Hong Kong ? Five more patients with severe acute respiratory syndrome have died in Hong Kong, including four who had been in good health before falling ill and failed to respond to treatment that has worked for others, health officials said Sunday.

These deaths raised concerns that the illness was able to kill younger, fitter patients who were previously thought to have a good chance of recovery. Many of Hong Kong’s previous SARS victims had also suffered from chronic illnesses such as heart or kidney disease.

“Their situation fluctuated wildly when they were admitted into hospitals,” said Dr. Liu Shao-haei, a senior executive of Hong Kong’s Hospital Authority, speaking about the five latest victims.

The fitter patients, aged 40, 41, 45 and 52, “just kept deteriorating” despite being placed under intensive care, Liu said. The fifth victim, a 66-year-old woman, had other chronic problems.

Three other SARS fatalities were reported Sunday in Singapore, bringing the global death toll to at least 133 people. About 3,000 people worldwide have been infected, most in Asia.

The World Health Organization list of SARS-affected areas includes Beijing, Guangdong and Shanxi provinces in China; Taiwan; Toronto in Canada; Singapore; and Hanoi in Vietnam.

In China, health officials who have been criticized for their initial handling of the disease took reporters on a tour of Beijing hospitals Sunday to show they are ready for further outbreaks.

Also Sunday, Cathay Pacific Airways said one of its executives warned in a memo that its entire passenger fleet could be grounded if traffic keeps falling as the disease hammers Asia’s travel industry.

After the WHO said April 2 that travelers should avoid coming to Hong Kong or neighboring Guangdong province, Cathay’s traffic plunged from about 30,000 passengers a day to less than 10,000 and the carrier was losing $3 million a day, newspapers reported.

Even the mannequins in a clothing shop are covered with masks in Hong Kong, which has been hit hard by severe acute respiratory syndrome. Some of the deaths reported Sunday involved fitter patients not responding to treatment.

Hong Kong’s Airport Authority said on Sunday that traffic at Chek Lap Kok international airport has plunged by about a third compared with last year.

Even in SARS-free Cambodia, tourism was taking a big hit.

In the tourism town of Siem Reap, home to the Angkor temples, hopes of attracting 1 million visitors this year are fading. Siem Reap saw arrivals reach 800,000 last year.

There were 42 new cases of SARS reported in Hong Kong on Sunday, bringing the total number of cases in the country to 1,150. Of that number, 223 have recovered and been discharged.