June 11, 2009

World Health Organization Declares Global Flu Pandemic

The World Health Organization (WHO) declared a flu pandemic on Thursday, raising its alert to the highest level of phase 6.

The move indicates the first pandemic flu since 1968 is now underway.

The declaration of a pandemic means the disease, widely referred to as swine flu, is spreading geographically, but does not indicate how virulent the virus is. 

Widespread transmission in Victoria, Australia, indicating the virus is now entrenched outside North America, was one of the main triggers in the decision to declare a pandemic.

The new H1N1 strain, which emerged in April in Mexico, has since spread throughout the world.  To date, there have been 28,774 infections reported in 74 countries, including 144 deaths, according to WHO's latest figures of laboratory-confirmed cases.

The WHO called on governments throughout the world to prepare for a long, sustained battle against the relentless virus.

"With today's announcement, WHO moves from an emergency to a longer-term response. Based on past experience, this pandemic will be with us for some months, if not years, to come," said WHO Director-General Dr Margaret Chan in a letter to staff obtained by Reuters.

Pregnant women, people aged 30-50 or those with chronic conditions such as diabetes, asthma or obesity are deemed at highest risk, Chan said during a press briefing.

Many countries, such as the U.S., Australia and Chile, are reporting that the new H1N1 virus is crowding out seasonal flu, becoming the predominant influenza strain, Chan added.

Although the virus is "pretty stable" for now, it could mutate into a more lethal form, Chan said, to include characteristics of the H5N1 bird flu virus circulating widely in poultry.

"So it is incumbent on WHO and all members to stay vigilant and alert for the next year or two or even beyond," said Chan.

"When you're talking about pandemic influenza, you are talking about a marathon, you are not talking about a sprint," said Keiji Fukuda, the U.N. agency's top influenza expert.

The WHO restated its recommendations that nations not close their borders or enact travel restrictions, advice echoed by U.N. Secretary-General Ban Ki-moon.

"This is not a surprise," said CDC director Dr. Thomas Frieden during a news conference with reporters.

"It is expected based on the data."

A unanimous experts' decision was based on an overall assessment in the eight most-affected countries "“ Mexico, the U.S., Australia, Britain, Canada, Chile, Japan and Spain "” which showed the virus is spreading in a sustained way, said Chan.

"Collectively, looking at that, we are satisfied that this virus is spreading to a number of countries and it is not stoppable. Moving to pandemic phase six level does not imply we will see an increase in the number of deaths or very severe cases. Quite on the contrary. Many people are having mild disease, they recover without medicines in some cases and it is good news," she said.

It will be difficult to accurately measure the impact of the disease as it develops and spreads throughout the world.

"It is very hard to get a sense of how many people are really dying from something like pandemic flu," Fukuda added.

Chan said the WHO's global assessment was that the pandemic was moderate.  However, this might differ at the national level.

"Although the pandemic appears to have moderate severity in comparatively well-off countries, it is prudent to anticipate a bleaker picture as the virus spreads to areas with limited resources, poor health care, and a high prevalence of underlying medical problems," she said.

The Geneva-based agency advised pharmaceutical firms to remain committed to the completion of a seasonal influenza vaccine for the northern hemisphere's upcoming winter within the next two weeks.  Seasonal fu kills up to half a million people annually, affecting primarily the elderly, and causes severe illness in millions.  Therefore, a premature switch in vaccine production to cope with the new H1N1 flu could put many at risk.

"So our recommendation is they need to finish the seasonal vaccine and then move over. That is pretty good in terms of dovetailing the production of the two types of vaccine. So I think that this may just work out," said Chan.

Chan said the WHO would collaborate with regulatory authorities to achieve fast-track approval of H1N1 vaccines that are safe and effective to ensure they are available as soon as possible.  Nevertheless, initial doses of any vaccine would not be available before September, she said.

An influenza pandemic could cause significant disruptions to business as workers stay home due to illness or to care for family members.  Additionally, authorities may need to restrict gatherings or movements of large numbers of people or goods.

But world markets were unmoved by the WHO's pandemic declaration, and instead remain focused on a potential global economic recovery.

The H1N1 influenza strain can be treated by common antiviral drugs, such as oseltamivir, the generic name of Roche Holding's Tamiflu tablets, and GlaxoSmithKline's Relenza.

Department of Health and Human Services Secretary Kathleen Sebelius and Department of Homeland Security Secretary Janet Napolitano issued a joint response to the WHO's decision to raise the pandemic threat level.

"Today's decision by the WHO was expected and doesn't change what we have been doing here in the United States to prepare for and respond to this public health challenge. Once we saw how fast this virus was spreading, we activated our pandemic plans and started doing all the things we needed to do to keep the public as safe and secure as possible," the statement read.

"What this declaration does do is remind the world that flu viruses like H1N1 need to be taken seriously. Although we have not seen large numbers of severe cases in this country so far, things could possibly be very different in the fall, especially if things change in the Southern Hemisphere, and we need to start preparing now in order to be ready for a possible H1N1 immunization campaign starting in late September," said Secretary Sebelius in the statement.

"We responded to the H1N1 outbreak from the outset with the presumption that a pandemic was likely, so this decision comes as no surprise. We acted aggressively to stay ahead of the virus as it spread across the country. Now our challenge is to prepare for a possible return in the fall," said Secretary Napolitano.

"The Obama Administration has been working together across the government and will continue to do so over the weeks and months ahead to keep the American people safe. We are reaching out to our partners in state and local government, in school districts and the private sector to urge them to modify and update their pandemic plans. We are working with our scientists to test and prepare a possible vaccine. And we are working with governments around the world to share what we know and learn from what is happening in their countries," the joint statement read.


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