Presentation on theme: "Avian Influenza Symptoms in Birds Texas A&M University College of Veterinary Medicine College of Veterinary Medicine."— Presentation transcript:
Avian Influenza Symptoms in Birds Texas A&M University College of Veterinary Medicine College of Veterinary Medicine
2006 Avian Influenza This presentation is about Avian Influenza as it affects birds Clinical Symptoms of Avian Influenza
2006 Avian Influenza A contagious viral infection and/or disease of many avian species including poultry, wild and exotic birds, ratites, shore birds and migratory waterfowl. The highly pathogenic form of the disease is characterized by severe depression, decrease in egg production, high mortality, edema, hemorrhage, and frank necrosis. All H5 and H7 infections are reportable to the World Organization for Animal Health (OIE). Dennis Senne 2005
2006 Avian Influenza Low pathogenic avian influenza (LPAI) –Associated with mild illness in poultry –Can evolve into highly pathogenic viruses –Associated with poultry outbreaks worldwide High pathogenic avian influenza (HPAI) –Causes high mortality in domestic poultry –Subtypes H5 and H7
2006 Avian Influenza H5N1 virus electron micrograph of avian influenza H5N1 virus
2006 Avian Influenza Host Range Host Range Exotic BirdsExotic Birds Domestic PoultryDomestic Poultry
2006 Avian Influenza Peri-domestic species Occasional isolations of avian influenza virus from starlings and house sparrows (in contact with infected poultry) Replication of some avian influenza virus in these species (experimental)
2006 Avian Influenza Natural Reservoirs of Influenza A Viruses Wild aquatic birds Majority are represented by two Orders: by two Orders: 1. Anseriformes (ducks, 1. Anseriformes (ducks, geese, and swans) geese, and swans) Dennis Senne 2005
2006 Avian Influenza Natural Reservoirs of Influenza A Viruses 2.Charadriiformes (gulls, terns, and shorebirds) Usually show no Usually show no clinical disease clinical disease Dennis Senne 2005
2006 Avian Influenza The Muscovy Ducks Natural Reservoir
2006 Avian Influenza How are these viruses transmitted and maintained in these species? Transmission: Fecal/Oral route Heavy fecal shedding by infected ducks Long term persistence in water Isolation of AIVs from surface water Maintenance: Bird to bird Persistence in environment
2006 Avian Influenza Clinical Signs Incubation period 3-5 days Severe depression Decreased food and water consumption Drastic decline in egg production Many birds affected
2006 Avian Influenza Turkeys with Avian Influenza Many birds are depressed and huddling cvm.umn.edu
2006 Avian Influenza Clinical Signs DehydrationHuddling Subcutaneous swelling of the head and neck area Nasal and oral cavity discharge
2006 Avian Influenza Note swollen head, and discharges. Wattle is cyanotic and necrotic.
2006 Avian Influenza
2006 Avian Influenza Clinical Signs Huddling
2006 Avian Influenza Clinical Signs Ruffled feathers Swollen, cyanotic (blue) combs and wattles Conjunctivitis with respiratory signs
2006 Avian Influenza Clinical Signs CoughingSneezingDiarrhea Sudden death
2006 Avian Influenza Clinical Signs Huddling Sinusitis Respiratory signs D. Halvorson I. Capua D. Halvorson
2006 Avian Influenza
2006 Avian Influenza Clinical Signs Sudden onset and high mortality Birds found dead Dennis Senne, 2005
2006 Avian Influenza Post Mortem Lesions Post Mortem Lesions Lesions may be absent with sudden death
2006 Avian Influenza Lesions Head and neck edema Swollen and cyanotic combs and wattles Petechial hemorrhages on internal membrane surfaces
2006 Avian Influenza
2006 Avian Influenza Lesions Excessive mucous exudate in the lumen of the trachea, or severe hemorrhagic tracheitis Petechiae on the inside of the sternum, on the serosa and abdominal fat, serosal surfaces and in the body cavity
2006 Avian Influenza Lesions HPAI - Opened swollen wattle.
2006 Avian Influenza Hemorrhages and edema
2006 Avian Influenza Edema
2006 Avian Influenza Petechial hemorrhages on internal membrane surfaces
2006 Avian Influenza Lesions Hemorrhages of the trachea
2006 Avian Influenza Hemorrhages of the trachea
2006 Avian Influenza
2006 Avian Influenza Lung hemorrhage and edema
2006 Avian Influenza Note hemorrhages and edema around the heart
2006 Avian Influenza Lesions Hemorrhages on the mucosal surface of the proventriculus, particularly at the juncture with the gizzard Hemorrhages and erosions of the gizzard lining Hemorrhagic foci on the lymphoid tissues in the intestinal mucosa
2006 Avian Influenza Hemorrhages of the intestine
2006 Avian Influenza Hemorrhages on the mucosal surface of the mucosal surface of the proventriculus, particularly at the juncture with the gizzard
2006 Avian Influenza Hemorrhage in intestinal serosa, mucosa
2006 Avian Influenza Hemorrhagic foci on the lymphoid tissues in the intestinal mucosa
2006 Avian Influenza Lesions Severe congestion of the musculature
2006 Avian Influenza Lesions Severe kidney congestion, sometimes with urate deposits in the tubules Hemorrhages and degeneration of the ovary
2006 Avian Influenza Differential Diagnosis Clinically indistinguishable from virulent Newcastle Disease Suspect with: Sudden death Drop in egg production Facial edema, cyanotic combs and wattles Petechial hemorrhages
2006 Avian Influenza Differential diagnosis Water deprivation Heat exhaustion Toxins – food or water borne
2006 Avian Influenza Disease Summary Avian influenza is a contagious viral disease of birds characterized by respiratory signs, depression and reduced feed and water intake. In egg laying birds there is a decline in egg production and quality. There are two pathotypes of Avian Influenza virus: the most common is low pathogenic AI (LPAI) and the other is highly pathogenic AI (HPAI).
2006 Avian Influenza Disease Summary The most virulent form (HPAI) was once called fowl plague. At the 1981 International Symposium on Avian Influenza, the term fowl plague was replaced with the term "highly virulent" influenza virus infection. The Avian Influenza epidemic of required yet new terms to describe relative pathogenicity of different isolates of the same serotype (nonpathogenic, low-pathogenic, highly pathogenic).
2006 Avian Influenza Disease Summary Avian Influenza outbreaks have occurred throughout the world. LPAI is common in large turkey-producing areas, particularly where semi- confinement or range-rearing is still widely practiced. Outbreaks are more sporadic in other areas of the United States. AI can occur in most, if not all, species of birds. In the United States, most outbreaks have been in turkeys. A few outbreaks have occurred in chickens. Humans, horses, pigs, and some wildlife species may be infected with influenza viruses, and a cycle between birds and swine exists.
2006 Avian Influenza Disease Summary A chicken outbreak of LPAI in 1983 mutated into HPAI in resulting in a federal-state eradication program that required the depopulation of 17 million birds. Similar outbreaks of LPAI in Mexico in 1992 and Italy in 1999 also mutated into HPAI causing severe losses.
2006 Avian Influenza Disease Summary Influenza viruses vary widely in pathogenicity and ability to spread among birds. Two pathotypes are recognized: LPAI and HPAI. These pathotype designations are derived from laboratory inoculation of 8 susceptible chickens; LPAI isolates cause death in 0 to 5 of 8 chickens and HPAI isolates cause death in 6 or more. Although most H5 and H7 isolates are low path viruses, so far all HPAI outbreaks have been due to H5 or H7 viruses.
2006 Avian Influenza Special thanks to the staff at Plum Island Animal Diagnostic Center, Dr Corrie Brown and Dr John El-Attrache for the use of images from their presentations. Also, thanks to the Pohler family and to Elisabeth Bush for allowing me to photograph their birds. SUZANNE BURNHAM