Teresa V. Dormitorio, Joseph J. Giambrone, and Kenneth S. Macklin Poultry Science Department Auburn University

Contagious respiratory viral disease ILTV: herpesvirus; DS DNA genome ~155kb Symptoms (mild/severe): coughing of mucus & blood; conjunctivitis; swollen sinuses; increased mortality. Losses induced by ILT have an important economic impact on the poultry producer and the US export market.

Transmission between houses and farms can occur by airborne particles or fomites. By contaminated people & equipment (shoes, clothing, used feeders, cages, waterers, etc.) Virus is highly resistant outside host, but is susceptible to many disinfectants. Herpesviruses hallmark: can remain dormant in the animal’s nervous system & latent virus reactivated by stress factors or a compromised immune system.

February 13 – /day mortality February 14 – depopulated (4 houses) February 15 – ILTV identified by diagnostic lab February 22 – 1 st sampling (house environment and ill birds) March 7 – 2 nd sampling April 11 – 3 rd sampling “One mile away is an egg laying facility”

Use real time PCR and virus isolation to evaluate viral load in the environment of a commercial broiler farm after an ILTV outbreak. Determine effects of cleaning, disinfection, composting of the litter, and the use of a recombinant vaccine on persistence of ILTV. Characterize an ILTV field isolate and comparison with vaccine viruses using PCR-RFLP.

1 st sampling – 9 days after outbreak House empty for 8 days; heated; Litter decaked & conditioned Nipple drinkers Walls, curtains Fan louvers brooders Beetles Loose uncaught birds

ILTV detection from swabILTV detection from CAM 90% of swabs + for ICP4-ILTV 50% of + have Cp = % of CAMs + for ICP4-ILTV 5 ILTV + on swab, became - on CAM On 1 decreased Cp 1 swab- became + on CAM

House#- SampleDescriptionPCR on swab (Cp)PCR on CAM (Cp) 3-S1 IBrooder near door>35 3-S4 INipple drinker- front, right S8 INipple drinker- mid, right30>35 3-S10 ITop of water line- mid, right27negative 3-B11 IBeetles- mid, right S13 IBrooder- mid, left28negative 3-S17 IFan louvers- back, right29>35 3-B19 IBeetles- back, left34negative 3-S21 ITrachea- outside bird S22 ITrachea- inside bird27negative O-S23 IEye – outside bird B24 IBeetles- front32negative 2-S26 IFan louvers, mid left>35uncertain 2-S29 IWall- mid right>35 2-B32 IBeetles – mid rightnegativeNo CAM O3-S33 IWater in puddle-backnegative24.71 O3-S35 IOutside curtain, middle opening> O3-S36 IOutside curtain, middle>35uncertain O-S38 IPuddle between 2 & 3Invalid PCR+ but no Cp O-S40 IMud outside#3, left front>35negative

-23 days after outbreak; 2 days before chick placement -Heating, cleaning, disinfecting -Curtains replaced -Chicks vaccinated in ovo with recombinant vaccine 2 nd sampling

3 rd sampling 8 weeks after outbreak; repacement birds 5 weeks old

M123456M M) DNA Marker 1)LT- Blen (CEO) 2)LT-IVAX (TCO) 3)Laryngo-Vac (CEO) 4)Trachivax (CEO) 5)S21 - field isolate 6)AviPro (CEO) M) DNA Marker Lanes: 200 BP 5000

ILTV was found in environmental samples and non-caught ill birds 9 days after an LT outbreak. ICP4 DNA still detectable after heating, cleaning and disinfecting the house, but live virus was not detected and may have been eliminated. In ovo vaccination of new flock with a recombinant vaccine and disinfection procedures may have helped prevent recurrence of an LT outbreak on this farm.