Update: On Thursday, the World Health Organization declared the H1N1 virus a pandemic. Director-General Margaret Chan said the virus is now unstoppable but that the danger is moderate.

The agency repeated its advice to countries not to close borders or establish travel restrictions but to be watchful. Infections reached nearly 30,000 confirmed cases in 74 countries, including 144 deaths. But infections so far have been mild in most people.

The declaration of the first influenza pandemic in 41 years followed an emergency meeting of flu experts in Geneva. Under the W.H.O.'s system, declaring a "phase 6" or pandemic does not mean that a disease has become more severe. It only means that there is an increasing number of infections in different parts of the world.

United Nations Secretary-General Ban Ki-moon called a meeting next Monday of the U.N.'s influenza steering committee to decide "our immediate next steps."

___

Correction attached

Transcript of earlier radio broadcast:

This is the VOA Special English Health Report.

As of Tuesday, seventy-three countries had reported more than twenty-six thousand cases of the new H1N1 flu virus. A World Health Organization official, Keiji Fukuda, said these confirmed cases included two hundred forty-nine deaths.

Keiji Fukuda speaks at a meeting on the H1N1 influenza virus in Geneva, Switzerland in May

Doctor Fukuda, the agency's top flu expert, says the virus continues to spread in North America. And there are increasing reports from South America as well as from other southern countries.  

Australia has had more than one thousand cases, the largest number outside North America. The state of Victoria has been most affected.

But the United States has had by far the most confirmed cases. More than thirteen thousand were reported as of Monday, including twenty-seven deaths.

The H1N1 outbreak began in Mexico in March. Mexico has reported more than one hundred deaths. An unusual number of flu cases have been found in young people who were otherwise healthy.

The W.H.O. has an influenza warning system in which phase six means that a pandemic is taking place. In recent days the United Nations agency has moved closer and closer to such a declaration.

As of Tuesday officials had not yet announced a change from phase five. But Doctor Fukuda said the public should understand what a pandemic means.

KEIJI FUKUDA: "By going to phase six, what this would mean is that the spread of the virus is continued and that activity has become established in at least two regions of the world. It does not mean that the severity of the situation has increased or that people are getting seriously sick at higher numbers or higher rates than they are right now."

Doctor Fukuda, an acting assistant director-general, said the W.H.O. has been working with the member states to prepare for a pandemic. Scientists are working on vaccines to protect against the new virus. Governments have been gathering supplies of anti-viral drugs.

But public health officials have also had to consider the risks if the public overreacts to a pandemic declaration. Doctor Fukuda pointed out that hospitals might quickly fill with people who are worried but not especially sick. Then hospitals might not be able to care for other patients who really do need help.  

The last flu pandemic was in nineteen sixty-eight, caused by the so-called Hong Kong flu. Scientists say the common name for the new disease, swine flu, is misleading. The virus combines human, bird and pig viruses. But, as Doctor Fukuda pointed out, eating meat from pigs has not been a danger.

And that's the VOA Special English Health Report, written by Caty Weaver. For more health news, go to voaspecialenglish.com.

___

Correction: The W.H.O.'s Keiji Fukuda at first told a press briefing on Tuesday that there were 249 deaths from the new H1N1 virus. However, he later corrected the number to 140.