Australian scientists have come up with a way to predict how many COVID-19 cases could be present on an international flight, as governments weigh up the prospect of borders reopening.
The model forecasts the number of potential infections on each flight by measuring the number of incoming passengers and the rates of disease in the countries they're travelling from.
Researchers from the CSIRO and Queensland University of Technology evaluated Australia's travel bans at the start of the pandemic and found the changes had lowered the number of imported COVID-19 cases by 88 per cent.
"The model is a flexible framework that can be used to quantify the effects of travel restrictions and to evaluate proposed relaxations," CSIRO research scientist Jess Liebig said on Wednesday.
"It also enables us to pinpoint the groups of travellers most likely to be carrying the virus, so authorities can more efficiently direct healthcare and biosecurity control strategies."
The model also considers in-flight transmission of the virus and the related report notes reporting mechanisms "can vary greatly" across countries.
Scientists applied the model to two scenarios: one with open borders and another reflecting the actual travel restrictions implemented by Australia between January and June 2020.
During this period Australia introduced travel bans on China, Iran, South Korea and Italy due to their high rates of COVID-19 before a full travel ban on all foreign nationals commenced on March 20, 2020.
"Our modelling shows that without travel restrictions, over 48,000 COVID-19 cases were likely to have been imported to Australia from January to May 2020," Dr Liebig said.
The model is the first to quantify the expected number of COVID-19 importations from all countries globally into a particular country, Queensland University of Technology's Professor Raja Jurdak said.
"The effectiveness of travel bans on individual countries varies widely and depends heavily on the behaviour of returning residents and citizens," Prof Jurdak said.
"If we can better understand and forecast the likely spread of COVID-19 through air travel, we can make more informed decisions about when and how to reopen international borders."
The research paper, 'Should international borders re-open? The impact of travel restrictions on COVID-19 importation risk', was published in the journal BMC Public Health.
Australian Associated Press
