual evidence of risk from Covid, or simple
>>>(sensible) caution all infections?
>>>
>>The eye and associated areas have been regarded as a viable route of
>>infection for over a century :-
>>https://jamanetwork.com/journals/jama/article-abstract/220430
>>
>>>One thing we do know is that a lot of the often misinformed
>>>Covid precautions have at least protected against other illnesses in the
>>>last two years. For example, all that hand sanitisng didn't do much to
>>>block Covid but probably reduced food poisoning.
>>>
>>Without experimenting you have no proof for that. COVID was known to
>>persist longer on non-absorbent surfaces (e.g. handrails, door handles
>>etc.) while alcohol is efficient in destroying membranes that hold
>>viruses together as well as being a long-proven general antiseptic.
>
>I'm asking what actual research has been done about how Covid is spread. Or are they just assuming it's similar to other
>diseases (when we know it's not)?
>
There is plenty of research material available but as a novel disease
it is currently more heavily based on observation and experience.
>
>>Hand sanitising doesn't work when people don't practise it and I have
>>been around long enough to see that there are plenty of people who are
>>best described as selfish filthy bastards when it comes to considering
>>community hygeine.
>
>Yes, I agree that hand sanitising is good for public health, but just question whether it does much to slow the spread
>of Covid specifically. Has anyone done any actual research? They certainly hadn't when the advice was first given.
>
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/897598/S0574_NERVTAG-EMG_paper_-_hand_hygiene_010720_Redacted.pdf

Note that it can be inferred that standard door handles on
manually-opened doors, supermarket trolley/basket handles etc. are an
infection risk which simultaneous use of sanitisation should be
effective against.