Epidemiologists have warned Australia will inherit more cases of COVID-19 from India, and other countries, while rigorous testing regimes still fall short of detecting people who have low viral loads while travelling.
A 41-year-old man tested positive while in the Howard Springs facility earlier this week – the first confirmed case among Australians repatriated from India since flights resumed at the weekend.
The man’s positive diagnosis came despite all passengers being subject to a stricter testing regime which stopped 70 passengers from boarding.
Adrian Esterman, from the Biostatistics and Epidemiology department of the University of South Australia, explained how COVID-19 cases can and will enter Australia undetected.
“Picture this scenario: someone has a PCR test and it comes out negative 72 hours before they leave for the airport,” professor Esterman told NCA NewsWire.
“The person then picks up virus at airport, where they also have an antigen test. That is rapid, but it‘s negative because viral levels are still too low.
“The person travels for two days while the virus is brewing inside them. They get to Australia and the viral load could still be too low to return a first positive test.”
Professor Esterman said it was inevitable Australia would inherit more cases in quarantine from countries such as coronavirus-ravaged India – which reported a record 4,329 deaths on Tuesday while its total reported cases topped 25 million – as well as under siege nations in Europe and the UK and the US.
“Absolutely we will have more cases from India, the UK, the US, but as Australia’s vaccination rates improve, it becomes less of an issue,” he said.
“Testing regimes before flights should improve and the whole operation will become less risky.”
The federal government’s travel ban on flights from India was enacted due to a spike in cases in hotel quarantine, with more than half of overseas acquired cases in the facilities originating from the country.
Those who return now are being repatriated to Howard Springs, a makeshift COVID-19 quarantine facility on the outskirts of Darwin that was converted from a mining camp.
Northern Territory health authorities are not trying to stamp out the virus in the facility completely, rather they have set a cap of 50 active cases before considering suspending flights from India again.
Mr Esterman said state governments would need to move all quarantine operations away from tourist hotels in major cities to stronger facilities such as Howard Springs.
“At the beginning of the pandemic, governments weren’t prepared so hotels in cities were probably a good idea.” he said.
“But it’s now we realise hotels are not designed to contain COVID-19. Howard Springs was designed as a mining camp and it makes for a perfect quarantine camp because there are cabins with air separating them.
“Eventually, we hope there is a traffic light system similar to the UK where travellers coming from a green light country are subject to less strict quarantine measures than someone coming from a high risk country.
“But I think quarantining overseas arrivals, in whatever capacity, will be in place for many months if not a year or two.”