The head of the World Health Organization has declared the first influenza pandemic in 41 years after intense consultations with top officials from countries that are experiencing rapid transmission of the novel A (H1N1) flu virus at the community level, and with international experts monitoring the global outbreak.

“The world is now at the start of the 2009 influenza pandemic. We are at the earliest days of the pandemic,” Margaret Chan, WHO director general, told a news conference, shortly after she decided to raise the level of influenza pandemic alert from phase 5 to the maximum, phase 6.

“We have reason to believe that this pandemic, at least in its early days, will be of moderate severity,” she said and noted “the virus is contagious, spreading easily from one person to another and from one country to another.”

Dr Chan took the decision after a conference call on Wednesday with health officials from the eight most affected countries—the United States, Mexico, Canada, the United Kingdom, Spain, Australia, Japan and Chile—followed by a meeting on 11 June with the …