Saturday
May022009
Pandemic Or What?
Coffee Brown MD, University of New Mexico, Talk Radio News
There are three main differences between a normal flu and a pandemic flu, as described by the Department of Homeland Security: incidence, virulence, and demographics.
Incidence refers to how many of us will get it. In a normal year, about 15 percent of 300 million Americans, or about 45 million people will get infected. In a pandemic, rates rise to 25-50 percent, or 75-150 million cases.
Virulence refers to how many of us will die of the infection. In a normal year, that’s about 0.07 percent, or about 35 thousand out those 45 million. In 1918, mortality was about 2.5 percent, which would be about 7.5 million deaths, given today’s population.
Demographics refers to which of us are at most risk. In a normal year, nearly all deaths occur in people over 65 years old. In 1918 and 1957, mortality was highest among school-aged children and young adults.
This summary, with some calculations, comes from information provided by DHS and presented at GlobalSecurity.Org
Let’s compare the 2009 A-H1N1 Flu. “Atypical flu” may be a handier name. “Swine flu” is passe’.
Incidence: As of 05/02/09: There have been 615 confirmed cases in 15 countries. Attack rates so far are too low and data too incomplete to meaningfully calculate.
Virulence: Mortality in Mexico, the country hardest hit so far, is 16 out of 397 cases: about 4 percent, which works out to four thousand per hundred thousand (a common way of expressing this type of number).
The one U.S. death might properly have been considered a Mexican death, since that child contracted the disease there. If calculated as U.S. data: one death out of 141 cases: about point seven percent. If that fatality is not charged to the U.S. account, the mortality rate outside of Mexico is zero percent as of this writing.
Demographics: Reports say that the Mexican victims were young, but I have not been able to locate details to confirm that. The World Health Organization says that more study would be needed to confirm that younger people are more at risk.
Other: The other elements of this flu that merit precautions are that it is genetically unique, meaning we may have no immunity, and that it is slightly out of season, meaning that it exhibits at least some unpredictable behavior.
We are still at phase 5, so clusters of cases in multiple countries, which would define phase 6, have not yet been confirmed.
Per the WHO, there no travel advisories at this time.
Do masks help? Yes, no, and maybe. Yes: as tiny as viruses are, they could slip right through any screen that we could breathe through, but the virus is carried in droplets of exhaled moisture, and those droplets do stick to the mask. No: But the masks dry, and it’s not clear whether the virus survives and detaches into the inhaled air. Maybe: the real test would be whether people with masks get fewer infections (though such people probably also take more precautions in general), and the Centers for Disease Control and Prevention says that data is not yet available.
There are three main differences between a normal flu and a pandemic flu, as described by the Department of Homeland Security: incidence, virulence, and demographics.
Incidence refers to how many of us will get it. In a normal year, about 15 percent of 300 million Americans, or about 45 million people will get infected. In a pandemic, rates rise to 25-50 percent, or 75-150 million cases.
Virulence refers to how many of us will die of the infection. In a normal year, that’s about 0.07 percent, or about 35 thousand out those 45 million. In 1918, mortality was about 2.5 percent, which would be about 7.5 million deaths, given today’s population.
Demographics refers to which of us are at most risk. In a normal year, nearly all deaths occur in people over 65 years old. In 1918 and 1957, mortality was highest among school-aged children and young adults.
This summary, with some calculations, comes from information provided by DHS and presented at GlobalSecurity.Org
Let’s compare the 2009 A-H1N1 Flu. “Atypical flu” may be a handier name. “Swine flu” is passe’.
Incidence: As of 05/02/09: There have been 615 confirmed cases in 15 countries. Attack rates so far are too low and data too incomplete to meaningfully calculate.
Virulence: Mortality in Mexico, the country hardest hit so far, is 16 out of 397 cases: about 4 percent, which works out to four thousand per hundred thousand (a common way of expressing this type of number).
The one U.S. death might properly have been considered a Mexican death, since that child contracted the disease there. If calculated as U.S. data: one death out of 141 cases: about point seven percent. If that fatality is not charged to the U.S. account, the mortality rate outside of Mexico is zero percent as of this writing.
Demographics: Reports say that the Mexican victims were young, but I have not been able to locate details to confirm that. The World Health Organization says that more study would be needed to confirm that younger people are more at risk.
Other: The other elements of this flu that merit precautions are that it is genetically unique, meaning we may have no immunity, and that it is slightly out of season, meaning that it exhibits at least some unpredictable behavior.
We are still at phase 5, so clusters of cases in multiple countries, which would define phase 6, have not yet been confirmed.
Per the WHO, there no travel advisories at this time.
Do masks help? Yes, no, and maybe. Yes: as tiny as viruses are, they could slip right through any screen that we could breathe through, but the virus is carried in droplets of exhaled moisture, and those droplets do stick to the mask. No: But the masks dry, and it’s not clear whether the virus survives and detaches into the inhaled air. Maybe: the real test would be whether people with masks get fewer infections (though such people probably also take more precautions in general), and the Centers for Disease Control and Prevention says that data is not yet available.
tagged A-H1N1 flu, Atypical Flu, Centers for Disease Control and Preventio, Coffee Brown MD, Department of Homeland Security, GlobalSecurity.Org, Incidence, University of New Mexico, Virulence, WHO, demographics, dhs, pandemic, swine flu, talk radio news, world health organization in News/Commentary
Swine Flu Still Going Strong
The H1N1 virus, widely known as swine flu, is responsible for 127 deaths and more than 27,000 documented cases of infection in the U.S., explained medical experts Tuesday.
Dr. Anthony S. Fauci, Director of the National Institute of Allergy and Infectious Diseases, discussed the implications of the virus’ spread. He clarified the difference between seasonal and pandemic influenza, while noting that the two categories of disease could potentially overlap.
According to Fauci, seasonal flu is “exquisitely predictable,” and the population has immunity to similar strains of the disease. The seasonal flu causes approximately 36,000 deaths per year in the U.S.
The pandemic flu is comparatively unpredictable. Fauci said that this sort of virus is “new enough that the...vast majority of the population has had not only no exposure to the virus, but they haven’t had exposure to anything that’s even related to that virus.” Because the population has no “residual immunity” to this new virus, the disease is more likely to harm young people, who normally are not deeply affected by the seasonal flu.
The World Health Organization declared a flu pandemic for the first time in 41 years on June 11th.
Fauci said that many measures to protect the public’s health have been taken over the past several months, beginning with low-tech measures such as closing schools. The CDC has isolated the virus, and five companies are currently working to create a vaccine to potentially be administered to the population dependent on a more deadly or wide-spread H1N1 strain.
He said that the recent strain of H1N1 is not as dangerous as other related viruses.
“It’s not killing a high percentage of people, and the same thing holds true for transmissibility,” said Fauci.
Fauci also noted that the virus has been “remarkably constant” and not susceptible to mutations that could render a vaccine ineffective. “Can it change to the point of veering away from the vaccine we’re making? Yes. Is it doing it? No.”
Dr. Harvey V. Fineburg, President of the Institute of Medicine, warned that health care officials should not underestimate the potential threat, even though a campaign to immunize millions of Americans overestimated the impact of the virus in the 1970s.
“In 1976, the focus of policy-makers and public health authorities were almost entirely driven by the worst case. Today we have to be careful not to make the complementary error of having all of our attention only on the most likely case,” Fineburg explained.
The mortality rate for documented H1N1 cases in the U.S. is 0.46 percent.