Lockdowns are the crudest possible form of public health intervention. Far better is to identify the correct mechanism of spread for a pathogen and use that insight to control the infection at its source: just as we did with cholera in the 19th century
In London, cholera outbreaks in 1832 and 1849 killed a total of 14,137 people, because the Thames had become severely contaminated by overflow from sewerage. They'd got the mechanism of spread wrong, thinking it was spread in the air by "miasmas" en.wikipedia.org/wiki/1854_Broa…
The "miasma" theory is very archaic. "Malaria" for example means "bad air" in Italian. Medieval plague doctors wore respirators with aromatic scents in them to ward off the foul-smelling "miasmas" to avoid getting infected en.wikipedia.org/wiki/Plague_do…
It took a huge struggle to overcome the miasma theory of cholera spread before the waterborne theory was accepted. As with the idea that #COVIDisAirborne physicists took the lead. Michael Faraday wrote to @thetime in July 1855 about testing "the degree of opacity” vs. white paper
Like our aerosol physicists today, Faraday's warnings were ignored. In 1855, Dr John Snow published arguing it was a waterborne disease. It was universally ignored. Snow did not live to see the success of his theory which wasn't fully accepted until 1866 collections.nlm.nih.gov/ext/cholera/PD…
It was not until things got so bad with the Great Stink of London of 1858 that parliament finally took action. Led by engineer Joseph Bazalgette, a system of public sewerage was installed. As a result, cholera was eliminated from London theapricity.com/forum/showthre…
City after city that emulated London in installing public sewerage systems eliminated cholera without antibiotics or vaccines. Snow and Faraday were right: cholera was waterborne, not airborne. Once they'd got the mechanism of spread right they could control it at its source
The problem with the idea that #COVIDisAirborne is that it sounded to opponents too much like the archaic miasma theory. The evidence for aerosol spread is now overwhelming compared to that for droplet theory. As with cholera, we now know how to control the disease at its source!
Just as cleansing the water eliminated cholera in the 19th C, then our task today is to clean the air. We have the technology to filter the air. We must mandate the use of these + high-grade masks (N95, KF94, KN95) for everyone until COVID is eliminated. Because #COVIDisAirborne
Lockdown is a crude tool that comes from the Middle Ages. Social distancing at 1.5m doesn't work against aerosols that travel distances and linger even after a person leaves a room. If you rely on these, you'll need longer/harder lockdowns to compensate
The moral of the story is that the model of lockdown/social distancing works poorly when #COVIDisAirborne because it fails at primary source control of the infection unless it is made so draconian people have zero contact with each other
In a cholera epidemic you wouldn't tell people it's fine to keep drinking faecally contaminated drinking water as long as you're vaccinated. So why say the same thing for an airborne virus? #COVISisAirborne
A more in-depth review of the history of the theory behind aerosol spread of disease, covering much the same territory poseidon01.ssrn.com/delivery.php?I…
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Malaria is vector-borne. How would you hasten the spread of malaria? By telling people to protect themselves against malaria by handwashing instead of using mosquito nets.
HIV is body-fluid-borne. How would you hasten the spread of HIV? By telling people to protect themselves against HIV by handwashing instead of using condoms (or PEP/PrEP)
Cholera is waterborne. How would you hasten the spread of cholera? By telling people to protect themselves against cholera by handwashing instead of boiling their drinking water.
Despite ancient origins, “contagionism” remained deeply unpopular because it implied the need for lockdowns to contain spread. Libertarian miasmatists claimed diseases weren't contagious. They regarded themselves as too modern for nasty Medieval lockdowns.
That's why when Semmelweis came up with the contagionist concept of handwashing to reduce disease spread, the whole libertarian medical world gasped in abject horror.
The idea of explosive contagiousness still terrifies people today. If a virus is airborne, like measles, it implies high-grade contagionism, leading to government to downplay the severity of the eruption: “Oh, it's nothing a dab of hand gel can't fix”.
This article on the outbreak of Cryptosporidium infections in Queensland is riddled with problems and contradictions. abc.net.au/news/2024-02-2…
It states: “Health officials say the spread of the illness can be controlled by proper hygiene and hand washing.” Yet, it also says, “You don't need to get much water in your mouth to potentially get a case.” How does handwashing stop that?
QLD Health claims: “What we saw with СОVID was people taking … precautions and washing their hands and limiting contacts, which led to a suppression of other communicable diseases. It's not surprising that there's a bit of a rebound where people are getting a bit complacent.”
Statements claiming that SARS-CoV-2 can't possibly be airborne because that would imply it is frightfully contagious, with an R0 more like measles, reminds us of how divisive a concept contagionism has been through the centuries. 🧵
Miasmatists held that miasmatism was more modern and libertarian, as opposed to contagionism, which had been used since the Middle Ages to justify quarantines and lockdowns to contain person-to-person transmission.
If you were a miasmatist, you held that lockdown and quarantine were useless since diseases were never contagious from person to person but spread by miasmas. It was your attitude to lockdown that determined whether you were a miasmatist or a contagionist.
A nice photo illustrating why surgical mаsks don't work as respiratory protective equipment. You can see big gaps at the top, sides, and bottom. All the air you breathe in goes through the gaps and enters your lungs unfiltered. Photo from a respirator ad by Koken.
But—you may object—surgical mаsks have excellent particle filtration efficiency (PFE). So they must work…right? A high PFE means nothing if the air you breathe in sneaks past unfiltered through these gaps rather than going through the filter. armbrustusa.com/pages/mask-tes…
This is why mаsks don't work. But there is a device that does work to stop you from inhaling airborne pathogens, and it is formally designated a “respirator” because it is designed to be tight-fitting enough not to allow leaks. #WearARespie
A bit of commentary on this @JAMANetworkOpen paper. It just means that HCWs should get a fresh respirator after they remove their respirators for a meal break mid-shift. Simple. 🧵 jamanetwork.com/journals/jaman…
The mechanism of fit failure is uncomplicated. It is strap fatigue. The reason trifolds didn't last as long is that they were Auras, which have super thin straps. This is not the case with Trident trifolds. It has nothing to do with the facepiece design (cup, duckbill, trifold).
The authors note, “the safety of reuse found that N95 fit was reduced after 5 donnings and doffings”. This is because it stretches the straps, provoking strap fatigue. The solution is to get fresh straps.