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Public emergency declared over flu fears
World Health Organization says situation evelving quickly
By Helen Branswell
Last Updated: 25th April 2009, 6:19pm
The World Health Organization declared the fast moving swine flu outbreak a "public health emergency of international concern" on Saturday, giving itself powers to ask member states to beef up surveillance for the virus.
But the Geneva-based organization decided for now against raising the pandemic threat level from the current Phase 3, saying it needs more information to determine if that response is appropriate.
"The situation is evolving quickly," WHO Director General Dr. Margaret Chan said from Geneva during a media teleconference before an emergency meeting, adding that the swine flu virus has "pandemic potential."
"A new disease is, by definition, poorly understood. We do not yet have a complete picture of the epidemiology, or the risk, including possible spread beyond the currently affected areas."
WHO will likely get more information in short measure. Probable human swine flu cases -- caused by a new influenza A H1N1 swine flu virus -- were reported in a number of new locations in the United States on Saturday.
Health officials in New York City said they found a cluster of eight probable cases, teenagers in a school where more than 100 students had been out sick this week. The city?s health department flew samples to the U.S. Centers for Disease Control in Atlanta for confirmatory testing and said an answer was expected Sunday.
Kansas state health officials announced they had confirmed two cases as well, bringing to 11 the confirmed cases in the United States. There have been seven cases in California and two in Texas.
The viruses were first discovered in California about 10 days ago. Late this week it was confirmed outbreaks of respiratory illnesses in parts of Mexico -- including densely populated Mexico City -- were due to this new flu strain. Mexican authorities have reported 20 confirmed deaths, nearly 50 suspected deaths and more than 1,000 suspected cases.
Prime Minister Stephen Harper?s office said the prime minister "was briefed this weekend on the flu outbreak and is aware of the situation."
There was no word Saturday from the Public Health Agency of Canada. On Friday, Canada?s Chief Public Health Officer Dr. David Butler-Jones said there were no cases yet in this country.
With the mounting evidence of efficient person-to-person spread, infectious disease experts suggested Canada is likely to see its first cases soon.
"We now apparently have widespread swine H1N1 throughout the United States which tells us that it is highly infectious, therefore having all the makings of the next pandemic strain," said Dr. Donald Low, chief microbiologist at Toronto?s Mount Sinai Hospital.
"It is just a matter of time before we recognize it here."
To date only the United States and Mexico have confirmed cases.
Declaring the outbreak a public health emergency of international concern allows the WHO to ask member states to enhance surveillance for human swine flu cases and report those they find to Geneva. A statement issued by the agency Saturday did not preclude the possibility the pandemic threat level would rise in coming days.
The group advises but the decision rested with Chan, who rushed back to Geneva overnight Friday from Washington. She said Saturday that "in the assessment of WHO, this is a serious situation which must be watched very closely."
The decision not to raise the pandemic alert level puzzled some observers and drew criticism from others.
Infectious diseases expert Dr. Michael Osterholm said the decision to keep the pandemic alert level at Phase 3 -- which in WHO terms means no or very limited human-to-human transmission -- "surely flies in the face of all the science that we have."
Osterholm, who heads the Center for Infectious Diseases Research and Policy at the University of Minnesota, said it?s critical that the WHO remain an unimpeachable source of authoritative information. "If they begin to make decisions about science-based facts because of policy concerns, they will quickly lose that necessary credibility," he said.
Just hours before the New York City announcement, the CDC said it had no new reports of cases, but that it expected to see new cases in new places, given the pattern of spread so far.
Announcement of cases in the U.S. is a state responsibility. Similarly in Canada it is expected that provinces and territories, not the federal government, will announce cases as they occur.
The CDC reiterated that it does not think there is any merit in launching an effort to try to snuff out the virus -- a notion the WHO had espoused in planning for a possible pandemic caused by the H5N1 avian flu virus.
"We don?t think containment is feasible," said Dr. Anne Schuchat, the CDC?s interim deputy director for science and public health. "Having found virus where we?ve found it, we are likely to find it in many other places."
She and others noted that so far, in the U.S. at any rate, cases have had relatively mild symptoms similar to seasonal flu.
Officials, including the WHO, are puzzled as to why the disease profile seems more severe in Mexico. But they suggest a number of factors may account for the seemingly different pictures. They include the possibility other pathogens may also be circulating there or that Mexican authorities aren?t spotting more mild cases.
It is not clear how long the virus has been spreading in humans, though the WHO said Mexican officials noticed an uptick of influenza-like illness starting around March 18.
Chan said the viruses causing infections in Mexico and parts of the southwestern United States are "genetically the same" -- a never-before-seen hybrid containing genes from swine viruses from the Americas and Asia as well as some genes from avian and human flu viruses.
Scientists at Canada?s National Microbiology Laboratory and the U.S. Centers for Disease Control have typed and sequenced virus samples from Mexico over the past several days.
"This is an interesting virus. It?s a brand new virus, not only to humans but to the world," Dr. Frank Plummer, scientific director of Canada?s national lab, said at an Ottawa news conference on Friday.
"About 80 per cent of the virus is highly related to a North American body of swine flu that?s been around for a number of years, but about 20 per cent of it comes from an Eurasian variety of swine flu first seen in Thailand, so it?s recombined to create something totally new."
"How it did that, where it did it, when it did it, I don?t think we know yet."
Testing has shown the viruses are resistant to two old flu drugs, amantadine and rimantadine, but are susceptible to the flu antivirals Tamiflu and Relenza, which are in many national emergency stockpiles, including Canada?s.
Chan said Mexico has "a sizable supply" of Tamiflu.
The WHO director general said while Mexican authorities have been co-operative, the picture there remains too blurred to make a judgment on how widespread infections are or about what percentage of cases are severely ill or dying. The WHO has sent experts to Mexico to help with the assessment and the CDC is also sending a team of experts.
"It is important that we get to the bottom of the matter as soon as possible," she said. "Speed is important. Capacity is important. And we are addressing both."
A number of reports have suggested previously healthy young adults -- people ranging from their mid 20s to mid 40s -- are making up a higher than expected percentage of the cases. With regular flu, young children and the elderly are generally at highest risk.
Some observers have wondered if this pattern suggests that if this virus were to spark a pandemic that it might look like the disastrous Spanish Flu of 1918, which is estimated to have killed upwards of 50 million people worldwide. Death rates among young adults were disproportionately high in that pandemic, the worst in recorded history.
Chan cautioned against that kind of assumption.
Chan also said it is too soon for WHO to consider issuing travel advisories urging people to avoid travelling to the areas where cases have been discovered.
On Saturday, the mayor of Mexico City announced all public events were being cancelled until further notice.
Though human H1N1 viruses have been circulating for decades, it is not clear how much protection previous infection with them would confer against a swine flu virus and in particular this swine flu virus, which looks unlike any experts have seen before.
Flu viruses from an animal source -- whether pigs, birds or other mammals -- have the potential to cause pandemics because they are generally so different from human viruses that people have little or no immunity to them.
Widespread illness would be expected to occur if the viruses take off and become a pandemic strain. But the severity of the illness caused depends on the virus.
World Health Organization says situation evelving quickly
By Helen Branswell
Last Updated: 25th April 2009, 6:19pm
The World Health Organization declared the fast moving swine flu outbreak a "public health emergency of international concern" on Saturday, giving itself powers to ask member states to beef up surveillance for the virus.
But the Geneva-based organization decided for now against raising the pandemic threat level from the current Phase 3, saying it needs more information to determine if that response is appropriate.
"The situation is evolving quickly," WHO Director General Dr. Margaret Chan said from Geneva during a media teleconference before an emergency meeting, adding that the swine flu virus has "pandemic potential."
"A new disease is, by definition, poorly understood. We do not yet have a complete picture of the epidemiology, or the risk, including possible spread beyond the currently affected areas."
WHO will likely get more information in short measure. Probable human swine flu cases -- caused by a new influenza A H1N1 swine flu virus -- were reported in a number of new locations in the United States on Saturday.
Health officials in New York City said they found a cluster of eight probable cases, teenagers in a school where more than 100 students had been out sick this week. The city?s health department flew samples to the U.S. Centers for Disease Control in Atlanta for confirmatory testing and said an answer was expected Sunday.
Kansas state health officials announced they had confirmed two cases as well, bringing to 11 the confirmed cases in the United States. There have been seven cases in California and two in Texas.
The viruses were first discovered in California about 10 days ago. Late this week it was confirmed outbreaks of respiratory illnesses in parts of Mexico -- including densely populated Mexico City -- were due to this new flu strain. Mexican authorities have reported 20 confirmed deaths, nearly 50 suspected deaths and more than 1,000 suspected cases.
Prime Minister Stephen Harper?s office said the prime minister "was briefed this weekend on the flu outbreak and is aware of the situation."
There was no word Saturday from the Public Health Agency of Canada. On Friday, Canada?s Chief Public Health Officer Dr. David Butler-Jones said there were no cases yet in this country.
With the mounting evidence of efficient person-to-person spread, infectious disease experts suggested Canada is likely to see its first cases soon.
"We now apparently have widespread swine H1N1 throughout the United States which tells us that it is highly infectious, therefore having all the makings of the next pandemic strain," said Dr. Donald Low, chief microbiologist at Toronto?s Mount Sinai Hospital.
"It is just a matter of time before we recognize it here."
To date only the United States and Mexico have confirmed cases.
Declaring the outbreak a public health emergency of international concern allows the WHO to ask member states to enhance surveillance for human swine flu cases and report those they find to Geneva. A statement issued by the agency Saturday did not preclude the possibility the pandemic threat level would rise in coming days.
The group advises but the decision rested with Chan, who rushed back to Geneva overnight Friday from Washington. She said Saturday that "in the assessment of WHO, this is a serious situation which must be watched very closely."
The decision not to raise the pandemic alert level puzzled some observers and drew criticism from others.
Infectious diseases expert Dr. Michael Osterholm said the decision to keep the pandemic alert level at Phase 3 -- which in WHO terms means no or very limited human-to-human transmission -- "surely flies in the face of all the science that we have."
Osterholm, who heads the Center for Infectious Diseases Research and Policy at the University of Minnesota, said it?s critical that the WHO remain an unimpeachable source of authoritative information. "If they begin to make decisions about science-based facts because of policy concerns, they will quickly lose that necessary credibility," he said.
Just hours before the New York City announcement, the CDC said it had no new reports of cases, but that it expected to see new cases in new places, given the pattern of spread so far.
Announcement of cases in the U.S. is a state responsibility. Similarly in Canada it is expected that provinces and territories, not the federal government, will announce cases as they occur.
The CDC reiterated that it does not think there is any merit in launching an effort to try to snuff out the virus -- a notion the WHO had espoused in planning for a possible pandemic caused by the H5N1 avian flu virus.
"We don?t think containment is feasible," said Dr. Anne Schuchat, the CDC?s interim deputy director for science and public health. "Having found virus where we?ve found it, we are likely to find it in many other places."
She and others noted that so far, in the U.S. at any rate, cases have had relatively mild symptoms similar to seasonal flu.
Officials, including the WHO, are puzzled as to why the disease profile seems more severe in Mexico. But they suggest a number of factors may account for the seemingly different pictures. They include the possibility other pathogens may also be circulating there or that Mexican authorities aren?t spotting more mild cases.
It is not clear how long the virus has been spreading in humans, though the WHO said Mexican officials noticed an uptick of influenza-like illness starting around March 18.
Chan said the viruses causing infections in Mexico and parts of the southwestern United States are "genetically the same" -- a never-before-seen hybrid containing genes from swine viruses from the Americas and Asia as well as some genes from avian and human flu viruses.
Scientists at Canada?s National Microbiology Laboratory and the U.S. Centers for Disease Control have typed and sequenced virus samples from Mexico over the past several days.
"This is an interesting virus. It?s a brand new virus, not only to humans but to the world," Dr. Frank Plummer, scientific director of Canada?s national lab, said at an Ottawa news conference on Friday.
"About 80 per cent of the virus is highly related to a North American body of swine flu that?s been around for a number of years, but about 20 per cent of it comes from an Eurasian variety of swine flu first seen in Thailand, so it?s recombined to create something totally new."
"How it did that, where it did it, when it did it, I don?t think we know yet."
Testing has shown the viruses are resistant to two old flu drugs, amantadine and rimantadine, but are susceptible to the flu antivirals Tamiflu and Relenza, which are in many national emergency stockpiles, including Canada?s.
Chan said Mexico has "a sizable supply" of Tamiflu.
The WHO director general said while Mexican authorities have been co-operative, the picture there remains too blurred to make a judgment on how widespread infections are or about what percentage of cases are severely ill or dying. The WHO has sent experts to Mexico to help with the assessment and the CDC is also sending a team of experts.
"It is important that we get to the bottom of the matter as soon as possible," she said. "Speed is important. Capacity is important. And we are addressing both."
A number of reports have suggested previously healthy young adults -- people ranging from their mid 20s to mid 40s -- are making up a higher than expected percentage of the cases. With regular flu, young children and the elderly are generally at highest risk.
Some observers have wondered if this pattern suggests that if this virus were to spark a pandemic that it might look like the disastrous Spanish Flu of 1918, which is estimated to have killed upwards of 50 million people worldwide. Death rates among young adults were disproportionately high in that pandemic, the worst in recorded history.
Chan cautioned against that kind of assumption.
Chan also said it is too soon for WHO to consider issuing travel advisories urging people to avoid travelling to the areas where cases have been discovered.
On Saturday, the mayor of Mexico City announced all public events were being cancelled until further notice.
Though human H1N1 viruses have been circulating for decades, it is not clear how much protection previous infection with them would confer against a swine flu virus and in particular this swine flu virus, which looks unlike any experts have seen before.
Flu viruses from an animal source -- whether pigs, birds or other mammals -- have the potential to cause pandemics because they are generally so different from human viruses that people have little or no immunity to them.
Widespread illness would be expected to occur if the viruses take off and become a pandemic strain. But the severity of the illness caused depends on the virus.
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