Surface Survival of SARS-CoV-2

Seriously, how long can this thing survive on surfaces?

In an earlier post, I referenced some preliminary research suggesting that SARS-CoV-2, the virus that causes COVID-19, can live in the air and on surfaces between several hours and several days. This work, originally released as a pre-print and recently finalized and published in the New England Journal of Medicine, found the virus is viable for up to 4 hours on copper, 24 hours on cardboard, 48 hours on stainless steel, 72 hours on plastics, and is also detectable in the air for 3 hours. 

A lot of posts present this information out of context and headlines can make it sound frightening, “SARS-CoV-2 Lives on Plastic for 72 Hours!!!” However, what’s more important is the amount of virus that’s still alive. It’s <0.1% of what the investigators started with. So, infection is theoretically possible but extremely unlikely at the levels they saw after a few days. 

Another important thing to mention lies in the experimental design of the aerosol component of the study. It has some caveats. They found that the virus can be detected in the air for 3 hours in the lab. However, in nature, respiratory droplets fall to the ground at a faster speed than the aerosols generated in their experiments. This is because the lab-generated aerosols are smaller (<5 μm) than what is produced from a cough or sneeze, so they remain in the air at face-height longer than the natural, heavier particles. It’s not a perfect comparison (though science rarely is, we just do our best). The size of these particles can affect how they move through the air and how they impact a surface. 

So, at the end of the day you’re more likely to become infected through the air if you’re next to an infected person versus a contaminated surface. Make sure you clean surfaces with disinfectant or soap – they work because they disturb the oily external layer of the virus keeping it from infecting your cells. 

Resources: SARS-CoV-2 and COVID-19

What to do if you have symptoms of coronavirus disease 2019 (COVID-19) and have not been around anyone who has been diagnosed with COVID-19

What to do if you have confirmed or suspected coronavirus disease (COVID-19)

National Institutes of Health (NIH) – Vaccine Research Efforts on Coronavirus (COVID-19)

Schools/Education – For updates on school closures and information and guidance for parents

Employment Security Department of WA State – Links and FAQs for workers and businesses affected by coronavirus

Business and Workers – Links and FAQs for workers and businesses affected by coronavirus

Retail businesses guidelines from Department of Public Health

Workplace Practices – handwashing and social distancing recommendations for employers


Have general questions? Comments?

Email asktheoptimisticscientist@gmail.com or comment below!

Reliable Sources of Information

Where can I find the most reliable, up-to-date numbers on confirmed cases?

There are several resources out there that compile the information from multiple sources. When evaluating any information, please remember to critically assess:

  1. The source itself and their goals
  2. How the data and findings are described
  3. What has been reported, and what has not; and
  4. The quality of the information

Globally –> World Health Organization (WHO)

Globally –> Abdul Latif Jameel Institute for Disease and Emergency Analytics/Imperial College (J-IDEA): https://www.imperial.ac.uk/jameel-institute/

United States –> 

  1. Coronavirus.gov – Combined White House/Dept of Health & Human Services/CDC resource, this is your starting point for information & resources at the federal
  2. Centers for Disease Control (CDC)

NOTE: The CDC is providing accurate numbers for the country as a whole, but if you want more up-to-date information on a daily basis, please check the department of health or public health websites for your particular state or county. If you click the CDC link above, and then click a state, it will bring you to that department of health’s website.

Washington State –> Washington State Department of Health

NOTE: The state of Washington’s department of health website also has data broken down by county.

King County –> Public Health – Seattle & King County

Why do some numbers vary between sources (NY Times, Politico, nCov2019.live, etc)?

It depends on two main things – when you’re looking, what you’re looking at, and where the numbers are coming from. Some sources update only once a day, others multiple times a day. Some pull from multiple inputs, or count confirmed cases in addition to information gained from reporting and interviews with credible sources. Some may have more than one laboratory in a given area that may be reporting with different frequencies during a given day. Your best best is to stick with the public health authority at the level your question is directed to, but consulting multiple sources like the ones listed above can give you the big picture view of this pandemic.

John’s Hopkins has a live tracker that provides interesting insights.


Have general questions? Comments?

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The Novel Coronavirus – Key Terms

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The novel coronavirus, or SARS-CoV-2, is the virus responsible for the COVID-19 illness.

What is the novel coronavirus?

Okay, first things first, let’s start with a few key terms to clarify any mixed messages you may be receiving.

Coronavirus: The name given to a family of viruses that cause disease of varying severity in mammals and birds. Viruses from this family can be responsible for the common cold, but other members of this family have caused two large-scale pandemics in the past two decades, sudden acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). Viruses are classified into families based on their structure and genetics, so it’s kind of like coronaviruses are the Mariners.

SARS-CoV-2 (sudden acute respiratory syndrome coronavirus-2 or the novel coronavirus): This is the specific name of the novel viral organism. If we continue our example from above, this would be a specific baseball player (Ichiro, Ken Griffey Jr, etc). It’s novel, or new, because this a virus that our immune systems have never seen before.

COVID-19: This is short for coronavirus disease 2019 and the name of the disease/illness caused by the novel coronavirus that originated in Wuhan, China in 2019.

Epidemic: A sudden increase in the number of cases of a disease above what is typically expected in a given area.

Pandemic: An epidemic that has widespread human infection in multiple countries across the globe.

Signs: Objective measurement to characterize an illness during a physical exam by a healthcare provider (e.g. temperature, respiratory rate, oxygen saturation).

Symptoms: Subjective evidence of an illness or abnormal process occurring in the body and reported by the patient (e.g. fatigue, nausea, anosmia, ageusia, myalgia).

Incubation Period: The time from when someone is infected to when symptoms develop. Based on existing evidence-based research, the incubation period of SARS-CoV-2 and other coronaviruses (e.g. MERS-CoV, SARS-CoV) ranges from 2–14 days. 50% of people will become ill 5 days after infection.

Infectious Period: The time when an infected person, who may not be showing symptoms, can transmit the virus to others. While it varies from person to person, it is typically ~ 7 days.

Molecular test — RT-PCR (Reverse transcription polymerase chain reaction): This is a molecular diagnostic test that identifies the presence of virus in the body through collection of nasopharyngeal, oropharyngeal, or other respiratory specimens by swabbing. The turn-around time for results varies greatly depending on the laboratory doing the test, but the current range is somewhere between 1 and 5 days.

Antibody Test — Serology: Blood test with a turn-around time of typically same day, but sometimes can take a couple of days. Serology is especially important because it may detect previous infections in people who had few or no symptoms.

Antigen test — Rapid: Rapid diagnostic test with a turn-around time of less than one hour. Antigen tests look for specific proteins on the surface of the virus and can diagnose an active infection.


Have general questions? Comments?

Email asktheoptimisticscientist@gmail.com or comment below!