"Our big concern, the very big concern, is that those people came off the cruise with no knowledge of COVID actually being on their ship," he said. "If they think that it's not necessary to do the 14 days, and if they think that it's okay to be wandering around, the clear message from me ... is, no, it's not. "It is actually serious because if we had 2700 passengers on that ship we want to know that every single one of them is in quarantine.” The number of confirmed coronavirus cases in NSW jumped by 75 to 382 in the 24 hours since 11am on Thursday - the biggest increase to date.

Five people aboard the Ruby Princess had influenza-like illness before they boarded in Wellington, New Zealand on March 14. They were tested before boarding and all were negative for COVID-19 at that time. Several passengers developed flu-like symptoms while at sea. A doctor on board swabbed 13 passengers who were checked for COVID-19 once the ship arrived in Sydney. All passengers were instructed to self-isolate and allowed to disembark the vessel, which was considered low risk because it was arriving from New Zealand. Two passengers aged in their 70s are being treated in the dedicated COVID-19 intensive care ward at Royal Prince Alfred Hospital. One patient is severely unwell. A third passenger - a Tasmanian - has also been diagnosed and a fourth, also in Tasmania, is awaiting test results after developing symptoms.

Chief Health Officer Kerry Chant said all passengers have been sent emails and text messages alerting them to the situation, directing them to self-isolate and contact health authorities if they develop symptoms. Some passengers have not responded to the messages. Mr Hazzard urged anyone who knew any individuals aboard the ship to make sure they were self-isolating. Sixty-three per cent of the passengers are Australian residents, 20 per cent are US residents and the rest are from a variety of other countries. All close contacts of the confirmed cases will also be identified and informed. The crew member who tested positive is still on the Ruby Princess with 1050 other crew. Dr Chant said NSW Health had been in contact with the cruise line, which was managing the situation.

"They have doctors on board the ship, they have ICU facilities ... now with all the passengers off the ship they have the ability to reallocate all the crew to single rooms with bathrooms," Dr Chant said. She said the cruise line was working with the Centre of Disease control on cleaning protocols "drawing on the best knowledge or what has gone on cruise ships before" and were "very confident" they could contain the virus. The Princess cruise line also operates the Diamond Princess vessel on which almost 700 people contracted coronavirus when it was quarantined in Japan for two weeks in February. Loading Replay Replay video Play video Play video In a statement a spokesperson for Princess Cruises said all passengers with flu-like symptoms, as well as their cabin occupants, were in isolation aboard the ship to minimise their contact with other guests. The 13-night cruise was cut short and returned to Sydney when the federal government announced its travel restrictions earlier this week.