A man has tested positive to Covid-19 in Perth hours after he was released from hotel quarantine and sent into the community, where he dined and shopped.
Health officials are conducting more tests to determine the threat to residents but so far they suspect they are dealing with a “shedder case”.
The man, a maritime worker, returned to Perth from Colombia via the United States in May and had tested positive for the virus 16 days ago. He tested negative on day 10 of hotel quarantine and was released from the Pan Pacific Hotel on Friday afternoon. He returned a “moderately strong” test on Saturday which has seen him return to hotel quarantine.
“He has returned to hotel quarantine based on an abundance of caution,” WA Health said.
“Contact tracing is underway, again as a precaution.”
WA health authorities say they don’t believe he was infectious while in the community, despite visiting a pharmacy, telephone store and a hotel in Perth’s CBD.
Western Australia’s chief health officer Andrew Robertson said authorities are taking a “cautious approach” but they believe the man is a “non-infectious chronic shedder”.
“What he’s shedding is viral particles, he’s not shedding the virus, so we don’t believe he is a major concern to the community,” Mr Robertson said on Sunday.
“This is not uncommon and represents persistent fragments of the virus that cannot infect others.
“His result suggested a higher level of virus than has previously been found in these situations.”
In a statement WA Health said that further testing was consistent with a long-term non-infectious shedder, but “further viral cultures and genome sequencing are required to confirm this”.
Mr Robertson said “for some reason” a small percentage of people shed after they’ve recovered from the virus, which occurs when particles are shed into the back of the throat and released into the environment.
“Some people shed more often and more commonly, sometimes if they’ve had another infection like a cold, it exacerbates it. Generally it just occurs in some people and not others.
“We were concerned, this is an unusual finding,” he added.
But, he reassured, “the risk is very low and we don’t believe this individual is infectious.”
“The Department of Health believes he has not been infectious while in the community and the risk of transmission is very low.
“The Department, however, is taking a very cautionary approach and will contact people who have been at venues that he visited.”
The man “does not have a variant of concern” and was previously vaccinated against COVID-19.