Sars virus in Hong Kong seen mutating rapidly

6.00pm


HONG KONG - The Sars virus has been mutating rapidly in Hong Kong, making a cure or vaccine more difficult, a group of scientists said today.

The findings came as Hong Kong reported eight more Sars deaths, figures that show the mortality rate has risen to 10.6 per cent from five per cent two weeks ago, and 2.5 per cent in late March.

Another 11 new cases were reported in Hong Kong but that was the lowest figure in six weeks and seemed to support a recent WHO assertion that the disease had peaked in the city.

"The virus is mutating fast. Such a quick mutation means that even if there is a cure it may become ineffective. Even a diagnostic test may not be able to detect it if it has undergone change," said Dennis Lo, one of a team of microbiologists who have just finished a study on the Sars virus.

"It could pose problems in developing a cure and a vaccine," he said, adding it was not yet clear if the rapid mutation meant that recovered patients would be immune to re-infection.

Severe acute respiratory syndrome has killed 170 people in Hong Kong and cumulative cases have risen to 1,611, second only to mainland China.

Doctors are now treating Sars patients with a mix of anti-viral drugs and steroids, but these are not always effective and they are looking at additional medication as well.

Lo and his colleagues at the Chinese University of Hong Kong isolated the virus in 11 victims and found four strains.

Another team member, John Tam, told Reuters the strains came from related groups of victims and showed the virus had mutated within the two months since the outbreak surfaced in the city.

"The virus changed from one strain to another," Tam said.

Experts studying the outbreak have said it is caused by a new strain in the coronavirus family, which causes the common cold, and originates from an animal source.

But little else is known of a disease that is mainly passed by droplets through sneezing and coughing and whose symptoms include high fever, cough and pneumonia.

The microbiologists at the Chinese University discovered four strains of the virus, all with different genomic sequencing.

They said the next step would be to find out if the changes had resulted in changes in Sars symptoms. A higher proportion of Hong Kong patients have recently been suffering from diarrhoea compared with earlier victims.

Canada pledges $126 million to fight Sars

Meanwhile the Canadian government said today it would set aside C$100 million ($126 million) this year to combat Sars, a deadly respiratory infection that has killed more than 400 people worldwide, including 23 in Canada.

In a statement from Prime Minister Jean Chretien's office, the government detailed steps it said were aimed at protecting the health of those who live in Canada and visit the country.

Those included measures to help Canadians affected by the nonmedical consequences of the outbreak such as the dampening effect on tourism.

"To manage this effort, the Government of Canada has set aside a minimum of C$100 million this fiscal year for the fight against Sars," the government said.

The government's current fiscal year began in April.

In Toronto, the flashpoint of the Sars outbreak in Canada, Mayor Mel Lastman said that combined with C$118 million earmarked by the Ontario provincial government and a C$25 million advertising campaign, the federal funds will put Toronto "on the road to recovery."

Earlier on Friday, Federal Industry Minister Allan Rock, who is responsible for tourism, said Canada would soon launch an aggressive world-wide campaign to persuade tourists that it is safe to visit Toronto as health officials report fewer Sars patients in hospitals. The campaign will likely be launched next week.

"We're going to be bringing some money to the table; others will as well, I'm certain, and the focus will be on moving quickly and aggressively to send the message to all the markets that Toronto is a safe place to be and it's open for business," Rock told reporters.

Toronto, where there have been 23 deaths and at least 264 cases of Severe Acute Respiratory Syndrome, is the only place outside Asia where people have died from the viral infection.

Ontario health officials said on Friday that 176 people, or two-thirds of Sars patients, had been discharged from hospital, an increase from 127 on April 23.

They also said there were 30 active probable hospital cases as of Friday, compared with 53 on April 23.

For a week, Toronto, China and Hong Kong were subjects of a World Health Organisation advisory warning people to stay away. But the WHO rescinded the warning for Toronto this week, to the relief of hard-hit hotels, restaurants and shops.

The government responded to the lifting of the ban with full-page advertisements in Canadian newspapers on Friday.

- REUTERS