Australia is facing its first major spreading event of the Omicron variant after two guests on a Sydney boat cruise have likely contracted the strain, health authorities warn.
Five people on the evening cruise around Sydney Harbour on Friday have tested positive to Covid-19 so far. There were more than 140 people on board the cruise, advertised as a nineties-themed boat party.
NSW Health said "preliminary results indicate two [of the five confirmed cases] are likely to have [Omicron]".
Health authorities are now scrambling to trace all on board, with guests and staff ordered to isolate alongside members of their household until a negative test result is received.
Several parties have proven to be super-spreader events in Europe, supporting the early theory the variant is particularly infectious.
In Norway, a Christmas party led to at least 17 Omicron cases, which has since spiralled to more than 50 cases across Oslo.
In Spain, a party of more than 150 healthcare workers led to nearly half of guests testing positive to Covid-19. It is suspected they are infected with Omicron.
The guests at these parties have been vaccinated, with experts warning Omicron is showing signs of being able to evade prior immunity.
“It definitely demonstrates a very high secondary attack rate,” biostatistics professor Tom Wenseleers at the the Katholieke Universiteit Leuven told New Scientist.
NSW has now recorded 31 known Omicron cases, while the state reported a spike in daily Covid cases on Wednesday.
Cases were up 143 infections to 403, although the number of tests was also higher by roughly 30,000.
Chief Health Officer Kerry Chant predicted Omicron cases would rise in the coming days, with some likely linked to the cluster surrounding to schools and a climbing gym in Sydney's west.
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