12 January 2012
Stephen
M. Apatow
Founder,
Director of Research & Development
Humanitarian
Resource Institute
Humanitarian University
Consortium Graduate Studies
Center
for Medicine, Veterinary Medicine & Law
Phone:
203-668-0282
Email:
s.m.apatow@humanitarian.net
Internet:
www.humanitarian.net
Pathobiologics
International
Internet:
www.pathobiologics.org
Humanitarian
Intervention Initiative
Operational
Security Consultancy
Internet:
www.H-II.org
|
| LAHORE – Around 15 peacocks have
been expired at
the Safari Park during the last seven days due to bird flu virus,
authorities said on Tuesday. -- Bird
flu claims 15 peacocks at park: The Nation, 11 January 2011. |
HPAI/LPAI H5N1 - Billions of Birds Killed Points to Crisis in
Pandemic
Authorities have spent billions of dollars and destroyed billions
of domestic birds in efforts to curb the virus’s spread and ensure
the safety of the food supply. -- Avian
Influenza (H5N1): Wildlife
Conservation Society.
Preventing the nightmare of 11 million
animals (mostly healthy) killed
during the 2001 UK FMD Outbreak is a
top priority with Low pathogenic Avian Influenza H5N1, which is
endemic
in migratory birds and mammals and in most cases does not cause
clinical disease. -- Keynote
Address: DNA
Based Detection Technologies, Stephen M. Apatow, Los Alamos: Future
of Biodetection Systems, 2006.
Special
Operations Forces Truths: Competent Special Operations Forces
cannot be created after emergencies occur.
Restricted
access to diagnostic tests and incomplete information
regarding surveillance, containment and control of Avian Influenza H5N1
has set the stage for a full blown crisis, in the event of the
evolution of a pandemic strain that is easily transmissible between
humans. To date, fear driven non-science based panic, resulted in
the
depopulation of billions of birds throughout Asia and across the
globe....
The
reality: there are two types of H5N1 avian influenza challenges:
(1) Highly Pathogenic Avian Influenza (HPAI) that has a high mortality
rate for infected birds and (2) Low Pathogenic Avian Influenza (LPAI),
both are endemic
in migratory birds and mammals. [1] No
country has the capacity to
claim they are bird flu free.
------------------------------------------------
Hosts:
Listing from CIDRAP: Avian
Influenza (Bird Flu): Agricultural and Wildlife Considerations:
Avian influenza A viruses can infect a variety of
domestic and wild avian species (including chickens, turkeys, ducks,
domestic geese, quail, pheasants, partridge, parrots, gulls,
shorebirds, seabirds, emu, eagles, and others). The clinical
manifestation of infection in birds ranges from asymptomatic infection
to rapidly fatal disease (see References:
Horimoto 2001).
Aquatic Birds
Ducks, shore birds, and gulls are considered the
natural reservoirs for avian influenza viruses (see References:
Fouchier 2004; Webster 1992). These waterfowl generally do not develop
disease when infected with avian influenza viruses (see References:
Horimoto 2001); however, H5N1 appears to be virulent for a variety of
wild bird species.
- An outbreak of H5N1 among
migratory geese and other
wild birds in Qinghai province, China, was identified in May 2005 (see
References:
Chen 2005; Liu 2005).
- An outbreak in wild swans
occurred in Azerbaijan in
February 2006, and severe illness from H5N1 influenza has been
recognized in a variety of other wild bird species (see References:
Gilsdorf 2006; Olsen 2006; USGS National Wildlife Health Center: List
of species affected by H5N1 influenza).
- North American wood ducks and
laughing gulls are
susceptible to illness and death from highly pathogenic H5N1 avian
influenza viruses (see References:
Brown 2006).
Domestic Birds
Domestic chickens and turkeys are susceptible to
severe and potentially fatal influenza A caused by HPAI strains. Over
the past several years, numerous H5N1 outbreaks have been recognized in
chickens and an H5N1 outbreak in turkeys was identified in 2005 (see
Oct 13, 2005, CIDRAP
News story). Investigators in Asia showed that asymptomatically
infected domestic ducks shed more H5N1 virus for longer periods in 2004
than in 2003, which may be a factor in amplifying the spread of H5N1 to
domestic poultry (see References:
FAO/OIE/WHO 2004).
Other Avian Species
H5N1 infection has also been reported in other
avian
species.
- Another report demonstrated the
presence of H5N1
influenza virus in asymptomatic eagles that were smuggled from Thailand
into Belgium in 2004 (see References:
Borm 2005).
- HPAI H5N1 viruses were isolated
from asymptomatic
tree sparrows in the Henan province of China in 2005 (see References:
Kou 2005).
Mammals
- Influenza A viruses have
traditionally been known
to cause disease in horses, pigs, whales, and seals; however, the range
of several influenza A subtypes is expanding to different mammalian
species.
- H5N1 influenza A has now been
shown to infect cats,
leopards, tigers, civets, and dogs (see References:
European Centre for Disease Prevention and Control Influenza Team 2006:
H5N1 infections in cats; Keawcharoen 2004; Songserm 2006: Fatal avian
influenza A H5N1 in a dog; Songserm 2006: Avian influenza H5N1 in
naturally infected domestic cat; Thanawongnuwech 2005; Webster 2006;
Yingst 2006).
- Some experts are concerned
that domestic cats
could play a role in transmission of H5N1 to humans, although this has
not been documented to date (see References:
Kuiken 2006). Asymptomatic infection has been reported in domestic cats
(see References:
Leschnik 2007), and the Food and Agriculture Organization of the United
Nations (FAO) recommends that avian influenza in cats should be closely
monitored (see References:
FAO: 2007).
- A report involving cats
experimentally infected
with H5N1 demonstrated that infected cats excreted the virus via the
respiratory tract and the digestive tract, suggesting that in addition
to the respiratory route, other routes of transmission may play a role
in spread among mammalian hosts (see References:
Rimmelzwaan 2006).
- Cat-to-cat transmission of
H5N1 can occur (see References:
WHO 2006: Influenza research at the human and animal interface).
- H5N1 was identified in pigs in
China in 2001 and
2003 (see References:
Cyranoski 2004). The virus also was found in pigs in Indonesia in 2005
when 5 of 10 pigs tested in western Java were shown to be
asymptomatically infected (see References:
Cyranoski 2005) and again in 2006 on the Indonesian island of Bali (see
Oct 10, 2006, CIDRAP
New story). A recent laboratory study, however, found that domestic
pigs have low susceptibility to H5N1 viruses; experimental inoculation
resulted in asymptomatic infection or mild symptomatic infection
limited to the respiratory tract and tonsils (see References:
Lipatov 2008).
- H5N1 recently has been isolated
from an infected
mink and a stone marten in Europe (see References:
WHO 2006: Influenza research at the human and animal interface).
- A study demonstrated that calves
can be
experimentally infected with H5N1 virus (see References:
Kalthoff 2008).
- A recent report found that
raccoons can become
infected with avian and human influenza A viruses, shed and transmit
virus to virus-free animals, and seroconvert (see References:
Hall 2008).
- Red foxes have been shown to be
susceptible to H5N1
infection when fed infected bird carcasses (see References:
Reperant 2008).
- Cases of canine influenza caused
by H3N8
have been recognized in the United States in recent years; this subtype
traditionally has been found in horses (see References:
Crawford 2005, Yoon 2005).
------------------------------------------------
Limited access to
human diagnostic tests has resulted in a global black hole
regarding data on clinical, subclinical and atypical infection with
either HPAI or LPAI H5N1 Avian Influenza
strains [2].
See:
Avian
Influenza A/(H5N1) Cumulative Number of Confirmed Human Deaths:
Global Health Policy (As of August 19, 2011).
Why
such a discrepancy? In part, it's about agricultural
economics, prevention
and control of H5 and H7 low pathogenicity avian influenza in the live
bird marketing system. In the United States, the gold standard of
biosecurity might work, but in developing countries (170 +) we need
science based biocontainment and safety standards established before we
destroy the food supply.
If
we
had a human pandemic H5N1 strain evolve and widespread testing then
expanded across the globe, findings of
infection or evidence of previous
infection,
could fuel a drive to destroy all impacted food production
animals, while
the endemic wildlife challenge in the global ecosystem
is untouchable. This is all while
human
transmissible strains of avian influenza virus that
originated from H5N1 are H3N2,
H1N1 - H2,
H9, H7).
We
watched such a challenge when over 11 million farm animals (mostly
healthy) were destroyed during the 2001 UK Foot and Mouth Disease (FMD)
outbreak. Why? a vaccination policy was not in place, lab
validated
handheld diagnostics tests (RT-PCR) [3] were not approved to assist
rapid
surveillance, containment and control strategies and
the economic objective of the country was to be designated FMD or
disease Free.
Despite all the energy set forth to prevent this crisis, once we were
in a crisis responsive mode it, was too late. [4]
This
nightmare with Avian Influenza H5N1 must be prevented, since
the
damage to the global food supply, while in the midst of a
humanitarian
emergency and food crisis, would be catastrophic. [5]
The
following discussion points are outlined in the paper "Controlling
H5 and H7 virus infections," Should there be a
change in the
definition of avian influenza for legislative control and trade
purposes?:
D.J. Alexander. [6]
If it
is accepted that greater statutory control of H5 and H7 LPAI
viruses is necessary to avoid probable emergence of HPAI viruses then
the options are relatively limited. The apparent choices are:
1. Retain the current definition with a recommendation that countries
impose restrictions to limit the spread of LPAI of H5 and H7 subtypes.
This option essentially maintains the status quo, in that in recent
years most countries/states have reacted to try and limit infections of
LPAI H5 and H7 viruses when they have occurred in poultry. It has
proved successful in some countries and unsuccessful in others.
2. Define statutory AI as an infection of birds/poultry with any AI
virus of H5 or H7 subtype.
This option follows the precedent in present definitions of slaughter
of birds infected with potentially HPAI viruses (see above), since it
is currently thought that all H5 or H7 LPAI viruses may mutate to
virulence. The added advantages of this option are that diagnosis of
both LPAI and HPAI is greatly simplified and would result in quicker
implementation than the current definition as it requires neither
invivo testing or sequencing of the amino acids at the HA cleavage
site. There are however several disadvantages. There is currently lack
of knowledge of the prevalence of H5 and H7 virus infections of
poultry, especially species other than turkeys and chickens. In the EU
during 2003 member states have been carrying out point prevalence
surveillance studies in poultry in an attempt to address this lack of
knowledge. There may well be reluctance among farmers to consider
slaughter of birds showing few, if any, signs and this could lead to
failure to investigate mild respiratory disease or even to covering up
infections with LPAI. Some decision would have to be made on whether to
treat species such as commercial ducks differently to turkeys and
chickens. There is no evidence that H5 and H7 LPAI viruses are likely
to mutate while infecting ducks and the prevalence of LPAI viruses of
these subtypes could be high in commercial ducks in some countries
(Shortridge 1999).
3. Define statutory AI as any infection with AI virus of
H5 or H7
subtype, but modify the control measures imposed for different
categories of virus and/or different types of host.
This option is intermediate to options 1 and 2. It is envisaged that
there would be a legal requirement for the notification of all H5 and
H7 infections to the regulatory authorities and there would be
statutory imposition of control measures. However, although the
presence of HPAI virus would require stamping out, lesser measure could
be imposed for LPAI virus infections. Such measures would need to be
carefully considered and specified, but could include: voluntary
slaughter or early marketing, stringent defined biosecurity measures,
epizootiological tracing and surveillance. Possibly infections of
commercial ducks could be controlled differently, but the need to
prevent spread to other poultry would be paramount.
References:
- Avian
Influenza (Bird Flu): Agricultural and Wildlife Considerations:
CIDRAP, Last updated December 1, 2011. Url: www.cidrap.umn.edu/cidrap/content/influenza/avianflu/biofacts/avflu.html
- PRO/AH>
Avian influenza, human (140): atypical infections,
05-SEP-2006
20060905.2522. Url: www.pathobiologics.org/ivphc/ref/h5n1_200609052522.html
- Diagnostic
specificity of a real-time RT-PCR in cattle for foot-and-mouth disease
and swine for foot-and-mouth disease and classical swine fever based on
non-invasive specimen collection: Veterinary Microbiology 132
(2008) 158–164. Url:
ddr.nal.usda.gov/bitstream/10113/21459/1/IND44106532.pdf
- 2002
Award for Excellence in Outbreak Reporting on the Internet:
International Society for Infectious Diseases, ProMED-mail. Url: www.humanitarian.net/promed2002.html
- Avian
influenza: food safety issues: World Health Organization.
Url: www.who.int/foodsafety/micro/avian/en/index1.html
- Should
there be a change in the definition of avian influenza for legislative
control and trade purposes?: D.J. Alexander. Volume 8 Avian
Influenza: Prevention and Control Schrijver, Remco S.; Koch, G.
(Eds.), 2005, IX, 152 p., Softcover, ISBN: 978-1-4020-3440-4. Url:
library.wur.nl/frontis/avian_influenza/12_alexander.pdf
Related:
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