Severe acute respiratory syndrome coronavirus 2
Abbreviated as SARS-COv-2, (Severe Acute Respiratory Syndrome Coronavirus 2), is a member of the family of viruses called coronviridae, that also includes the common cold virus, flu, SARS(Severe Acute Respiratory Syndrome caused by SARS-Coronavirus-1) and MERS(Middle East Respiratory Syndrome). An infection with SARS-COv-2 causes COVID-19.
Around 2003-2004, a type of coronavirus called SARS-CoV-1(Severe Acute Respiratory Syndrome 1), emerged from China and infected more than 8,000 people mostly in China, Hong Kong, and other South Asian countries. SARS-CoV-1 was eradicated by intensive contact tracing and case isolation measures and no cases have been detected since 2004. SARS-CoV-1 is the human coronavirus most closely related to SARS-CoV-2. In the stability study the two viruses behaved similarly, which unfortunately fails to explain why COVID-19 has become a much larger outbreak.
Characteristics of SARS-COv-2
Since the initial outbreak name as COVID-19, in December of 2019 in Wuhan, China, SARS-COv-2 has spread to over 150 countries around the world and has been declared as a pandemic by the, WHO. As one of the most aggressively spreading viruses, SARS-COv-2 has many unique characteristics that make it more potent as a pathogen that can spread rapidly among communities.
How SARS-COv-2 spreads?
SARS-CoV-2 can persist on plastic and stainless steel surfaces for up to 3 days (at 21-23oC, 40% RH), with a half-life of 13-16 hours. SARS-CoV-2 has an aerosol half-life of 2.7 hours (particles <5 μm, tested at 21-23oC and 65% RH).
Surrogate Coronavirus data:
- Studies suggest that other coronaviruses can survive on nonporous surfaces up to 9-10 days (MHV, SARS-CoV) and porous surfaces for up to 3-5 days (SARS-CoV) in air conditioned environments (20-25oC, 40-50% RH)
- Coronavirus survival tends to be higher at lower temperatures and lower relative humidity (RH), though infectious virus can persist on surfaces for several days in typical office or hospital conditions
- SARS can persist with trace infectivity for up to 28 days at refrigerated temperatures (4oC) on surfaces.
- Beta-coronaviruses (e.g., SARS-CoV) may be more stable than alphacoronaviruses (HCoV-229E).
- No strong evidence for reduction in transmission with seasonal increase in temperature and humidity.
- One hour after aerosolization approximately 63% of airborne MERS virus remained viable in a simulated office environment (25oC, 75% RH)
- The aerosol survival of related human coronavirus (229E) was relatively high, (half-life of ~67 hours at 20oC and 50% RH), indicating ~20% of infectious virus remained after 6 days.
Both higher and lower RH reduced HCoV-229E survival; low