The A(H1N1) influenza outbreak has officially reached global pandemic levels, the public health arm of the United Nations announced today, as it raised its warning system to Phase 6.
The World Health Organization (WHO) stressed that Phase 6, the highest level on its pandemic alert scale, refers to the spread of the virus and not its severity.
The upgrade to Phase 6 means that sustained human-to-human transmission of the virus has spread beyond North America, where it was concentrated, with WHO reporting 28,774 verified cases of the infection in 74 countries, including 144 deaths, as of this morning.
“The world is now at the start of the 2009 influenza pandemic,” WHO Director-General Margaret Chan told reporters in Geneva, adding that the spread of the virus is unstoppable.
“On present evidence, the overwhelming majority of patients experience mild symptoms,” said Dr. Chan, and WHO does “not expect to see a dramatic jump in the number of severe or fatal infections.”
She noted that the virus tends to infect younger people with the majority of cases, in areas with widespread outbreaks, occurring in people under 25 years of age, and around 2 per cent of cases have suffered very severe symptoms, such as life-threatening pneumonia.
Dr. Chan added that the most severe and fatal infections have been in adults between the ages of 30 and 50 years, a significantly different pattern to epidemics of regular seasonal flu which generally claims frail, elderly people.
“Of greatest concern,” said Dr. Chan. “We do not know how this virus will behave under conditions typically found in the developing world.”
People in the developing world are particularly vulnerable to severe reactions to the infection, as more than 99 per cent of maternal deaths occur in poor countries, and around 85 per cent of the burden of chronic diseases is concentrated in low- and middle-income countries, said Dr. Chan.
“It is prudent to anticipate a bleaker picture as the virus spreads to areas with limited resources, poor health care and high prevalence of underlying medical problems.”
Countries where outbreaks appear to have peaked should prepare for a second wave of infection, warned Dr. Chan, adding that countries with no reported cases or only a few infections should remain vigilant.
“I understand that production of vaccines for seasonal influenza will be completed soon, and that full capacity will be available to ensure the largest possible supply of pandemic vaccine in the months to come.”
WHO recommends no restrictions on travel or border closures, said Dr. Chan. “We are all in this together and we will all get through this together,” she stated.
Speaking at his monthly news conference in New York today, Secretary-General Ban Ki-moon stressed the need for preparedness, especially in the wake of WHO’s announcement.
“We must be watchful. We do not know what picture will emerge in the coming months,” he stated. “The virus has hit mainly developed countries. That is likely to soon change – and it will have consequences.
“We must therefore be prepared. Our best response is a firm demonstration of global solidarity,” Mr. Ban said, adding that he will convene a meeting of the Influenza Steering Committee in New York on Monday to “map out our immediate next steps.”