title: Real-time PCR quantification of infectious   laryngotracheitis virus in chicken tissues,   faeces, isolator-dust and bedding material over  28 days following infection reveals high levels   in faeces and dust.
abstract: Infectious laryngotracheitis (ILT) is an important disease of chickens caused by ILT virus (ILTV). We used the Australian SA2 and A20 vaccine strains of ILTV to determine tissue distribution and excretion characteristics of ILTV in specific-pathogen-free chickens and to determine whether ILTV is readily detectable in environmental samples such as faeces, bedding material and dust using real-time quantitative PCR. Three groups of 10 freshly hatched chicks were placed in isolators and infected orally with high doses of the two strains of vaccine virus or left unchallenged as controls. Over a 28-day post-infection (p.i.) period, faecal and serum samples were collected at frequent intervals from six individually identified chickens in each group. Dust and litter samples from the isolators were collected less frequently. Tissue samples were collected from three to four sacrificed or dead/euthanized birds at 6, 14 and 28 days p.i. Infection resulted in clinical ILT, a pronounced antibody response and sustained qPCR detection of the viral genome in the trachea, Harderian gland, lung and kidney up to 28 days p.i. A high level of the viral genome was also detected in faeces between 2 and 7 days p.i., declining by about approximately four orders of magnitude to low, but detectable, levels at 21 and 28 days p.i. The finding of high-level shedding of ILTV in faeces warrants further investigation into the epidemiological role of this, and the sustained high levels of ILTV observed in dust suggest that it may be a useful sample material for monitoring ILTV status in flocks.
authors: Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.|Central University Laboratory, Tamilnadu Veterinary and Animal Sciences University, Chennai 600051, India.
authors: Parimal
authors: P
authors: Roy
authors: Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
authors: A F M
authors: AFM
authors: Fakhrul Islam
authors: Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
authors: Susan K
authors: SK
authors: Burgess
authors: CSIRO FD McMaster Laboratory, Locked Bag 1, Armidale, NSW 2351 Australia.
authors: Peter W
authors: PW
authors: Hunt
authors: CSIRO FD McMaster Laboratory, Locked Bag 1, Armidale, NSW 2351 Australia.
authors: Jody
authors: J
authors: McNally
authors: Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
authors: Stephen W
authors: SW
authors: Walkden-Brown
mesh_terms: D000822:Animal Husbandry / Q000295:instrumentation; D000818:Animals; D001315:Australia / Q000453:epidemiology; D002645:Chickens / Q000821:virology*; D004391:Dust / Q000032:analysis; D005243:Feces / Q000821:virology*; D006566:Herpesviridae Infections / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D001352:Herpesvirus 1, Gallid / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D011201:Poultry Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D004391:Dust