The world is officially in the grip of the first global flu pandemic for 40 years, health officials said today.

The World Health Organisation (WHO) has declared that H1N1 swine flu has reached the status after more than 27,000 cases were confirmed across several continents.

The decision to raise its global alert level from five to six — officially signalling a pandemic — came after a day-long emergency meeting of the WHO to discuss the implications of widespread outbreaks of illness in the Americas, Europe and Asia.

“The world is moving into the early days of its first influenza pandemic in the 21st century.

Times Archive, 1957: New flu epidemic

The new type of influenza which is now rife in the Far East is expected to spread to most parts of the world

• Four deaths after influenza

• More deaths from influenza

Multimedia

• Archive blog: 15 ways to fight a flu epidemic

Related Links

• Swine flu pandemic is threat to school term

• Analysis: why has the WHO waited so long?

• Australian spread is catalyst for new alert

Multimedia

• MAP: track the progress of swine flu

• The Swine Flu page

“The (swine flu) virus is now unstoppable," said Dr Margaret Chan, the WHO chief.

A disease is classed as a pandemic when transmission between humans becomes widespread in at least two regions of the world.

The last global flu pandemic came in 1968 over the so-called “Hong Kong” flu, which killed about 1 million people worldwide.

The latest H1N1 viral strain — a combination of previously circulating animal and human strains — emerged in Mexico in April and since then 27,737 cases have been confirmed in 74 countries worldwide since March.

Community spread - in which infections cannot be traced to known cases - has already been confirmed in the North and South America. But WHO officials are reported to have been alarmed by a sudden spike of cases in Australia, and also by rising numbers in Europe.

A total of 25 new cases of the H1N1 virus in England confirmed today by the Health Protection Agency increased the British total to 822. At least 20 schools have been forced to close.

The Department of Health said that the WHO announcement had no immediate implications for the public, but could prompt Governments to take extra prevention measures, such as imposing travel bans and ordering increased vaccine production.

In a statement, the NHS Confederation, which represents health service managers, said: “The confirmation of a level-six global pandemic reinforces the need for the NHS to ensure all the flu plans already in place at local level are as comprehensive as possible and thoroughly tested. We need to avoid complacency in dealing with a virus that is an unknown and seems to be spreading quickly."

So far the virus has caused relatively mild, cold-like symptoms with headaches and vomiting although 141 have died in six countries and health officials are watching closely to see whether the virus has the capacity to mutate or cause more severe illness.

The Government’s chief medical officer Sir Liam Donaldson said before the announcement that a WHO pandemic declaration would not significantly change the way the UK was dealing with swine flu.

But he said that the Health Protection Agency was planning to focus the use of anti-viral drugs on close contacts of people carrying the virus, rather than the wider circle of contacts who have been treated so far.

Sir Liam said: “The declaration of a pandemic per se doesn’t make a big difference to the to the way we are handling the outbreaks we have.”

He added: “We are going to continue to investigate every case that occurs and treat their contacts with anti-virals even though they may not be ill.”

Official guidance from the WHO states: “Assessment of the severity of a pandemic is complex. Experience has shown that past influenza pandemics have varied in terms of severity and that the associated health impacts may vary significantly based on a variety of factors.”

A Department of Health spokesperson said: “The WHO alert levels reflect the global view and any action taken in the UK would be based on the situation here.

"The Department of Health will assess the current situation in the UK before making any recommendations.

"We are monitoring the situation constantly and if anything changes we will respond accordingly.”

Explore World News

• World Agenda

• Iraq News

• US & Americas News

• Europe News

• Middle East News

• Afghanistan News

• Asia News

• Africa News

• Ireland News

Times Recommends

• Times Charity Appeal: SolarAid
• Is it Black Monday all over again for Dubai?
• Behind the scenes at the biggest deal