The World Health Organization prescribed caution in the civet cull.
The Philippines also isolated a woman and her husband who might be infected, triggering fears across Asia that a second season of the highly contagious illness might be at hand.
The Chinese Health Ministry said the illness contracted by a 32-year-old television producer in the southern province of Guangdong "has been confirmed as a diagnosed case" of SARS. WHO also confirmed the case as SARS.
SARS, which first broke out in Guangdong in November 2002, infected more than 8,000 people and killed 774 worldwide — mostly in Asia — before it was brought under control in June.
A battery of previous tests on the man, who was hospitalized on Dec. 20, by mainland Chinese labs had proven inconclusive, and his samples were examined by scientists in Hong Kong during the weekend. By Monday, the ministry said, "all the results show that the man has contracted the SARS virus."
The patient's condition was reported stable Monday afternoon, the government said, and those who came into contact with him have shown no symptoms of SARS. Still, it warned the Chinese public: "Be vigilant."
WHO, while also urging vigilance, emphasized that one confirmed case in China does not constitute a threat to public health. "It is safe to travel to all areas of China," WHO said in a statement. During last year's outbreak, the agency issued travel advisories against visiting SARS-affected areas.
The confirmation represents the first known case of SARS contracted in China since July — and the first this season to come from the general population. Two other cases — in Singapore and Taiwan — were linked to researchers who apparently had been exposed in laboratories.
The diagnosis came hours after China ordered 10,000 civet cats in wildlife markets — and several related species — killed in its southern province of Guangdong after genetic tests suggested a link to the patient there. The civet has long been suspected as a vector for the disease's suspected jump from animals to humans.
The slaughter will be completed by Saturday, the government said early Tuesday.
All of Guangdong's wildlife markets were ordered to close on Monday, Feng Liuxiang, deputy director of the province's health department, said on national television. The weasel-like mammals are considered a delicacy in Guangdong and are served in wild game restaurants.
Researchers at Hong Kong University said they had found similarities between a virus found in the civet cats and in the suspected SARS patient, suggesting the disease might have recently jumped from animals.
"We will take resolute measures to close all the wildlife markets in Guangdong and to kill the civet cats," Feng said on the noon newscast of China Central Television.
CCTV said about 10,000 civets were believed to be on sale in Guangdong wildlife markets.
Zhong Nanshan, director of the Guangzhou Institute of Respiratory Diseases, said species related to civet cats also will be killed, including raccoon dogs, Chinese ferret badgers, hog badgers and Eurasian badgers. It wasn't immediately clear how many animals in total might be slaughtered.
On Monday night, WHO urged the Chinese government to be cautious in its planned mass slaughter, saying a reckless culling could eliminate evidence of the disease's origins — and create new dangers as well.
"We could indeed be destroying the evidence," Dr. Jeffrey Gilbert, a WHO animal expert, said at a news conference in Beijing.
Dr. Julie Hall, the WHO's SARS team leader in Beijing, said caution also was warranted to prevent any infection that could come from a mass killing of the animals. "There is a potential hazard there," she said.
SARS killed 349 people on China's mainland before subsiding in June.
China banned trade in civets and 53 other wild animals last April amid sweeping efforts to stop the spread of SARS. That prohibition was lifted in August despite warnings by scientists that the animals might still be a health threat.
Meanwhile, stringent tests on air travelers continued across Asia.
Chinese health officials denied reports by Hong Kong newspapers that a waitress at a wild game restaurant in Guangzhou, the Guangdong provincial capital, was a suspected SARS case.
"We do have a fever patient due to pneumonia, but this has no direct connection with any suspected SARS case," the official Xinhua News Agency quoted Wang Ming, deputy director of the Guangzhou municipal disease prevention and control center, as saying.
Malaysian health officials also ruled out SARS in a 31-year-old woman who was hospitalized with a fever after visiting Guangzhou.