How is COVID-19 spread?
As COVID-19 belongs to the
coronavirus family – closely related to the Severe Acute Respiratory Syndrome (SARS) & Middle East Respiratory Syndrome Coronavirus (
MERS) virus – the primary route of transmission is the inhalation of small respiratory droplets from an infected person.
These small droplets produced from an infected person (symptomatic or asymptomatic) usually arise from sneezing, coughing, and even talking. Thus, those within proximity of less than 1 meter from an infected person are at a high risk of inhaling viral particles from an infected person.
Larger respiratory droplets (talking and coughing mildly) only remain in the air for a short period and typically do not travel distances greater than 1 meter. However, smaller respiratory 'nuclei' from sneezing (aerosolized) can travel distances greater than 1m.
The current evidence suggests that in most cases COVID-19 is transmitted by respiratory droplets, though symptomatic individuals that sneeze (less common in COVID-19 than flu) can propel particles much further. Thus, the risk of infection inside enclosed spaces is far greater than being outside.
Other indirect routes of transmission may include coming into contact with contaminated surfaces (called fomites) as a result of contagious droplets falling on these surfaces. When someone touches an infected surface and then touches their face (close proximity to mouth, nose, and eyes), the risk of the virus entering the body is significantly increased.
Coronaviruses, in general, have poor survivability on surfaces thus the risk of getting infected by touching parcels or shopping items is relatively low (the virus can only survive up to 1 day on cardboard and up to 2 days on plastic).
Amidst the pandemic, it is advisable to wipe surfaces and packets with a detergent disinfectant or alcohol wipes. Many shops and supermarkets now employ hygiene measures such as hand sanitizers and disinfectants before entrance. It is important for restaurants and takeaways to enhance hygiene efforts in order to make food in these contexts safe.
Lastly, some evidence has suggested the presence of SARS-CoV-2 RNA in stool samples from infected people – though whether these are infectious virus particles is still to be seen. Some evidence does point to infectious viral particles being present after flushing the toilet and keeping the toilet lid down reduced this supposed spread.
It is also safe to assume, based on all the emerging evidence, that all bodily secretions except for sweat may contain infectious virus particles. However, none of these routes are thought to be the main infection route for SARS-CoV-2, although caution is advised.