infectious coryza update - memberclicks coryza up… · –reservoir of infection = chronically ill...
TRANSCRIPT
Infectious Coryza Update
Danielle Botting, DVM, MPH
Technical Services Veterinarian
Hy-Line North America / H&N North America
Overview
– Pennsylvania outbreak
– Background information
– Clinical signs (symptoms)
– Treatment options
– Prevention
Current Affected Regions
– Pennsylvania
– California
– Arizona
– Colorado
– Southeast US
– Recent case in Ohio
Pennsylvania Outbreak
– Between December 2018 and August 2019, 56 confirmed farms diagnosed with Infectious Coryza in PA– ~12 million birds affected– Several with multiple affected flocks– Majority involved layers (34)– 6 pullet farms– 16 broiler farms
Pennsylvania Outbreak
– Disease occurred in all ages of layers (18-110 weeks)– Majority were older flocks
– Pullets ranged from 8-16.5 weeks
– Broilers ranged in age from 33-50 days
Pennsylvania Outbreak
– Mortality and egg production drops varied between flocks
– Layer flocks = 8-43% egg production drop, mortality 3-4x higher than average
– Broilers were marketed – total mortality unknown
– Pullet mortality variable (some normal, approx. 1-8%)
Infectious Coryza: Background
– Bacteria: Avibacterium paragallinarum
– Acute respiratory disease of chickens
– Disease seen primarily in pullets and layers, and occasionally in broilers
– Factors leading to disease:
– Poor biosecurity, stress of other diseases, naïve flocks (no vaccine)
Background
– Chickens of all ages are susceptible
– Susceptibility increases with age (“old chicken disease”)
– No public health significance – not a food safety issue
Transmission
– Reservoir of infection = chronically ill or healthy carrier birds
– Infected flocks are constant threat to uninfected flocks– Direct contact, airborne droplets, fomites, and/or
contaminated drinking water– Multi-age farms tend to perpetuate the disease– Not transmitted in eggs
Infection
– Incubation period = 1-3 days once exposed
– Whole flock affected within 10 days
– Disease duration is ~2-3 weeks (if uncomplicated)
– Other diseases can lead to increased morbidity and mortality – prolonging the disease
Symptoms
– Significant drop in feed and water consumption– Upper respiratory signs = nasal discharge, sneezing,
and swelling of face under the eyes– Not all flocks in PA had respiratory symptoms***
– Depression– Drop in egg production – Diarrhea– Mortality
Pictures courtesy of Dr. S. Davison. New Bolton Center, PA.https://extension.psu.edu/avian-coryza
Symptoms
– Clinical disease can last 2-3 weeks in uncomplicated cases, or up to 8-9 weeks if complicated with other diseases
– Other signs of bacterial infection: peritonitis, pericarditis, perihepatitis and/or airsacculitis
Diagnostics
– Clinical signs (symptoms)
– Lesions
– Bacterial culture and/or
– PCR testingCulture of Avibacterium paragallinarum.
Photo from Avian Disease Manual, 7th Ed.
Diagnostics
– Fragile bacteria – can be difficult to grow on culture growth media
– PCR (detection of DNA) is ideal test
– In PA cases, also diagnosed E. coli, Gallibacterium anatis, Infectious Bronchitis (IBV) viruses, etc.
Treatment
Treatment:– Antibiotics may reduce clinical
signs– Treat secondary bacterial infection
(e.g. E. coli)– Chlortetracycline (Aureomycin) in feed – Higher dose– Relapses can occur when treatment
stops
– Live E. coli vaccination
Prevention
Prevention:– BIOSECURITY! BIOSECURITY! BIOSECURITY!
– Vaccination
Feed Other Poultry and Animals
Water People Manure
Insects
Vehicles and Equipment
Wild BirdsVaccine Crews &
Equipment
Rodents
Housing
Main Biosecurity Rules
– No live poultry at home– Danish-style entry/shower-in facility– Maintain line of separation (LOS)– Farm-dedicated clothing and footwear for all
employees and visitors– No unnecessary visitors– C&D equipment, vehicles, etc. – Pest control (rodents, insects, wild birds)– C&D house between flocks
Biosecurity Program
Contingency plans
Isolation
Traffic control
Hygiene
QuarantineMedicationVaccination
Monitoring Documentation Communication
of Results
Eradication ofVertically
TransmittedDiseases
Continuing Education
Auditing
Sesti, 2001
– Remove birds
– Dry clean
– Wet clean with detergent
– Rinse and let dry
– Disinfect
– Fumigate
Cleaning & Disinfection
Infectious Coryza Survivability
– Low survivability – only ~2-3 days outside of the bird
– Easily killed by heat, drying, and disinfectants
Coryza Vaccines
– Commercial inactivated vaccine
– Autogenous inactivated vaccine
– Inactivated vaccines must be injected – individual bird handling
– Most producers have opted to include 1 commercial + 1 autogenous vaccine into program
– Availability remains the big determining factor
Vaccination
– Commercial bacterins may not fully protect against all field strains
– 3 serotypes: A, B and C
– Limited cross protection
– Recommend vaccine use in high challenge areas –administered before move to layer house
Dr. Jim Stockam, DVM:
Update on vaccine performance trials
Thank you, questions?