Posted on 06/28/2006 2:52:44 PM PDT by Judith Anne
Avian influenza, or influenza A (H5N1), has 3 of the 4 properties necessary to cause a serious pandemic: It can infect people, nearly all people are immunologically naive, and it is highly lethal. The Achilles heel of the virus is the lack of sustained human–human transmission. Fortunately, among the 124 cases reported through 30 May 2006, nearly all were acquired by direct contact with poultry. Unfortunately, the capability for efficient human–human transmission requires only a single mutation by a virus that is notoriously genetically unstable, hence the need for a new vaccine each year for seasonal influenza. Influenza A (H5N1) is being compared to another avian strain, the agent of the "Spanish flu" of 1918–1919, which traversed the world in 3 months and caused an estimated 50 million deaths. The question is if we are ready for this type of pandemic, and the answer is probably no. The main problems are the lack of an effective vaccine, very poor surge capacity, a health care system that could not accommodate even a modest pandemic, and erratic regional planning. It's time to get ready, and in the process be ready for bioterrorism, natural disasters, and epidemics of other infectious diseases.
In May 1997, a child in Hong Kong died of influenza. The case, in retrospect, seems to have been the first known human infection with influenza A (H5N1), or avian influenza. After 18 cases and 6 deaths in Hong Kong, this virus appeared to be controlled and possibly eradicated by the end of 1997. But it returned in 2003, and it has subsequently continued to evolve and spread. By May 2006, this virus had caused the deaths, from culling or infection, of more than 140 million domesticated birds in 153 countries and infections in 218 patients, with 124 deaths—a mortality rate possibly as high as 55% (1). The poultry infections extended from Asia to Africa, the Near East, Europe, and Eurasia; the human infections have been primarily in Asia but also in Turkey, Egypt, Iraq, and Azerbaijan. Influenza experts have consistently warned that pandemic influenza is inevitable and historically has occurred at intervals of 11 to 42 years. The worst pandemic in recorded medical history was Spanish flu (H1N1) in 1918 and 1919. The last pandemic was Hong Kong flu (H3N2) 37 years ago in 1968 and 1969. The question now is whether avian influenza will be that next pandemic. The missing link to pandemic spread is lack of sustained person-to-person transmission. The H5N1 influenza virus could acquire property by mutational adaptation of the avian strain, as with the Spanish influenza, or by reassortment through dual infection with human and avian strains as occurred in 1957 (Asian influenza) and 1968 (Hong Kong influenza) (2). Analysis of H5N1 shows that it is avian, and nearly all cases have resulted from direct contact with poultry; human-to-human transmission has been reported but is rare. Those who are skeptical about an H5N1 pandemic point out that genetic changes to facilitate efficient person-to-person transmission are unlikely to occur by either mechanism, since the virus has not acquired this property during 10 years of existence. If they are right, H5N1 will remain primarily an avian pathogen that sporadically causes disease in people, with most cases occurring in those who have close contact with sick poultry.
Should we base our planning on this optimistic scenario? The problem for planners is that a pandemic like that of 1918 has unimaginable consequences, and yet we can't calculate its probability. Most people feel that we should plan for the worst. Complacency is not acceptable. Furthermore, if H5N1 proves to have a limited impact, the planning will improve our preparedness for a future pandemic influenza strain or even another public health disaster, such as SARS (severe acute respiratory syndrome), smallpox, or anthrax.
The experience with the 1918 pandemic influenza is the basis for planning for pandemic avian influenza. The rationale for this strategy is the clinical and virologic similarities between the 2 strains. The 1918 strain traversed the globe in 3 waves and caused an estimated 50 million deaths, including 675 000 in the United States. An unusual feature of the infection was the high mortality rate in healthy persons 15 to 35 years of age (1, 2). By contrast, the annual death toll in the United States for seasonal influenza is about 36 000, and most deaths occur in persons older than 85 years of age. Although some victims of the 1918 pandemic had bacterial pneumonia, most appeared to die of respiratory failure with a characteristic hemorrhagic alveolitis. Dr. Isaac Starr's graphic account of the typical 1918 case is reprinted in this issue: "As their lungs filled with rales the patients became short of breath and increasingly cyanotic. After gasping for several hours they became delirious and incontinent, and many died struggling to clear their airways of a blood-tinged froth that sometimes gushed from their nose and mouth" (3). This course with respiratory failure in young adults sounds similar to the Asian cases of avian influenza, except that many of the patients with avian influenza died despite access to antibacterial agents, antiviral agents, and ventilatory support (4, 5). Despite modern intensive care, the mortality rate for avian influenza is about 20-fold higher than that for the influenza of 1918. The 1918 pandemic and avian influenza also have virologic similarities. Analysis of the reconstructed 1918 pandemic influenza strain shows unusual similarities with H5N1, including the fact that both strains have genes of avian influenza viruses (2, 6, 7).
This issue contains 2 relevant articles on this topic. The first is a summary of the policy monograph of the American College of Physicians addressing the health care response to pandemic influenza (8). The second, quoted in the preceding paragraph, was originally published in Annals by Isaac Starr and is a riveting account of his experience as a medical student at the University of Pennsylvania working as a nurse during the 1918 pandemic (3). In this editorial, I describe some of the most important issues about planning for pandemic influenza and appraise the prospects for preparedness (3, 8).
Current planning assumptions are based largely on the anticipated experience if a virus comparable to the 1918 flu strain were to cause a pandemic now. The medical consequences would include the following: 1) The attack rate in the United States would be 30%, causing 90 million cases; 2) of those infected, about 50% would seek medical care; 3) the excess mortality would be 209 000 to 1 903 000 deaths; and 4) the outbreak in a community would last about 6 to 8 weeks.
--snip--
The pandemic influenza of 1918–1919 was a punishing chapter in medical history, with a death toll higher than that of World War I. The potential effect of an avian influenza pandemic has been equated to that of a global tsunami. The United States is leading in the scientific effort to contain pandemic influenza with a vaccine and antiviral agents, although the initial efforts have been disappointing. The federal government has presented a public health plan, which the College has endorsed in general terms. The federal plan is quite similar to European plans in terms of surveillance, use of vaccines and antiviral agents, and implementation of travel restrictions and social distancing (24). One major difference is that the European plans are largely national, in contrast to the U.S. strategy of making operational planning a regional responsibility. The challenge in the United States will be to achieve a coordinated plan in a health care system that is unique among nations in the independence of each unit of service, has an incredibly large shortfall in surge capacity, and currently could not begin to manage the magnitude of the 1918 epidemic in Philadelphia as described by Isaac Starr.
The needs for pandemic influenza preparedness are extensive and expensive. Preparing to meet them will require a major scientific effort to modernize vaccine development, substantial expansion of in-country production capacity for development of antiviral agents and vaccines, effective surveillance systems in agriculture and people, and regional planning for catastrophic health crises. The part of this plan that appears most deficient is the last: regional planning that includes local leadership, surveillance, effective communication systems, methods to expand surge capacity, plans to maintain essential services, identification of health care priorities, and guidelines for care. Most communities haven't begun this work, at least not with an integrated regional plan. For this, there needs to be financial support, a timeline, and public accountability for meeting deadlines. Preevent planning is critical. Once pandemic flu strikes a community, it is likely to be over in 3 to 4 months
For those of us who are already informed, here it is in a (rather large) nutshell.
Please ping your lists to this article for discussion.
Thanks.
I'm holding out for eboli or swine flu.
Caring for victims of an influenza pandemic will endanger health care workers.
---
SARS was a recent prototypic example of an infection that had a high mortality rate and high risk for health care workers, who accounted for more than 20% of cases.
The health care professions rose to this occasion, and few if any reports of failure to serve exist.
A survey of 10 511 health care workers in Singapore during the SARS outbreak confirms this judgment:
Seventy-six percent of respondents said that caring for patients with SARS involved great personal risk but was also simply part of their job.
Forty-nine percent reported social stigmatization, and 31% reported ostracism by family members .. The experience in Toronto indicated good participation by health care workers but also a substantial psychological impact.
If Avian Flu becomes as easily transmissible as common flu it could be nearly as bad as the Black Plague in medieval Europe, where about 1/3 of the total population died.
Because:
...this virus [avian flu] had caused ... infections in 218 patients, with 124 deaths—a mortality rate possibly as high as 55%An unusual feature of the infection [1918 strain] was the high mortality rate in healthy persons 15 to 35 years of age.
Despite modern intensive care, the mortality rate for avian influenza is about 20-fold higher than that for the influenza of 1918.
...many of the patients with avian influenza died despite access to antibacterial agents, antiviral agents, and ventilatory support.
Hope someone comes up with an effective vaccine.
I suggest you leave your neighbor alone.
By Zafrir Rinat
"Dr. Reuven Yosef, an ornithologist, decided to close the Eilat International Birding and Research Station, where he has been trapping and ringing birds for 20 years, a few weeks early this year. The reason: A sharp drop in the number of birds passing through Eilat on their annual spring journey from Africa to Europe."
"Worried about this shift in migration, Yosef contacted the Bonn, Germany-based organization responsible for implementing the international convention on protecting migrating birds, and asked it to conduct an urgent investigation into the acute decrease in the number of birds."
I wonder?
ping
It's hard to say what bird flu is going to do. Based on what it's already done, it's not good...But none of us can see around corners.
Obviously, I'm concerned about a pandemic. There are many nations in areas where H5N1 is endemic in the wild bird population who have little infrastructure to monitor and control outbreaks. WHO is, frankly, not much help.
But I guess it could just...go away.......
What the General Public should know and understand about Respirators and Avian Influenza (H5N1)
Currently, we are not aware of any country or government in the world recommending the use of respirators by the general public for the virus that causes Avian Influenza H5N1 (Bird Flu) or any other influenza.
However, the World Health Organization (WHO), US Center for Disease Control (CDC), US Occupational Safety and Health Administration (OSHA), and several European and/ or National Health Protection agencies have recommended that health care workers exposed to patients with confirmed or suspected Avian Influenza use respiratory protection during certain procedures.
Government approved particulate respirators help reduce exposure to the Avian Influenza virus and recommendations include US NIOSH approved N95, European CE certified EN143P2 / EN149 FFP2, EN149FFP3, or higher-level respiratory protection.
Recommendations for respiratory protection have also been made for workers involved in culling and inspecting infected birds, and for people exposed to sick birds.
It is believed that most cases of Avian Influenza (H5N1) infection in humans have resulted from contact with infected poultry or contaminated surfaces.
In such situations, people should avoid contact with infected birds or contaminated surfaces, and should be careful when handling and cooking poultry.
Strict hand hygiene, such as frequent handwashing, must also be performed.
In addition to direct contact with infected poultry or contaminated surfaces, it is possible that the particles that contain Avian Flu virus could become airborne.
As other airborne biological agents, airborne Avian Flu virus, can be filtered by respirators with particulate filters.
Biological agents, such as viruses, are particles and can be filtered by particulate filters with the same efficiency as nonbiological particles having the same physical characteristics (size, shape, etc.).
However, unlike many non-biological particles, biological agents do not have exposure limits established by the government.
This means that any amount of virus particles you breathe may be unsafe.
Therefore, while respirators will help reduce exposure to airborne avian influenza virus particles, there is no guarantee that the user will not contract avian flu.
Respirators may help reduce exposures to airborne biological contaminants, but they don’t eliminate the risk of exposure, infection, illness, or death.
Nevertheless, if people in the general public make a personal decision to use a government approved respirator to help reduce their exposure to airborne influenza virus, they need to understand that:
1. Reducing exposure to the airborne influenza virus particles does not mean that the risk of exposure, infections and illness has been eliminated. Respirators only reduce the number of airborne particles that can get into your breathing zone.
Also, respirators will not prevent you from catching the flu in other ways such as touching your mouth, nose or eyes with contaminated hands or objects, or eating contaminated food.
At this time the CDC recommends the best precaution for the general public is hand washing.
2. In order for a respirator to be most effective, you must properly wear the respirator during the entire time you’re exposed. Removing the respirator to eat, drink, or smoke while you are in a contaminated area means you will be increasing the amount of virus particles you are breathing. You should contact the respirator manufacturer for further information on proper fit.
3. Fit of the respirator to your face is very important to minimize the number of virus particles getting inside your respirator. Particles can enter your respirator through any leaks between the respirator and your face large enough to let them in. Hair from beards and mustaches or anything that prevents the respirator from directly touching your skin can prevent a proper seal.
Following the fitting and the fit-checking instructions that come with the respirator are very important. Achieving a good fit means more of the air you breathe goes through the respirator filter.
4. Respirators are not intended for use by children or by individuals with a medical condition, such as asthma, emphysema or a history of heart disease, which may be aggravated by use of a respirator. If you have such a condition, consult your health care provider before use.
5. Disposable respirators should be thrown away after they are used and should not be shared with others.
6. Be sure to read and follow all instructions on the fit, use and warnings provided by the manufacturer before using any respirator.
7. Please be cautious of claims being made by websites and other sources regarding the use of respirators for protection against Avian influenza. We recommend that you reference CDC, WHO, and other government authorities for guidance.
February 3, 2006
Thanks, Joe. Taking them off and decontaminating them also presents a risk. Respirators and other personal protective equipment can help, but are not foolproof.
Are a significant portion of the birds which might have otherwise have been migrating through dead somewhere, or have they been accounted for in other areas?
In the article he notes:
He is not the only one to express concern recently over the fate of migrating birds. Early this month, BirdLife, the foremost bird protection organization in the world, published a long-term study revealing that over the last three years, the number of bird species that migrate from Africa to Europe - to nest in the spring - has fallen by more than 50 percent. Researchers in Eilat and Europe believe that the dwindling numbers are connected to environmental problems like climatic changes, and increased use of herbicides and pesticides in Africa.
snip
Alon says that the falling numbers in Eilat may have been caused by some birds choosing alternative migration paths. He notes that shifts in the number of migrating birds from year to year are not extraordinary. He also cites massive flooding at the Eilat birding park this year, which may have prevented the birds from stopping at the site. "We observed a decrease mainly in the species of birds that pass over Eilat rather than those in the north of the country," Yosef says.
"The flood at the birding park did not damage the area where we do our tagging, where birds may stop to rest and eat. It is true that there are years when we witness a shift in the numbers of birds, but the decrease this year is far beyond the usual changes, and represents something extreme. We must examine whether this is an ongoing problem."
(emphasis mine)
thanks for the ping!
I agree. In Delaware and New Jersey they are blaming lower numbers of certain migratory birds on overharvesting of horseshoe crabs by commercial fishermen.
One day's worth of beard renders a respirator largely ineffective--in a chemical/fine particulate environment.
A five-O'clock shadow might be enough to cause exposure to a biological through leakage, so everyone who has to shave better add lots of razor blades to their list as well...
Offhand, that sounds like another PC reason to me.
Which birds are they blaming the shortage on?
You would have to ask that question, wouldn't you.
I knew the name when I typed the first message, but it is gone....
But yes, I agree it could be another PC reason, which to me is REALLY assinine, considering the nature of the poultry industry not only in Delaware, but the entire DelMarVa Peninsula.
OTOH, the people blaming the commercial fishermen have long been trying to shut those guys down in Delaware and will resort to any means possible - but that's a topic for another day and another thread.
Thanks for posting this, will read later and pass on to anyone I know who hasn't gotten it yet.
I'm holding out for mad cow...
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