Alan Baxter ♛ Profile picture
Sep 30, 2020 19 tweets 3 min read Read on X
So: What is Wrong with COVID-19 Hotel Quarantine in Australia? A thread.

After difficulties with compliance to COVID-19 stay-at-home orders for returning travellers, Hotel Quarantine became the mainstay of infection management for these people in Australia. /2
But the efficacy of this program has varied enormously between states. Here I argue that the key difference lies in ventilation. /3
Think, for a moment, about the hotel rooms you have stayed in: Most would be serviced by one of two types of air handling: a) Natural ventilation modified by a split system air conditioner; or b) A mechanical (ducted) ventilation system. /4
Natural ventilation requirements are dealt with in Section 3 of AS 1668.2, which refers to BS5925. There are three methods that can be used to calculate requirements, but for the sake of brevity, I will refer only to one: Prescriptive opening size and location. /5
I will take the most problematic design that has full compliance with the Standard: In an enclosure containing 2 people with low metabolic activity, & over 2 square metres of floor space/occupant, openable openings must be no less in effective area that 10% of floor area. /6
The critical issue is that in cold weather, the occupants may choose to leave these openings closed. /7
Mechanical (ducted) ventilation systems are dealt with in Section 4 of AS 1668.2. There are two methods that can be used to calculate requirements; I will only discuss the most problematic example of the most simple method. /8
The prescriptive procedure incorporates minimum mandatory requirements for single enclosures (e.g. a hotel room): In an enclosure containing 2 people with low metabolic activity, & a room temperature at or below 27C, the outdoor air supplied should be >5 L/s/person. /9
In some cases, exhausted room air is partially reused to supply air for low occupancy spaces, such as corridors. /10
Clearly, as a generalisation, these standards are adequate for hotel rooms. However AS 1668.2 has many mechanisms for accommodating air-borne contaminants, which might not be considered in the case of low occupancy hotel rooms. /11
I would argue that as the point of Quarantine is to contain infection, with the clear expectation that some travellers will be infected. /12
The transmission of SARS-CoV-2 occurs via four routes: Direct contact, fomites (inanimate objects), droplet and aerosol. Analysis of super spreader events shows that most can probably be attributed to aerosol concentration in poorly ventilated spaces. /13
The standards for mechanical ventilation of enclosures for health care functions is given in Section 6 of AS 1668.2, & those for Infectious Isolation Rooms in paragraph 6: /14
The minimum outdoor airflow rate delivered to Infectious isolation rooms should be the greater of 10 L/s/person and 2 L/ square metre & should have a controlled room air pressure that is lower than that of adjacent enclosures. /15
Given that these requirements are much more demanding than those for low occupancy residential purposes, the majority of hotels are unlikely to meet them or be suitable for quarantine. /16
Distributed accommodation of separate cabins or bungalows, temporarily modified to ensure high natural ventilation, may be an effective alternative. /17
And one hotel style common in Queensland may also be relatively effective, as it consists of external corridors and naturally ventilated rooms, often ventilated by sliding doors to a balcony, which in warm weather, are often opened. /18
And this last point may be the most significant reason for the large difference in efficacy between hotel quarantine programs between the colder southern, and warmer northern states in Australia – incidental differences in ventilation adequacy between hotel designs. <end>
@ThreadReaderApp unroll please

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Alan Baxter ♛

Alan Baxter ♛ Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @AlanBixter

Sep 6
Anthony Whealy is a former New South Wales Supreme Court judge whree he served alongside Brereton, chair of The Centre for Public Integrity, and a former assistant commissioner to the NSW Independent Commission Against Corruption. /2
Anthony Whealy is a former New South Wales Supreme Court judge and is highly critical of the National Anti-Corruption Commission: /3
“I was severely disappointed and disturbed to see that the power to hold public hearings had been very seriously limited by the addition of the requirement that there be exceptional circumstances,” says Whealy, who is now chair of The Centre for Public Integrity. /4
Read 12 tweets
Jun 28
COVID damages the frontal lobes, particularly the dominant frontal lobe, which plays a key role in moderating socialisation. It tempers social impulses, like violent or sexual urges. But is there any evidence the ongoing COVID pandemic has changed social behaviours? /2
A new report from the Australian Bureau of Statistics finds that there were 35,138 victims of sexual assault recorded nationwide in 2023, a 31-year high.
The rate of women killed by an intimate partner in Australia increased by ~30% in 2022-23, compared to the previous year. /3
The number of blackmail and extortion victims has increased by 56% to 3380 people, while there were 409 victims of homicide and related offences, up 20 victims on the previous year. Australia’s road toll has been increasing since 2020, reaching 1,253, the highest since 2018.
Read 6 tweets
Apr 26
"The damage of the WHO’s false claims continue to reverberate today. Doctors and hospitals continue to infect their patients with flu, RSV, strep, and now COVID as infection control measures like HEPA filtration go completely unmentioned in the new guidance document. " /2
"Hospitals continue to place highly infectious patients close to COVID-negative patients, falsely believing that curtains and a few feet of distance will protect vulnerable sick people." /3
"Doctors and nurses continue to lack proper PPE, while acquiring Long COVID at high rates and dealing with out-of-control hospital crowded all over the world." /4
Read 5 tweets
Apr 18
I have been made aware of a major risk factor some people have that makes COVID a more serious risk for them than for others. As far as I know, there has not been a systematic study to quantify this risk, nor been any public health attempt to warn this group. /2
About 25% of the adult population have a patent foramen ovale. This is a hole between the left and right atria (upper chambers) of the heart. This hole exists in everyone before birth, but most often closes shortly after being born. /3
Normally, a PFO is not a significant problem. A small proportion of blood might pass through it from right to left sides of the heart, by-passing the lungs, but the proportion of air not oxygenated is not functionally significant. /4
Read 14 tweets
Apr 9
Prof Crab and I took a very similar set of domestic strategies to deal with COVID. I thought I might summarize them below: /2
But first, some basic principles: 1) COVID is primarily transmitted by aerosols - minute micro-droplets that waft in the air like cigarette smoke. 2) It is transmitted from an infected person to an uninfected person. /3
3) Some infected people are much more likely to transmit infections than other people. 4) Some locations are much more likely to allow transmission of infections. 5) Some behaviors are much more likely to allow transmission of infections. /4
Read 16 tweets
Dec 1, 2023
This is a tricky post. This time, 4 years ago, I was contacted by a person in a major government scientific organization. They said that they (pleural) had tried to warn the (then Morrison) government of an outbreak of a SARS-like virus in China. /2
They said that they had been warned directly by Chinese scientists, who were greatly concerned about the possibility of the disease spreading. They said that the government had not responded. /3
To put this in context, this was around the time of many major bush fires (Hawaii) resulting in a heavy demand for face masks. I posted the alert on Twitter & attempted to purchase N95/P2 masks from pharmacies. /4
Read 6 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

:(