The number of passengers and crew exhibiting flu-like symptoms aboard a Holland America Line cruise ship travelling around South America has spiked by more than 80 per cent — from 42 to 77 cases — in just two days.

A total of 247 Canadians are among the 1,243 passengers on the Zaandam, which also has 586 crew members.

On Tuesday, Holland America said in a statement that 30 passengers and 47 crew members are now sick. It comes after the cruise line first reported 42 "influenza-like" cases on Sunday among passengers and crew.

The Zaandam had initially planned to dock 10 days ago in Punta Arenas, Chile to allow passengers to fly home amid the growing COVID-19 pandemic. But the country refused to allow anyone to disembark, and the ship is currently sailing off the coast of Peru with no confirmed docking plans.

The spike in reported illnesses is heightening worries for Tanya Williams, of Waterloo, Ont., whose 73-year-old father, John, is on the ship. She believes that rapid spread could be a sign of a potential COVID-19 outbreak on board.

"I'm very concerned," said Williams. "I really want him to come home."

She said her father told her a few days ago that he had developed a cough and a sore throat.

Anna and Chris Joiner are shown on board the Zaandam, which is currently stranded at sea in South America but attempting to make its way back to Florida. (Submitted by Chris Joiner)

It is currently unclear whether the sick individuals on the Zaandam have COVID-19, the illness caused by the novel coronavirus which has quickly spread on several other cruise ships. The Zaandam has no COVID-19 test kits on board.

But Holland America said Tuesday that a sister ship is en route to deliver extra supplies, staff and test kits to the Zaandam. The ships are set to meet up on Thursday, off the coast of Panama.

Holland America said the sick individuals on board have been quarantined and that the rest of the passengers and non-essential crew have been asked to remain in their cabins.

"Food gets delivered to our cabins, sort of a hodgepodge of things," said Canadian passenger Chris Joiner, who has confined himself to his cabin with his wife, Anna. "We are keeping our spirits high and staying busy."

A warning

The South American cruise departed Buenos Aires on March 7 and was originally scheduled to end in San Antonio, Chile on March 21. But the voyage was cut short on March 14 due to concerns over the global spread of COVID-19.

The Zaandam is now returning north, with plans to dock in Fort Lauderdale, Fla., on March 30.

However, Holland America says it has yet to secure permission to pass through the Panama Canal.

"Alternative options also are being developed," the cruise line said in its statement.

Holland America Line's Cruise ship ZAANDAM was denied disembarking for passengers in Chile.<br>Now this ship with 842 passengers and 542 crew is heading North while seeking a suitable port /country to debark. <a href="https://t.co/pm7kkHuOhL">pic.twitter.com/pm7kkHuOhL</a> —@captsingh

A day before Holland America announced there were ill people on board, Williams sent an email to the cruise line to inform it of her father's symptoms and to warn the cruise line to take the prospect of a COVID-19 outbreak seriously. She said she has yet to receive a reply.

"I wanted them to know that there was concern and that they were accountable," said Williams. "I also wanted to know what they were doing about it. What is their plan if there's an outbreak on the ship?"

Holland America also didn't reply to a request for comment from CBC News.

The Zaandam cut its voyage short on March 14 but its passengers haven't been permitted to disembark at ports in South America. (Holland America Line)

Now that there is a yet-to-be-diagnosed illness spreading on the ship, Williams said she hopes the cruise line will seek help from the Canadian government.

Global Affairs Canada told CBC News that the federal government is working closely with Holland America to ensure the safe return of Canadian passengers.

"We are doing everything to provide assistance under these unprecedented circumstances," spokesperson Krystyna Dodds said in an email.

Another COVID-19-hit Princess ship

Elsewhere, the coronavirus pandemic is taking its toll on other cruise ships.

On Tuesday, an Australian woman in her 70s died after falling ill from COVID-19 while aboard a cruise on the Ruby Princess, which docked in Sydney on March 19, health officials in New South Wales said in a statement .

More than 130 others who were on the ship have now also tested positive, said NSW Health, adding that no cases of COVID-19 had been identified by doctors on board before people disembarked.

The ship and its 2,700 passengers had set sail for a New Zealand cruise on March 8.

The Ruby Princess is the third Princess cruise ship to experience a coronavirus outbreak.

This month, 78 passengers and crew tested positive for COVID-19 who travelled on the Grand Princess, before it ended its journey in northern California. And in February, more than 700 people aboard the Diamond Princess in Japan contracted the virus. Nine have since died.