The latest deaths pushed Hong Kong's total to 40 and raised concerns that severe acute respiratory syndrome was able to kill some younger, fitter patients who were previously seen as having a good chance of recovering with a combination of anti-viral drugs and steroids.
"Their situation fluctuated wildly when they were admitted into hospitals," said the senior executive manager of Hong Kong's Hospital Authority, Dr. Liu Shao-haei. Many of Hong Kong's previous fatalities had suffered also from chronic illnesses such as heart or kidney disease.
The fitter patients, aged 40, 41, 45 and 52, "just kept deteriorating" despite being placed under intensive care, Liu said, without offering any immediate explanation. A 66-year-old woman whose death was reported Sunday had other chronic problems.
Earlier Sunday, Cathay Pacific Airways acknowledged that an executive warned in a memo that its entire passenger fleet could be grounded if traffic keeps falling as the disease hammers Asia's travel industry.
A Cathay spokeswoman insisted Sunday there were no plans to cease operations. But the memo — first reported in local newspapers underscored the financial damage SARS has wrought.
The latest Hong Kong deaths, plus three reported in Singapore Sunday, pushed the global toll to at least 133. There were 42 new cases of SARS reported in Hong Kong on Sunday, bringing the total here to 1,150, although 223 have recovered and been discharged.
Hong Kong Chief Executive Tung Chee-hwa met with Chinese President Hu Jintao in the border city of Shenzhen on Saturday to discuss SARS, and Tung acknowledged it was not under control, the Hong Kong government said Sunday.
Tung told Hu that Hong Kong experts have a basic understanding of how it can be transmitted and treated, and Hu offered to help if Hong Kong runs short on medical supplies or protective gear, a government statement said.
After the World Health Organization said travelers should avoid coming to Hong Kong or neighboring Guangdong province, Cathay's traffic plunged from about 30,000 passengers a day to below 10,000 and the carrier was losing US$3 million a day, newspapers reported.
The South China Morning Post quoted Cathay's director of flight operations, Nick Rhodes, as writing in a memo: "We forecast the number of passengers could fall to less than 6,000 per day in May, in which case we will have to consider grounding the entire passenger fleet."
Cathay spokeswoman Rosita Ng confirmed to The Associated Press that Rhodes had distributed a staff memo Friday after a top-level briefing by Chief Executive David Turnbull.
Ng said the reference to grounding the fleet was Rhodes' "interpretation" of Turnbull's comments, but that Cathay has "no plans to stop operations at any future date."
Ng declined to release the memo or discuss it further.
Responding to the leak, Cathay said in a statement it has implemented some contingency measures to "maintain its services, preserve cash and minimize expenditure." Cathay has temporarily scrapped 42 percent of its flights, and said "more measures will be implemented as and when necessary."
Meanwhile, Hong Kong's Airport Authority said Sunday that traffic at Chek Lap Kok airport has plunged to about a third of where it stood last year, with 30 percent of the flights canceled in recent days, and warned "our core business is under threat."
Nine of the latest cases were reported in two buildings of a residential complex on Hong Kong Island, following big earlier outbreaks in Kowloon and the suburban New Territories.
It was believed the victims were infected by a patient who wasn't hospitalized until a week after becoming sick, said Deputy Health Director Dr. Lam Ping-yan. Lam said the situation in Hong Kong's Chai Wan district was different from the big outbreak at Amoy Gardens, where about 300 people were infected with the disease, about half of them in one building.
In Manila, presidential spokesman Ignacio Bunye said Filipino maids planning to return home from Hong Kong will be checked by doctors at the Philippine Consulate in the territory. About 145,000 maids from the Philippines work in Hong Kong.