CME INDIA Presentation by Admin.

No one says that we are over-masking in response to COVID-19. But now it appears scientifically that we are over-cleaning.

Dr A K Singh, Endocrinologist, Kolkata shares: Meanwhile this paper is making news – no evidence of fomites transmission yet šŸ¤”šŸ¤”

This article, published in www.washingtonpost.com on 11.12.2020, has been written by Joseph G. Allen who is an associate professor and director of the Healthy Buildings program at Harvard Universityā€™s T.H. Chan School of Public Health.

Madness, we witnessed since March 2020?

In December 2020, we can remember the early days. The panic of touching any article, humiliation of food handlers, pizza boy stories, dermatitis of hands due to sanitation mania and what not. So hot was the story of fomite and live corona virus. We searched about it and secreted adrenaline day and night.

New twist in story, How real?

CDC says:

  • COVID-19 spreads less commonly through contact with contaminated surfaces.
  • Respiratory droplets can also land on surfaces and objects. It is possible that a person could get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or eyes.
  • Spread from touching surfaces is not thought to be a common way that COVID-19 spreads.

Joseph G. Allen questions:

  • Not a single documented case of COVID-19 transmission from surfaces exists till date.
  • So why, then, are we spending a small fortune to deep clean our offices, schools, subways and buses?
  • So, are we over-cleaning in response to pandemic?
  • Droplet transmission is the prime mode of entry of virusā€”this reality exists
  • So, if you follow regular hand-washing, thereā€™s no need to constantly disinfect surfaces.
  • Shared air is the problem, not shared surfaces.
  • Transmission of a disease through ā€œfomitesā€ is certainly possible.
  • Many viruses, such as rhinovirus and norovirus, are transmitted through contaminated surfaces. But thatā€™s just not really the case for COVID-19.
  • Best way to interpret the mystery of COVID transmission – We donā€™t know exactly how much fomite transmission occurs for COVID-19, but evidence suggests itā€™s not common.

Steps must be in continuity

  1. The virus must be transmitted to a surface, either by a sick person touching it or a respiratory droplet landing on it.
  2. Once on the surface, the virus starts to decay, and the only studies that show that the virus can survive on a surface for a long time. But only there should be unrealistic large amount of it. Something like someone spits a blob of saliva on the surface.
  3. The coronavirusā€™s genetic material has been found on all kinds of surfaces in hospitals and in the air, but, this does not mean it is infective. Virus has been not cultured from fomite. But it has been cultured from air.

Fomite transmission-certainly not driving the pandemic.

Shared surface is not the culprit.

  1. Suppose as unfortunate person you immediately grabbed a door handle right after an infectious person sneezed on it. Be cool, there would be a significant reduction in how much is transferred from the surface onto your hand. Further the virus gets inactivated even while on your hand.
  2. Worst scenario is if you touched that contaminated doorknob and then immediately touched your mouth, even then not all of the virus on the hand would get transferred to the mouth.
  3. Even if the virus did make it into your mouth would need to find an appropriate receptor there or make it to your respiratory tract.
  4. So, Joseph says that when we look at this entire causal chain, itā€™s easy to see that if fomite transmission is happening, itā€™s minor and certainly not driving the pandemic.

We have a big solution

  • Most important, we can prevent fomite transmission through regular hand-washing or use of hand sanitizer.
  • Cleaning every surface after every touch is an impossible task; the easier and more effective approach is to break the chain at the person.

The intense focus on fomite transmission is a critical issue

  • Almost all organizations are spending massive amounts of time and money addressing a ghost problem – this is a big comment by Dr Joseph.
  • Airports, Malls, Commercial establishments etc. are spending huge amount of money and man power ā€“ is it useless? Looks so.
  • On top of that, the use of all of these extra cleaning products releases chemicals into the air that can be extremely harmful to our health. This money and time are better spent elsewhere.

Finally, Joseph says:

  • We should continue to wash our hands and pay attention to hygiene, but we only have so much time, energy and money to spend on reducing the risk of transmission.
  • If the vast majority of transmission occurs through the air rather than fomites, and airborne transmission is what is driving superspreading events, then we should shift our effort toward cleaning shared air, not shared surfaces.


CME INDIA Learning Points

  • A clinically significant risk of SARS-CoV-2 transmission by fomites has been assumed on the basis of studies. But these have little resemblance to real-life scenarios.
  • Emanuel Goldman highlighting experiments done under controlled laboratory conditions suggest persistence of SARS-CoV-2 on inanimate surfaces for days, with potential implications for viral transmission. But the absence of real-life studies investigating the infectious potential of SARS-CoV-2 on contaminated inanimate material and patient fomites, particularly in high-risk hospital wards do not support it.
  • No attempt was made to culture SARS-CoV-2 from the environmental swabs which would have helped to understand the significance of SARS-CoV-2 RNA positive samples in terms of infectious potential.
  • More importantly, attempts to culture the positive swabs on Vero E6 cells were unsuccessful, suggesting that patient fomites and surfaces are not contaminated with viable virus.
  • Environmental contamination leading to SARS-CoV-2 transmission is unlikely to occur in real-life conditions, provided that standard cleaning procedures and precautions are enforced.
  • To date, there is no evidence to suggest that consuming food is associated with COVIDā€19. Nevertheless, COVIDā€19’s impact on food safety and security have been grave.


CME INDIA Tail Piece

  • China now reports few to none domestically transmitted COVID-19 cases – only 12 cases were reported on Dec. 15.
  • But a flurry of recent cases has Chinese public health officials worried. They claim that the cases stemmed from workers who had contact with imported food and packages.
  • Beijing has now banned nearly 100 suppliers from 20 countries and at one point recommended travel restrictions in at least two cities.
  • There’s a problem with this theory. The cases directly contradict international health guidance, which says such transmission is highly unlikely

Sources:

  1. Goldman E. Exaggerated risk of transmission of COVID-19 by fomites. Lancet Infect Dis 2020; published online July 3. https://doi. org/10.1016/S1473-3099(20)30561-2
  2. Van Doremalen N, Bushmaker T, Morris DH, et al. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. N Engl J Med 2020; 382: 1564ā€“67
  3. Colaneri M, Seminari E, Piralla A, et al. Lack of SARS-CoV-2 RNA environmental contamination in a tertiary referral hospital for infectious diseases in Northern Italy. J Hosp Infect 2020; 105: 474ā€“76. 5
  4. Colaneri M, Seminari E, Novati S, et al. Severe acute respiratory syndrome coronavirus 2 RNA contamination of inanimate surfaces and virus viability in a health care emergency unit. Clin Microbiol Infect 2020; 26: 1094.e1ā€“e5.
  5. We are over-cleaning in response to covid-19. – Opinion by Joseph G. Allen, Charles Haas and Linsey C. Marr. Dec. 11, 2020


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