Researchers attempt to shed light on possible means of in-hospital spread of SARS-CoV-2.
The world is currently experiencing the near-global spread of the novel SARS-CoV-2 virus. Scientists from all over the globe are attempting to gather and process as much information as possible in order to slow or halt the spread of the disease. One of the most important areas of research is examining the exact mechanisms by which the virus spreads. Although much of the research and discussion has focused on direct person-to-person transmission, there are reports that the coronavirus can be transmitted indirectly through contaminated objects in the environment.
A new research letter published in the Journal of the American Medical Association examines the potential for COVID-19 to spread through the air and through the contamination of environmental objects (e.g. surfaces, protective equipment) (1). The research letter focuses on three infected patients at an outbreak centre in Singapore. These patients were being kept in infection isolation rooms. These rooms are specifically designed to contain the spread of airborne pathogens.
Over the course of 10 days between January 24th and February 3rd, researchers collected a series of samples at sites around these isolation rooms. They also collected samples from the personal protective equipment worn by staff exiting the isolation rooms and analyzed them for the presence of the virus.
Is coronavirus airborne?
The researchers found that when samples were taken after the room had been cleaned, viral indicators were absent. However, when samples were taken before routine cleaning, 87% of sites in the room tested positive for the presence of the virus. All air samples tested negative and barring a solitary exception, all samples from personal protective equipment tested negative. Samples from the toilet area within the isolation room also tested positive, suggesting that the disease may also be transmissible by the fecal-oral route.
The potential significance of these results is enormous. It is of vital importance that the scientific community obtains as much information about the spread of the virus as quickly as possible. This evidence suggests that the disease passes into stools. It also suggests that the virus does not survive very well in the air and that cleaning effectively removes viral contaminants. However, the environmental contamination in the room that had not been cleaned was significant. This suggests that viral contaminants from expired droplets may settle in the environment. These pose a risk of transmission, again emphasizing the need for good hygiene practices.
Overall, because of the need to publish the evidence rapidly, this study suffers from some obvious limitations. Foremost amongst these is clearly the extremely small sample size. As such it is suggestive rather than definitive, but of vital importance nonetheless.
Written by Michael McCarthy
1. Ong SWX, Tan YK, Chia PY, Lee TH, Ng OT, Wong MSY, et al. Air, Surface Environmental, and Personal Protective Equipment Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) From a Symptomatic Patient. JAMA. 2020.
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