Thread by @Protect_BC

Our 15th briefing is today at noon!

If someone in your household catches Covid, is it inevitable that you'll be infected too? No! Experts discuss how to avoid it.

We will livetweet the briefing here. Please join us. #bcpoli

https://twitter.com/Protect_BC/status/1518369262825394176

Starting now! Welcome to our 15th briefing. Please follow along! protectbc.ca/livestream/ #bcpoli

Dr. @DrFiliatrault of @Protect_BC is introducing "Covid in the House: Protect Your Loved Ones" and is making a land acknowledgment. First guest today is a professional mechanical engineer @joeyfox85, with a decade of HVAC experience & is a school board engineer. #bcpoli

@DrFiliatrault @joeyfox85 Our second guest is @amandalhu who is a Clean Air advocate & certified filter technician. They will help us to understand what we can do in the home to prevent others being infected in the home when a house/family member is infected. It can be done!

@DrFiliatrault @joeyfox85 @amandalhu @DrFiliatrault talking about the reasons to avoid infection rather than giving in: risk of long-term damage to any organ system in the body as well as the risk of long-covid.

@DrFiliatrault @joeyfox85 @amandalhu @DrFiliatrault is reminding us that, as discussed in our prior briefing with experts @kprather88 and @jljcolorado, Covid is airborne. Simply breathing and talking are aerosol generating procedures, & Covid can hitch a ride on those aerosols you produce.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @DrFiliatrault reminding us that while airborne particles are in greater density close to a person, particles can concentrate far from the source and hang there, if you spend a lot of time in a space, esp if it's small, you risk infection even if the room has been vacated.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado 3 important messages:
1. Exposure does not mean infection
2. Covid's main mode of transmission: airborne
3. Once we know how Covid spreads, we can prevent transmission in the home.
Now we go to @joeyfox85

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado Engineer @joeyfox85:
Masks are the best line of defence! Respirators (like N95) are best and are actually more functional. Surgical masks are far better than cloth masks but not as good as N95s. Choose a comfortable respirator - many diff types of N95. Just find one that fits.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado Caveat with this chart is that it was designed for earlier and less transmissible variants but it still applies.
It's not true that an N95 needs to be fit-tested.
Non-fit-tested respirators (N95) still vastly outperform cloth masks and surgical masks

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado And yes, while one-way-masking isn't as good as two-way (everyone in masks), it's still good - an N95 will most likely prevent you from being infected.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado Another myth about N95s is that they are one-time use. They're not - even 3M says you can reuse masks, as long as you haven't damaged or dirtied them too much. This makes them more affordable. If you still can't afford N95, there are other options. Surgical masks acceptable..

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado To increase the efficiency of a surgical mask, use the fold and tuck method to increase the efficiency and safety of your mask

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado Now @joeyfox85 is talking about ventilating your living space. 2 types:
natural ventilation, ie bringing fresh air into your house (windows)
and
mechanical ventilation.
To boost natural ventilation, turn on bathroom/kitchen fans & open a window, or...

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado If your house has a furnace, you can use the furnace's air circulation system to filter the air. You can replace the furnace's filter with a MERV13 filter, which does a good job of filtering furnaces out of the air. Some houses also have an HVAC system - it too has a filter.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado Now we're hearing from @amandalhu on filtration. A mask as a filter for your face, but to filter the air in spaces, a cost-effective way of doing this is to build your own Corsi-Rosenthal box. You need 4 MERV 13 square filters, a square box fan, some duct tape & cardboard.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado .@amandalhu It seems intimidating at first to build your own air filter, but it comes together really easily! Please remember air filters have a direction - make sure that the arrows point inwards to the centre of the box. Air will go in thru the filters, out through the fan...

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado .@amandalhu - There are actually many different ways to build a Corsi-Rosenthal box (C-R box) - you can even build a triangular one with fewer filters! There are many resources online to help you find one to build - see Clean Air Crew and others.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado The more filtration (say, MERV13 vs MERV11) and the more filters you use, the more filtration you get. The more filtration you can get, the better. Put the filter as close to the person who's infectious as possible.
There are also commercial versions available; more $$$$ tho.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado See @marwa_zaatari for comparisons of per-unit cost of filtration. But making your own Corsi-Rosenthal box will always be cheapest.

@amandalhu doesn't recommend in-device UV air purifiers at this point.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari .@amandalhu is reviewing some of the methods that @joeyfox85 earlier listed to remove virus-laden air from the space and bringing in fresh air, or just to trap virus particles that are circulating inside.

Hu points out that people are infectious for much longer than 5 days.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari .@amandalhu recommends using rapid tests for longer than 5 days to determine whether your family member/housemate is still infectious!

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari How do make an isolation room in a house or apartment? The weak point is the bathroom, which is a shared room. The sick person isolates in the BR. The red cloud is emanating from the infected person. They should mask as much as poss, & in those shared spaces. Others also wear N95

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari Open as many windows as you can in the sick room. If you have a fan that can blow air out a window, that's also helpful. If you have a filter near the person, that also helps. Keep their door closed, and block the bottom of their door with a towel/blanket. But when door opens...

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari While the sick person exits their isolation room, others should go out or on a balcony. While that's going on, make sure all extraction fans in the home are turned on. Do vent rooms the infected person has been in for at least half an hour, before you unmask. @joeyfox85 agrees.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari .@DrFiliatrault points out that it's key to close the lid on the toilet before flushing. Flushing is an aerosol generating process! There is virus in our bodily fluids - and they point out this is good advice in general!

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari .@amandalhu If I had my way, I would put an air purifier everywhere there is currently a plexiglas barrier. Plexiglas would only work if this were a droplet spread disease, but it's airborne. The filter is far more effective.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari ..@joeyfox pointing out that if you have two air filters/Corsi-Rosenthal boxes, put one in the room with the infected person, and another outside their room.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox Make sure that you're not sucking air OUT of the sick room and into the space - this means making sure windows are open in the rest of the space. - @joeyfox85

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox .@joeyfox saying you need to create negative pressure in the sick room and bathroom when they're using it. All this info comes from Clean Air Crew, which he highly recommends.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox You don't want air to be sucked out of the bedroom the infected person is in, so it's very important that if their room has a return air register for a a forced air/HVAC system, you must tape plastic over it!

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox If you don't have mechanical ventilation in your home, but need to move air from green zone to red zone & not other way around, do this with windows and fans.
The window is key because if you create negative pressure in a room, you can draw bad exhaust from appliances into room.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox To sum up, @DrFiliatrault lists our key points and the items you will want to add to your toolkit to prevent Covid infection in the home, if someone gets sick.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox .@amandalhu has a mnemonic limerick for remembering how to ventilate and increase safety in spaces.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox .@joeyfox85 is explaining the difference between a "mask" and a "respirator." A mask is called a respirator (usually if there's a 90 in the # it's a respirator - KN94, N95) when it has higher level filtration and good seal.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox .@joeyfox85 also mentioned this. Drier air means more virus floating around.

https://twitter.com/karamcnair/status/1519403758555258880

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox Now to Q&A!
First Q from a listener:
why do some of the plans of the isolation rooms have the door to the room blocked, and some with the bottom cut open?

It will depend on whether you can create negative pressure in that room, and exhaust its air to the outside.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox Humidity does 3 things:
1. The virus doesn't live well at 40--60% humidity - it does well at both ends of the spectrum.
2. Your immune system also does poorly at v low humidity
3. Low humidity increases aerosols in the air because it reduces droplet size thru evaporation

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox .Engineer @joeyfox No. This is not true of any school space I have seen. And @amandalhu says this has become a widespread belief and has been brought up in many school boards, but it's not true. Many school boards have had success with hepafilters in classrooms

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox Q: What's the role of the CO2 monitor when isolating someone with COVID in your house?

This is not its main use. It's more for measuring public spaces, but it's a measurement of the ventilation of the space generally.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox @amandalhu saying that she actually prefers to keep the spaces isolated from each other. The only danger would be if the isolation room had no window, & your gas appliances could suck carbon monoxide etc. into the neg pressure room. Then you need air from green zone to enter red

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox Q about fire hazard re using old fans with dust around motors. @amandalhu says it's usually OK to leave these filters on 24/7 & the filters don't create enough resistance to overheat the fan. @joeyfox85 says new fans are better tho, have a fuse in the plug that shuts off w heat.

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox To sum up, you can prevent infection in the house - just because one of your family or roommates gets Covid, it doesn't mean you have to!

Preventing Covid infection needs to be our societal priority going forward. Thanks everyone! Resources will be posted to our website #bcpoli

@DrFiliatrault @joeyfox85 @amandalhu @kprather88 @jljcolorado @marwa_zaatari @joeyfox Thanks for doing briefing notes! @anarchodelphis

https://twitter.com/anarchodelphis/status/1519408008148643840