Montreal City Weblog

Kate 09:05 on 2020-03-04 Permalink Reply  

• Clément 09:18 on 2020-03-04 Permalink

  I don’t know that much about public health.

  But even if they were sanitized every day, wouldn’t that only benefit the very first rider of the day?

• Ephraim 09:49 on 2020-03-04 Permalink

  There are treatments that do last, but that’s mostly anti-bacterial and not anti-viral. The best bet is to wipe down the pole or wear gloves.

• Chris 09:52 on 2020-03-04 Permalink

  Plus there’s short term vs long term considerations. Overusing anti-bacterials, anti-virals, anti-biotics, etc. is an arms race with evolution, the bugs adapt too.

• Blork 10:32 on 2020-03-04 Permalink

  While waiting for the train to start its run at Longueuil this morning and STM employee walked through carrying a rag and a bottle of Lysol. I didn’t see if she sprayed anything. Seems a bit Sisyphean.

• EmilyG 10:56 on 2020-03-04 Permalink

  It’d help people with weakened immune systems.
  Not everyone is healthy/able-bodied.

• Kate 12:32 on 2020-03-04 Permalink

  But would it, EmilyG? Clément’s point about any sanitizing only lasting for minutes is valid, as is Chris’s point about over-use of disinfectant. Also, it seems most rhinoviruses and coronaviruses are exchanged by droplets, not surfaces.

  Plus, there are bound to be people sensitive to too much disinfectant.

• EmilyG 14:05 on 2020-03-04 Permalink

  It would indeed. The general public isn’t very knowledgeable about how to protect weaker-immune-system people. Many of these people are worried, as healthy people are stockpiling sanitizer and masks.
  But yes, there are also people sensitive to disinfectant, and you can’t possibly accommodate everybody.

• Ian 14:55 on 2020-03-04 Permalink

  I think that the regularity with which I see gum on the bus seats is proof enough that nobody ever, ever, ever bothers to clean the handrails unless they are obviously dirty – and given that I see escalators in the metros cleaned by dragging a dirty mop over them, well…

  I’m pretty sure city sidewalks are cleaner than any surface on the bus or metro.

• MtlWeb 18:54 on 2020-03-05 Permalink

  There are misconceptions regarding Covid-19 and the methods of transmission. An intensivist from Vermont has published the following (all referenced to medical literature) on Monday. It is part of a thorough and quite frankly, amazing summary based on the most recent scientific evidence; if you would like to read the references, let me know and I will post the links.

  Large droplet transmission
  COVID-19 transmission can occur via large droplet transmission, with a risk limited to ~6 feet from the patient; this is typical for respiratory viruses such as influenza; transmission via large droplet transmission can be prevented by using a standard surgical-style mask.

  Airborne transmission
  Controversial whether COVID-19 can be transmitted via an airborne (small particles which remain aloft in the air for longer periods of time) route . Airborne transmission would imply the need for N95 rather than surgical masks. Airborne precautions were used with MERS & SARS out of an abundance of caution, rather than any clear evidence that coronaviruses are transmitted via an airborne route. This practice has been carried down to COVID-19. Guidelines disagree about whether to use airborne precautions:
  The Canadian and WHO guidelines both recommend using only droplet precautions for routine care of COVID-19 patients & both recommend airborne precautions for procedures which generate aerosols as seen in a critical care area (ICU, ER, OR). Note that the CDC recommends using airborne precautions all the time when managing COVID-19 patients. Applying airborne precautions for all patients who are definitely or potentially infected with COVID-19 will likely result in rapid depletion of N95 masks. This will leave healthcare providers unprotected when they actually need these masks for those aerosol-generating procedures which are intended to manage the critically ill. In a pandemic, the Canadian and WHO guidelines may be more sensible in countries with finite resources. FYI, this resource utilization of N-95 and other PPE is a concern within our network in Montreal.

  Contact transmission (fomite-to-face)
  This mode of transmission tends to be overlooked, but it may be incredibly important. This is how it works:
  (i) Someone with coronavirus coughs, emitting large droplets containing the virus. Droplets settle on surfaces in the room, creating a thin film of coronavirus. The virus may be shed in a variety of other bodily fluids as well such as sputum, nasal secretions, stool, saliva, urine, and blood which means there are a variety of other ways that an infected person could shed the virus into the environment.
  (ii) The virus persists on fomites in the environment. Human coronaviruses can survive on surfaces for up to ~7 days. It’s unknown how long COVID-19 can survive but it might be even longer as some animal coronaviruses can survive for weeks.
  (iii) Someone else touches the contaminated the surface hours or days later, transferring the virus to their hands.
  (iv) These hands touch the oropharynx (mouth) or nasopharynx (nose) area which will result in transmission of infection.
  Any effort to limit spread of the virus MUST BLOCK contact transmission. The above chain of events can be disrupted in a variety of ways:
  (a) Regular cleaning of environmental surfaces using 70% ethanol or 0.5% sodium hypochlorite solutions.
  (b) Hand hygiene since a high concentration ethanol neutralizes the virus and is easy to perform, so this might be preferable even if hands aren’t visibly soiled.
  (c) Avoidance of TOUCHING YOUR face. This is nearly impossible, as we unconsciously touch our faces constantly. The main benefit of wearing a surgical mask could be that the mask acts as a physical barrier to prevent touching the mouth or nose.
  Any medical equipment such as a stethoscope earpiece could become contaminated with COVID-19 and potentially transfer the virus to other providers.

  Asymptomatic transmission
  This method could potentially occur in two ways.
  (1) Transmission despite a lack of symptoms seems to be possible.
  (2) An additional carrier state could occur in patients who have clinically recovered from the virus, but continue shedding the virus. A recent study found that after convalescence, patients may continue to test positive for COVID-19 for weeks even though the clinical significance of these results is unknown. Convalescing patients probably have a low viral load and relatively low risk of transmission. CDC guidelines are vague on how long patients with known COVID-19 should be isolated. There are suggestions that it may be advisable to obtain two paired culture tests with each pair collected >24 hours apart, prior to discontinuing precautions.

  R⌀
  R⌀ is the average number of people that an virus-infected person transmits the virus to.
  If R⌀ is 1, the epidemic will increase exponentially.
  Current estimates put Covid-19’s R⌀ at ~2.5-2.9 which is a bit higher than seasonal influenza. The R⌀ is a reflection of both the virus and also human behaviour. Interventions such as social distancing and improved hygiene will decrease R⌀. The control of spread of COVID-19 in China proves that R⌀ is a modifiable number that can be reduced by effective public health interventions. Note that the R⌀ on board the Diamond Princess cruise ship was 15 – illustrating that cramped quarters with inadequate hygiene will increase R⌀.

  Sorry about the long read but it is vital that some basics are followed by everyone as we will see the number of cases in the city ramp up over the next few weeks. Hand-washing, hand-washing and more hand-washing for everyone, not just those who are feeling unwell. We need to learn from what worked in China and what did not. Being part of our medical system x 30 years, I can assure you that our centres have been actively prepping but with air travel continuing to/from affected countries & without any self-quarantine mandated by the ministere, the virus’ ability to not trigger symptoms in carriers allows it the potential to spread.

• Kate 21:34 on 2020-03-05 Permalink

  Thank you for all these details, MtlWeb.