A case involving a Hong Kong man infected recently with the mysterious swine virus was reported Thursday, deepening concern over the possible local impact of the disease that has killed 31 people in Sichuan and bringing the number of local infections to 10 since May 2004.

The Center for Health Protection said the latest local case of a human infection by the swine streptococcus suis II bacteria involved a 26-year-old interior decorator who has not traveled to the mainland recently and has had no contact with pigs. He was admitted to hospital July 5 and discharged a week later.

The Center for Health Protection said it does not know how he was infected. No details have been given on the other nine cases, apart from the fact that one of those infected died.

From 1983 to 1994, there were 25 cases of human streptococcus suis infections in Hong Kong, according to a Chinese University study. In 1983, an Australian medical journal said the virus was the leading cause of meningitis in Hong Kong.

Secretary for Health, Welfare and Food York Chow insisted Thursday there is still no evidence to support a complete ban on pork imports despite the mainland suspending all pork, mutton and other meat exports from Sichuan.

His stance outraged legislators who raised the specter of the early local response to the 2003 SARS epidemic. Independent Albert Chan said he was astonished by the government's position.

"Must the government wait until someone dies or there is an outbreak in Hong Kong before it realizes the seriousness of the matter and does something?'' he asked.

The Ministry of Health Thursday revised the total human infections to 152. Of these, 27 are in a critical condition, while six more towns in Sichuan have reported human infection cases.

At a special meeting of the Legco health panel, Chow was criticized by legislators from all parties over his reluctance to ban imports of frozen pork. Chow said there was no precedence, no international guidelines and no scientific evidence to support such a move.

He said pork contaminated with the streptococcus bacteria was found worldwide and as much as 50 percent of pork imported from Holland, New Zealand and Australia bore the bacteria.

"We must base any decision for a ban on scientific evidence, international guidelines and practices.

"Hong Kong has absolute sovereignty over its public health and food safety matters and will not be subject to political pressure.

"At the moment, we have no such plan to ban pork imports from Sichuan. The principle will not be changed. We need evidence to impose a ban, or else Hong Kong's integrity and credibility of being an international city will be damaged,'' Chow said.

He noted that the mainland ban was imposed for business reasons rather than public health.

Food and Environmental Hygiene Department assistant director Thomas Chung told the panel that, so far this year, Hong Kong has imported more than 18,000 tons of frozen pork from Sichuan, of which 5,000 tons came from the two most affected cities - Ziyang and Neijiang.

"We will not trace the frozen pork that has been imported, or take samples for streptococcus tests, because the product has passed state inspection and the public need not panic,'' Chung said.

But he warned that bacteria inside the frozen meat may be revived when it was defrosted, so it must be thoroughly cooked and carefully handled to prevent infection, whether from swine streptococcus bacteria or other agents.

Chow said he is most concerned about whether the bacteria has mutated, but said so far the Health Ministry has said no mutation was found. At the invitation of the ministry, three experts from Hong Kong arrived in Sichuan Wednesday to help determine if a large outbreak is possible.

The group includes a Hospital Authority infectious disease consultant, an epidemiologist, and a Health Department pathologist.

"Locally, we will inspect pigs that have died during the outbreak to compare the gene sequence of the bacteria found in Sichuan,'' Chow said.

He insisted the government has taken all necessary precautions and that if new information merits a ban, the government will not hesitate to do so.

Legislators from all parties were unhappy.

Democratic Alliance for Betterment and Progress of Hong Kong (DAB) member Wong Kwok-hing said it is worrying the government refuses to test for streptococcus bacteria in frozen pork imported from Sichuan.

Fellow DAB member and panel vice-chairman Wong Yung-kan said the government should ban imports of frozen pork from the whole province and test for bacteria. "The mainland authorities have acted responsibly by banning exports, while the local authorities are reluctant,'' he said.

Medical sector legislator Kwok Ka-ki questioned whether the cause of the disease might be something other than the streptococcus bacteria.

Chow said the government receives updates several times a day from the Health Ministry, and insisted that the public should not be afraid to eat pork because it is still "very safe'' to do so, as long as hygiene is maintained during slaughtering and handling of raw meat and that it is fully cooked.

Democrat legislator Andrew Cheng said Chow's response was reminiscent of his ill-fated predecessor, Yeoh Eng-kiong, and former health director Margaret Chan in the first days of the Sars epidemic.

In 2003, Yeoh told the public there was "no outbreak'' - despite being contradicted publicly by his own doctors - while Chan told the public that she ate chicken every day in an ill-fated attempt to soothe public fears over Sars and bird flu.

Chow said the risk of the pig disease infecting people on a mass scale is lower than either mad cow disease and bird flu.

The Legco panel passed a non-binding motion demanding the government ban imports of Sichuan frozen pork until the infection is brought under control and the route of transmission is fully understood.

matthew.lee@singtaonewscorp.com