Once the source of the H7N9 infection is found, how should the Chinese authorities you organize the response? Regarding that it is more than likely that animal-to-human contact could cause a human pandemic, all existing response methods are doomed to fail.
One of the remaining options is the novel Anoxia method, based on the absence of oxygen under atmospheric conditions. When the Chinese authorities able to apply this technique throughout all provinces, using well-equipped and trained firefighters, they could be able to stop the pandemic before it starts. The Anoxia method is therefore the weapon of choice.
1. Page 1 of 8 4/29/2013
Safe Culling Methods in Emergency
Response to the Current H7N9
Outbreak in China
Introduction
The central theme of this paper is which culling methods to choose and howto
organize the response to deal with the current outbreak of the H7N9virus in China.
Last MondayApril 22nd
, 2013 the WHO announced that a
number of people who hadtested positive for a new strain of
bird flu in China had no history of getting in direct contact
with poultry. State media reported that the total number of
H7N9 bird flu cases had increased to more than 100. The
virus that has killed over 20 people to date continues to
develop and it´s characteristics remain a mystery.
In the case of this outbreak of H7N9 the source of infection is yet unknown. It
appears in animals and humans alikeandsince this is a new strain there still is no
vaccine available for humans or animals.We don’t know which mammals are
receptive to H7N9. There is no other option than to mass cull all diseased and
suspected animals to stop the spread of the virus. During this process the operators
will have to make sure the culling operations themselves o not spread the virus even
further.
How would you communicate the risks to all people who
musthandle diseased animals as part of their duties? Their
personal life might be at risk. The Case Fatality Ratio
(CFR)calculated as of 21 April 2013amounts to 21%. The
potential CFR, if the present number of serious cases with
severe flu symptoms is included, grows up to 78%.That is a
serious risk compared to the CFR of 0,45%1
for the H1N1
‘Swine influenza’ virus (WHO 2009).
Considering the high CFR there should be absolutely no
contact between humans and (possibly) infected animals. This makes all techniques
and methodologies to cullanimals, which have been used in the past obsolete. There
are no proven techniques for mass culling available, other than brute force and a
large number of people to carry out the operation. This would be detrimental to the
goal of containing the virus
In this presentation I will outline the available methods for mass culling of farmed
animals and propose a novel method, which eliminates direct contact between relief
1 http://www.virology.ws/2009/06/16/how-many-people-die-from-influenza/
Overview outbreaks April 24, 2013
Disinfection at checkpoint in
China
2. Page 2 of 8 4/29/2013
workers and animals. Eradication of contamination does not only require
appropriate technology but also a functional organizational structure as well as well-
trained staff. I shall also go into these aspects to propose a full working solution to
effectively deal with the present situation.
Culling Methods
Start from scratch and virtually unprepared
China has developeda large-scale and densely populated farming industry (in the
coastal regions); traditional small-scale based farming systems (close to towns) and a
large number of backyard farms (in the counties). In an ideal scenario every farm
would have its own depopulation plan, but obviously this is not the case. It would
imply local workers are being aware of the principles of biosecurity and are able to
transfer knowledge to the farmers in the field.This is still a bridge too far in China.
This makes creating tactical plans for mass culling operations very complicated
because of the huge differences in tackling the problem of reducing the spread of
the virus. When a crisis is announced, the workersare turned into culling staff and
ordered to eradicate the virus. Let´s have a look at the options at hand.
Traditional mass killing
In times of a viral pandemic crisis, the local crisis manager is
in charge. The only method he is familiar with is the
traditional method of mass culling of (potential) virus-
carrying animals. He has been drilled in following orders
that have been construed to kill suspect animals as quickly
as possible. No consideration has been given to the risk of
turning relief workers into virus carriers.
Let’s assume the outcome of research on H7N9concludes that
poultry is one of the sources of infection, what are the options?
In Asia, poultry is normally culled by sending in a large army of poorly trained
localworkers. Usually under-equipped field workers with large bags; chasing animals,
catching them and putting them in a bag. Next cause of action is to hit them as hard
as they can until the animal is dead. The last phase is throwing the bags in a pit; add
fuel and woodchips to the pit and burn the animals. Job finished.
International standards, human safety and animal welfare are not part of the
equation.
Assumeanother type of mammal would be a source of infection, whichtechniques are
available, and could they be applied?
For other animals, there are no standard methods available to cull large quantities in
the field. The results of the mass culling of pigs in South Korea in 2010 shows that
even in a country with a well-developed agricultural industry, mass depopulation of
Traditional culling of
Chickens in Asia
3. Page 3 of 8 4/29/2013
in total 1/3 of the countries pig population. This has led to catastrophic2
failure of
emergency response measures, including live burial and live incineration of pigs.
Techniques instead of human power
China haslearned from SARS response measures and is likely to be able to activate
emergency response measures according to their plans much better than any of the
neighboring countries. However, sending in large groups of workers, or large groups
of military personnel would increase the risk of human infections. In this case the
risk is not just that people get sick, but also because there is a the risk that they
could become carriers of the virus. This time, the culling must be carried out with an
absolute minimum of workers.Using Techniques instead of a huge pool of
manpower. That is new to China.What are the options?
Modern slaughter/killing techniques
What slaughter/killing techniques have been developed so far that could be applied?
The first methods to think of are the more traditional slaughter/killing methodsthat
are in use during normal slaughter procedures.E.g:Take the methods described in
the EU Legislation EU 1099/20093
.Thesecame into force January 1st
, 2013.
Method 1) knifes (Halal, mainly in Asia and Africa4
)
Method 2) electrical shock methods (poultry, sheep,
pigs, sheep, goats)
Method 3) gas (CO2 as gas or as dry ice)
Method 4) lethal injection (killing method for all animal
types)
Method 5) shooting masks (penetrating/non-
penetrating)
Method 6) barbiturates (killing method)
Method 7) guns
Methods 1, 2, 3, 4 and 5 are not applicable because they include Animalto Human
contact. In all of these methods, animals need to be handled by personnel in one
way or another and/or include bleeding the animals to death. Only the use of poisons
and gunsis an option amongst traditional slaughter/killing methods. Unfortunately,
in practice, these methods prove to be very difficult to execute during outbreak
situations.
Mass depopulation methods
Specific methods and techniques of mass culling have been developed during
previous outbreak situations in both Europe and North America. All of them have
been based on the principles of Hypoxia and suffocation.
Method 8) Stable gassing: drive all animals into barns and close all doors; and
windows; close all ventilation holes; cover all walls with plastic sheets and start
pump in CO2 gas. This method is based on the principle of hypoxia (reducing the
2 http://www.boiseweekly.com/Cobweb/archives/2011/01/17/14-million-pigs-being-buried-alive-in-south-korea
3 http://n2gf.com/?p=401
4 http://www.couriermail.com.au/news/cruel-slaughter-no-surprise/story-e6freomx-1226068986305
4. Page 4 of 8 4/29/2013
level of oxygen) and is in use in Europe and Northern America to cull large
numbers of broilers.
Method 9)water based Firefighting foam: put all animals under a blanket of very
small foam bubbles, blocking the Trachea of the animal; a method based on
smothering animals to death. In use in the USA to cull large numbers of broilers.
Method 10) Container/big bag culling: animals are collected out of their stables
and carried to closed containers or big bags filled with CO2.
Method 8 and 9 are ruled out due to the absence of these techniques in Asia and thus
the absence of well-trained operators. Method 10 is ruled out because it calls for
Animal to Human contact.
Brutal methods
What are left are the more brutal and cruel methods. These methods are obviously
not described in national plans. Besides the absolute cruelty and total neglect of all
international standards, brutalmethods are the “weapons of last resort”. Only
executed if there are no other options left.
Method 11) drive the animals to lorries and load them up; transport them to a
large burial place (a hole in the groundof at least 10 meters deep); dump the
animals into the pit and bury them alive.
Method 12) drive the animals into an old shed: put the shed on fire and burn the
animals to death.
Method 13) drive all animals to the river and dump them
Method 14) collect all animals and burn them alive in ovens and furnaces.
Cruel methods call for Animal to Human contact.Method 11, 12and 14 demand
transportation, mostly through populated areas. If animals are buried (method 11),
dogs can scavenge dead animals out of the pits and the virus can permeate into the
ground-and thus drinking water. If animals are burned, the heat can disperse
contaminated dust and feathers thus allowing the virus to become airborne. Method
13 will increase the risks of infection for everything that lives in the water or on the
riverbanks.
New techniques
Sick, crippled and diseased animals deserve to be treated with respectand in
accordancewith theOIE Terrestrial Animal Health Code5
. Without suitable
techniques, there is no room for the OIE Code. In times of crisis everything will be
allowed. It is not just an issue of how we treat animals in a humane way. When
diseases are highly contagious, human safety is at stake as well.
During the outbreak ofAvian Influenza in Holland and Belgium 20036
it became clear
that the disease spreads much quicker when a lot of people are involved in bringing
the crisis under control. At the start of the outbreak, theReproduction Ratio was
5 http://www.oie.int/index.php?id=169&L=0&htmfile=chapitre_1.7.6.htm
6 http://n2gf.com/?p=863
5. Page 5 of 8 4/29/2013
8.67
. One farm leads to the infection of 8,6 other farms and the Dutch relief workers
played a vital roll in the spread of the virus, mainly because of inadequate use of
personal protection equipment. As a result 50% of all extension workers were
carrying antibodies8
. They played an important role inthe spread of the virus
throughout the countries.
Method 14) Anoxia
Evaluating the outbreak and the methods used to contain the spread of the virus,
the conclusion was that a radical different methodwas called for, in order to
overcome the risk of infections related to the use of culling techniques. New
methods, specially designed for the purpose of killing sick and crippled animals on
the farm, were required as well as culling a selection of animals on the farm or in the
field or the massindiscriminate culling of large quantities of animals. Thenew method
should at least meet three criteria:
1. Generally applicable to slaughter and kill animals outside the regular
slaughter channels, regardless of the species - their size or - their age
2. Excluding direct Animal to Human contact
3. Maximizing animal welfare, completely in line with the OIE Code
A research project was started in 2004, following the evaluation of the stamping out
procedures (on 1.100 farms) during the H7N7 outbreak in 2003. The result was the
inception of what is now called the Anoxia method9
.This method is based on the
principles of total absence of oxygen. The Anoxia method is the first technique that is
based on the on the principles of exposingconscious animals to high Nitrogen levels
resulting in death by anoxia. The principle of Anoxia is part of the New EU directive
EU 1099/200910
,which is in force since January 1st, 2013.
Prototypes of Anoxia equipment have been developed and the technique has been
successfully tested by dr. Marien Gerritzen in both 200711
and 201012
, carried out at
Wageningen University WUR (Holland) andby dr. Dorothy McKeegan at the
University of Glasgow in 200913
.
InJanuary 201314
a project has been started at the Dutch PIG Innovation Center VIC
Sterksel (part of Wageningen University WUR) to test the Anoxia under practical
conditions.
Anoxia15
is the medical description of a total absence of oxygen. All mammals
breathe atmospheric air that contains 78% N2. Air contains also oxygen because itis
part of the metabolic processes:oxygen is transported by bonding with hemoglobin,
which is presentin red blood cells. The anoxia method results in transporting only
7 http://n2gf.com/?p=860
8 http://n2gf.com/?p=951
9 http://n2gf.com/?p=705
10 http://n2gf.com/?p=401
11 http://n2gf.com/?p=286
12 http://n2gf.com/?p=385
13 http://n2gf.com/?p=391
14 http://n2gf.com/?p=478
15 http://n2gf.com/?p=808
6. Page 6 of 8 4/29/2013
pure nitrogen to all organs. The absence of oxygen results in the stunning of the
animal after about 30 seconds. Death occurs without any notice.
This is how the anoxia method is implemented
Production of large foam bubbles, filled with
99% nitrogen gas;
Nitrogen is produced by compressing
atmospheric air;
The air is split in oxygen and nitrogen (the
oxygen is released in the atmosphere again)
and the nitrogen is used to blow large
bubbles;
Animals are stunned by immersion in a
blanket of bubbles;
The animal stays calm, the brain does not
issue an alarm as it does not detect the low
levels of oxygen(unlike gassing with CO2 in
which the brain will detect alack of oxygen
and the animal will panic due to
asphyxiation’;
The animal dies within 1,5 minutes due to a lack of oxygen.
Applicability in China
How to organize a mass culling operation?
In case of the latest H7N9 outbreak, officials on the national and regional levels are
working overtime to be able to inform the general population about the risks of this
virus. There is a big difference in preparing a response organization on national level,
on regional (inspection) level and on an operational level:
National government officials are responsible for implementing
(international) guidelines into legislation
Regional veterinary- and human health inspections are responsible for
turning these guidelines into standard procedures
Local officials are in charge of carrying out procedures.
In the case of China,Regional inspection services in 34 provinces are working with
about 300.000 veterinarians and human health specialists in order to locate the (still
unknown) source of the infection.All tasks are carried out by local teams in the
provinces, putting the totalnumber of people working on the current H7N9 outbreak
on around 2.000.000 to 3.000.000. Most of them are veterinary and human health
workers (relief workers) responsible for carrying out the procedures that are issued,
by local officials. Without the basic knowledge of the source of the virus, their task is
so huge and there is hardly any room for training all relief workers in time.
Foam nozzle
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Thinking two steps ahead
At the moment the source of the infection is found, it is the responsibility of the
regional governments to organize and execute the culling operations, leaving the
execution of guidelines in the hands of the largest group: local relief workers. They
can only rely on what they know, and in most cases they are only familiar with
traditional methods of killing animals.In most cases, these people are only trained in
the basic response principles, which come down to following orders from higher
authorities.
Considering the risks of Animal to Human infection, the culling operations should not
be carried out by large masses of unprepared and unskilled local relief workers.
Instead of that, the Anoxia method, excluding Animal to Human infection should be
the preferred method of choice, carried out by specially trained staff.
A well-trained force is available: the Fire Brigade
Provided the relief effort capacity is big enough the novel Anoxia method canprevent
a large-scale human viral outbreak. It is safe, it functions according to the OIE
guidelines, it is efficient and effective and most of the components needed are
already locally available.
The applicability is amazingly easy because of it´s simplicity. What is needed is a well-
trained ‘army-like’ organization, trucks carrying water, mobile power
generators/compressors,and oxygen generators (using the compressed Nitrogen
instead of oxygen), special detergent and foam nozzles.
The party that has most of these elements in house is the local fire bureau:
They have the best-trained people in any community, used to work under
hazardous conditions
Most hardware to engage in a mass culling operation using the Anoxia
method is already available within the force
They are used to improvise and similar to a fire outbreak
The foam nozzles and the special detergent are produced in China; available; and
ready to use. If needed, there are specialized companies, offering rental services for
heavy-duty power suppliers, compressors and oxygen generators (similar to the
petrochemical- and offshore industries).
Don’t buy weapons at wartime
When China is able to apply this technique throughout all provinces, they are able to
mass culling of animals. The Anoxia method is also scalable, so no matter if you have
to kill single animals, cull a selection of animals, or mass cullmillions of animals: with
enough fire brigades at hand, the Anoxia Method can be applied.The Anoxia method
is therefore the weapon of choice.
About the author
Harm Kiezebrink (1958) is an international consultant on animal disease outbreak
control. He has hands-on experience in various mass culling operations and
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developed new technologies for optimum performance. He is a regular advisor or
national governments and international organizations.
Contact details
Address: Chaoyang Park Westroad, Parkview Tower 3 App 11A, Beijing
Phone: +86 135 201 93 755
Mail: harm.kie@gmail.com