Rapid worldwide spread triggered the announcement, experts say
THURSDAY, June 11 (HealthDay News) -- The World Health Organization on Thursday declared the first influenza pandemic since 1968, triggered by the H1N1 virus's rapid spread across North America, Australia, South America, Europe and regions beyond, agency officials said.
The move pushes the WHO alert status on the swine flu outbreak from phase 5, where it has remained for weeks, to its highest and pandemic level of phase 6.
WHO had convened an emergency teleconference earlier in the day to discuss the situation with leading flu experts, the Associated Press reported.
A surge in cases of H1N1 swine flu in Australia might have been the final criteria needed to tip the balance and spur a pandemic declaration, agency officials had warned on Tuesday.
Cases in Australia rose by more than 1,000 on Monday, with most occurring in the southern state of Victoria. Rapid spread of the virus in a region beyond North America has been considered a key factor in labeling the outbreak a pandemic.
A pandemic declaration does not mean that cases have gotten more severe, one expert noted.
"A World Health Organization level 6, which in effect states that H1N1 infections are now worldwide in distribution, is simply a declaration of the extent of geographic spread, and not a statement of severity of the clinical disease," said Dr. Pascal James Imperato, former New York City health commissioner and dean of public health at the State University of New York's Downstate Medical Center. "The disease remains relatively mild in most people. A positive consequence of this declaration is that it empowers countries to move forward with vaccine production."
On Tuesday, WHO flu chief Keiji Fukuda said the agency was concerned about the possible "adverse effects" of moving the alert from its current status of phase 5 to the highest level, phase 6, indicating a full pandemic, the AP reported. Fukuda cited concerns over possible panic among the public or inappropriate steps taken by governments.
On Wednesday, WHO director Margaret Chan held a teleconference with representatives from eight countries with large swine flu outbreaks to determine if a pandemic should be declared.
The U.S. Centers for Disease Control and Prevention is slate to hold its own press conference on the H1N1 outbreak at 12:45 pm Thursday.
According to the latest WHO data, there are now 27,737 reported cases of swine flu infection across 74 countries, including 141 deaths. That includes 13,217 cases and 27 deaths reported as of June 5 in the United States by officials at the U.S. Centers for Disease Control and Prevention.
Though the vast majority of infections and deaths have occurred in Mexico (the source of the outbreak) and the United States, person-to-person transmission is now being reported in Australia and Chile, as well as Great Britain, Spain and Japan, according to published reports.
But Fukuda also expressed concern Tuesday about reports of unusually large numbers of severe cases among Canada's Inuit population, according to AP.
The vast majority of swine flu cases globally have remained mild, but some of the deaths have occurred in otherwise healthy people, the WHO noted. "Approximately half the people who have died from this H1N1 infection have previously been healthy people," Fukuda said. He called that "one of the observations which has given us the most concern."
Since the outbreak started in April, health officials in the United States have also said that infections have been mild for the most part, and most people recover fairly quickly. Testing has found that the H1N1 virus remains susceptible to two common antiviral drugs, Tamiflu and Relenza.
During the next few months, CDC scientists will be looking to see if the swine flu virus mutates or becomes resistant to antiviral medications or is more easily spread among people.
U.S. health officials have said there's no way to tell now if the H1N1 virus will be more virulent when -- and if -- it returns to the Northern Hemisphere with the approach of winter.
A vaccine for the swine flu virus could be ready by October, if research and testing proceed on pace this summer. Candidate viruses have been shipped to vaccine manufacturers, agency officials said.
It's still not clear whether such a vaccine is needed. Any decision to move forward would be based on several factors, including the severity and spread of the virus and whether there's a safe and effective vaccine, the CDC has said.
For more on swine flu, visit the U.S. Centers for Disease Control and Prevention.
SOURCES: Pascal James Imperato, M.D., M.P.H., dean, Graduate Program in Public Health, State University of New York Downstate Medical Center, New York City; Associated Press; U.S. Centers for Disease Control and Prevention
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