TUESDAY, June 9 (HealthDay News) -- A surge in cases of H1N1 swine flu in Australia may tip the balance and cause the World Health Organization to soon declare the first flu pandemic since 1968, agency officials said 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.
"We are getting really very close to knowing that we are in a pandemic situation," WHO influenza chief Keiji Fukuda said in Geneva.
He 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 Associated Press reported. Fukuda cited concerns over possible panic among the public or inappropriate steps taken by governments.
However, "on the surface of it, I think we are in phase 6," said Margaret Chan, the WHO's director-general. According to Chan, it is crucial to verify that H1N1 has become established beyond North America before a pandemic is declared. "Once I get indisputable evidence, I will make the announcement," she said Tuesday.
On Wednesday, Chan held a teleconference with representatives from eight countries with large swine flu outbreaks to determine if a pandemic should be declared. After the teleconference, the WHO announced that an emergency meeting with its flu experts would be held Thursday, the AP reported.
According to the latest WHO data, there are now 25,288 reported cases of swine flu infection across 73 countries, including 139 deaths. That includes 13,217 cases and 27 deaths reported as of last Friday in the United States by officials at the U.S. Centers for Disease Control and Prevention.
While the vast majority of infections and deaths have occurred in Mexico (the source of the outbreak) and the United States, person-to-person transmission in 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 patients 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.