Covid-19 Myths & Facts: Are cloth masks better than N95? Can anaesthesia machines be converted into ventilators?

— By KK Aggarwal

312: CDC recommends people wear cloth masks to block the spread of COVID-19

Fact. Yes. Surgical masks and N95 respirators should be reserved for health care workers.

The Centers for Disease Control and Prevention (CDC) released new guidelines today recommending that people in the US wear homemade face coverings to prevent the spread of the novel coronavirus.

The CDC is additionally advising simple cloth coverings to help people who may have the virus and do not know it keep from transmitting to others.

The White House task force and the CDC have been re-evaluating their mask recommendations over the past few days. Research shows that people without symptoms can infect others, and that the virus may spread when people speak or breathe — not just when they cough or sneeze. “In light of this new evidence, the CDC recommends and the task force recommends people wear cloth face coverings in public settings where other distancing measures are difficult to maintain.

If people cover their faces with a cloth mask or another barrier, it may blunt the amount of virus-laden particles they release.

There is limited evidence that these types of makeshift masks prevent the spread of disease, though some research shows that they do reduce the amount of particles a person wearing them spreads. Some experts say that they’re better than nothing. The CDC says people should continue to stay six feet apart when in public as much as possible, even if they’re wearing masks.

Some cities and states, like Colorado and New York City, had already asked people to cover their faces when out in public.

313: Groups at Higher Risk for Severe Illness

Fact: Based on what we know now, those at high-risk for severe illness from COVID-19 are:

People 65 years and older

People who live in a nursing home or long-term care facility
What You Can do if You are at Higher Risk of Severe Illness from COVID-19
Learn how you can help protect yourself if you are at higher risk of severe illness from COVID-19.

People of all ages with underlying medical conditions are at higher risk for severe illness, particularly if the underlying medical conditions are not well controlled. This includes people with:

Chronic lung disease or moderate to severe asthma
Serious heart conditions
Conditions that can cause a person to be immunocompromised, including cancer treatment, smoking, bone marrow or organ transplantation, immune deficiencies, poorly controlled HIV or AIDS, and prolonged use of corticosteroids and other immune weakening medications.
Severe obesity (body mass index [BMI] of 40 or higher)
Diabetes
Chronic kidney disease and who are undergoing dialysis
Liver disease

314: Younger people can be serious

Yes, Fact: In Italy, one of the largest outbreaks in the world, 10% to 15% of all people in intensive care are under 50.
In Korea, one in six deaths have been people below the age of 60

Last month, world health officials referenced a study in China that looked at 2,143 cases of children with confirmed or suspected COVID-19 that were reported to the Chinese Centers for Disease Control and Prevention between Jan. 16 and Feb. 8.

That study showed that more than 90% of the cases were asymptomatic, mild or moderate cases. However, nearly 6% of the children’s cases were severe or critical, compared with 18.5% for adults.

315: Stability of SARS-CoV-2 in different environmental conditions, SARS-CoV-2 in wastewater, and guidance on repurposing anaesthesia machines as ventilators

Fact: According to a study published in The Lancet Microbe, SARS-CoV-2 can be highly stable in a favourable environment, but it is also susceptible to standard disinfection methods.

Alex W. H. Chin, MD, University of Hong Kong, Hong Kong, China, and colleagues conducted various experiments to test the stability of SARS-CoV-2 at different temperatures, on various surfaces, and its susceptibility to disinfection methods.

First, the researcher measured the stability of SARS-CoV-2 at different temperatures. SARS-CoV-2 in virus transport medium (final concentration ∼6.8 log unit of 50% tissue culture infectious dose [TCID50] per mL) was incubated for up to 14 days and then tested for its infectivity.

Results showed that SARS-CoV-2 is highly stable at 4 degrees Celsius, but sensitive to heat. At 4 degrees Celsius, there was only around a 0.7 log-unit reduction of infectious titre on day 14. When the incubation temperature increased to 70 degrees Celsius, the time for virus inactivation was reduced to 5 mins.

The researchers then investigated the stability of this virus on different surfaces, including paper, tissue paper, wood, cloth, glass, banknotes, stainless steel, plastic, and surgical masks. Briefly, a 5 μL droplet of virus culture (∼7.8 log unit of TCID50 per mL) was pipetted on a surface and left at room temperature (22 degrees Celsius) with a relative humidity of around 65%. The inoculated objects retrieved at desired time-points were immediately soaked with 200 μL of virus transport medium for 30 mins to elute the virus.

No infectious virus could be recovered from printing and tissue papers after a 3-hour incubation, whereas no infectious virus could be detected from treated wood and cloth on day 2. By contrast, SARS-CoV-2 was more stable on smooth surfaces. No infectious virus could be detected from treated smooth surfaces on day 4 (glass and banknote) or day 7 (stainless steel and plastic).

Strikingly, a detectable level of infectious virus was still present on the outer layer of a surgical mask on day 7 (∼0.1% of the original inoculum).

316: can povidone iodine kill the virus

Yes; The researchers also tested the virucidal effects of disinfectants by adding 15 μL of SARS-CoV-2 culture (∼7.8 log unit of TCID50 per mL) to 135 μL of various disinfectants at working concentration.
Disinfectants included household bleach, hand soap, ethanol, povidone-iodine, chlorhexidine, and benzalkonium chloride. With the exception of a 5-minute incubation with hand soap, no infectious virus could be detected after a 5-minute incubation at room temperature.

316: Can the virus survive in waste water

In an article, published in The Lancet Gastroenterology & Hepatology, researchers report the detection of SARS-CoV-2 in wastewater.

From February 17, 2020, onwards, Willemijn Lodder, and Ana Maria de Roda Husman, Centre for Infectious Disease Control, Bilthoven, the Netherlands, took samples once a week from human wastewater collected at Amsterdam Airport Schiphol, Haarlemmermeer, the Netherlands, for virus analyses. Samples tested positive for virus RNA by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) methodology 4 days after the first cases of coronavirus disease 2019 (COVID-19) were identified in the Netherlands on February 27, 2020.
This could be explained by virus excretion from potentially symptomatic, asymptomatic, or pre-symptomatic individuals passing through the airport.

Furthermore, human wastewater sampled near the first Dutch cases in Tilburg, Netherlands, also tested positive for the presence of viral RNA within a week of the first day of disease onset. These findings indicate that wastewater could be a sensitive surveillance system and early warning tool, as was previously shown for poliovirus.

317: Faeco oral transmission

Fact: Whether SARS-CoV-2 is viable under environmental conditions that could facilitate faecal-oral transmission is not yet clear…[however], the possibility of faecal-oral transmission of COVID-19 has implications, especially in areas with poor sanitation where diagnostic capacity might be limited, such as Africa. Wastewater surveillance, especially in areas with a scarcity of data, might be informative, as we have previously shown in monitoring antibiotic resistance on a global scale.

318: Can you convert anaesthesia machines into ventilators

American Society of Anesthesiologists (ASA) have published guidance on how to safely and effectively convert anaesthesia into life-sustaining mechanical ventilation for patients during the COVID-19 pandemic, when there are not sufficient ICU ventilators to meet patient care needs.

Although guidance is available from the manufacturers, the guidance may not convey all of the clinical considerations. Anaesthesia professionals will be needed to put these machines into service and to manage them while in use. Safe and effective use requires an understanding of the capabilities of the machines available, the differences between anaesthesia machines and ICU ventilators, and how to set anaesthesia machine controls to mimic ICU-type ventilation strategies.

Reference: https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(20)30003-3/fulltext
SOURCE: The Lancet Microbe, The Lancet Gastroenterology & Hepatology, and American Society of Anesthesiologists

((The writer is President, CMAAO, HCFI and Past national President IMA))