Airborne spread of COVID-19 can occur in restaurants
At a time when NSW and Queensland restaurants are recording high numbers of COVID cases, infectious disease experts have announced there are four different methods which may be driving up restaurant related COVID numbers.
Raina Macintyre, a professor of Infectious diseases and biosecurity at the Kirby Institute said the virus could spread in a restaurant setting in a number of ways, stating, “It could be spread by the respiratory route or by contact (touching). It has been documented that airborne spread can occur in restaurants.
“If there are people who got infected without direct contact, then airborne is the most likely route.
“Spread from toilets is also possible, as the virus is shed in faeces and can be aerosolised by flushing or can contaminate taps, door handles etc.
“The contact investigation will identify which infected contacts had direct contact versus those that did not.”
COVID-19 is not considered to be a foodborne disease, however coronaviruses have the ability to remain on surfaces such as cutlery, plates and wine glasses.
It can also be contracted by coming into contact with high touch surfaces such as doorknobs, chairs and tables. These are areas that may have been coughed or sneezed on by an infectious person, leaving droplets that could then infect someone else.
Professor Macintyre referred to a case study, COVID-19 Outbreak Associated with Airconditioning in Restaurant, Guangzhou, China, 2020 by Jianyun Lu of the Guangzhou Center for Disease Control and Prevention where they studied an outbreak in an airconditioned restaurant.
The study shows just how virus droplets could could travel from one spreader via an air conditioning system in a confined space. The study indicates that one member of a family infected with COVID-19 dined at a restaurant and not only did his family members who were seated with him contract the disease, but so too did many other diners who were seated at surrounding tables.
It goes further to explain that patrons on three other levels of the building also contracted the disease in the days following.
Smear samples were taken from the air outlet and inlet. The results were negative for coronavirus, however scientists studying this case concluded, “droplet transmission … prompted by airconditioned ventilation” was the probable cause of the outbreak.
The case study also concludes that “strong airflow from the air conditioner could have propagated droplets” from table to table.
13 new cases were reported overnight in NSW, with only one in Queensland. Victoria recorded 429 cases as it enters into stage four lockdown and registered a “state of disaster”.
Irit Jackson, 4th August 2020
