Should we squash the curve?
James Cook University scientists say Australia and the World are facing hard choices in the months and years ahead.
Professor Emma McBryde from JCU’s Australian Institute of Tropical Health and Medicine led a study examining different scenarios for the spread of the COVID-19 pandemic.
Professor McBryde said the main message is that Australia’s current policy of ‘flattening’ the infection curve may mean a much lower and later peak, but still leads to a very substantial number of cases and deaths and an overwhelmed health service.
“If there is a reproduction number above one, each person infects two to three others and the cycle repeats. However, if we can reduce the reproduction number below one, what we call ‘squashing’ the curve, then an epidemic will not occur,” she said.
Professor McBryde said bringing the reproduction number below one would require a stringent combination of social distancing of the entire population, home isolation of identified cases and household quarantine of their family members as a minimum.
“The problem with this strategy is that herd immunity, where a sufficiently high proportion of individuals are immune to the disease after catching it, is not achieved. This means secondary epidemic waves are almost inevitable and the measures taken need to be sustained over a long period of time,” she said.
Professor McBryde said the country had three choices.
“We can relax restrictions and allow a huge loss of life. Or we can maintain a reproduction rate under one, with its attendant severe restrictions until a vaccine is found, if it is found.With the knowledge that this may not allow society and the economy to function. Or we can allow limited circulation of the virus while protecting the vulnerable, acknowledging that segregation of society to isolate the elderly and at-risk would require unprecedented changes to our social structures and lifestyles,” she said.
Professor McBryde said Australia’s efforts in containing COVID-19 are looking very promising but there were still stark choices ahead.
Professor Emma McBryde