Organism Organism Economic Impact
tarix 26.11.2016 ölçüsü 458 b.
Organism Organism Economic Impact Epidemiology Transmission Clinical Signs Prevention and Control Actions to Take RNA Vesiculovirus RNA Vesiculovirus Family Rhabdoviridae Major serotypes Affects horses, cattle, swine, camelids, humans Closely resembles exotic vesicular diseases including FMD Early 1800s Early 1800s Horse illness resembling VSV 1927: Virus identified 1950s: Human infections recorded 1982-83: Outbreak in western U.S. Previously, epizootic waves typical Now an annual occurrence in U.S. 1998-99: NM, CO, TX; 130 positives 1998-99: NM, CO, TX; 130 positives 2004-05: TX, NM, CO; 470 positives 2006: WY; 29 positives 2009: TX, NM; 7 positives 2010: AZ; 4 positives 1928: California dairy herds 1928: California dairy herds 1995: New Mexico beef herd Losses due to: Increased culling, increased mortality Reduced milk production Labor, medicine, veterinary costs Western hemisphere North, Central, and South America Emergence in eastern hemisphere? 2009: Bahrain, Laos (suspected) 2009: Pakistan (limited regions) Southwest U.S. Outbreaks in warmer regions Southeast U.S.: enzootic cycle Morbidity Morbidity Range: 5 to 90% Most animals seroconvert Mortality Vectors Vectors Sandflies Blackflies Seasonal outbreaks Direct contact Infected animals Contaminated objects Direct contact Direct contact Infected tissues, vesicular fluid, saliva Insect bites Aerosol Incubation period Incubation period Fever and vesicles that resemble FMD Horses severely affected Oral lesions Coronary band lesions Cattle, pigs Cattle, pigs Vesicular lesions Oral, mammary gland, coronary band, interdigital region Usually isolated to one body area Salivation, lameness Recover within 2 weeks Gross lesions Gross lesions Histopathology Degeneration of epithelial cells Before collecting or sending any samples, the proper authorities should be contacted Before collecting or sending any samples, the proper authorities should be contacted Samples should only be sent under secure conditions and to authorized laboratories to prevent the spread of the disease Vesicular diseases are clinically indistinguishable! Vesicular diseases are clinically indistinguishable! But, symptoms in horses are suggestive VSV vs. FMD VSV less contagious VSV lesions generally found in one area of the body Virus isolation Virus isolation Vesicular fluid or epithelium ELISA, complement fixation, virus neutralization Antibody tests Paired serum samples ELISA, complement fixation, virus neutralization No specific treatment available Supportive care Fresh, clean water Electrolytes if necessary Soft feeds Antibiotics for secondary infection Good prognosis Production animals may suffer losses Incubation period: 1 to 6 days Incubation period: 1 to 6 days Headache, fever, retrobulbar pain, malaise, nausea, limb and back pain, oral vesicles (rare) Self-limiting disease, supportive care Recovery can be prolonged Death is rare Clinical diagnosis difficult Clinical diagnosis difficult Differentials include: Coxsackie A group viruses (Hand, foot and mouth disease) Herpes simplex Diagnosis via serology Low incidence of human illness Low incidence of human illness Chance of infection when handling contaminated tissues Biosafety level 3 Personal protective equipment Recover in 4 to 7 days IMMEDIATELY notify authorities IMMEDIATELY notify authorities Federal Area Veterinarian in Charge (AVIC) http://www.aphis.usda.gov/animal_health/area_offices/ State State veterinarian http://www.usaha.org/StateAnimalHealthOfficials.pdf Quarantine Easily inactivated Easily inactivated Area must be free of organic matter Contact time of at least 10 minutes Disinfectants Phenolic, halogen-based disinfectants Soda ash, 2% iodophores Chlorine dioxide, 1% chlorine bleach 1% cresylic acid Quaternary ammonium Vaccines used in some endemic regions of Central, South America Vaccines may be available during an outbreak Contact state veterinarian for availability information Do not buy from positive herds for 3 months post-infection Do not buy from positive herds for 3 months post-infection Segregation and isolation necessary for controlling spread Sanitation Insect control programs World Organization for Animal Health (OIE) World Organization for Animal Health (OIE) U.S. Department of Agriculture (USDA) Center for Food Security and Public Health USAHA Foreign Animal Diseases (“The Gray Book”) www.usaha.org/pubs/fad.pdf Development of this presentation was funded by grants from Development of this presentation was funded by grants from the Centers for Disease Control and Prevention, the Iowa Homeland Security and Emergency Management Division , and the Iowa Department of Agriculture and Land Stewardship to the Center for Food Security and Public Health at Iowa State University. Authors: Danelle Bickett-Weddle, DVM; Anna Rovid Spickler, DVM, PhD; Kristina August, DVM; James A. Roth, DVM, PhDReviewers: Bindy Comito Sornsin, BA; Kerry Leedom Larson, DVM, MPH, PhD
