Hello Chicobird234 ,
I have found several excellent resources for you. I am including
excerpts from these sites, but there is a great deal more information
on each site.
Exactly what does it take for an avian flu virus to become able to
live in a human host? How hard it that?
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?It is important not to confuse human cases of avian influenza with
cases of human influenza. Human influenza (?the flu?) is a common
respiratory disease that spreads easily and rapidly from person to
person. Although different strains of avian flu virus circulate
year-round among birds, the virus does not usually spread to people.
In rare instances, however, people do contract avian flu. The exact
mode of transmission from birds to people is not known, but most human
cases of avian flu have been traced to direct contact with live
infected birds or their droppings. The scientific evidence to date
shows that avian flu virus does not spread easily or rapidly from one
person to another.?
?At this time, there is no vaccine to provide people with specific
protection against avian flu. Studies suggest that certain anti-viral
drugs designed to fight human influenza may also help prevent serious
illness in people who become infected with the avian flu virus.?
?As noted earlier, the avian flu virus does not spread easily or
rapidly among humans. However, flu viruses have the capacity to mingle
with one another and morph into a new strain. This is one of the
reasons that health officials keep such a close watch on outbreaks of
avian flu. If someone with human influenza also becomes infected with
avian influenza, there is a chance that the viruses could mingle and
turn into a new virus that spreads easily from person to person. This
could lead to a worldwide epidemic (or pandemic) of influenza. No one
would have immunity to the new virus, and it would take four to six
months to develop a new vaccine.?
This site warns that there is a slim chance that the avian flu virus
could be transmitted from raw or undercooked poultry or eggs. Follow
good kitchen hygiene, and never use cutting boards or utensils that
have had contact with raw poultry on other foods, without a thorough
washing in hot soapy water. Well cooked poultry and eggs appear to
pose no risk.
http://www.hc-sc.gc.ca/iyh-vsv/diseases-maladies/avian-aviare_e.html
?How do humans get avian flu?
So far, virtually all the 100 or so avian-flu cases identified in
humans can be traced directly back to contact with live chickens.
Infected birds pass the virus through feces, and it affects humans
that breathe in the fecal dust. The virus is not passed on in the meat
or eggs, so there's no danger from eating cooked chicken.
How can the virus mutate into one that can be passed from human to human?
Viruses are notorious shape-shifters, able to constantly rearrange
their genes and swap genetic material with different strains.
Virologists are watching carefully for evidence that the microbe has
begun swapping genetic material with a human virus -- that's when it
could turn deadly for people. One worrisome sign: This summer
Indonesia said the virus was found in pigs, which often act as
incubators for human infections.
Are we sure that avian flu will turn deadly for humans?
No. The virus may never mutate into a form that's harmful to people.
Or it could change into a relatively benign bug. Infectious-disease
experts fret that the world is overdue for a flu pandemic since for
hundreds of years four have occurred every century.
In the past 100 years, the world has seen three, of varying
deadliness: The Spanish flu of 1918, which killed 500,000 Americans;
an outbreak in 1957-58 that killed 70,000; and the Hong Kong flu
outbreak of 1968-69 that caused 37,000 deaths.
Most experts, however, believe H5N1, if it does end up threatening
humans, will probably be quite deadly because of its similarity to the
Spanish-flu virus. Also, doctors have noticed that more people are
surviving the infection recently than they were when H5N1 was first
discovered. That's not necessarily a good thing. It could mean that
the virus is mutating into one that is easier to carry -- and spread.
Ominously, the Spanish-flu virus, which also started in birds,
followed a similar evolutionary path.?
http://www.businessweek.com/technology/content/oct2005/tc20051010_0869_tc024.htm
According to the World Health Organization: ?Does the virus spread
easily from birds to humans? No. Though more than 100 human cases
have occurred in the current outbreak, this is a small number compared
with the huge number of birds affected and the numerous associated
opportunities for human exposure, especially in areas where backyard
flocks are common. It is not presently understood why some people, and
not others, become infected following similar exposures.
A pandemic can start when three conditions have been met: a new
influenza virus subtype emerges; it infects humans, causing serious
illness; and it spreads easily and sustainably among humans. The H5N1
virus amply meets the first two conditions: it is a new virus for
humans (H5N1 viruses have never circulated widely among people), and
it has infected more than 100 humans, killing over half of them. No
one will have immunity should an H5N1-like pandemic virus emerge.?
The article goes on to say that no efficient and continued
transmission from human to human has been established. The risk exists
that this can happen as long as birds continue to be carriers of the
H5N1 virus.
?What changes are needed for H5N1 to become a pandemic virus?
The virus can improve its transmissibility among humans via two
principal mechanisms. The first is a ?reassortment? event, in which
genetic material is exchanged between human and avian viruses during
co-infection of a human or pig. Reassortment could result in a fully
transmissible pandemic virus, announced by a sudden surge of cases
with explosive spread.
The second mechanism is a more gradual process of adaptive mutation,
whereby the capability of the virus to bind to human cells increases
during subsequent infections of humans. Adaptive mutation, expressed
initially as small clusters of human cases with some evidence of
human-to-human transmission, would probably give the world some time
to take defensive action.?
Because of copyright laws, I am unable to post all of the plentiful
information on this site. Please read this site, as it should answer
all your questions, and more!
http://www.who.int/csr/disease/avian_influenza/avian_faqs/en/
?? A bird flu virus may mutate to a human form that becomes as deadly
as the ones that killed millions during three influenza pandemics of
the 20th century.
? "We are expecting more human cases over the next few weeks because
this is high season for avian influenza in that part of the world,"
Gerberding said in remarks at the national meeting of the American
Association for the Advancement of Science.
? Although cases of human-to-human transmission have been rare, "our
assessment is that this is a very high threat" based on the known
history of the flu virus, she said.
? In Asia, there have already been a number of deaths among people
who caught the flu from chickens or ducks.
? The avian flu now spreading in Asia is part of what is called the
H1 family of flu viruses.
? There had been small appearances of the H1-type of avian viruses in
other years, but nothing like the H5 now rampaging through the birds
of Asia.
http://www.newstarget.com/005348.html
?The health risk to humans from low pathogenic avian influenza viruses
is less well established, but is likely to be lower. Although this
document focuses on highly pathogenic avian influenza (HPAI), it is
considered prudent to take all possible precautions to the extent
feasible when individuals have contact, as part of control and
eradication activities, with birds infected by any avian influenza
virus.?
http://www.phac-aspc.gc.ca/publicat/daio-enia/index.html
?"If it is proven to be human-to-human transmission, then we have to
be very careful and we might have to close the border," Health
Secretary York Chow told reporters.
"But that won't happen immediately. We need to have some time to
investigate to be sure that this is a new virus and has the risk of
human-to-human transmission."
The warning came as the H5N1 widened its spread in Europe and as
officials in Thailand said on Thursday that bird flu has killed a
48-year-old man in the southeast Asian nation, its first human death
in a year.?
http://www.alertnet.org/thenews/newsdesk/HKG271731.htm
Does Tamiflu make a difference if a person is exposed? Is its effect
constant in all persons?
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?William M. Burns, CEO Roche Pharma Division, commented: "For Tamiflu,
the key need today is the rapid expansion of production capacity.
Patients' needs in case of a pandemic remain our top priority. We have
already significantly expanded production capacity internally and by
working in close collaboration with other companies, and we will
continue to do so. In addition, we are prepared to discuss all
available options, including granting sub-licenses, with any
government or private company who approach us to manufacture Tamiflu
or collaborate with us in its manufacturing. In support of the global
effort to fight a potential pandemic, we would be prepared to discuss
such sub-licenses to increase the manufacturing of Tamiflu, provided
such groups can realistically produce substantial amounts of the
medicine for emergency pandemic use, in accordance with appropriate
quality specifications, safety and regulatory guidelines".
Tamiflu is designed to be active against all clinically relevant
influenza viruses and key international research groups have
demonstrated, using animal models of influenza that Tamiflu is
effective against the avian H5N1 strain circulating in the Far East.
As a result, more governments are stockpiling Tamiflu therefore Roche
is expanding a collaborative production network to meet the increasing
demand. The manufacturing process for Tamiflu is complex and lengthy.?
?Tamiflu is designed to be active against all clinically relevant
influenza viruses.3 It works by blocking the action of the
neuraminidase (NAI) enzyme on the surface of the virus. When
neuraminidase is inhibited, the virus is not able to spread to and
infect other cells in the body.
Tamiflu delivers:
? 38 percent reduction in the severity of symptoms1
? 67 percent reduction in secondary complications such as bronchitis,
pneumonia and sinusitis in otherwise healthy individuals2
? 37 percent reduction in the duration of influenza illness5,3
? Tamiflu was shown to provide up to 89 percent overall protective
efficacy against clinical influenza in adults and adolescents who had
been in close contact with influenza-infected patients?
http://www.roche.com/med-cor-2005-10-18
Again, WHO says this:
?Two drugs (in the neuraminidase inhibitors class), oseltamivir
(commercially known as Tamiflu) and zanamivir (commercially known as
Relenza) can reduce the severity and duration of illness caused by
seasonal influenza. The efficacy of the neuraminidase inhibitors
depends on their administration within 48 hours after symptom onset.
For cases of human infection with H5N1, the drugs may improve
prospects of survival, if administered early, but clinical data are
limited. The H5N1 virus is expected to be susceptible to the
neuraminidase inhibitors.
An older class of antiviral drugs, the M2 inhibitors amantadine and
rimantadine, could potentially be used against pandemic influenza, but
resistance to these drugs can develop rapidly and this could
significantly limit their effectiveness against pandemic influenza.
Some currently circulating H5N1 strains are fully resistant to these
the M2 inhibitors. However, should a new virus emerge through
reassortment, the M2 inhibitors might be effective.
For the neuraminidase inhibitors, the main constraints ? which are
substantial ? involve limited production capacity and a price that is
prohibitively high for many countries. At present manufacturing
capacity, which has recently quadrupled, it will take a decade to
produce enough oseltamivir to treat 20% of the world?s population. The
manufacturing process for oseltamivir is complex and time-consuming,
and is not easily transferred to other facilities.?
http://www.who.int/csr/disease/avian_influenza/avian_faqs/en/
?Experts confirm major role for Tamiflu in pandemic management and
call for stockpiling -
New data presented at the InterScience Conference on Antimicrobial
Agents and Chemotherapy (ICAAC), Washington DC confirm that Tamiflu
(oseltamivir), an oral neuraminidase inhibitor (NAI), is effective
against human and avian H5N1 influenza virus.1 These data are
particularly important as avian influenza strains, such as H5N1, are
considered by experts to be the most likely source of a pandemic
strain, against which older antivirals are not effective. This highly
pathogenic strain is currently circulating in Vietnam and Thailand,
and is responsible for the deaths of more than 30 people since
January.?
http://www.medicalnewstoday.com/medicalnews.php?newsid=15790
?There is no vaccine currently available for humans to counter the
effects of bird flu should it become capable of being transmitted
between humans. Additionally there is no treatment available to 'cure'
patients infected with bird flu. The only treatments available today
are those that will alleviate the symptoms of flu and reduce the
ability for the virus to be transmitted within the body and
particularly within the lungs thereby reducing the efficiency of viral
transfer within the greater population.Always consult a qualified
doctor before taking any course of treatment.?
?Tamiflu has been approved by the FDA as an oral anti-viral drug for
the treatment of uncomplicated influenza in patients one year and
older whose flu symptoms have not lasted more than two days.
Tamiflu's efficacy for the prevention of influenza has not been
established in immunocompromised patients.
Tamiflu is for treating adults, adolescents, and children one year of
age and older with the flu whose flu symptoms started within the last
day or two.
Tamiflu is also used to reduce the chance of getting the flu in adults
and adolescents age thirteen and over who have a higher chance of
getting the flu because they spend time flu sufferers.?
This page has numerous links to avian flu information.
http://www.avflu.com/
A blog opinion on Tamiflu
http://www.marginalrevolution.com/marginalrevolution/2005/10/dont_put_your_f.html
Is the Health Care community capable of fully responding to this threat?
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?Is the world adequately prepared?
No. Despite an advance warning that has lasted almost two years, the
world is ill-prepared to defend itself during a pandemic. WHO has
urged all countries to develop preparedness plans, but only around 40
have done so. WHO has further urged countries with adequate resources
to stockpile antiviral drugs nationally for use at the start of a
pandemic. Around 30 countries are purchasing large quantities of these
drugs, but the manufacturer has no capacity to fill these orders
immediately. On present trends, most developing countries will have no
access to vaccines and antiviral drugs throughout the duration of a
pandemic.?
http://www.who.int/csr/disease/avian_influenza/avian_faqs/en/#prepared
Here is a Strategic action plan, proposed by WHO:
http://www.who.int/csr/resources/publications/influenza/WHO_CDS_CSR_GIP_05_8-EN.pdf
?GENEVA (Reuters) - Health and veterinary officials from across the
world hope to clinch a global plan on Wednesday for tackling bird flu
before it mutates into a form that could sweep the globe and kill
millions of people.
Highlighting the threat, China said an outbreak there announced last
week had now spread to 18 townships, making controlling the disease
that much harder.
The officials meeting in Geneva are focussing on steps to stamp out
the H5N1 avian virus in poultry as well as better prepare nations
should a pandemic break out.
Health experts say that is most likely in Asia where the virus has
killed 64 people, is endemic in most poultry flocks and where farmers
live close to their livestock.?
http://today.reuters.co.uk/news/newsArticle.aspx?type=topNews&storyID=2005-11-09T101921Z_01_YUE926047_RTRUKOC_0_UK-BIRDFLU.xml&archived=False
A repeat of the 1918 flu?
?Scientists have re-created the ?Spanish flu? virus that killed up to
50 million people in 1918-19 and shown that it shared traits with the
H5N1 strain of avian flu.
An analysis of the re-created pathogen has shown that, like its modern
cousin, it began as a bird virus and jumped species into humans with
mutations that made it peculiarly virulent and lethal.
Dr. Jeffrey Taubenberger of the US Armed Forces Institute of Pathology
and other scientists have just published papers in Science and Nature
demonstrating that the 1918 virus was an avian virus in origins.
"We now think that the best interpretation of the data available to us
is that the 1918 virus was an entirely avian-like virus that adapted
to humans," Taubenberger told reporters in a telephone briefing.
"It suggests that pandemics can form in more than one way."
The more deadly 1918 pandemic virus is unlike the 1957 and 1968 flus
in that the 1918 flu did not recombine with human influenza strains.
That the 1918 strain did not recombine with human influenza strains
and at the same time that it was orders of magnitude more lethal is
probably not a coincidence.?
http://www.futurepundit.com/archives/003027.html
Notice that in February 2005-11-09 ?A new strain of bird flu virus
has cropped up in a flock of chickens in Lancaster County,
Pennsylvania. The virus was detected during routine surveillance and
no chickens or humans have shown any symptoms of disease. State health
authorities believe it poses no risk to human health.
A related strain, however, triggered a pandemic in 1957, causing
nearly 70,000 deaths in the United States and 30,000 deaths in the
United Kingdom. The virus was a bird strain that apparently acquired
the ability to infect people.?
http://www.genomenewsnetwork.org/articles/2004/02/20/avian_flu.php
As far as the flu or Tamiflu affecting everyone in a standard manner -
no. The elderly, debilitated, and very young will be more susceptible
than others. Tamiflu is meant to help reduce chances of getting Avian
flu in those over 13 years of age, and timing, as noted in the answer
above is important.
There you go! If you?ve watched the news, you may notice that
conflicting reports on avian flu are rampant. Experts even disagree
with other experts. Since many physicians and researchers are
speculating at this point, its hard to say which route the avain flu
will take.
If any part of my answer is unclear, please request an Answer
Clarification, before rating, and I will be happy to respond.
Sincerely, Crabcakes
Search Terms
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H5N1 mutates human
Avian flu virus mutates + human form
Avian flu mutation
Human transmission + bird flu
Efficacy Tamiflu + avian flu |
