COVID-19 could spread faster in winter
COVID-19 restrictions should be lifted in batches with a three-week pause between each new change to check whether the lifting of restrictions has fuelled spread of the virus, Australia's leading universities have said.
A major report on the coronavirus recovery from Australia's leading Group of Eight universities called the 'Roadmap to Recovery', has been provided to the Federal Government.
It says Australia has two options as it tries to recover from the COVID-19 crisis - eliminate the illness, or, controlled adaptation which entails controlling the spread of the virus while society adapts to ongoing infections.
Meanwhile, as eastern states shiver through a cold snap, the government has released expert advice it has received warning there could be an increase in COVID-19 infections during winter.
Respiratory viruses generally spread faster in winter because lower air temperature and humidity increase both the survival of viruses and the droplets which spread the viral particles through the air.
Reduced ultraviolet B (UVB) light during winter can lead to lower vitamin D, which may impair the body's innate immune defences, the report notes.
However, the advice said public health policies such as social distancing and population density were just as important as temperature in the spread of the virus.
Expert scientists working for the Rapid Research Information Forum (RRIF) chaired by Australia's Chief Scientist, Dr Alan Finkel provided the advice and were also asked whether people could get reinfected with COVID-19.
"While we cannot say for certain that reinfection is not possible, the evidence for reinfection is so far not compelling," the scientists have told the government.
However, the experts warn a decline in immunity or mutations in the virus could result in a future scenario in which reinfection is possible.
A separate group of scientists were asked whether wastewater could be used to monitor the spread of COVID-19 and advised it was possible but warned there was a risk some areas could be stigmatised if the information was made public.
University of Adelaide public health expert Professor Tracy Merlin who worked on the Roadmap to Recovery report said restrictions on international and intrastate travel would need to remain for at least six months and any returning essential travellers will have to be subject to the quarantine restrictions.
"For other containment measures we are recommending that restrictions be lifted in batches, with a pause of a minimum of three weeks in between, to determine the impact on spread and case numbers," she said.
Controlled adaptation must be supported by extensive testing and surveillance, rapid, effective case detection, case isolation and contact tracing of the majority of cases, she said.
If the government decided to pursue the elimination strategy there would be fewer total infections, hospitalisations and deaths, and once achieved there could be faster relaxation in social distancing and other restrictions.
However, Australia would likely have to continue the lockdown in certain jurisdictions beyond mid-May, possibly for another 30 days, the report said.
It would involve waiting for new local cases to fall to zero, and then maintaining this for two incubation periods, about two weeks before lifting restrictions.
"The number of asymptomatic carriers in Australia is not known and may pose a potential risk to this strategy," the report said.
The report says some form of technological tracing is necessary to control spread of the virus. International travel bans will have to continue for the next six months and any returning essential travellers will be subject to the quarantine restrictions.
"If some countries have their epidemics under control in a manner same as ours, then our Government may explore establishing a special bilateral travel understanding," the report said.
Originally published as COVID-19 could spread faster in winter