A review of several respiratory droplet studies has revealed that the 1.5 metre distancing guidelines could provide insufficient protection for health workers.
The evidence suggests N95 respirators should be the first and only choice for front line health professionals, according to researchers from the University of NSW and Massachusetts Institute of Technology (MIT) who conducted the systematic review of ten studies which was published this week in the Journal of Infectious Diseases.
Eight of the ten studies found that respiratory droplets travelled more than 2m and up to 8m from the person emitting them, far further than 1-2 metre guideline set out by international health agencies including WHO.
Head of the Biosecurity Program at the Kirby Institute, Professor Raina MacIntyre, says that the study also has implications for guidelines on social distancing.
“The guidance we are given for social distancing of 1.5 meters is based on the belief that 1-2 meters is a safe distance to avoid being sprayed by large droplets and that these droplets would be the main emissions containing the virus and able to cause disease,” she says.
“But the body of evidence shows that droplets can be expelled further than 2m. Smaller particles that can’t be seen or felt may remain suspended in a ‘cloud’ and then carried for hours in ambient air, so they can end up traveling much longer distances.”
The paper’s lead author UNSW Engineering’s Prateek Bahl says the study provides “a more comprehensive picture of the mechanisms underlying infection transmission via exhalations, which is important at this time of COVID-19 pandemic and beyond.”
The authors say their findings show the two different levels of protection currently advised for health care workers treating COVID-19 patients need re-evaluating.
>> Read the original article here
Source: MedicalXpress
