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Zoonotic Diseases. Zoonotic Diseases of Avian Origin. What is Zoonosis? A disease of animals that can be transmitted to humans Zoonotic Diseases: Diseases of reasonable significance Infrequent, rare or potential diseases Infrequent or potential diseases indirectly associated with birds.
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Zoonotic Diseases of Avian Origin • What is Zoonosis? A disease of animals that can be transmitted to humans • Zoonotic Diseases: • Diseases of reasonable significance • Infrequent, rare or potential diseases • Infrequent or potential diseases indirectly associated with birds
Zoonotic Diseases • Result from a variety of causes, infectious and non-infectious. • Infectious: bacterial, viral and parasitic agents. • Non-infectious: nutritional imbalance or mycotoxicosis.
Diseases of Reasonable Significance • Infrequent or Potential Diseases Indirectly Associated with Birds • Infrequent, Rare or potential Diseases
Diseases of Reasonable Significance • Chlamydiosis • Salmonellosis • Campylobacteriosis • Yersiniosis • NewCastle Disease • Allergic Alveolitis • West Nile encephalitis
Infrequent or Potential Diseases Indirectly Associated with Birds
Infrequent or Potential Diseases Indirectly Associated with Birds • Staphylococcal food poisoning • Aspergillosis • Histoplasmosis • Cryptococcosis
Infrequent, Rare or Potential Diseases • Mycobacteriosis • Colibacillosis • Erysipelas • Listeriosis • Influenza • Rabies • Cryptosporidiosis • Toxoplasmosis
Chlamydiosis • Caused by a bacterium, C. psittaci • 159 avian host species • One fourth are psittacines • 114 species of free living wild birds • Other names: • Psittacosis – psittacine birds • Ornithosis - other avian species
Chlamydiosis • Mammals occasionally transmit C.psittaci to humans. • Certain strains of C. psittaci infect sheep, goats and cattle: cause chronic infection of reproductive tract • These strains are transmitted to persons when they are exposed to placenta of infected animals • Person to person transmission has been suggested, but not proven
Chlamydiosis • Most C. psittaci infections of humans result from exposure to pet psittacine birds • However, transmission has been documented from: Free-ranging birds, including doves, birds of prey, Shore birds • Infection usually occurs by inhalation of the organism which has been aerosolized from dried feces or respiratory secretions of infected birds • Mouth to beak contact, handling of infected birds, plumage and tissues
Disease in Psittacines • Unapparent carriers to a fulminating disease • Majority of birds are carriers • Incubation period varies from few days to several days • Organism is excreted in feces and nasal discharge • Clinical signs include: conjunctivitis, dyspnea, diarrhea and emaciation
Disease in Psittacines • Shedding of the organism can be activated by stress, shipping, crowding • Clinical signs include: Lethargy, anorexia, ruffled feathers, conjunctivitis (serous or mucopurulent ocular discharge, dyspnea, diarrhea (excretion of green to yellow-green urates) and emaciation
Chlamydiosis • Reportable Disease in 47 of 50 states. • CDC 1975 – 1984: 1,136 cases (8 deaths) 1984 – 1991: 1,344 cases (11 deaths) • People at risk: • Owners of pet birds, pet store employees, pigeon fanciers, farms, poultry processing plant employees, veterinarians, wildlife handlers, zoo employees
Diagnosis and Treatment • Difficult to diagnose the disease in the live bird • Post-mortem examination: impression smear from pericardial sac, air sac or liver • Treatment: tetracyclines/doxycyclines
Chlamydiosis • C. psittaci is susceptible to most disinfectants and detergents • Use a 1:1,000 dilution of quaternary ammonium compounds, 1:100 dilution of bleach • All birds confirmed for Cp should be isolated and treated
Salmonellosis • All avian species: • Finches, poultry, budgerigars, cockatiels, Amazon parrots, Macaws, waterfowl, pigeons, black birds, ostriches, penguins, sea gulls, sparrows, starlings • Acquired from other animals (rodents) • Human cases have involved types found in wild birds • Clinical signs: diarrhea with blood, weight loss and depression
Salmonellosis • Salmonella -2500 serotypes • Major problem in poultry industry
CampylobacteriosisC. jejuni • C.jejuni a widespread food-borne pathogen • Human infection are associated with acute illness, abdominal pain, diarrhea • Infection is acquired by consumption of contaminated poultry meat, water, milk and food products • Estimated cases in the USA 2.5 million
CampylobacteriosisC. jejuni • Herbivores/scavenger birds: lower prevalence in herbivores than in scavenger birds • Free living birds – significant reservoirs • Black birds, pigeons, sparrows, starlings, crows, gulls, puffins, magpies, bulbuls, migratory waterfowl, flemingos Commercial poultry (Ducks, broilers, turkeys, egg production flocks, parent breeding flocks)
Yersiniosis • Y. pseudotuberculosis • Y. enterocolitica • 50 species of wild and domestic birds • Pigeons and doves – most common • Swollen lymph glands
Tuberculosis • M. avium • Endemic in many parts • Reported in a vast number of birds • Humans are resistant • Infrequent cases occur • AIDS, leukemia patients (high risk)
Allergic alveolitis • Significant avian zoonotic disease • Common life-threatening • extrinsic allergic alveolitis, Budgerigar dander pneumonicosis, pigeon breeder lung • UK – 8% in budgie owners • Acute, sub acute or chronic forms • Reduction in lung capacity, hypersensitivity reaction to feathers, dust and fecal materials
Newcastle Disease • Caused by NewCastle Disease virus (NDV) • Reported in 241 species of birds representing 27 of the 50 orders of the class. • Highly susceptible birds include: domestic poultry, pigeons, psittacines, ostriches • Waterfowl are least susceptible. • Double-crested cormorants- 1990 outbreak in North America
Newcastle Disease • Newcastle disease virus is a human pathogen • In the UK the virus is placed in Hazard group 2 of the Advisory Committee on Dangerous pathogens • Not life threatening • Eye infections, reddening, excessive lacrimation edema of the eyelids, conjunctivitis and sub-conjunctival haemorrhage
Newcastle Disease • Both vaccinal strains and strains virulent for poultry may infect humans • Human to human spread has never been reported • People known to have been infected with NDV: Lab workers, Veterinarians in diagnostic labs (contact with infective material), vaccination crews when live vaccines are administered as aerosols. • 1943-1971:– 37 cases of human infections
West Nile Encephalitis • West Nile virus – Flavivirus • First isolated in West Nile province in Uganda • Reported from Israel, Romania, Russia, France, South Africa • U.S.A. since early summer of 1999 • Humans get West Nile encephalitis by the bite of a mosquito (primarily culex spp) that is infected with WNV
West Nile Encephalitis • What is the basic transmission cycle? • Mosquitoes become infected when they feed on infected birds, which may circulate the virus in their blood for a few days • After an incubation period of 10 days to 2 weeks, infected mosquitoes can then transmit WNV to humans and animals when while biting to take blood • The virus is located in the salivary glands
Mosquito vector Incidental infections West Nile Virus Transmission Cycle West Nile virus West Nile virus Incidental infections Bird reservoir hosts
West Nile virus infection in humans • Febrile, influenza-like illness with abrupt onset • Moderate to high fever • Headache, sore throat, backache, myalgia, arthralgia, fatigue • Rash, lymphadenopathy • Acute aseptic meningitis or encephalitis • Most fatal cases >50 years old.
West Nile Encephalitis History WNV in USA • Prior to August 1999, WNV had never been reported in US • In 1999, 62 cases of severe disease, including 7 deaths occurred in the New York area. • Large die-off of American crows. A total of 18 native bird species demonstrated morbidity and mortality in 1999 High mortality in hooded crows, sparrows, WNV was isolated from crows • WNV was isolated from dead cat in the New york area • Year 2001- 12 states, 21 humans, 63 horses, 4304 birds (78 species), 480 mosquito pools positive for WNV
West Nile Encephalitis • Can you get the WNV directly from birds? • There is no evidence that a person can get the virus from handling live or dead infected birds. ??? • Is there a vaccine for WNV? No