Ebola will NOT go airborne

This is an easy to read summary combining and comparing the field studies and experiments that many are quoting. Importantly it also includes conclusions from the most recent study done by the group that originally did the pig to monkey experiments, results of which were published in Nature a month ago.

Will post links at bottom of article.


Pigs And Primates: Addressing The Airborne Ebola Allegation 08.12.2014

Is Ebola Airborne? It's a question of pigs and primate

The Ebola outbreak in West Africa has gained international attention, due in part to the recent declaration of a Public Health Emergency of International Concern (PHEIC). In turn, public health officials have been asked to enact stricter infection prevention and control measures to ensure spread is minimized. The guidelines stem from the evidence demonstrating the virus can only be transferred through direct contact with bodily fluids and contaminated surfaces and equipment. But while these are widely accepted routes of transmission, another more problematic option continues to be debated.

Is Ebola airborne?

Airborne infection is a specific form of spread in which an individual becomes infected while maintaining a distance of over six feet from an sick person. The transfer is based on the physical properties of aerosols, defined as a suspension of particles ranging from 0.001 to 100 micrometers in size. In order for this type of spread to occur, the liquid components of aerosols, known as droplets, must be able to defeat gravity and travel greater than a six foot distance.

If a droplet is over 60 micrometers, it is a ‘large droplet’ and will fall relatively quickly. If the size is between 10 and 60 micrometers, it is a ‘small droplet’ and it can spread up to six feet. If it is smaller than 10 micrometers, it is a ‘droplet nuclei’ and can spread even further distances. Airborne transmission therefore can only occur through droplet nuclei.

The possibility of airborne Ebola infection was first investigated during a 1979 outbreak in South Sudan. The researchers examined the spread of the virus within families and sought to determine if there was any definitive airborne spread. Unfortunately, there was no possible way to prove one way or the other as evidence of close contact precluded any opportunity to identify airborne routes. They concluded transmission through the air may be possible, but highly difficult.

In 1995, during an outbreak in the Democratic Republic of the Congo, the question arose yet again. In this case, surveillance of the cases revealed five patients had contracted the virus without direct contact with an infected individual. This suggested there might be the possibility of aerosol transmission. The possibilty was reinforced by an animal study in the same year in which non-direct contact was observed between monkeys. While they authors could not rule out droplet infection, they suggested the airborne route was a definite possibilty.

The search for a definitive answer continued for years until a Canadian team published a strong case for airborne transmission. In the study, the group took piglets, infected them with the Ebola virus, and placed them into a room containing cages holding four cynomolgus macaques sitting 4.5 feet above the floor. Over the next two weeks, samples were collected from animals, cages and the air in the hopes of finding the virus. Within seven days, the macaques became rather unwell and virus was detected in their bodily fluids. In addition, virus was found to exist both in the cages and in the air.

The results appeared to be conclusive due to several reasons. There was a large separation between the pigs and primates; they could not have had direct contact. There was evidence of virus in the air suggesting the route was airborne. Finally, the macaques became ill with Ebola. It seemed to be a slam dunk.

There was, however, one caveat. Pigs are the most efficient species for generation of short-range, large and small droplets capable of traversing the distance between the floor and the cages. There may have been transmission to the macaques through droplets sent upwards. Though this was unlikely,the team could not definitively say Ebola was spread through the airborne route.

To attain final confirmation, the team needed to conduct one last experiment. Last month ( Aug 2014 in Nature and link given below)), they reported those findings and learned how a caveat can all but cancel out a conclusion. For those in the airborne transmission camp, this was a rather large no .

For this study, the team decided to take the porcine paradox out of the equation. They tested whether the virus could transmit between primates. Sets of two cages were spread across a room with at least 3 feet between them. In one set were infected cynomolgus macaques; in the other were healthy Rhesus macaques. They were kept together for up to 28 days and observed for any signs of transmission. There was, however, none. Not only did the healthy monkeys survive, there was no evidence of any virus transmission in their bodily fluids.

In retrospect, the authors believed the use of pigs gave the airborne argument an unfair advantage. Pigs could produce significantly more virus than primates, suggesting a greater chance for droplet spread. In addition, because of the massive amount of shedding pigs display when sick, there was a greater opportunity for the monkeys to become infected through the respiratory tract. However, this type of spread is droplet, not airborne. There was no other option than to conclude Ebola was simply not an airborne virus.

Although the question of airborne transmission may be put to rest thanks to this study, there are still concerns for anyone coming within a six foot radius of an infected individual to prevent droplet spread. This means ensuring the use of a mask along with gloves, gown and eye protection and adherence to proper disinfection procedures afterwards. Even if not airborne, Ebola is still one of the most dangerous pathogens and we need to be vigilant and resilient to contain outbreaks and keep new ones from starting.

http://www.nature.com/srep/2014/140725/srep05824/full/srep05824.html
http://www.popsci.com/blog-network/under-microscope/pigs-and-primates-addressing-airborne-ebola-allegation?dom=PSC&loc=recent&lnk=6&con=of-pigs-and-primates-addressing-the-airborne-ebola-allegation


As a further note, I understand why they are saying this about pig to human perhaps mode of transmission is different. Look on google pictures of west point and you can see many people live near or with pigs. Perhaps that is something of note. Droplet transmission is not true airborne in an epidemiological sense. If Ebola which requires so few viral particles to transmit were true airborne the Ro number surely would be massive.

On top of this many of the infected aid workers suggest they contracted Ebola not while working in the units but outside. Dr Brantley blames the evaluation of patients brought to A&E which was not done in full gear. He had faith, he comforted relatives in a physical way when he shouldn't have, Dr sacra was in maternity, William pooley and the baby story. We have UK doctors who have returned after working 3 month rotations directly with Ebola patients, and they are fine. So far it just doesn't add up to true airborne.

That said they are learning all the time during this outbreak, I hope they learn quicker and help these poor people who must be confused and terrified.

Hpx

this whole argument reminds me of descriptions of medieval churchmen

arguing over how many angels could dance on the head of a pin

this article settles it for me

COMMENTARY: Health workers need optimal respiratory protection for Ebola

http://www.cidrap.umn.edu/news-perspective/2014/09/commentary-health-workers-need-optimal-respiratory-protection-ebola

this virus may not meet the strict definition of air borne

but you damn well better treat it as such

especially if you are a health care worker

CDC recommendations are killing people

pure and simple

CIDRAP standards will keep docs and nurses alive

pure and simple

pick which you should follow

your life depends on it

We believe there is scientific and epidemiologic evidence that Ebola virus has the potential to be transmitted via infectious aerosol particles both near and at a distance from infected patients, which means that healthcare workers should be wearing respirators, not facemasks.1"

conventional ways of thinking just don't cut it on this matter

think outside the box

CIDRAP is so far ahead on this issue it makes WHO and CDC look like rank amateurs

and getting control of a disease as deadly as EBOLA is not gonna be achieved by amateurs

WHO's failure to recognize the seriousness of this outbreak early on

has led to MANY deaths

and will probably be responsible for tens of thousands more

who ya gonna listen to???

who ya gonna put your faith in ???

"

I don't think it is through stubbornness or lack of insight that they are not advising the use of respirators in west Africa. Respirators have problems of their own.

Wearing respirators is not a decision taken lightly from what I have read there are health hazards involved which are greatly amplified by the conditions these medics are working under in West Africa.

With respirators the lungs and heart have to work much harder. For example the amount of dead space in respirators is the amount of expired air that must be rebreathed before fresh air is obtained. Additionally masks with positive pressure features means more resistance to overcome, making harder breathing. The temperature of inspired air in the masks is alarming at around 49°C, which can results in heat stress, as you lose ability to breath cool air. Face masks get hot but not like that. Blood pressure, resp rate, and heart rate significantly increases in these masks,   The pulmonary and cardiac effects of wearing respirators are amplified by temperature and time wearing equipment, and may mean genuine risk of spontaneous pneumothorax and risk of barotrauma, sudden death when working in hostile hot environments.

Asthmatic people could not wear them under these conditions, either could medics with suboptimal health.

Respirators also restrict visual fields, effect vocal communication and decrease awareness of surroundings. Hearing is also impaired, and they can give feelings of depersonalisation ( spaced out). Concentration can become harder. An important consideration is panic. Respirators are restrictive to breathing and uncomfortable. They often produce panic attacks both because people are breathing higher concentrations of warm carbon dioxide, and also because psychological they are in an already stressful situation and they can feel they are being chocked by the restricted breathing. Panic is not uncommon in people wearing respirators, something firemen, military etc are trained to overcome.

I am sure thoses with military backgrounds know the ins and outs but sometimes it is hard to predict who will react that way...and you don't want untrained health professionals panicking in an Ebola ward while taking someone's blood.

So it is not just a case of sticking respirators on people, when they themselves could create a whole set of different problems. At the moment the benefit risk assessment they have done weighs down on not recommending respirators, and it will be interesting to see how and if that changes.

That said I am a huge hippocrite for if it were me I would prefer a respirator, however would not like to be stuck in Ebola ward with a panicking collegue.

Hzpad

Hi Germ Nerdier

sorry for delay in reply but had to get all the kids to bed before reading your article.

Firstly I am sorry about getting your name wrong it is the automatic word processing....... However I can see how being called Been Nerdier by my word processor may have offended, the blame I assure you is technology.

I do however fail to see how the discussion has deteriorated and you feel thin veiled hostility.... I am sorry you feel like that. I am only disagreeing with some of the points, an active discussion. Surely I have a right to challenge in a non aggressive respectful way. You were happy to quote and rapidly dismiss my post and bluntly claim I was simply wrong by attaching the 4 words " IT DOES INFECT EPITHELIUM." You then posted in quick succession some articles and I read them, then posted back my opinion on your evidence, which I feel is weak.

The lab I am in revels in debate, when we peer review articles I admit we can be a bit harsh, and our lab meetings are no place to go with a hangover. We have been called pit bulls cause we do argue amongst ourselves, ( though none of us look as good as blue Louie) I am sorry if you feel hostility but I am only disagreeing with the scientific evidence you presented. I am not being personal or deteriorating the topic as you suggest.

So back to the science. We can agree to disagree on the point about the ebola anchor glycoprotein. You say it was an intact protein, but did you read what they did to the actual protein, it was not intact, it was extensively genetically altered, the amino acids ( building blocks of the protein), in the tail end were chopped off, How can it be intact when they chopped the tail off. Also why did they need to alter it to get it into the respiratory epithelial cells, perhaps because the original natural Ebola glycoprotein couldn't anchor. The genetic sequence of this glycoprotein they created doesn't fit the sequence on genebank, so it is no longer an Ebola glycoprotein hence why in the authors had to change its name to (EBOΔO).

We will also disagree with the cell line used. Of course I am not saying use humans as you perhaps slightly sarcasticly suggested, but there are better 3D culture systems available, invasive assays etc which are more realistic than basic experimentally primitive monocultures which they used.

So in summary lets agree to disagree. On your side you feel the paper demonstrates clearly that wild type Ebola can infect respiratory epithelium, on my side I feel it does not and was never the aim of this cystic fibrosis funded paper to do that.....we are both entitled to think as we think.

The other article (2013) which you added in your last post and which you claim shows that I am again wrong and that Ebola does infect respiratory epithelium was interesting. At the risk of offending you again, I am really sorry but I just don't think it does.

So in this paper they were not saying Ebola naturally infects by the respiratory route, in fact in the introduction they clearly state " aerosol exposure as a means of human infection has never been documented". They wanted to devise a model to artificially push virus down into resp tract. They did this for a good reason. Not because they think it occurs in nature but because Ebola could be weaponised to be airborne. If this occured how would they know how to treat victims. So this study was to show how it would act in humans after this type of entry. ( weapon grade pathogens are very different to wild type, adding tissue tropism for resp tract is a real fear of a biological weapon.).

This potential future threat of a weaponised ebola engineered as a resp virus is taken seriously, and actually what they are referring to in your quote from the paper. They were NOT talking about natural Ebola infection, they are talking about a potential military weapon .This is a US Army Medical Research Institute of Infectious Diseases study.

I quote from the same paper:    Aerosol exposure as a means of human infection has never been documented. EBOV, however along with several other highly pathogenic agents, has the potential to be used in biowarfare as aerosolized weapons and are therefore classified as biological select agents and toxins (BSATs).

So the study was always a " what if study"

Now if you look in the methods section of the paper this is important for it shows what they actually had to do to get Ebola to infect the respiratory lymphoid tissue ( lymphoid not outer respiratory epithelium) of their monkeys ( bloody shame).. They put them in a sealed head only chamber then they nebulised a large quantity of the virus forcing it through a 3 JET SYSTEM shooting it forcfully down into the lungs. From here it seems to have gained access to the respiratory draining lymph nodes, probably taken there by engulfment by lung resident alveolar macrophages and antigen presenting cells whose job is to home to lymph nodes. I also presume damage by the jet nebuliser would have ruptured endothelium, a cell type we know Ebola does have high affinity for.

I just can't see anywhere in the paper that it can enter or did enter respiratory epithelium. If it could surely there would not have been needed to jet hose the poor monkeys, just squirted it up their nose, like they seem to do for true respiratory viruses. Respiratory associated lymphoid tissue ( where it showed up 48hrs post exposure in monocytes and macrophages) is part of the common mucosal immune system, so you could even argue some virus may have entered via the gut ( mouth is also in head chamber) and migrated there ( there is a common motorway between gut and resp lymphatics).

Perhaps I am wrong I do not work on such things as live animals.

However I am still not convinced about your initial statement to me that the Ebola virus displays tissue tropism for respiratory epithelium.

So let's agree to disagree and respect each others opposing opinion. Therhere no veiled hostility and I can only apologise if it came across that their was.

This forum is so diverse and that is its strength, everyone has their own opinion and expertise. As I said it helped me as a pregnant woman surrounded by H1N1 back in 2009. I thought I was going nuts with my concerns that up till then noone had taken seriously, until I came here and read like minded people. There is no hostility from me.


Hzpad

Ok here is a (likely truly) stupid question...

Back in summer there was discussion of scientists looking for host etc. As we are talking here about 'spreaders' (sorry no idea what tech name would be)... could blowflies carry it? Not trying to sound moronic here, but when you watch World Vision etc on tv - they always have flies crawling out of mouths, eyes. If it only takes one fomite to infect the next person - couldn't a blow fly crawling on a body or a sick person waiting outside a hospital get it onto legs/body and then when landing on next person - deposit to them (microscopic cuts on hands etc)???? So the blowfly would act as pollinator with people being flowers so to speak? If this is a possible way it's spreading, it won't travel that way here (after freeze up) in fall till good thawing in spring - so about 5-6 months at least. but then it lives on door handles etc longer in cold... not good either way

Nuwbie1 I had about the same question on page 2. I did search the above is what I found.

Dead right (literally) if you are near a patient with ebola.  Droplet/airborne does affect the decision to SIP though.

Grossed myself out now thinking about getting a droplet of someone else's snot in my mouth

There have been over 250 genetic changes to the Ebola virus within a short period. Our knowledge of viruses does not extend to some obscure viruses that may have been encountered from ancient Egypt on the opening of tombs and also we are losing the war creating antivirals. With the coming of 1.2 million cases of Ebola possibly just in Africra, airborne or not, we could still have a Pandemic. CDC is taking airborne precautions because they are worrried and it has been demonstrated that this virus can be transmitted through the air species to species by a Canadian research team. So it's the first - http://globalbiodefense.com/2012/11/19/canadian-study-shows-airborne-transmission-of-ebola/

This Canadian group did 3 pieces of research and it is strange why people are stopping after the second part of their study not reading the work they did after the 2012 study which lots are referring to. They published the final piece of the puzzle just this year in March in Nature. SAME CANADIAN GROUP finished their research. This was the final chapter in summary.

Quote: the Canadian team needed to conduct one last experiment.

For this study, the team decided to take the pig paradox out of the equation. They tested whether the virus could transmit between primates. Sets of two cages were spread across a room with at least 3 feet between them. In one set were infected macaques; in the other were the healthy macaques. They were kept together for up to 28 days and observed for any signs of transmission. There was, however, none. Not only did the healthy monkeys survive, there was no evidence of any virus transmission in their bodily fluids.

In retrospect, the authors believed their original use of pigs had given the airborne argument an unfair advantage. Pigs could produce significantly more virus than primates, suggesting a greater chance for droplet spread. In addition, because of the massive amount of shedding pigs display when sick, there was a greater opportunity for the monkeys to become infected through the respiratory tract. However, this type of spread is droplet, not airborne. There was no other option than to conclude Ebola was simply not an airborne virus.

Although the question of airborne transmission may be put to rest thanks to this study, there are still concerns for anyone coming within a six foot radius of an infected individual to prevent droplet spread. This means ensuring the use of a mask along with gloves, gown and eye protection and adherence to proper disinfection procedures afterwards. Even if not airborne, Ebola is still one of the most dangerous pathogens and we need to be vigilant and resilient to contain outbreaks and keep new ones from starting.


So droplet transmission and airborne may seem like picking hairs, but epidemiologically they are miles apart. It matters a huge deal. You don't contact trace in airborne and you stand no chance of containment in one region for long within weeks it is global, because the secondary cases, tertiary cases with airborne numbers are geographically very wide spread. Not seeing this yet.

For example take Freetown in Sierra Leone a city of 1 million but only 10 Ebola cases in last 6 months, whereas the villages surrounding it are getting hammered, with collectively 110 cases in the outskirts last week alone. If true airborne no chance city would have been spared this long.



http://www.nature.com/srep/2014/140725/srep05824/full/srep05824.html
http://www.popsci.com/blog-network/under-microscope/pigs-and-primates-addressing-airborne-ebola-allegation?dom=PSC&loc=recent&lnk=6&con=of-pigs-and-primates-addressing-the-airborne-ebola-allegation

Yes, it is not nit-picking when the differences magnify at each transmission (or near miss).

Makes sense to me!

And about three quarters of a BILLION in China already acting as mixing vessels for all kinds of nasties...

The average virus particle weighs about 10 fentograms.
That weight is not very much.

I know this was posted in all honesty Josh, but the article itself is not honest. 

In 2012 the scientists who did the original Reston experiments went back and finished the job.  Hazlepad publishes the details about 11 posts ago on this very thread. 

Respirators are probably a good idea as droplet infection is common close-up, but most of the medical practitioners who have caught the virus did so meeting and treating asymptomatic sufferers.  They wore no gear for that as they assumed they were safe.

The problem comes/came because the WHO keeps telling us that it is not contagious until symptoms show and THAT piece of information is clearly wrong.  It has been demonstrated wrong and is not in keeping with the knowledge already held about viral transmission in general.

It does present an airborne vector when pigs are infected as it makes them sneeze, but that does not mean H2H airborne transmission.

Sorry to jump on the post but this type of irresponsible, panic mongering and probably deliberate misinterpreting of the facts is all too common in the current press.  As a point of interest I generally look forward to your posts as reasoned and intelligent.  I do not blame you for this reporter's BS.

A lot of people wondering how health care workers getting sick. The highest toll in this group has been in the unit in Kenema. Below is extracted from a recent article from Dr Daniel Bausch. He is an infectious disease expert who has worked in Uganda with Ebola and has been working for months in Sierra Leone and Liberia Ebola wards.

This is someone working prolonged in the epidemic epicentre and daily in isolation wards. He is a friend of Dr Khan.

He describes below 2 doctors to 60 highly infectious Ebola patients, with no other support staff to clean up the vomit and diarrhoea on the floor they walking about in. Full link given at end, article is really good, and horrifically sad.

So here is what he said to the question How do health care workers, who we're told are incredibly proficient at their job, end up getting infected with Ebola? Is there something going on that we don't completely understand.

Quote.

A lot of focus has been placed on the PPE — the personal protective equipment — you know, the masks and gloves and gowns, and things like that. But it's overly simplistic to say those don't work, or the virus is different. If you go into that situation in Kenema, once a few health care workers get sick, you get into this really negative cycle. So you're working in a ward, somebody gets sick, dies. The next day, not many people [come to] work. And then it gets into a negative cycle where the ward gets even more unsafe.

Because a safe ward, it's not only about masks and gowns and gloves, it's about having the right proportion of health care workers to the patients, it's about having sanitation workers. You go into a ward, it's not unusual to see that someone has fallen out of bed or in delirium has crawled out of bed. They can be on the floor soiled with stool or vomitus or blood. And what should happen is that a team of three or four or five different people, all with the sanitation officer who has some bleach to spray, comes over, carefully decontaminates that area, carefully gets this patient back into a bed.

But when I was in Kenema last month, myself and one other doctor, we got gowned up to go in and do our rounds. And unbeknownst to us, the nurses had gone on strike again. We go in, there's about 60 patients with Ebola in the ward, [and] he and I are the only two health care workers that are there.

The analogy I've been using, it's like saying, well, you've trained somebody to be a pilot. So there's the plane, go fly the plane, without thinking: What about mechanics? What about the other people who have to guide the plane down the runway? You don't have all the very important supporting personnel that you need for [Ebola], and so it's been a tragic situation


There was a day when I was in Kenema last month where I thought we just need to close this [hospital]; it's just not ethical to keep doing this with health care workers getting infected. But what do you do? You have 60 people who have Ebola. What do you do with them? Do you say, "Go back to your home"? If you send them all home, that's infecting five more people in each household. So you try to get things as safe as you can [in the hospital] and soldier on we do.

http://www.npr.org/blogs/goatsandsoda/2014/09/22/349882298/dr-daniel-bausch-knows-the-ebola-virus-all-too-well

Satori wrote: recommendations for the use of respirators for health care professionals  comes form CIDRAP hardly a fly by night organization lets go to Africa you  wear a gown ,gloves and an N95 I'll follow CIDRAP recommendations I wonder who will come home alive ??? to paraphrase Darwin its not the biggest or strongest who necessarily survive its the ones who recognize quickly that change has occurred and  rapidly adapt to the new rules and lets not ignore this inconvenient little FACT when dealing with ebola in a research setting its always done in a biolevel 4 right ? but when dealing with it in the field or in a hospital biolevel 4 suddenly is irrelevant ??? stand back and watch the corpses pile up adapt or  DIE

It appears that Ebola did go airborne among primates and was transferred through the venilation system to other apes that were not even in the same room and became infected in 1989.  There is a good reason why CDC is taking precautions and wearing masks - there may be limited spread through the air. However, what is more significant is that we may not need to start a serious Pandemic as infected people fly  back from West Africa. As oppossed to almost dogmatic religious statemtent is cannot and never well be airborne, the incident in 1989 shows it can.

People here don't as a rule touch dead bodies. They do not do burials themselves and yet, in health care facilities, a doctor catching it is not that different than the U.S.  If we start bringing them back in greater numbers, health care workers are going to get infected.

I, for the record, do not think we are safe from the spread of this in the U.S. I told people about the Pandemic in 2009 and both CDC and WHO were in continual denial until it was declared a Pandemic.

Also, I have several sources that this is contagious before one becomes symptomatic for up to 21 days.

I will post more on this on my thread.

Medclinician

Med - the two groups of monkeys at HRC came from the same exporters four days apart, and that facility in the Philippines had an outbreak of hemorrhagic disease in both animals and humans at the time of the shipments. It's far more likely that the monkeys arrived at HRC already infected and at different stages of the incubation period than Reston Ebola managing to make it's way through the ventilation ductwork. Subsequent testing of HRC staff found asymptomatic human infections too - could they not have conceivably spread it as they worked with the animals? Of all the possible explanations, airborne transmission is by far the least likely.
BL4 is for pathogens for which there is no vaccine or cure that cause severe illness or death in humans - they may be airborne, but they may also be primarily transmitted by droplets contacting mucous membranes (like Nipah) or even needle sticks.

I think you are right, Josh. 

I think we are all agreed that it is contagious BEFORE symptoms occur.  Lets just call it limited airborne instead of droplet transmission.   The debate on semantics is tiresome.

My only stipulation here is:  Droplet transmission/limited airborne means sheltering in place will work, whereas it would be stupid in an infection which was truly airborne, unless you had a bunker with porcelain air filters. 

This site is stuffed to the gills with preppers, we even call ourselves "AFTers", as we will come out again after!  Most of us have the bug-in and bug-out preps.  If we assume the virus is fully airborne then bugging-out gives a minutely increased chance of survival, if you can get far enough away, though the risks of contagion by other ways make this a very RISKY option and it is irresponsible to the community at large too, as it will spread the virus almost all of the travellers will pick up in transit.  Most who do this will die.  If we accept its ability to travel by air is very limited, assuming no idiot has deliberately aerosolised/weaponised it, Bugging-in becomes a very SAFE option. 

It is important to remember that this virus is very efficient at transmitting itself by ALL body fluids and the foamites/residue they leave, and that it is contagious BEFORE symptoms appear. 

There is a reason I keep on argueing.  I confess I am getting very, very tired of it.  Again and again I repeat myself as people quote the members of the press who "DO NOT GET IT!", reporting on science they fail to understand, from scientists using poor methodology.  Arguements which had been conclusively disproven keep re-emerging.

So I give up.  If people want to convince themselves it is fully airborne/ becoming fully airborne they can be my guest.  I have had enough of repeating myself.  I shall just bug-in and wait to see who makes it with me. 

Sorry Jacksdad, Your echo has developed laryngitis!  I know you care deeply, but you can't save the determinedly suicidal.

I also like the saying "if you hear hoofprints don't think zebras think horses."

It is not about us here on a forum saying airborne vs droplet vs direct contact. The reason these differences exist and are defined is for governments trying to target resources, which until recently were scraping the barrow.

If it true airborne, in the numbers we are seeing, then one consequence is that they wouldn't contact trace and isolate anymore, and they would stop door to door education on direct contact avoidance. There would be no point wasting money as even avoiding physical interactions is not going to stop airborne contamination. Instead most resources would be transfered into treatment rather than a containment plan.

So what if it is not airborne, you are then condemning people to a fate that they maybe able to avoid, through quarantine of contacts, and education about burial practices, contact, hand hygiene. etc. So following the old "Absence of proof is not proof of absence." thought process in this scenario may be a bit simplistic, and cause further harm.

Before throwing water on fire you should know what is burning.

However we are not the policy makers. Good points on both sides of debate, and guess it is up to each of us to make up our own mind. I agree there is not any evidence of airborne, others feel there clearly is, fair dos.

PS Just to clarify this does not mean that I personally rule out short range disperse via aerosols from violent diarrhea and projectile vomiting, toilet flushing, getting into eyes mouth mucus membranes etc, just not full airborne.

I will also leave this debate here, have said enough on the topic, let others speak.

"I also like the saying "if you hear hoofprints don't think zebras think horses"

It's alright, Techno - I'm almost at the same point. Can't say we didn't try

Let's End It