What to Know
As soon as someone in your home tests positive, please have everyone in the home who is able wear a mask.
If you have a better mask (a respirator, or a surgical mask you can modify with knots or a brace for a better seal), put it on the person who is positive. In some cases the positive person won’t be able to wear a mask well - they’re not recommended for children under two years of age, and some children may feel very unwell. Others in the home should wear masks to protect themselves.
It’s helpful to read this document in advance of anyone in your home testing positive so that you have some time to gather supplies.
We understand this won’t always be the case. We have a good mutual aid network in New Brunswick and there are always caring people who want to help. If someone in your home is positive already and you don’t have all the supplies you need, definitely reach out within your community and to New Brunswick COVID safety advocates like PoPNB if you would like help obtaining some of these supplies.
We should also encourage government, charities, service organizations, and other groups that are supposed to help citizens to make these supplies more available.
In Nova Scotia for example, there was a pulse oximeter lending program. If you have time, it would be wonderful if you would share this document within your community group and reach out to others to help make these supplies more available and this information more accessible.
Note that this information differs from what provincial Public Health organizations have been communicating.
Provincial Public Health departments have failed to adequately recognize the airborne (aerosol) route of transmission of COVID. Scientists have proven the airborne or inhalation route of transmission to be the dominant route of transmission, so it’s very challenging that the provincial departments have thus far failed to acknowledge this, as it makes providing accurate guidance to people or even other provincial departments impossible. For some trusted organizations and physicians who do accurately communicate about airborne transmission, you can see Peterborough’s Medical Officer of Health Dr. Thomas Piggott, Niagara’s public health officer Dr. Mustafa Hirji, and Public Health Agency of Canada’s Chief Public Health Officer Dr. Theresa Tam.
In the United States, the airborne route was properly recognized in March with EPA’s Clean Buildings Challenge, and the White House’s Let’s Clear the Air on COVID.
Avoiding Transmission
Now that you have the background - what steps can you take to avoid household transmission?
There are wonderful resources available to guide you through this, linked near the end of this document. The main thing to keep in mind is airborne transmission. COVID is spread by the virus SARS-CoV-2. When we breathe, talk, shout, sing, cough, etc., we emit particles from our lungs. Some are larger, and some are very small. SARS-CoV-2 is attached to some of these emissions from the respiratory system of someone with COVID who is contagious. While larger emissions will fall quickly, the smaller particles hang in the air like second-hand smoke. Others in the home are susceptible to infection if they breathe in those particles. The current variants are very transmissible, and infection, even in vaccinated people, can take place with only a brief exposure. Aerosols can take hours to settle - they can remain suspended in the air for hours, even after the contagious person has left the room.
How to reduce those risks?
If possible, you will want to isolate the COVID positive person. You want to clean the air so that any virus isn’t remaining suspended in the air for others to breathe in. Masks - ideally, respirators (N95-type masks) - work as both PPE and source control.
The COVID positive person should wear a mask when they leave the isolation room to come out to use the bathroom, etc. This is source control - the person wears a mask and it keeps the aerosols that transport the virus from becoming part of the shared room air. The mask works to trap the virus. On the other people in the home, the mask is personal protective equipment - breathing in through the mask keeps the aerosols with the virus on the outside of the mask, out of their nasal passages and lungs. If you keep the isolation room’s air separate from the rest of the house, everyone doesn’t have to wear a mask all the time.
Ventilation and Filtration
You can make the air inside your home safer and reduce transmissions by using ventilation and filtration.
To augment ventilation: open windows. They do not have to be wide open to make a big difference. Opening windows works best when you open more than one. In the isolation room, the window should be open. In the rest of the home, it helps to also have the windows open. You can use fans to pull fresh air in even faster. If it is cold outside, you can open the windows a small amount for a few minutes, close them, and open them again in 20 minutes. You may want to use sweaters, blankets, space heaters to keep people warm while ensuring adequate ventilation. If you have a CO2 monitor, you can keep an eye on how good the ventilation is in your home, but you don’t need one - just keep opening the windows often. In the links section below there is a link to isolation room diagrams by Canadian engineer Robert Bean.
If you do not have combustion appliances, you can also run exhaust fans - for example, your bathroom fans or your range hood fan over your stove. Be sure to check if your home is at risk of backdrafts from combustion appliances such as a woodstove, gas stove, or gas water heater before running your exhaust fans continuously. If you don’t have combustion appliances, you can run your exhaust fans continuously to improve ventilation. If you do have combustion appliances, you can still run exhaust fans sometimes - for example, if you must share a bathroom with the COVID+ve person, they should run the exhaust fan after a shower. If you are using ventilation and filtration, you will want to leave the bathroom unoccupied for at least 30 mins after the COVID positive person has been in it, to ensure there have been enough air changes in the room before you use it.
Filtration: buy or borrow a portable HEPA filter unit or a Corsi-Rosenthal box. You can build a Corsi-Rosenthal box for about $120, or cheaper if you attach a single furnace filter to a fan instead of building the 4-sided filter cube. You can buy a small HEPA unit for about $100, though larger units for bigger spaces will be $200-300. If you only have one air filter device, put it directly in the isolation room with the COVID positive person and have it running all the time.
Air filters are able to filter all the air in a room several times per hour, as long as they are the right size for the room. When the air passes through the filter, the HEPA or MERV filter traps the aerosols with the virus so clean air emerges. This makes your home far less risky as there will be less SARS-CoV-2 in the air. If you have more than one filter, you can place one outside the isolation room, near the bathroom, or in the area of the house the other family members are using.
If you have a furnace in your home, see if you can upgrade your furnace filter to MERV 13. This won’t help with close-range aerosol transmission, but it will help decrease the amount of virus and other pathogens in your home’s air.
If the COVID positive person is over age 2, you should obtain rapid tests from NB’s rapid test distribution locations so that you can determine when the person with COVID is no longer contagious.
This is another area where provincial governments have been promoting misleading information. For months, GNB had written on its website that rapid tests could be positive for 90 days. This is not the case. Rapid tests work differently than PCR. Rapid tests should only turn positive while the virus is replicating, and should match well with the infectious period of the person.
Note that many people find their rapid tests are positive beyond 5 days of their COVID infection.
The 5-day isolation period is not supported by evidence, as many people are contagious beyond 5 days. If you are committed to trying to stop household transmission, it’s important to be aware that you may continue to test positive on a rapid test for 7, 8, 9, even 10 days. An evidence-based and prudent approach to exiting isolation is to test until you have 2 negative rapid tests, 24 hours apart. You may wish to start using rapid tests on day 5 or 6 to see if you are negative yet. It is prudent to do a cheek and throat swab as well as a nasal swab. You can use the same swab. If your test on day 5 is negative, repeat it the next morning on day 6. If that is also negative, you have taken many precautions against household transmission and can leave isolation knowing you did everything reasonable to break the chain of transmission. If your first rapid test is still positive, wait a day and try again. Someone outside your household can pick up your rapid tests as long as they have your confirmation e-mail. Looking for more info on testing to exit isolation? See this twitter thread:
Resources on Preventing Airborne Transmission
There are many authoritative resources that describe these proven methods to reduce household transmission. There are excellent diagrams available showing how to make an isolation room in various home setups. For more information, please see:
Ontario engineer Joey Fox’s twitter thread about stopping household transmission:
On April 6, 2022, CBC Radio’s program Information Morning (Saint John) had Joey Fox on to elaborate in more detail. This is essential listening for anyone with COVID in the home! https://www.cbc.ca/listen/live-radio/1-28/clip/15905085
Protect our Province Alberta (http://popab.ca) had a briefing dedicated to stopping household transmission - this is a video but you can also download it to listen to audio only.
Canadian engineer Robert Bean has written instructions with diagrams on how to make an isolation room in a variety of housing situations. This information is referred to in the PoPAB briefing - very helpful to have a look at the information and diagrams yourself.
Prof. Jose-Luis Jimenez twitter thread on how to avoid airborne transmission:
For lots more information on how to reduce transmissions, including information about how to make a Corsi-Rosenthal box, visit CleanAirCrew.
Dr. Prowell in the US posted a great tweet thread about reducing household transmission:
Immunocompromised twitter user Lazarus Long has been collecting success stories from homes that stopped household transmission - this thread contains 20 examples:
Supplies
Supplies you might like to have to manage COVID-19 at home:
Pulse oximeter: $40 at Wal-Mart, $60-70 at pharmacies. Check with your healthcare provider to verify what levels of oxygen saturation indicate a need to seek medical attention. Check your oxygen saturation at least twice a day. Note that readings may be less accurate on young children, and depending on skin tone, and other factors.
Throat lozenges for sore throat
Advil and tylenol for fever, aches
Powerade, pedialyte, popsicles for hydration
Tissues for runny noses
Easy meals and nutritious drinks, soups
Humidifier for cough, comfort
Ice pack
Tea, honey for cough (do not give honey to infants due to risk of botulism)
A Word on Surface Transmission
Up to this point, fomite transmission has not been a significant source of COVID transmission - in fact there are no definitively proven cases of surface transmission (3 cases were suspected, but airborne transmission can’t be ruled out). CDC estimates the odds of getting infected by touching a contaminated surface to be 1 in 10,000. Cleaning surfaces may be effective in preventing other illnesses, and future variants may involve surface transmission, but currently to prevent household COVID transmission it is most important to focus on cleaning the air and stopping the air bridge that SARS-CoV-2 uses to travel to a susceptible person.