After much uncertainty, the World Health Organisation has now confirmed that even people who don’t appear sick could be spreading the coronavirus.
But this doesn’t mean everyone should rush off to get tested, an Australian infectious disease expert has warned.
The confusion began on Monday.
The WHO’s technical lead for coronavirus response Dr Maria Van Kerkhove said: “it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual”.
Her comment was widely interpreted as meaning people without symptoms rarely transmitted the virus.
The WHO has found that COVID-19 transmission from an asymptomatic patient is "very rare". COVID-19 technical lead Dr Maria Van Kerkhove says, contact tracing data from various countries shows that this appears to be the case. pic.twitter.com/byIFPW6RjY
— BFM News (@NewsBFM) June 9, 2020
But on Tuesday, Dr Kerkhove moved to clear up any “misunderstandings” at a live Q&A, saying “this is a major unknown”.
“The majority of transmission that we know about is that people who have symptoms transmit the virus to other people through infectious droplets,” she said.
“But there is a subset of people who don’t develop symptoms, and to truly understand how many people don’t have symptoms, we don’t actually have that answered yet.”
In other words, it is possible that people without symptoms could unknowingly spread the disease.
So what does this mean for our testing?
Should we be expanding our testing criteria to ensure all Australians can get tested, not just those who are showing flu-like symptoms or suspect they have been in contact with a known case?
Bill Bowtell, a strategic health policy adviser and Adjunct Professor at the University of New South Wales, said testing everyone without symptoms would be a “waste of time and resources”.
“At the moment, we have very low levels of community transmission,” he told The New Daily.
“If you said everybody in Australia should be tested – all 26 million people – the time, effort and resources would be out of proportion to the benefits we’d derive from it.”
But widespread testing was still very important and we shouldn’t ease the pedals yet, he said.
“Testing is the key, but I think we’ve got the balance right at the moment,” said Adjunct Professor Bowtell, who helped lead Australia’s response to the AIDS crisis, said.
“You’d think if there were lots of asymptomatic carriers who were carrying the virus, we’d know about it in Australia because it would show up.
“The figures don’t seem to suggest there are large numbers of asymptomatic carriers who are spreading it and it would be showing up in doctor’s surgeries and test results if that were the case.”
Adjunct Professor Bowtell said the WHO should be forgiven for its mixed messaging.
“Every day, something new and puzzling crops up about the coronavirus,” he said.
“We’ve only known about this for six months in science, so the authorities and doctors are looking at this with an eagle eye.”