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Detecting and Preventing Disease - Introduction
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Detecting and Preventing Disease - Introduction • Worldwide, END and HPAI have been responsible for devastating disease outbreaks in commercial poultry production as well as in backyard flocks. The U.S. and other countries with modern production systems control such outbreaks through government programs that relate to trade restrictions and the destruction of infected flocks. • By the end of this lesson, you will be able to: • Define the causative agents of diseases • Define how a virus operates and spreads in the environment • Discuss one example of how an outbreak of disease in animal agriculture impacts the economy • Understand the difference between an animal carrying a disease agent and exhibiting the clinical signs • Define and list the actions to take if the clinical signs of END and AI are recognized • Identify the clinical signs for END and AI in poultry • Know what to do to prevent the spread of END and AI
Causative Agents and Signs of END • Exotic Newcastle Disease: • Is a contagious and fatal viral disease • Affects all species of birds • Is so deadly that many birds die without showing any signs of disease • Can be found worldwide • Clinical Signs of END • END affects your birds' respiratory, nervous and digestive systems. The incubation period for the disease ranges from 2 to 15 days. An infected bird may show the following signs: • Sneezing, gasping for air, nasal discharge and coughing • Greenish, watery diarrhea • Depression, muscular tremors, drooping wings, twisting of head and neck, circling and • complete paralysis • Egg production may either drop partially or stop completely • Production of thin-shelled eggs • Swollen tissues around the birds' eyes and neck • Sudden death • Increased flock deaths
How END Spreads • END spreads chiefly through the bodily discharges of infected birds to healthy birds. It • spreads rapidly among birds kept in confinement, such as commercially raised chickens. • Because high concentrations of the END virus are in bodily discharges of birds, the disease • also can be spread easily by people and equipment. • Mechanical means • Tractor • Truck • Shovels • Buckets • Farm owners and visitors • Non-Mechanical means • Shoes and clothing • The droppings of infected birds • Secretions from the nose, mouth and eyes of infected birds • Survival Period of the END Virus: • This virus can survive in a warm and humid environment for several weeks. This environment • could be birds' feathers, manure and other materials.
Causative Agents and Signs of AI • Domestic poultry is vulnerable to avian influenza (AI). Most AI strains are classified as low pathogenicity avian influenza (LPAI), and cause few clinical signs in infected birds. In contrast, high pathogenicity avian influenza (HPAI) causes a severe and extremely contagious illness and death among infected birds. • Clinical Signs of AI • The clinical signs of birds affected with all forms of AI may show one or more of the following: • Sudden death without clinical signs • Lack of energy and appetite • Decreased egg production • Soft-shelled or misshapen eggs • Swelling of the head, eyelids, comb, wattles and hocks • Purple discoloration of the wattles, combs and legs • Nasal discharge • Coughing and sneezing • Lack of neural coordination
Classification of AI • Based on the severity of the illness they cause, AI viruses can be classified into: • High Pathogenicity (HPAI) form: This is a very infectious and fatal form of the • disease that, once established, can spread rapidly from flock to flock. HPAI can lead • to high mortality • Low Pathogenicity (LPAI) form: Here, under field conditions, virus strains are • capable of mutating into HPAI viruses, which lead to greater illness among infected • birds
How AI Spreads • AI viruses are spread through: • Exposure of poultry to waterfowl • Illegal movement of poultry • Contaminated poultry equipment, manure, vehicles, egg flats, crates and people • whose clothing or shoes have come in contact with the virus
Be Alert! Birds Can Look Healthy But Be Carrying Disease Birds can appear healthy, yet be carrying a virus. For example, psittacine birds, such as parrots, can carry the END virus, yet not show clinical signs. Birds with low-path AI may appear healthy or have mild illness, however, LPAI can cause mild clinical signs such as some facial swelling, respiratory signs, and a slight drop in egg production. Birds with high-path AI usually have visual clues (such as nasal discharge and lack of energy and appetite) that indicate they are sick. Sudden deaths are another indication of HPAI.
Preventing an Outbreak of HPAI • To prevent an outbreak of HPAI on your farm, poultry producers should practice biosecurity • measures. These are some sound biosecurity practices: • Keep Your Distance: • Restrict access to your property and your birds • Consider fencing off the area where you keep your birds and make a barrier area if • possible. Allow only people who take care of your birds to come in contact with them • If visitors have birds of their own, do not let them near your birds • Game birds and migratory waterfowl should not have contact with your flock because they • can carry germs and diseases • Keep It Clean: • Wear clean clothes. Scrub your shoes with disinfectant • Wash your hands thoroughly before entering your bird area • Clean cages and change food and water daily • Clean and disinfect equipment that comes into contact with your birds or their droppings, • including cages and tools • Remove manure before disinfecting • Properly dispose of dead birds
Don't Haul Disease Home: • If you have been near other birds or bird owners, such as at a feed store, clean and • disinfect car and truck tires, poultry cages and equipment before going home • Have your birds been to a fair or exhibition? Keep them separated from the rest of your • flock for at least two weeks after the event • New birds should be kept separate from your flock for at least 30 days • Don't Borrow Disease From Your Neighbor: • Do not share lawn and garden equipment, tools, or poultry supplies with your neighbors or other bird owners • If you do bring these items home, clean and disinfect them before they reach your property
Know the Warning Signs of Infectious Bird Diseases • Sudden increase in bird deaths in your flock • Sneezing, grasping for air, coughing and nasal discharge • Watery and green diarrhea • Lack of energy and poor appetite • Drop in egg production or soft- or thin-shelled, misshapen eggs • Swelling around the eyes, neck, and head • Purple discoloration of the wattles, combs, and legs (AI) • Tremors, drooping wings, circling, twisting of the head and neck, or lack of • movement (END) • Early detection is important to prevent the spread of disease. • Report Sick Birds • Don't wait. If your birds are sick or dying call: • Your local cooperative extension office, or • Local veterinarian, or • The state veterinarian, or state animal diagnostic laboratory, or • U.S. Department of Agriculture • (USDA) Veterinary Services office: • - Toll-free hotline (1-866-536-7593) • - There is no charge for this service
AI and Human Health For information about AI and human health, see the Centers for Disease Control website at http://www.cdc.gov/flu/avian/
END and Human Health • END: • Is only an avian disease • Is not a threat to human health • May cause mild conjunctivitis for about two or three days
Types of Birds Affected by END and AI • Birds Affected by END • END is contagious and can kill all species of birds. It is one of the most infectious poultry diseases in the world. • Poultry hobbyists and owners of pet birds should be especially careful. Birds illegally smuggled into the United States are not quarantined and tested by the USDA and therefore may carry the END virus. If you buy a pet bird be sure to request certification that the bird has been legally imported or is of U.S. stock. • Birds Affected by AI • AI viruses can infect chickens, turkeys, pheasants, quail, ducks, geese, guinea fowl as well as • a wide variety of other birds. Migratory waterfowl can be infected with AI and END.
Economic Impact of Major Poultry Diseases • California • 1971-1973 (END): • 11.9 million birds either died or were destroyed • Cost: $56 million • 2002-2003 (END): • 3.4 million birds either died or were euthanized • Nationwide cost: $170 million • 5,352 federal employees, 2,338 state and local employees • Pennsylvania • 1983 outbreak (mutated to highly pathogenic strain - H5N2): • 22 million birds • Over $100 million • 2001 outbreak of low-pathogenic H7N2 avian flu: • 140,000 birds • $350,000 • Florida • 1980 (END): • 8,000 cage birds died • 30,307 birds had to be euthanized in 23 states • Cost: $1.66 million
What Happens in an OutbreakIn the event of an outbreak of HPAI and END, federal and state officials are likely to use tools such as quarantine, flock depopulation, and control of product movement to prevent the spread of the virus. • Animal health officials may: • Quarantine the affected areas • Monitor the uninfected birds for clinical signs until the quarantine is lifted • Humanely depopulate the infected birds in order to prevent its further spread • Remove carcasses of the birds from the premises in a manner that prevents the spread of infection. Clean and disinfect the area as quickly and thoroughly as possible
Identification of END and AI in Poultry • Diagnosis for these diseases is made at state, university or federal laboratories: • Clinical signs or testing of blood samples will provide evidence of the presence of a infection • A definitive diagnosis can be made on live birds by taking a tracheal, oropharyngeal or cloacal swab and identifying the virus • If birds are dead, the laboratory can sample respiratory or digestive system tissue or use tracheal, oropharyngeal, or cloacal swabs to identify the virus sample
How to Safeguard Your Birds Against an Outbreak of END and AIPracticing biosecurity is a means of protection against AI and END. • Precautions:END is a threat to birds. All bird owners should take the following precautions to avoid an outbreak of this disease: • Ask bird suppliers for copies of paperwork that prove their birds are imported into the United States legally or are from U.S. stock, were healthy before being shipped, and were transported in new or thoroughly disinfected containers • Keep records of all sales, shipments, and movements of birds • Separate all newly purchased birds from older ones for at least 30 days. Examine the new birds, checking for any signs of disease or illness before introducing them into your flock • Remember to practice the six biosecurity steps
SummaryEND and HPAI are the most infectious poultry diseases in the world. These diseases attack most species of birds. The outbreak of END in California and other western states in 2002 cost them and the Federal government over $170 million. It also cost countless bird and poultry owners their pets, and in some cases, their livelihoods.Therefore, the best way to prevent these diseases is by practicing good biosecurity.In this lesson, you learned about the: • Causative agents of END and AI • Type of birds affected by END and AI • Global nature of END and AI and the economic impact on the U.S. poultry industry • Clinical signs of END and AI • Difference between high-pathogenicity and low-pathogenicity • Actions to take if the clinical signs of END and AI are recognized • Process used to identify END and AI in poultry • Prevention of the spread of END and AI
How to Safeguard Your Birds Against an Outbreak of END and AI • Biosecurity is the only practical protection against an outbreak of AI or END. • Precautions: • All bird owners should therefore take the following precautions to avoid an outbreak of this disease: • Ask bird suppliers for copies of paperwork that proves their birds are imported into the United • States legally or are from U.S. stock, were healthy before being shipped, and were transported • in new or thoroughly disinfected containers • Keep records of all sales, shipments and movements of birds • Separate all newly purchased birds from older ones for at least 30 days. Examine the new • bird, check for any signs of disease or illness before introducing it into your flock
Summary • END and HPAI are the most infectious poultry diseases in the world. These diseases attack most species of birds. The outbreak of END in California and other western states in 2002 cost them and the Federal government over $170 million. It also cost countless bird and poultry owners their pets, and in some cases, their livelihoods. • Therefore, the best way to prevent these diseases is by practicing good biosecurity. • In this lesson, you learned about the: • Causative agents of END and AI • Type of birds affected by END and AI • Global nature of END and AI and the economic impact on the U.S. poultry industry • Clinical signs of END and AI • Difference between high-pathogenicity and low-pathogenicity • Actions to take if the clinical signs of END and AI are recognized • Process used to identify END and AI in poultry • Prevention of the spread of END and AI
Choose the correct answer 1. The following are Clinical signs of END: • Sudden death • Production of thick-shelled eggs • Drooping wings • Swollen tissues around the bird’s eye and neck • Mild conjunctivitis • Greenish, watery diarrhea • Complete paralysis Correct Answer: Sudden death, Drooping wings, Swollen tissues around the bird’s eye and neck, Greenish, watery diarrhea, Complete paralysis