What Does Severe Acute Respiratory Syndrome (SARS) Mean?
Severe Acute Respiratory Syndrome (SARS) is a viral respiratory illness first identified in China in 2002. It is caused by exposure to a type of virus called “Severe Acute Respiratory Syndrome-related Coronavirus” (SARS-CoV).
There are two main strains of SARS-CoV. The strain discovered in 2002 is referred to as SARS-CoV-1, whereas the strain discovered in late 2019 is referred to as SARS-CoV-2. The initial SARS-CoV-1 resulted in a 2002-2003 outbreak that spread to over a dozen countries in Asia, Europe, and South and North America before being contained. SARS-CoV-2 is responsible for the disease known formally as “Coronavirus disease 2019” (COVID-19) and resulted in a global pandemic.
Safeopedia Explains Severe Acute Respiratory Syndrome (SARS)
The SARS virus is an RNA virus with one of the largest genomes (number of genes) of any known virus. It is spread from animals, and both CoV-1 and CoV-2 appear to have originated from bats and eventually spread to humans via Chinese wet markets. Although wet markets are marketplaces that primarily sell fresh meat and produce (essentially the same as farmers markets), the specific wet markets that are associated with the spread of SARS were also known to traffic in exotic animals and to hold live animals on-site—both practices associated with the spread of the disease.
The initial 2002-2003 SARS-CoV-1 outbreak caused 8096 cases, including 774 fatalities, the majority of which occurred in mainland China. A smaller but still significant number of cases occurred in Hong Kong, Taiwan, Canada and Singapore, with all other countries only seeing a few scattered infections. In contrast, SARS-CoV-2 has caused over 111 million cases and 2.47 million deaths worldwide as of the time of this writing.
In 2016, the World Health Organization published a list of global R&D priorities which identified “diseases to be urgently addressed under the R&D blueprint”, including SARS-CoV as one of two “highly pathogenic emerging coronaviruses relevant to humans”.
Differences Between SARS-CoV-1 and SARS-CoV-2
The two extant variants of SARS (SARS-CoV-1 & SARS-CoV-2) account for two of the seven identified coronavirus strains which can infect humans. Of these, SARS-CoV-1 is considered to be eradicated in humans; however, as a zoonotic virus
(a virus that exists in and can be transmitted from other animals) it still exists in nature and could potentially reinfect humans in the future.
There are a number of discrepancies between SARS-CoV-1 and SARS-CoV-2 which explain the much greater success in spreading that the latter has had in comparison to the former. For example, the overall fatality level of SARS-CoV-1 is estimated around 14%, significantly higher than the ~0.2-2% rate that has been estimated for SARS-COV-2 (COVID-19 fatality rate estimates vary depending on a number of factors—estimates that have lower fatality rates are assuming large numbers of undetected cases).
The lower fatality rate and higher numbers of asymptomatic infections that are associated with CoV-2 create a situation in which it is more likely that individuals with COVID-19 will be healthy enough to spread the infection to others, creating a situation in which the disease is less deadly on a case-by-case basis but causes far more harm when viewed in-aggregate.
On a basic biological level, the two SARS strains have very similar levels of transmissibility: An R0 score of about ~2.5, which means that every individual infected will infect 2.5 additional people under “normal” social conditions (e.g., without social distancing measures, etc). This similarity (which does not account for variant types of CoV-2), demonstrates the extent to which factors such as the presentation of the virus affect its ability to spread effectively through a population.
SARS and Occupational Safety
There are two primary dimensions to the relationship between SARS and occupational health and safety:
- As it relates to healthcare providers (HCPs) and others with direct or potential direct exposure to SARS patients
- As it relates to the broader worker population that may be at risk of exposure to SARS (due to the low incidence of SARS-CoV-1, this dimension is primarily relevant to SARS-CoV-2)
Within healthcare settings, healthcare workers could rely on a variety of regulatory infection control standards in order to protect themselves against exposure to either strain of SARS; however, these persons are still at an elevated risk of infection due to their proximity to the virus. Additionally, the strain placed on healthcare systems by SARS-CoV-2 has increased the risk of both accidental or purposeful non-compliance by tired and stressed HCPs. HCPs who do not normally need to obey strict infection control procedures may also have more difficulties complying correctly with various safety measures.
Non-healthcare occupations typically do not have existing infection control standards that they can rely on to prevent the spread of SARS-CoV-2 in their workplace; infection risks at these workplaces are typically considered negligible, and as a result they do not have infection control standards developed for them. Because of this, most legal obligations for SARS-CoV-2 rely on the use of General Duty-type clauses as well as COVID-19-related public health orders enacted by the authority having jurisdiction (AHJ) over the workplace in question.