Table of Contents
Poultry Diseases of Sixties to Eighties, Retrospective Review
History of Newcastle disease in Australia
History of Avian Influenza in Australia
International experience with AI
A SHORT HISTORY OF MAREK’S DISEASE IN AUSTRALIA
History of ILT in Australia
Influence of viral strain and route of inoculation in the transmissibility of infectious laryngotracheitis virus (ILTV) vaccines
Reproduction ratios of ILTV in field and experimental settings
What have we learnt from full genome sequence of the Australian ILTV strains?
Differential expression of ILTV genes and its relevance to virulence
History of avian mycoplasmosis in Australia
Influence of GAP-A gene expression in serological response to ts-11
History of Pasteurellosis and Infectious Coryza in Australia
Rapid multiplex PCR assay for typing Pasteurella multocida isolates
New findings on necrotic enteritis
Enteric viruses of chickens and turkeys
History of IBV in Australia
Characterisation of a dominant vaccine-derived quasi-species in the IBV VicS vaccine
Analysis, attribution and food safety
Campylobacter; New Zealand Style, The Last 5 Years, A Processors Perspective
New Issues with Salmonella
Salmonella enterica Serovar Sofia Virulence Factors
What customers tell us – Eggs and Chicken Meat
From one species to another – can Avian Pathogenic E. coli cross that road?
Does the Australian poultry industry really need an E. coli vaccine?
Poulvac® E.coli vaccine.
Candidate APEC E. coli vaccines lacking tonB and fur genes
Changes in regulatory requirements for registration of immunobiological products (vaccines)
What does it mean to be a minor species?
Application of metagenomics in poultry research
Paramyxoviruses isolated recently from Victorian pigeons
The Biosecurity of Mass Poultry Mortality Composting
Some unique things about the Australian poultry industries
1
Invited Speakers
Professor Peter Doherty
Professor Peter Doherty won the Nobel Prize in Physiology or Medicine in 1996, for the discovery of how the immune system recognises virus-infected cells. He was Australian of the Year in 1997, and has since been commuting between St Jude Children’s Research Hospital in Memphis and the Department of Microbiology and Immunology at the University of Melbourne. His research is mainly in the area of defense against viruses.
Peter Doherty graduated from the University of Queensland in Veterinary Science and became a veterinary officer. Moving to Scotland, he received his PhD from the University of Edinburgh Medical School. He is the first person with a veterinary qualification to win a Nobel Prize.
Professor Peter Doherty is also the author of several books, including “A Light History of Hot Air” and “The Beginners Guide to Winning the Nobel Prize”. One of his earlier publication is titled “Occurrence of Avian Infectious Bronchitis Virus in the Tissues of Experimentally Infected Chickens” in 1967.
Dr Michael Day
Dr. Day has 15 years of research experience in the biological sciences. He began his research career at Virginia Commonwealth University in Richmond, Virginia, where he developed quantitative and conventional PCR assays to detect and quantify the oyster parasite Haplosporidium nelsoni (the MSX disease agent) in the Chesapeake Bay. His graduate research continued at Miami University in Oxford, Ohio where he optimized molecular and biochemical techniques to study unusual pathways of ribosome binding and gene expression in the bacteria Streptomyces lividans and Escherichia coli. Dr. Day joinedSEPRL (ARS/USDA) in 2004 and has been since involved in characterising novel reoviruses in turkeys, and continued to work with poultry enteric viruses as a lead scientist in the Endemic Poultry Viral Diseases research unit at SEPRL.
Abstracts
Poultry Diseases of Sixties to Eighties, Retrospective Review
Balkar S. Bains
The emergence and rapid growth of broiler industry experienced the emergence of several diseases, which previously were not present or diagnosed in commercial poultry flocks. During the early development period of the broiler industry, there were more veterinarians employed in the control and treatment of diseases in broiler flocks than any other time in the short history of broiler industry. During this period veterinary schools began to focus a little more in the poultry diseases but the Agriculture colleges in various states increased their focus much more in poultry husbandry and diseases course. The graduates from various colleges were employed in the broiler industry to focus on the husbandry and clinical diagnosis of current diseases and work as assistants to the veterinarians. This period also will be remembered for the emergence of private diagnostic laboratories and research activities within the major broiler companies. The objectives of the diagnostic laboratories was to provide rapid response to confirm field diagnosis and investigate causative agents in the emerging diseases and where possible recommend appropriate control measures.
The genetic development of the broiler chicken was mainly carried out by the major companies in New South Wales and therefore controlled the supply of day old chickens for commercial broiler breeder flocks. The unintended consequences of the controlled supply of day old chickens from New South Wales, was that the recipient states also received all the infectious agents that were vertically transmitted from the parent breeder flocks. This factor has been very significant in the recipient states to limit their ability to control and prevent the diseases in their local flocks. The veterinarians employed by major companies were relatively inexperienced and thus faced a period of rapid learning for an extended period. The government laboratories were willing and helpful when ever their services were needed. This review is intended to just mention the most significant diseases as to their incidence and no attempt is made to provide details in this summary. The diseases are grouped in the order of category from highly significant to relatively low significance in both economic and treatment and control measures.
Category 1
Pullorum
Pullorum was the first significant disease in early sixties that was spread from parent breeding companies in NSW. Its eradication by 1968 only become possible following the recognition and production of new antigen derived from the new serotype of S.pullorum isolated from field cases of the disease. At this time the poultry industry act was also reviewed and changed to allow non veterinarian persons be permitted to carry out whole blood agglutination test under the supervision of a veterinarian or a person approved by a veterinarian. The ultimate responsibility of reporting remained with the veterinarian who is to sign the document for submission to the appropriate government department.
Infectious bronchitis Uraemia
This was a new disease to everyone, there was nothing published or found in the usually preferred text books on poultry diseases at that time. It was learning on the job and a painfully slow process. Through the combined efforts of researchers the causative agent was identified to be a virus. There was no commercial vaccine available for the control and prevention of this infection. The diagnostic laboratories in each company isolated their own strain of virus and appropriately attenuated for vaccine production. In QLd, I was able to isolate a local virus strain from infected kidneys in a broiler chicken and attenuated the virus by 48 embryo passages. This attenuated strain was then used as a seed material for production of local vaccine in 1968 for use in company controlled broilers and breeder flocks. The vaccine was successful in the control and prevention of the disease with the exception of two large multiage broiler farms that could not be operated as all – in – all - out basis. This locally produced vaccine was used till the commercial vaccine was available late in seventies.
Mycoplasma gallisepticum
The frequent occurrence of Colibacillosis in broiler flocks was recognized as a secondary infection to M.gallisepticum (MG) infection. The dual infection commonly referred as CRD was prevalent in all commercial flock. Tylosin was the preferred prophylactic medication via drinking water to control MG infection. The eradication of MG from commercial flocks was not successful and the prophylactic medication with Tylosin was the preferred option in broiler and breeder flocks.
Paratyphoid infection
Towards the end of sixties S.typhimuriumbecame prevalent in broiler flocks with significant mortalities in commercial broiler flocks. The infection is vertically transmitted and there were no tests to eliminate carrier hens from the flock. The carcass contamination risk was high and therefore a major effort was devoted to minimize the risk of carcass contamination and control of S.typhimurium in broiler flocks. The epidemiological studies confirmed the wide spread presence of the organism in poultry and its environment.
Marek’s disease (MD) & Lymphoid Leucosis (LL)
Both of these infections were prevalent in all broiler and breeder flocks. The MD lesions in broiler chickens could be observed as early as 4 weeks of age. The accepted mortality in laying period was in the order of 1.5% per month. The negative impact due to immunosuppressive effect probably was more significant than actually appreciated at that time. The vaccine for the control of MD was available in early seventies.
Tenosynovitis
This virus infection suddenly appeared in early seventies in both broiler and breeder flocks. Te causative agent was readily identified but its origin certainly remained a mystery.
Infectious Bursal Disease (IBD)
The first evidence of bursa atrophy was observed in mid seventies and the problem was soon recognized in all commercial broiler and breeder flocks. The sudden emergence of IBD virus infection was a mystery.
Inclusion Body Hepatitis (IBH) & Infectious anaemia
Both of these diseases were diagnosed in the field in mid seventies and the origin and spread of these infections probably was never determined. It might have been coincidence that these infections followed the spread of IBD virus and its increased pathogenicity over time.
Ascites and Sudden death Syndrome
Accompanied the genetic progress the incidence of both Ascites and sudden death syndrome began to cause serious economic loss to the broiler industry.
Exotic Diseases
The serological evidence identified the presence of Newcastle disease (V4 strain) in Qld in mid sixties. There was a fierce debate on the possibility of quarantine orders to be issued but it was delayed till similar testing was completed in other states. Ultimately it was confirmed that V$ strain was wide spread in commercial broiler poultry.
In Qld ILT was a notifiable disease and no vaccination was allowed with departmental approval. The clinical cases of ILT were not observed till late seventies and early eighties.
Category 2
This group includes those diseases that were endemic and effectively controlled by vaccination and feed medication.
Fowl Pox and Avian Encephalomyelitis
Fowl pox was effectively controlled by vaccination but Avian encephalomyelitis outbreaks were some way responsible for the spread of the virus in susceptible flocks and thus leaving them immune for a considerable period post infection.
Coccidiosis
Coccidiosis outbreaks were frequent and for the control measures chemical anticoccidial were used in feed till 1973, then on Ionophore anticoccidials via feed medication provided a better control and significantly reduced the clinical outbreaks requiring treatment.
Necrotic Enteritis (NE)
NE was a new disease emerged during 1967 and causative agent identified as Clostridium perfringens. Clinical cases were treated with Bacitracin via drinking water and Bacitracin was used in feed as a preventative medication. The emergence of gangrenous dermatitis probably correlated with emergence of IBD virus during seventies.
Histomoniasis
Histomoniasis emerged as a significant disease in broiler flocks about 1973. Its incidence in broiler flocks lasted about three years and then declined and virtually disappeared. Both emergence and disappearance of the infection remained a mystery.
Skeletal abnormalities
The skeletal defects such as Spondylolisthesis and Dyschondroplasia began to emerge a serious problem that affected the locomotion in broiler flocks. Since no causative agent either infections or nutritional could be identified the possible role of genetic was popularly conceived. The incidence of Twisted tibia, Femoral head necrosis and slip tendonswere commonly observed.
Category 3
This group includes those infections that occurred infrequently and were not considered to be a major problem in broiler flocks.
Coryza
Coryza was mainly observed in commercial layer flocks and occasionally in breeder flocks. The individual bird treatment by Streptomycin S/Cu injection was the preferred and successful in controlling the infection.
Cholera
Apart from some outbreaks of the disease in turkey poults in sixties, the disease was occasionally observed in broiler breeder flocks. The treatment of choice was sulpha drugs with mixed success and control was mainly with use of autogenous vaccine.
Synovitis
The M.synoviae infection was observed towards the late seventies but never considered as of serious consequence in broiler flocks.
Category 4
Swollen Head Syndrome (SHS)
The SHS was first observed in early seventies in field cases but no pathogen associated with the disease was identified. The clinical observations were not considered to be of any significance at that time and regarded as being isolated case of unknown infection.
Reticuloendotheliosis Virus Infection (REV)
The REV infections resulted from the use of contaminated vaccine administered to day old chickens. The clinical disease was spectacular with very high morbidity and mortality. It took some time to identify the causative agent and the source of infection. Eliminating contaminated vaccine ultimately eliminated the disease. The ultimate production of vaccines in SPF eggs was triggered by the spread of REV via vaccine.
Category 5
Nutritional deficiencies
Vitamin A deficiency disappeared once the on farm mixing of feed replaced with the manufactured feed. The deficiency of Thiamin and Riboflavin were observed in breeder day old chickens and some time in breeder pullets. The appropriately administered respective vitamins via drinking water often result in complete recovery. The vitamin D3 deficiency was observed only occasionally, however the association of D3 as potential cause of Tibial Dyschondroplasia was never confirmed. The deficiency of vitamin E was observed in older birds and occasionally in chicks under two weeks of age. The Selenium was not a standard inclusion in feed till the Selenium deficiency was confirmed in broiler breeder flock in early seventies.
Fatty Liver and Kidney (FLKS) disease was proven to be Biotin deficiency in young broiler chickens, did cause severe mortality between 2-3 weeks of age broilers. Fatty liver in layer flocks often observed and thought to be choline deficiency.
Category 6
Parasites
The intestinal parasites in all commercial flocks were commonly observed and standard medication procedures were in place to minimize economic impact and spread of infection. The external parasites such as Lice infestation occurred in breeder flocks that warranted the use of approved treatments and appropriate prevention measures.
Category 7
Toxicity
Toxicity caused by some feed additives such as 3-nitro causing leg weakness or ataxia, a combination of Neftin and DOTincompatibility causing deaths in young chickens. Nicarbazin under excessive heat conditions and Monensin overdoses resulting deaths in broilers. The potential of Mycotoxins in feed was less well understood and rarely diagnosed.
Wet Litter
The incidence of wet litter was at its highest during winter months as a consequence of IB Ureamia and accompanied by the use of electrolytes to replace electrolyte balance and flush out uric acid from kidneys. The role of enteric virus infections as potential cause of wet litter was not well understood or investigated.
History of Newcastle disease in Australia
Paul Selleck
CSIRO, Australian Animal Health Laboratory
Newcastle disease was first identified in Indonesia in 1926, but was soon identified in many other countries, including England. The first reported outbreak of virulent ND in Australia was in Victoria in 1930, followed by a second outbreak caused by the same virus in 1932. From 1932 to 1966 Australia remained free of ND. In 1966 a shipment of chickens exported to Malaysia were identified as being infected with ND virus. This resulted in surveillance for ND in Australian that lead to the isolation and identification of the V4 strain in Queensland, and many other ND strains in Australia. During the 1970’s 1980’s and 1990’s many more ND viruses were isolated from both commercial poultry and wild birds. In 1998 Australia experienced another outbreak of virulent ND in Dean Park, Western Sydney. The virus responsible for this outbreak had been circulating in commercial poultry since the 1980’s as a respiratory virus and acquired virulence through two nucleotide mutations resulting in two amino acid changes in the fusion protein cleavage site. Multiple outbreaks occurred in chickens in the Mangrove Mountain area of Western Sydney and in Tamworth for over two years. Vaccination of chickens against ND was approved in 2001 and a 2002 survey of the poultry industry showed the presence of many genotypes of lentogenic NDV but no velogenic ND. The final recorded occurrence of a Peat’s Ridge-like virus was in commercial chickens at Meredith, Victoria in 2002. Ongoing surveillance for avian influenza in commercial poultry and wild birds has seen the subsequent isolation of many ND viruses. In 2011 an outbreak of velogenic ND occurred in pigeons, which has subsequently become widespread. This paper gives information on the Australian ND viruses and their relationships with ND viruses from other parts of the world.
History of Avian Influenza in Australia
Andrew Turner
Avian Influenza has come to be the most common poultry disease and this has come about due to the intensification and explosion in the poultry population over the last 50 years. Common before the 1920s, Highly Pathogenic Avian Influenza (HPAI) disappeared as Newcastle disease became the predominant epidemic avian virus infection.
Outbreaks of HPAI commenced again in 1957 in Scotland and 18 outbreaks followed in temperate climate countries until 1994. From 1994 outbreaks have escalated until in 2011 outbreaks on H5N1 and H9N2 occur nearly daily throughout most of Asia and parts of Africa.