Avian Influenza

BELLSOUTH TECHNICAL BULLETIN

© Bellsouth Pty. Ltd. and Jim Finger 01-07-2004

Avian Influenza, its implications for the Fancy Breeder.

Avian Influenza is a type A virus of the Family Orthomyxoviridae. There are three distinct groups A, B, C all of which are defined by the neucleoproteins, Group A effects horse pigs humans and birds. Groups B and C are minor human only diseases.

There are thousands of these virus and they are classified as subtypes using their antigenic differences. Now antigens are the structures that the body immune system can recognize and untimately latch onto when it responds, to destroy the invading particle.

The major measure of the antigens in AI are hemagglutinin (HA) and neuraminidase (NA), and minor measures are the neucleoprotiens. So when an influenza is found it is characterises by where it was found, then the species it was found in, the the HA And NA components, then sub strains with varaints of the neucleoprotiens.

These antigens stick out from the surface of the virus, and it looks like this.



The particular virus which cause us the trouble are called Highly Pathogenic Avian Influenze HPAI but if you read the old books these outbreaks were called fowl plague, and fowl pest with specific names in other languages. It seems they are always H5 and H7 varieties.

Lots of other influenza virus cause no disease at all.

Don’t Miss-diagnose the disease!!

It is very common today to hear small producers talk about their birds having the flu. The respiratury symptoms, bunged up eyes, bad breath, various sorts of cough and sneezing, general respiratory symptoms. None of these are influenza so we need to be careful about how we understand these diseases. There is a need for training for small producers more today than ever before as the commercial industry has moved from government supported veterinary services to company owned vet services.

Virus are interesting critters, they cannot themselves replicate, they need a host cell to multiply. So the virus takes over the host DNA and makes the host cells replicate itself instead of the normal cell. In the process the DNA can get mixed and extra material added to the virus DNA.

One of the interesting things about avian influenza is that there is something wrong with the virus. It has lost something in its makeup which ensures that it is stable. Reproducing organisms have a built in spell checker which makes sure that when they multiply, that is making duplicates of their genetic code, the duplicates are the same as the originals. It seems that influenza does not have this spell checker, so the virus can pick up some genetic information from the host cell. Mostly this information is of no value.

If the change to its DNA makes it reproduce better in a particular host then it can multiply faster, and survive in greater numbers. However it may still not cause disease. It is only in a host where it can multiply fast and at the same time cause disease in the host that we have a problem. Sometimes the problem occurs where there are several influenza virus in the same host and they pick up bits of one another and so make a complete new variety. If this happens, and the host where the mixing has occurred is susceptible, mortality and morbidity are possible. Sometimes the variety starts out not being able to effect the host much at all and as time goes on the more times the virus passes through the susceptible host the more virulent it becomes.

This has an important side benefit. It means the disease becomes self limiting in susceptible hosts, one they are all dead it has nowhere to go.

But it also means there is another problem, it can survive very nicely at a low level in non susceptible hosts which continue to shed the virus, and act as a reservoir of infection.


This is taken from the DPI report by Hugh Millar the Chief Veterinary Officer for Vic. Date 4 March 2004

1. Birds become ill quickly – birds go from "normal" to "gravely ill" or "dead" within 24 to 48 hours
2. A majority of the flock is ill or dead
3. Serious respiratory signs are observed – swelling and redness ( or blotchy patches on the skin ) of the
   
   head, comb, wattles and neck
   
   - coughing, sneezing, rasping respiration
4. A rapid drop in feed intake, water intake and egg production is noted <
5. Occasional nervous signs ( head tilt, birds that cannot stand or walk ) are seen
6. Typical "sick bird" signs – ruffled feathers, depression, closed eyes, weakness – are seen in a lot of the birds
7. Watery diarrhoea is present

Remember AI is a notifiable disease, which means if you are suspicious that a flock may have AI then you must report immediately to your DPI.

Here are a few slides which might assist in visual diagnosis.








50 week old birds,Dead tissue on comb and wattles 7 days after infection via inhaled Influenza.







50 week old birds,Hemorrhage, dead tissue, swelling on comb and wattles 7 days after infection via inhaled Influenza







Hemorrhages in the fat arround the heart 4 days after infection via inhaled Influenza. It is the pin prick sized red spots in the white fat.


12 week old birds, 4 days after nasal infection



Same E  , 12 week old birds, 4 days after nasal infection


Which leads us to the next part for discussion.


It seems at this time that the jury s still out on whether different strains of fowls have different abilities to handle HPAI.

It seems some fowls can tolerate the virus with no ill effect, , but it may be that the commercial strains seem more susceptible just because they are kept in larger numbers, and so the levels of the organism tend to be higher.

Waterfowl appear mainly uneffected, but are carriers

Many wild birds can be carriers

Susceptibility seems to be related to intensity of housing, but findings again seem inconsistent. It does seem that at times the virus initially is mild but as it circulated it gains in pathogenicity that is the ability to cause major disease.

More research is needed to answer some of the questions of susceptibility.


The commonly accepted view is that HPAI is transmitted by migratory birds.

Australia is under threat at this time from H5N1 by migratory birds in two ways.

A/ The creeping approach. AI has an incubation time of 3 days up to 14 days. The incubation time is dependent on the dose of infection, route of infection, susceptibility of the host, and time taken to diagnose. So if there is to be a wild migratory bird carry the virus from Asia, it must come from a place of contamination to a susceptible host before it dies itself. If it is a really bad AI then it can only move on by steps, as no susceptible bird can fly much distance before being bumped off by the virus. However it conceivably infect another flock along the way, which could then move it along etc.

B/ The infected bird could be a carrier, non susceptible variety which has some co location with susceptible species at this end. Ie some ducks which could fly all the way into Victoria carrying the virus and land on your dam and contaminate your birds.

But there is another route

The other option for H5N1 is air travel by a carrier host who has visited one of the locations of high probability of contamination, like a wet market in Hong Kong, a wonderful location of the virus, a great place as a reservoir, 1 million people a week visit the market in Mon Gok, live birds are killed, scalded plucked and processed on the spot, heat, hosts, humidity,

picked up some manure on their shoes, inhaled some of the virus which is now resident in the nasal passages, hopped on the plane and 10 hours later landed in Oz, and proceeded to check out his chickens which he missed so much while away on holidays.

Which really brings me to the point of the major possibility of contamination.

I quote from the Biosecurity newsletter March 2004 put out by Biosecurity Australia the risk assessor for the Commonwealth of Australia "With 3000 seizures of eggs and poultry products by AQIS at airports and mail centres in the last 12 months there is concerns that it could be bought in with food. "

At this point a little history is important.

 

 

A Map of Asia,  Note the types of Avian Influenze in the route of migratory birds in our part of the world.

There have been outbreaks of AI in Australia in modern times. 1976, 1985, 1992, 1994, 1995 1997

 

1976 In Victoria in chickens and ducks H7N7 Early Seventies H7 Eastern Europe, but none in Asia at the same time

1985 in Victoria in Chickens and Starlings H7N7 but none in Asia at the same time

1992 in Victoria in Broiler Breeders and ducks H7N3 No H7N3 in Asia at the same time

1994 in Queensland chickens N7N3 but none in Asia

1995 in Queensland H7N3 layer hens none in Asia but H7N3 in Pakistan

1997 in NSW chicken emu H7N4 none in Asia but in South Africa H7N4

Please note not a H5N1 amongst them, but all the asian outbreaks are H5 outbreaks. According to Mr Ken Shortridge a world expert in this area,  H7 HPAI is absent from almost everything in Hong Kong, and weak non positive reactions in only in a few samples. So how does that explain the Australian outbreaks.

 

I have an alternative view. The outbreaks of H7N7, H7N3, H7N4 seem to mirror the outbreaks of those diseases in Europe, the USA and Africa.

Could this be a marker to tell us that really the problem is importation of poultry material form infected areas by personal courier or by mail. Both these routes are at this time subject to great scrutiny by AQIS. In the past, that scrutiny was arguable less stringent than it is today. It is also apparent from the seizures that this is still a major risk route.

An examination of the Los Angeles outbreak of Newcastle Disease is also illuminating. This outbreak makes a model for what might happen to us if there were an outbreak in suburban Melbourne. Literally hundreds of small poultry and bird keepers had their flocks destroyed in an effort to contain the problem. It seemed only partly effective. Later it was discovered that the source of the outbreak was illegally imported fighting cocks from Mexico. Because it was an illegal activity, when mortalities started to occur in those secret flocks, no report was made, allowing the disease to become established and eradication so much harder. The code of silence didn’t help either. So drastic measures were taken. It is a bit much to expect a person who has already broken the law, and found his illegally imported birds dying, to front to the authorities and risk a visit to gaol for his "honest reporting"..

The Dutch experience is a little less applicable to us in one sense because The Netherlands is comparatively a very small country with many more chickens per sq kilometre, indeed I think there is  no square kilometre of Holland  without thousands of chickens. This means a problem in commercial chickens was quickly spread not only across the commercial industry but the hobby as well.

I think it is reasonable to assume that if there is an outbreak of HPAI in Australia, it is likely that we will follow the American and Dutch models and slaughter all in sight.

Metropolitan outbreak slaughter all

Country outbreak containment area

Possibility of carriers

Negative effect on trade

There is another problem looming for us as small poultry people. Because we keep our birds outside, we are likely to have wild birds in contact with ours. This means that if there is a problem with wild birds, they me be close enough to us to provide the contact necessary to infect our poultry. So we should keep the wild birds out. Which has its own set of difficulties.

 

This has the effect of some sections of the commercial community ,as happened with Ben Wells at Pix just a few weeks ago, calling for the end to free range poultry in Australia in the name of biosecurity. The large commercial interests see us as just a nusiance. So we should be got rid off. Now in fairness I see many poultry yards, and I want to shut a few of them down, just like I see a few commercial farmers whom I think need to be shut down. But unless we have a voice which is united to defend our interests our hobby will pass out of our control and disappear. I don’t mean chook keeping will disappear, I think that’s here to stay, but it will be the 4 chickens specified by the local council, and the exhibitions, and shows today will be only a part of the good old days.

Recently, I was given all the research papers of a CSIRO geneticist in poultry from Sydney. In there was all the files of his involvement in the importation programs for chickens. He was heavily involved both in attempts to import pure breeds of poultry, and some years later in attempts to preserve the genetic stocks already in Australia.

I was startled to see that the CSIRO, AQIS, the DPI several of the Ag departments all advocating the legal importation of pure breed stocks. So why didn’t it happen?

In the government view, there is no formal organization in Australia which represents the hobby poultry industry and who can tell the government what the hobby industry wants, and what it will do in return. In short, the Government wanted us to tell them which birds we wanted, how many, from which countries, and they wanted us to tell them that if they did that,

"we would black ban any smuggler or smuggled birds."

 

No one on our side stood up and said

 

"I represent the poultry hobby community, I will ensure that smuggling becomes unacceptable,"

 

and so today we have no legal importation, we just the voices who say our hobby should be closed completely.

So imports didn’t happen.



 

You know at least once a month, often once a week I get a call that goes like this, "Do you have a book on Marans?" No, not specifically, what sort of info are you needing? "I have marans so I want to know more about them." Where did you get them? I didn’t think there was any in Australia. "O yes I bought them from a fellow who got them from a very sick little old lady out in the country back of Griffith ( they got everything in the country out the back of griffith) and the family can trace them back to the first fleet, but she was sick and has no children so she wanted to give them to someone before she died." Vary the the breed, varieties, no names no packdrill etc.

I hear this story regularly. Sometimes its just a con to sell some more mongrels, other times?? We all know the real story behind the breeds which magically appear because I just mated this with that and suprize a red headed, purple eyed bumpy comb, multicoloured wicker whatnot appeared after just one generation, or I’ve been working on them for 20 years, when no one ever heard of the breeder before.

This sort of reputation is one which will get our industry closed down.

Yet on the other side we have some encouragement. I am pleased to see Meg Miller approached about a program for good morning Australia. A welcome development. Well, I think we have something to do with that. It has long been an argument of mine that the royal shows are the place to influence the public in a positive way about our industry. A place to teach about chooks and to again establish in the publics mind.

The positive ideas of keeping chickens. One of the ways I have advocated that is public displays, two in particular, chook washing and commentaried judging demonstrations. Both of these have an element of showmanship, of the spectacle about them. Last year when I was not at Sydney Royal, the chook washing was tried as a public demo and ended up on Good morning Australia. This year it was 4 sessions a day, and I believe this is excellent PR for our industry.

These sessions were on every tv news bulletin, current affairs and today type shows, in the press, on the international wire service. The exposure allows us to portray a credible, useful message about the value of our hobby.

There is an upsurge of popularity in backyard poultry and purebreeds, see the upsurge in interest in Auctions.

There is significant negative industry pressure as outlined earlier

 
 

So what can we do?

Its sometimes easy to say what is wrong and not so easy to say exactly the right way to fix it. But I am prepared to venture some suggestions. If we are to defend our hobby from those who perceive it is best gone, we will need to have a credible industry. And I think these things will make up a credible industry

1. We need Codes of conduct of hobby poultry in particular with regards to housing, cleanliness, and management standards. Codes which are reasonable, enforceable and presentable to the local councils.
2. I think there is a need to rethink the recognition of pure breed breeders. Ie master stud breeder, breeder, exhibitor, hobbyist. The status of such titles linked not only to quality of birds and proven ability to breed, and technical knowledge, but to meeting standards of management and disease status.
3. Studies of the disease status of Australian pure breed flocks. This could also include studies on disease resistance to major exotics. From this can flow education based on knowledge not on probability, and allow defence on the grounds of science not emotion. And I think the work we did a couple of years ago in Melbourne is an interesting piece of that puzzle.
4. A reliable public relations program to present pure breed poultry as desirable and essential for the future of our society. A combines approach which sees us presenting an image of value to the public, not a spin image, a true and fair image. It is only from there that more will keep chickens and so support our cause. I believe the Royals form part of that opportunity.
5. I think we need to put legal importation back on the agenda, as long as we are willing to follow the other parts of that equation, that is make it so politically incorrect to import. We need to development an Australian Breeds and varieties list.
   
   We need to have a process which enables the persons doing fair dinkum redevelopment work like the Brahma club, but at the same time we need to slam the lid on doing it the easy but illegal way. Remember when its illegal, if there is a mistake and a disease comes in where all the birds die, likely it will be hidden until its too late.

How can this happen, what it will need?

•  
  • time,
  • money,
  • workers,
  • political support, and
  • a fair deal of determination.
  • It will need a national body representing poultry hobbyists, with a committee able to spend money on the issues, brains to be able to properly develop the issues, brawn to carry them out, legal clout to make enforceable codes of conduct, it will need democratic support, it will need clean hands on the part of those involved. It will need to focus more of the grand issues rather than the minutae of whether the barr on the rock is too wide or too narrow, the standard for the serration on the comb is deep, too deep or not deep enough., or whether a bird is a few grams heavy or light.They may be important issues but we are in danger of concentrating on the colour of the feather left behind after the fowl has flown away and been eaten by the fox.

In short we need to continue the work started by the idea of a national poultry standard, and move it to a national pure breed poultry association.

I hope this study of a clear and present danger will encourage some lateral thought and action before it is too late.