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?