Flu experts discuss severity scale for WHO's phase 6

WHO Director-General Margaret Chan speaks to media during a news conference on the 62nd World Health Assembly at the United Nations European headquarters in Geneva May 19, 2009.

GENEVA (Reuters) - Flu experts held emergency talks on Friday to assess introducing a severity scale into the World Health Organization's top level of pandemic alert and to discuss the spread of the H1N1 virus, officials said.

WHO Director-General Margaret Chan called the emergency committee meeting, but no decision is expected on crossing the threshold to the highest phase, a spokeswoman said.

"The agenda is not to decide on phase 6, I would like to stress this," WHO spokeswoman Fadela Chaib told a news briefing in Geneva.

The talks lasted just over one hour and a statement was expected to be posted on the U.N. agency's website later on Friday, Chaib said.

WHO's pandemic scale remains at the second-highest level, phase 5 on a scale of 1 to 6. To declare a full-blown pandemic it would have to confirm sustained spread of the virus in one country in another region besides North America.

The United Nations agency has been weighing how to revamp its pandemic alert scale to reflect both the severity of the flu as well as its geographic spread.

This follows criticism that it may have caused undue panic about the new strain whose effects have been mainly mild apart from in Mexico, where it is known to have killed 103 people.

SEVERITY INDEX

"The director-general (Chan) will use the occasion to ask the emergency committee members -- the 'flu gurus' around the world -- how and if we should have some sort of severity index within phase 6," WHO spokesman Gregory Hartl told Reuters.

WHO's top flu expert Keiji Fukuda said earlier this week that one idea was to add three severity notches to the highest marker of 6, so the overall level can reach the peak even if the flu's effects remain moderate, and then be adjusted again later if the virus causes more serious health problems.

The experts will discuss the latest findings about the virus and review international public health-related measures, including travel restrictions and border closures which have not been recommended thus far, according to Hartl.

The new strain, commonly known as swine flu, has infected 21,940 people in 69 countries, killing 125 of them, according to the WHO. Mexico, the United States and Canada have borne the brunt of the illness and a case was confirmed in Saudi Arabia for the first time. Work continues on developing a vaccine.

Fukuda, the WHO's acting assistant director-general, said on Tuesday that the virus' spread in Australia, Britain, Chile, Japan, and Spain had nudged the world closer to a pandemic.

(Editing by Louise Ireland and Laura MacInnis)