Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

infectious laryngotracheitis

Toolbox

Datasheet

infectious laryngotracheitis

Summary

  • Last modified
  • 14 July 2018
  • Datasheet Type(s)
  • Animal Disease
  • Preferred Scientific Name
  • infectious laryngotracheitis
  • Overview
  • Gallid herpesvirus 1, better known as infectious laryngotracheitis virus (ILTV), is a member of the genus Iltovirus, subfamily Alphaherpesvirinae of the family Herpesviridae (...

  • There are no pictures available for this datasheet

    If you can supply pictures for this datasheet please contact:

    Compendia
    CAB International
    Wallingford
    Oxfordshire
    OX10 8DE
    UK
    compend@cabi.org
  • Distribution map More information

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report

Identity

Top of page

Preferred Scientific Name

  • infectious laryngotracheitis

Other Scientific Names

  • laryngotracheitis

International Common Names

  • English: avian infectious laryngotracheitis; avian infectious laryngotracheitis; avian laryngotracheitis

English acronym

  • ILT

Overview

Top of page

Gallid herpesvirus 1, better known as infectious laryngotracheitis virus (ILTV), is a member of the genus Iltovirus, subfamily Alphaherpesvirinae of the family Herpesviridae (Davison et al., 2009). ILTV is a pathogen of the respiratory tract of poultry, producing peracute, subacute and chronic or mild disease outbreaks (Guy and Garcia, 2008). All ages of poultry are susceptible to infection, and mortalities in peracute outbreaks may exceed 50%. Respiratory signs predominate, although decreased egg production may also occur in layers. Virus persists in a latent state in recovered birds, being shed intermittently. Where the virus is present, management often relies on the use of live attenuated vaccines. Vaccinal strains also establish latency and can be subsequently shed. Vaccinal strains have the potential to revert to virulence, and vaccinated and non-vaccinated birds should therefore not be mixed.

The distribution section contains data from OIE's WAHID Interface database on disease occurrence. Please see the AHPC library for further information on this disease from OIE, including the International Animal Health Code and the Manual of Standards for Diagnostic Tests and Vaccines. Also see the website: www.oie.int.

Hosts/Species Affected

Top of page

ILTV is predominantly a pathogen of chickens (Bagust and Guy, 1997). Although all ages are susceptible, the most characteristic signs of disease are seen in adult birds. Disease has also been reported in pheasants and peafowls (Cranshaw and Boycott, 1982). Experimentally induced infection of young turkeys has also been reported associated with an age-related resistance (Winterfield and So, 1968). Other species, including closely related galliforms are refractory to infection.

Distribution

Top of page

For current information on disease incidence, see OIE's WAHID Interface.

Distribution Table

Top of page

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

AfghanistanNo information availableOIE, 2009
ArmeniaDisease not reportedNULLOIE, 2000a; OIE, 2009
AzerbaijanDisease not reportedOIE, 2009
BahrainDisease not reportedNULLOIE, 2000a; OIE, 2009
BangladeshDisease not reportedOIE, 2009
BhutanNo information availableOIE, 2009
Brunei DarussalamNo information availableOIE, 1996; OIE Handistatus, 2005
CambodiaNo information availableOIE, 2009
ChinaRestricted distributionNULLGenChen et al., 1997; OIE, 2009
-Hong KongDisease not reportedNULLOIE, 1996; OIE, 2009
Georgia (Republic of)Last reported1990OIE, 2000a; OIE Handistatus, 2005
IndiaDisease not reportedNULLOIE, 1997; OIE, 2009
IndonesiaDisease not reportedOIE, 2009
IranDisease not reported2000OIE, 2000a; OIE, 2009
IraqDisease not reportedOIE, 2009
IsraelDisease not reported2005OIE, 2000a; OIE, 2009
JapanPresentNULLOIE, 2000a; OIE, 2009
JordanDisease not reported1991OIE, 2000a; OIE, 2009
KazakhstanDisease not reportedOIE, 2009
Korea, DPROIE Handistatus, 2005
Korea, Republic ofDisease not reported20050214OIE, 2000a; OIE, 2009
KuwaitDisease not reportedOIE, 2009
KyrgyzstanDisease not reportedNULLOIE, 1999; OIE, 2009
LaosNo information availableOIE, 2009
LebanonPresentNULLOIE, 2000a; OIE, 2009
MalaysiaDisease not reported200705OIE, 2000a; OIE, 2009
-Peninsular MalaysiaDisease not reportedOIE, 1996; OIE Handistatus, 2005
-SabahLast reported2002OIE, 2000a; OIE Handistatus, 2005
-SarawakReported present or known to be presentOIE, 2000a; OIE Handistatus, 2005
MongoliaNo information availableOIE, 2009
MyanmarPresentOIE, 2009
NepalDisease not reported2004OIE, 1997; OIE, 2009
OmanDisease not reportedOIE, 2009
PakistanNo information availableNULLOIE, 2000a; OIE, 2009
PhilippinesPresentNULLOIE, 2000a; OIE, 2009
QatarNo information availableOIE, 2009
Saudi ArabiaNo information availableNULLOIE, 1998; OIE, 2009
SingaporeDisease not reported1989OIE, 2000a; OIE, 2009
Sri LankaDisease not reportedNULLOIE, 1996; OIE, 2009
SyriaNo information availableOIE, 2009
TaiwanReported present or known to be presentChang et al., 1997; OIE Handistatus, 2005
TajikistanDisease not reportedOIE, 2009
ThailandDisease not reported2004OIE, 2000a; OIE, 2009
TurkeyNo information availableOIE, 2009
TurkmenistanNo information availableOIE Handistatus, 2005
United Arab EmiratesDisease not reportedNULLOIE, 1996; OIE, 2009
UzbekistanReported present or known to be presentOIE, 1996; OIE Handistatus, 2005
VietnamNo information availableOIE, 2009
YemenNo information availableOIE, 2009

Africa

AlgeriaDisease not reported1989OIE, 2000a; OIE, 2009
AngolaNo information availableOIE, 2009
BeninNo information availableOIE, 2009
BotswanaDisease never reportedOIE, 2009
Burkina FasoNo information availableNULLOIE, 1999; OIE, 2009
BurundiNo information availableOIE Handistatus, 2005
CameroonReported present or known to be presentOIE, 2000a; OIE Handistatus, 2005
Cape VerdeNo information availableOIE, 1997; OIE Handistatus, 2005
Central African RepublicNo information availableOIE Handistatus, 2005
ChadNo information availableOIE, 2009
CongoNo information availableOIE, 2009
Congo Democratic RepublicNo information availableOIE Handistatus, 2005
Côte d'IvoireDisease not reportedOIE Handistatus, 2005
DjiboutiDisease not reportedOIE, 2009
EgyptDisease not reported1991OIE, 1996; OIE, 2009
EritreaDisease not reported200702OIE, 2000a; OIE, 2009
EthiopiaDisease not reportedOIE, 2009
GabonDisease not reportedNULLOIE, 1997; OIE, 2009
GambiaNo information availableOIE, 2009
GhanaNo information availableOIE, 2009
GuineaNo information availableNULLOIE, 2000a; OIE, 2009
Guinea-BissauNo information availableOIE, 2009
KenyaNo information availableOIE, 2009
LesothoDisease not reportedNULLOIE, 1996; OIE, 2009
LibyaDisease not reportedOIE Handistatus, 2005
MadagascarDisease never reportedOIE, 2009
MalawiNo information availableOIE, 2009
MaliNo information availableNULLOIE, 1996; OIE, 2009
MauritiusDisease not reportedNULLOIE, 1996; OIE, 2009
MoroccoNo information availableNULLOIE, 2000a; OIE, 2009
MozambiqueDisease not reportedNULLOIE, 1998; OIE, 2009
NamibiaDisease not reported2007OIE, 2000a; OIE, 2009
NigeriaNo information availableOIE, 2009
RéunionNo information availableOIE Handistatus, 2005
RwandaNo information availableOIE, 2009
Sao Tome and PrincipeCAB Abstracts data miningOIE, 1999; OIE Handistatus, 2005
SenegalNo information availableNULLOIE, 2000a; OIE, 2009
SeychellesDisease not reportedOIE Handistatus, 2005
SomaliaNo information availableOIE Handistatus, 2005
South AfricaDisease not reported200804OIE, 2000a; OIE, 2009
SudanDisease never reportedOIE, 2009
SwazilandDisease not reportedOIE, 2009
TanzaniaNo information availableNULLOIE, 1996; OIE, 2009
TogoNo information availableOIE, 2009
TunisiaDisease not reported1998OIE, 2000a; OIE, 2009
UgandaAbsent, reported but not confirmedNULLOIE, 2000a; OIE, 2009
ZambiaDisease not reportedOIE, 2009
ZimbabweDisease never reportedOIE, 2009

North America

BermudaDisease not reportedOIE Handistatus, 2005
CanadaPresentNULLOIE, 2000a; OIE, 2009
-New BrunswickPresentAlexander et al., 1998
-OntarioPresentAlexander et al., 1998
GreenlandDisease never reportedOIE, 2009
MexicoPresentNULLOIE, 2000a; OIE, 2009
USARestricted distributionNULLOIE, 2000a; OIE, 2009
-DelawarePresentKeeler et al., 1993
-GeorgiaPresentAndreasen et al., 1990
-MarylandPresentKeeler et al., 1993
-North CarolinaPresentGuy, et al., 1989
-PennsylvaniaPresentKeller et al., 1992
-VirginiaPresentKeeler et al., 1993

Central America and Caribbean

BarbadosDisease never reportedOIE Handistatus, 2005
BelizeDisease never reportedOIE, 2009
British Virgin IslandsDisease never reportedOIE Handistatus, 2005
Cayman IslandsDisease not reportedOIE Handistatus, 2005
Costa RicaPresentNULLOIE, 1998; OIE, 2009
CubaDisease not reportedOIE, 2009
CuraçaoDisease not reportedOIE Handistatus, 2005
DominicaDisease not reportedOIE Handistatus, 2005
Dominican RepublicDisease never reportedOIE, 2009
El SalvadorDisease never reportedOIE, 2009
GuadeloupeNo information availableOIE, 2009
GuatemalaDisease never reportedOIE, 2009
HaitiDisease never reportedOIE, 2009
HondurasDisease never reportedOIE, 2009
JamaicaDisease not reportedOIE, 2009
MartiniqueNo information availableOIE, 2009
NicaraguaDisease never reportedOIE, 2009
PanamaNo information availableOIE, 2009
Saint Kitts and NevisNo information availableOIE Handistatus, 2005
Saint Vincent and the GrenadinesDisease never reportedOIE Handistatus, 2005
Trinidad and TobagoReported present or known to be presentOIE Handistatus, 2005

South America

ArgentinaRestricted distributionNULLOIE, 2000a; OIE, 2009
BoliviaAbsent, reported but not confirmedNULLOIE, 1996; OIE, 2009
BrazilDisease not reportedOIE, 2009
ChilePresentNULLOIE, 2000a; OIE, 2009
ColombiaDisease not reported200703OIE, 2000a; OIE, 2009
EcuadorDisease never reportedOIE, 2009
Falkland IslandsDisease never reportedOIE Handistatus, 2005
French GuianaDisease not reportedOIE, 2009
GuyanaDisease not reportedOIE Handistatus, 2005
ParaguayDisease not reportedOIE, 1996; OIE Handistatus, 2005
PeruPresentNULLOIE, 1996; OIE, 2009
SurinamePresentOIE, 1997
UruguayPresentNULLOIE, 2000a; OIE, 2009
VenezuelaDisease not reportedOIE, 2009

Europe

AlbaniaNo information availableOIE, 2009
AndorraNo information availableOIE Handistatus, 2005
AustriaNo information availableOIE, 2009
BelarusDisease not reported200502OIE, 2000a; OIE, 2009
BelgiumDisease not reported200709OIE, 2000a; OIE, 2009
Bosnia-HercegovinaDisease not reportedOIE Handistatus, 2005
BulgariaDisease not reported1994OIE, 1998; OIE, 2009
CroatiaDisease never reportedOIE, 2009
CyprusDisease not reported2004OIE, 2000a; OIE, 2009
Czech RepublicDisease not reportedOIE, 2009
DenmarkPresentNULLOIE, 2000a; OIE, 2009
EstoniaDisease not reportedOIE, 2009
FinlandDisease not reportedOIE, 2009
FranceNo information availableNULLOIE, 2000a; OIE, 2009
GermanyPresentNULLOIE, 2000a; OIE, 2009
GreeceDisease not reported2000OIE, 2000a; OIE, 2009
HungaryDisease not reported20080304OIE, 2000a; OIE, 2009
IcelandDisease never reportedOIE, 2009
IrelandDisease not reported1997Graham et al., 2000; OIE, 2009
Isle of Man (UK)Disease not reportedOIE Handistatus, 2005
ItalyNo information availableNULLOIE, 2000a; OIE, 2009
JerseyDisease never reportedOIE Handistatus, 2005
LatviaDisease never reportedOIE, 2009
LiechtensteinDisease not reportedOIE, 2009
LithuaniaDisease not reportedNULLOIE, 1996; OIE, 2009
LuxembourgDisease not reportedNULLOIE, 2000a; OIE, 2009
MacedoniaNo information availableOIE, 2009
MaltaDisease not reported2004OIE, 1999; OIE, 2009
MoldovaLast reported1992OIE Handistatus, 2005
MontenegroDisease not reportedOIE, 2009
NetherlandsPresentNULLOIE, 2000a; OIE, 2009
NorwayDisease not reported2005OIE, 2000a; OIE, 2009
PolandNo information availableNULLOIE, 1997; OIE, 2009
PortugalDisease not reported200801OIE, 2000a; OIE, 2009
RomaniaDisease not reported1999OIE, 2000a; OIE, 2009
Russian FederationDisease not reported2006OIE, 2000a; OIE, 2009
SerbiaNo information availableOIE, 2009
SlovakiaDisease not reportedOIE, 2009
SloveniaDisease not reportedOIE, 2009
SpainNo information availableNULLOIE, 1999; OIE, 2009
SwedenPresentNULLOIE, 2000a; OIE, 2009
SwitzerlandPresentNULLOIE, 2000a; OIE, 2009
UKPresentNULLHughes et al., 1991a; Graham et al., 2000; OIE, 2009
-Northern IrelandReported present or known to be presentOIE Handistatus, 2005
UkraineDisease not reported2004OIE, 2000a; OIE, 2000b; OIE, 2009
Yugoslavia (former)No information availableOIE Handistatus, 2005
Yugoslavia (Serbia and Montenegro)Disease not reportedOIE Handistatus, 2005

Oceania

AustraliaPresentNULLOIE, 2000a; OIE, 2009
Cook IslandsPresentOIE, 1997
French PolynesiaPresentOIE, 2009
GuamReported present or known to be presentOIE, 2000a
KiribatiReported present or known to be presentOIE, 1998
New CaledoniaDisease not reportedNULLOIE, 1996; OIE, 2009
New ZealandPresentNULLOIE, 2000a; OIE, 2009
SamoaDisease not reportedOIE Handistatus, 2005
VanuatuDisease never reportedOIE Handistatus, 2005
Wallis and Futuna IslandsNo information availableOIE, 2000a; OIE Handistatus, 2005

Pathology

Top of page

In the peracute form, postmortem changes are largely confined to the upper respiratory tract, with haemorrhagic tracheitis and blood clots and blood stained mucus in the lumen of the trachea (Tripathy, 1998; OIE, 2000b). In some birds, pneumonitis and air sacculitis may also be seen.

In the subacute form of the disease, postmortem findings are less severe, with mucoid exudate, possibly containing blood, being present in the trachea. Caseous yellow diptheritic membranes may be present on the mucosa of the larynx and upper trachea.

In the chronic/mild form, diptheritic and caseous necrotic plaques and plugs in the trachea, larynx and mouth are the predominant lesions. The sequence of histopathological changes that occurs in the trachea following infection begins with loss of cilia from, and enlargement of, epithelial cells accompanied by the disappearance of mucus glands. Syncytial formation in the mucosal epithelium with development of intranuclear type A inclusions occurs, with hyperaemia and congestion of the lamina propria and associated infiltration of lymphocytes and macrophages. This is followed by connective tissue proliferation and stratification of epithelium, with sloughing of epithelial cells into the lumen. Haemorrhage may also be evident. The luminal exudate additionally contains heterophils, macrophages, mucus, fibrin, cellular debris and erythrocytes. In more chronic stages, the tracheal mucosa may be replaced by a fibrinonecrotic membrane. In the lungs, lesions of bronchointerstitial pneumonia may be present. These include congestion and interstitial oedema with infiltration of macrophages and lymphocytes. Sloughing of the mucosa, syncytial formation with intranuclear inclusion bodies, and luminal exudate may be seen in the bronchi. Syncytial formation with intranuclear inclusion bodies may also occur in conjunctival mucosa (Jordan, 1966; Linares et al., 1994; Abbas and Andreasen, 1996).

Diagnosis

Top of page

Clinical Diagnosis



Clinical signs of coughing and gasping with bloody nasal discharges are highly suggestive of ILT in peracute cases. The respiratory signs in subacute and chronic/mild cases are less characteristic, but the presence of coughing and gasping is again suggestive of ILT.


Lesions



Whilst not in itself diagnostic for ILT, the presence of haemorrhagic tracheitis is highly suggestive of this diagnosis.


Differential Diagnosis



ILT, particularly in the subacute and mild forms, needs to be differentiated from a number of other respiratory pathogens. These include infectious bronchitis virus, avian rhinotracheitis virus, influenza A virus, paramyxovirus type 1, fowlpox virus, fowl adenovirus, Aspergillus spp. and avian mycoplasmosis.


Laboratory Diagnosis



Laboratory diagnosis is based on isolation of ILTV, demonstration of the presence of virus, viral proteins, viral DNA or inclusion bodies, or the detection of virus-specific serum antibodies (OIE, 2000b; Guy and Garcia, 2008).

The polymerase chain reaction and other approaches to the amplification of DNA/RNA are being used increasingly for ILT diagnosis. In addition to being very sensitive and not requiring prior isolation and growth of the virus in vitro, these techniques provide DNA that can be analysed to provide additional information to identify strains and to help put them into epidemiological and phylogenetic contexts (Guy and Garcia, 2008). Multiplex PCRs have been developed to detect ILTV and other avian viruses simultaneously (Tadese et al., 2007; Rashid et al., 2009; Mahmoudian et al., 2011) whilst real-time PCRs permit quantification of ILTV (Callison et al., 2007) and provide DNA for restriction-fragment analysis (Creelan et al., 2006) or sequencing. PCR can also be used to detect ILTV in formalin-fixed, paraffin-embedded tissues (Humberd et al., 2002). Real-time PCRs have also been developed using minor groove binder technology (Corney et al., 2010; McMenamy et al., 2011) and compared with a loop-mediated isothermal amplification assay (Ou et al., 2012). PCRs are also used for purity testing of avian viral vaccines (Ottiger, 2010).

Virus isolation may be performed on the dropped chorio-allantoic membrane (CAM) of 10-12 day old embyronated fowl eggs or on monolayered cultures of chicken embryo liver (CEL), chicken embryo kidney (CEK), chicken embryo lung (CELu) or chicken kidney (CK) cells. Of these, CEL and CK have been shown to be the most sensitive for primary isolation (Hughes and Jones, 1988). Virus replication in CAMs results in the production of characteristic pocks, whilst in cell cultures a characteristic syncytial cytopathic effect develops. Definitive confirmation of the isolation of ILTV may be made by electron microscopy, immunofluorescent staining, or virus neutralisation. Appropriate samples for virus isolation include tracheal swabs or tissue in transport medium containing antibiotics or tracheal tissue. Virus isolation is sensitive but requires appropriate facilities and may be time consuming, with samples in some cases requiring multiple passage before yielding a positive result.

Electron microscopy (EM) can be used to demonstrate the presence of virus particles in tracheal scrapings or exudate. EM is relatively insensitive compared to virus isolation, requiring 103.5/0.1ml of infectious virus (Hughes and Jones, 1988). However, it is a rapid test and has the advantage of not being unduly hindered by the presence of bacterial contamination or other viruses (Williams et al., 1994).

Immunofluorescent or immunoperoxidase staining of viral proteins may be performed either directly or indirectly using specific polyclonal or monoclonal antibodies. Tests may be performed on acetone-fixed tracheal scrapes or cryostat sections. The same methodology may be used to confirm the identity of viral isolates. Although both tests are typically less sensitive than virus isolation, they are quick to perform, giving a result in a matter of hours. Immunoperoxidase staining may be more sensitive than immunofluoresence, and has the added advantage of not requiring fluorescent microscope facilities (Guy et al., 1992; Abbas and Andreasen, 1996).

Agar gel immunodiffusion (AGID) may also be used to detect virus directly in tracheal samples, or alternatively in infected CAMs or cell cultures following initial amplification in the laboratory. Lines of precipitation (reactions of identity) are observed between a central well containing hyperimmune antiserum and peripheral wells containing ILTV antigen. AGID is relatively cheap and straightforward to perform, but is less sensitive than isolation techniques (York and Fahey, 1988) due to the greater amount of virus required to yield a positive result.

Antigen-capture enzyme-linked immmunosorbent assay (ELISA) may also be used to detect ILTV (York and Fahey, 1988). ELISA tests are relatively straightforward to run, and have the advantage of giving a result within a matter of hours. Sensitivity is reported to be comparable to virus isolation.

The observation of classical Cowdry type A intranuclear inclusion bodies in epithelial cells on histological examination of haematoxylin and eosin-stained tracheal sections may be used to diagnose ILT (OIE, 2000b). However, the reading of histology is a specialised task and requires the availability of appropriate facilities for preparation and cutting of sections. While the specificity of histopathology is high, the sensitivity tends to be low relative to virus isolation (Guy et al., 1992; Abbas and Andreasen, 1996).


Immunology and Serology


Following infection, serum antibody responses appear five to seven days post infection, peak around two weeks later and wane slowly thereafter. Detection of specific ILTV antibodies therefore provides indirect evidence of infection. Serological tests based on virus neutralization (VN), indirect immunofluorescence (IFA), AGID and ELISA have been described. In a comparative study, VN, IFA and ELISA were found to have comparable performance, with AGID less sensitive, although still satisfactory on a flock basis (Adair et al., 1985).

List of Symptoms/Signs

Top of page
SignLife StagesType
Digestive Signs / Anorexia, loss or decreased appetite, not nursing, off feed Sign
General Signs / Discomfort, restlessness in birds Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
General Signs / Haemorrhage of any body part or clotting failure, bleeding Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
General Signs / Increased mortality in flocks of birds Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
General Signs / Lack of growth or weight gain, retarded, stunted growth Sign
General Signs / Laryngeal, tracheal, pharyngeal swelling, mass larynx, trachea, pharynx Sign
General Signs / Oral cavity, tongue swelling, mass in mouth Sign
Nervous Signs / Dullness, depression, lethargy, depressed, lethargic, listless Sign
Nervous Signs / Head shaking, headshaking Sign
Ophthalmology Signs / Chemosis, conjunctival, scleral edema, swelling Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
Ophthalmology Signs / Conjunctival, scleral, injection, abnormal vasculature Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
Ophthalmology Signs / Conjunctival, scleral, redness Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
Ophthalmology Signs / Lacrimation, tearing, serous ocular discharge, watery eyes Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
Ophthalmology Signs / Purulent discharge from eye Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
Pain / Discomfort Signs / Pain, pharynx, larynx, trachea Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
Reproductive Signs / Decreased, dropping, egg production Poultry:Mature female Sign
Reproductive Signs / Soft, thin egg shell Poultry:Mature female Sign
Respiratory Signs / Abnormal breathing sounds of the upper airway, airflow obstruction, stertor, snoring Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Diagnosis
Respiratory Signs / Abnormal lung or pleural sounds, rales, crackles, wheezes, friction rubs Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Diagnosis
Respiratory Signs / Coughing, coughs Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Diagnosis
Respiratory Signs / Dyspnea, difficult, open mouth breathing, grunt, gasping Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Diagnosis
Respiratory Signs / Haemoptysis coughing up blood Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Diagnosis
Respiratory Signs / Increased respiratory rate, polypnea, tachypnea, hyperpnea Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Sign
Respiratory Signs / Mucoid nasal discharge, serous, watery Sign
Respiratory Signs / Purulent nasal discharge Sign
Respiratory Signs / Sneezing, sneeze Poultry:Day-old chick,Poultry:Young poultry,Poultry:Mature female,Poultry:Cockerel,Poultry:Mature male Diagnosis

Disease Course

Top of page

Infectious laryngotracheitis (ILT) is a respiratory disease, principally of the upper respiratory tract. Following natural infection, disease signs appear in 6-12 days (Jordan, 1966). Peracute, subacute and chronic (or mild) forms of the disease may occur (Tripathy, 1998; OIE, 2000b). The peracute form is characterised by sudden onset and rapid spread with high morbidity. In such outbreaks, mortality may exceed 50% (Jordan, 1966). Affected birds show characteristic clinical signs associated with respiratory distress. Birds may sneeze, gasp or cough, sometimes producing clots of blood. Gurgles, rattles and rales may be heard due to tracheal obstruction.

In the subacute form, morbidity is again high, but mortalities are typically lower, varying from 10% to 30%. The spread of disease and the development of clinical signs occurs more slowly, with respiratory signs observed for some days before deaths occur. Affected birds may also show conjunctivitis with associated lacrimation and swelling of the infra-orbital sinuses. The chronic/mild form of ILT may be seen subsequent to peracute and subacute outbreaks or as a distinct disease entity. Mortality rates are typically 1-2%, with losses occurring over a period of months. Affected birds may be unthrifty, with bouts of gasping and coughing accompanied by nasal or oral discharges. A considerable drop in egg production may also be seen in laying birds (Jordan, 1966).

Epidemiology

Top of page

ILTV is primarily a pathogen of fowl, although natural infection has also been reported in pheasants and peafowl (Cranshaw and Boycott, 1982). Turkey poults may also be infected experimentally (Winterfield and So, 1968). All ages of fowl are susceptible to infection, with disease having been reported in broilers, pullets and layers in birds from eight days to four years of age (Kingsbury and Jungherr, 1958; Jordan, 1966; Linares et al., 1994).

Infection with both field and vaccinal strains of ILTV results in a carrier state characterized by latency in the trigeminal ganglia interspersed with brief periods of spontaneous virus shedding over an extended period of time (Bagust, 1986; Hughes et al., 1987; Hughes et al., 1991b; Williams et al., 1992). Natural stress factors including re-housing, mixing and the onset of lay are recognised factors that will trigger recrudescence and shedding of latent virus (Hughes et al., 1989).

ILTV may be transmitted directly by contact with other fowl that are shedding virus, or indirectly. Of particular importance in relation to direct transmission is the mixing of vaccinated and non-vaccinated naïve fowl. Recrudescence and shedding of vaccinal virus under such conditions leads to infection of susceptible fowl. Although vaccinal strains of virus are of low virulence, serial passage of such strains through a susceptible population can produce highly virulent virus within six to ten passages (Guy et al., 1990; Guy et al., 1991; Kotiw et al., 1995). Indirect transmission of the virus may be effected by movements of people or equipment from farm to farm and by mechanical transmission by vermin, scavenging birds, or dogs in the absence of adequate disinfection, hygiene and biosecurity (Kingsbury and Jungherr, 1958; Jordan, 1966). In regions of intensive production, ILTV is usually well controlled by vaccination in commercial fowl, but may persist in backyard and fancier flocks (Bagust and Guy, 1997).

Impact: Economic

Top of page

Given that mortalities may exceed 50% (Jordan, 1966), ILT outbreaks can obviously have a significant economic impact. However there are little definitive data available on the cost of such outbreaks.

Zoonoses and Food Safety

Top of page

There is no evidence that ILTV is transmissible to humans or other mammals; it is not considered to be a food safety issue (Guy and Garcia, 2008).

Disease Treatment

Top of page

There are no effective means of treatment available for ILT. However, where a diagnosis is made early in the course of an outbreak, administration of vaccine may help reduce further morbidity and mortality (Kingsbury and Jungherr, 1958).

Prevention and Control

Top of page

Immunization and Vaccines


In regions with intensive poultry industries, ILT is often effectively controlled by the use of vaccines (Guy and Garcia, 2008). Typically, these are modified live vaccines containing virus strains that have been attenuated by serial passage in tissue culture (tissue culture origin [TCO] vaccines) or embryonated fowl eggs (chick embryo origin [CEO] vaccines) (Guy et al., 1990; Chang et al., 1997). Inactivated ILT vaccines are not used due to the high cost of production and application (Guy and Garcia, 2008). Recombinant viral vector vaccines against ILT are commercially available in some countries e.g. USA.

Vaccines given in the face of an outbreak will reduce virus spread and shorten the duration of disease (Bagust and Guy, 1997). In common with wild type virus, modified live vaccines are capable of establishing latent infections which may be followed by intermittent reactivation and shedding. Serial passage in susceptible birds can then lead to reversion to virulence, particularly in CEO vaccines (Guy et al., 1991), and vaccinal strains of virus have been implicated in many disease outbreaks (Guy et al., 1989; Guy et al., 1990; Keller et al., 1992; Chang et al., 1997; Graham et al., 2000). For this reason, modified live vaccines should not be used in regions where ILTV is not already present. The replication and transmissibility of two CEO ILT vaccines has been studied by experiment by Coppo et al., (2012a, b). Typically vaccines are given by eye drop to fowl at around four weeks of age, with revaccination of replacement birds at sixteen to twenty weeks of age. Vaccine needs to be stored and reconstituted properly to ensure that each bird receives an adequate dose of virus.

Commercially available virus vector vaccines for ILT based on herpesvirus of turkeys (HVT) and fowl poxvirus (FPV) have been developed and applied as they have advantages over modified live ILT vaccines; they are not transmitted from bird to bird, do not establish latent infections, and do not revert to virulence. The HVT-LT vaccine contains the ILTV genes for glycoproteins D and I, whilst the FPV-LT vaccine contains the ILTV genes encoding glycoprotein B and membrane-associated protein (Vagnozzi et al., 2012). The protection induced by these vector vaccines has been compared with that induced by live modified vaccine. Vagnozzi et al. (2012) reported that the vector vaccines, applied in ovo and subcutaneously, provided partial protection, and partially reduced clinical signs and virus replication in the trachea. The HVT-LT vaccine was more efficacious than the FPV-LT vaccine.

Husbandry Methods and Good Practice



Maintenance of adequate biosecurity is a prerequisite to preventing the introduction of ILTV onto poultry production sites (Guy and Garcia, 2008). Site quarantine and disinfection procedures should be used to prevent the introduction of virus on fomites such as clothing and personnel, vehicles, feed and equipment. The fabric of buildings should be maintained so as to prevent ingress of wild birds, and effective rodent and dog control protocols should be in place. Record keeping should be such as to prevent the possibility of vaccinated and non-vaccinated birds being mixed. Direct or indirect contact between commercial poultry and backyard or fancier flocks should be avoided. In the event of an outbreak, dead birds should be disposed of immediately, for example by burning or burying. Survival of the virus in the environment is variable, being influenced by a number of factors including dose, pH, temperature and exposure to light, but virus is considered readily inactivated by disinfectants and warm temperatures (Jordan, 1966; Bagust and Guy, 1997).

Local Control



Cooperation between government and industry can facilitate effective control of outbreaks (Bagust and Guy, 1997), allowing rapid diagnosis, introduction of vaccination and initiation of biosecurity and movement controls to minimise further spread.

References

Top of page

Abbas F; Andreasen JR, 1996. Comparison of diagnostic tests for infectious laryngotracheitis. Avian Diseases, 40:290-295.

Adair BM; Todd D; McKillop ER; Burns K, 1985. Comparison of serological tests for detection of antibodies to infectious laryngotracheitis virus. Avian Pathology, 14(4):461-469; 8 ref.

Alexander HS; Key DW; Nagy é, 1998. Analysis of infectious laryngotracheitis virus isolates from Ontario and New Brunswick by the polymerase chain reaction. Canadian Journal of Veterinary Research, 62(1):68-71; 25 ref.

Andreasen JR; Glisson JR; Villegas P, 1990. Differentiation of vaccine strains and Georgia field isolates of infectious laryngotracheitis virus by their restriction endonuclease fragment patterns. Avian Diseases, 34(3):646-656; 42 ref.

Bagust TJ, 1986. Laryngotracheitis (Gallid-1) herpesvirus infection in the chicken. 4. Latency establishment by wild and vaccine strains of ILT virus. Avian Pathology, 15(3):581-595; 25 ref.

Bagust TJ; Guy JS, 1997. Laryngotracheitis In: Calnek BW, Barnes HJ, Beard CW, McDougald LR, Saif YM, eds. Diseases of Poultry, 10th Edn., Iowa, Iowa State Univeristy Press, 527-540.

Callison SA; Riblet SM; Oldoni I; Sun S; Zavala G; Williams S; Resurreccion RS; Spackman E; García M, 2007. Development and validation of a real-time Taqman® PCR assay for the detection and quantitation of infectious laryngotracheitis virus in poultry. Journal of Virological Methods, 139(1):31-38. http://www.sciencedirect.com/science/journal01660934

Chang P-C; Lee Y-L; Shien J-H; Shieh HK, 1997. Rapid differentiation of vaccine strains and field isolates of infectious laryngotracheitis virus by restriction fragment length polymorphism of PCR products. Journal of Virological Methods, 66:179-186.

Coppo MJC; Devlin JM; Noormohammadi AH, 2012. Comparison of the replication and transmissibility of an infectious laryngotracheitis virus vaccine delivered via eye-drop or drinking-water. Avian Pathology, 41(1):99-106. http://www.tandfonline.com/loi/cavp20

Coppo MJC; Devlin JM; Noormohammadi AH, 2012. Comparison of the replication and transmissibility of two infectious laryngotracheitis virus chicken embryo origin vaccines delivered via drinking water. Avian Pathology, 41(2):195-202. http://www.tandfonline.com/loi/cavp20

Corney BG; Diallo IS; Wright LL; Jong AJde; Hewitson GR; Tolosa MX; Rodwell BJ; Ossedryver SM; Pritchard LI; Boyle DB, 2010. Detection and quantitation of gallid herpesvirus 1 in avian samples by 5’ Taq nuclease assay utilizing Minor Groove Binder technology. Avian Pathology, 39(1):47-52.

Cover; MS; Benton WJ, 1958. The biological variation of the infectious laryngotracheitis virus. Avian Diseases, 2:375-383.

Cranshaw GJ; Boycott BR, 1982. Infectious laryngotracheitis in peafowl and pheasants. Avian Diseases, 26:397-401.

Creelan JL; Calvert VM; Graham DA; McCullough SJ, 2006. Rapid detection and characterization from field cases of infectious laryngotracheitis virus by real-time polymerase chain reaction and restriction fragment length polymorphism. Avian Pathology, 35(2):173-179.

Davison AJ; Eberle R; Ehlers B; Hayward GS; McGeoch DJ; Minson AC; Pellett PE; Roizman B; Studdert MJ; Thiry E, 2009. The order Herpesvirales. Archives of Virology, 154(1):171-177. http://springerlink.metapress.com/content/g6t9250068857hv3/?p=9cc5a229eb094c38a73c173e04be9bb4&pi=23

GenChen F; YuanZhai D; WanGuang Z; ZhiLiang W; PeiLan L; WeiXiang Z, 1997. Isolation and identification of chicken infectious laryngotracheitis virus. Chinese Journal of Veterinary Science and Technology, 27:21-22.

Graham DA; McLaren IE; Calvert V; Torrens BM; Meehan BM, 2000. RFLP analysis of recent Northern Ireland isolates of infectious laryngotracheitis virus: comparison with vaccine virus and field isolated from England, Scotland and the Republic of Ireland. Avian Pathology, 29:57-62.

Guy JS; Barnes HJ Morgan L, 1990. Virulence of infectious laryngotracheitis viruses: comparison of modified-live vaccine viruses and North Carolina field isolates. Avian Diseases, 34:106-113.

Guy JS; Barnes HJ Smith L, 1991. Increased virulence of modified-live infectious laryngotracheitis vaccine virus following bird-to-bird passage. Avian Diseases, 35:348-355.

Guy JS; Barnes HJ; Munger LL; Rose L, 1989. Restriction endonuclease analysis of infectious laryngotracheitis viruses: comparison of modified-live vaccine viruses and North Carolina field isolates. Avian Diseases, 33:316-323.

Guy JS; Barnes HJ; Smyth LG, 1992. Rapid diagnosis of infectious laryngotracheitis using a monoclonal antiboy-based immumoperoxidase procedure. Avian Pathology, 21:77-86.

Guy JS; Garcia M, 2008. Laryngotracheitis. In: Diseases of Poultry, 12th edition [ed. by Saif, Y. M. \Fadly, A. M. \Glisson, J. R. \McDougald, L. R. \Nolan, L. K. \Swayn, D. E.]. Ames, Iowa, USA: Blackwell Publishing, 137-152.

Hughes CS Jones RC, 1988. Comparison of cultural methods for primary isolation of infectious laryngotracheitis virus from field material. Avian Pathology, 17:295-303.

Hughes CS; Gaskell RM; Bradbury JM; Jordan FTW; Jones RC, 1991. Survey of field outbreaks of avian infectious laryngotracheitis in England and Wales. Veterinary Record, 129(12):258-260; 12 ref.

Hughes CS; Gaskell RM; Jones RC; Bradbury JM; Jordan FTW, 1989. Effects of certain stress factors on the re-excretion of infections laryngotracheitis virus from latently infected carrier birds. Research in Veterinary Science, 46(2):274-276; 14 ref.

Hughes CS; Jones RC; Gaskell RM; Jordan FTW; Bradbury JM, 1987. Demonstration in live chickens of the carrier state in infectious laryngotracheitis. Research in Veterinary Science, 42(3):407-410; 20 ref.

Hughes CS; Williams RA; Gaskell RM; Jordan FTW; Bradbury JM; Bennett M; Jones RC, 1991. Latency and reactivation of infectious laryngotracheitis vaccine virus. Archives of Virology, 121(1-4):213-218; 23 ref.

Humberd J; García M; Riblet SM; Resurreccion RS; Brown TP, 2002. Detection of infectious laryngotracheitis virus in formalin-fixed, paraffin-embedded tissues by nested polymerase chain reaction. Avian Diseases, 46(1):64-74.

Johnson MA; Prideaux CT; Kongsuwan K; Sheppard M; Fahey KJ, 1991. Gallid herpesvirus 1 (infectious laryngotracheitis virus): cloning and physical maps of the SA-2 genome. Archives of Virology, 119:181-198.

Jordan FTW, 1966. A review of the literature on infectious laryngotracheitis (ILT). Avian Diseases, 10:1-26.

Keeler CL; Hazel JW; Hastings JE; Rosenberger JK, 1993. Restriction endonuclease analysis of Delmarva field isolates of infectious laryngotracheitis virus. Avian Diseases, 37:418-426.

Keller LH; Benson CE; Davison S; Eckroade RJ, 1992. Differences among restriction endonuclease DNA fingerprints of Pennsylvania field isolates, vaccine strains, and challenge strains of infectious laryngotracheitis virus. Avian Diseases, 36(3):575-581; 16 ref.

Kingsbury FW; Jungherr EL, 1958. Indirect transmission of infectious laryngotracheitis in chickens. Avian Diseases, 2:54-63.

Kotiw M; Wilks CR; May JT, 1995. The effect of serial in vivo passage on the expression of virulence and DNA stability of an infectious laryngotracheitis virus strain of low virulence. Veterinary Microbiology, 45(1):71-80; 21 ref.

Linares JA; Bickford AA; Cooper GL; Charlton BR; Woolcock PR, 1994. An outbreak of infectious laryngotracheitis in California broilers. Avian Diseases, 38(1):188-192; 3 ref.

Mahmoudian A; Kirkpatrick NC; Coppo M; Lee SangWon; Devlin JM; Markham PF; Browning GF; Noormohammadi AH, 2011. Development of a SYBR Green quantitative polymerase chain reaction assay for rapid detection and quantification of infectious laryngotracheitis virus. Avian Pathology, 40(3):237-242.

McMenamy MJ; McKillen J; Hjertner B; Kiss I; Yacoub A; Leijon M; Duffy C; Belák S; Welsh M; Allan G, 2011. Development and comparison of a Primer-Probe Energy Transfer based assay and a 5’ conjugated Minor Groove Binder assay for sensitive real-time PCR detection of infectious laryngotracheitis virus. Journal of Virological Methods, 175(2):149-155. http://www.sciencedirect.com/science/journal/01660934

OIE Handistatus, 2002. World Animal Health Publication and Handistatus II (dataset for 2001). Paris, France: Office International des Epizooties.

OIE Handistatus, 2003. World Animal Health Publication and Handistatus II (dataset for 2002). Paris, France: Office International des Epizooties.

OIE Handistatus, 2004. World Animal Health Publication and Handistatus II (data set for 2003). Paris, France: Office International des Epizooties.

OIE Handistatus, 2005. World Animal Health Publication and Handistatus II (data set for 2004). Paris, France: Office International des Epizooties.

OIE, 1996. HandiSTATUS II. World avian infectious laryngotracheitis animal health status 1996. http://www.oie.int.hs2/sit_mald_cont.asp?c_mald=85&c_cont=6&annee=1996.

OIE, 1997. HandiSTATUS II. World avian infectious laryngotracheitis animal health status 1997. http://www.oie.int.hs2/sit_mald_cont.asp?c_mald=85&c_cont=6&annee=1997.

OIE, 1998. HandiSTATUS II. World avian infectious laryngotracheitis animal health status 1998. http://www.oie.int.hs2/sit_mald_cont.asp?c_mald=85&c_cont=6&annee=1998.

OIE, 1999. HandiSTATUS II. World avian infectious laryngotracheitis animal health status 1999. http://www.oie.int.hs2/sit_mald_cont.asp?c_mald=85&c_cont=6&annee=1999.

OIE, 2000a. HandiSTATUS II. World avian infectious laryngotracheitis animal health status 2000. http://www.oie.int.hs2/sit_mald_cont.asp?c_mald=85&c_cont=6&annee=2000.

OIE, 2000b. Avian infectious laryngotracheitis. In: Manual of Standards for Diagnostic Tests and Vaccines, edition 4. Paris, France: Office International des Epizooties, 711-717.

OIE, 2009. World Animal Health Information Database - Version: 1.4. World Animal Health Information Database. Paris, France: World Organisation for Animal Health. http://www.oie.int

Ottiger HP, 2010. Development, standardization and assessment of PCR systems for purity testing of avian viral vaccines. Biologicals [Proceedings of the IABS International Workshop on "Viral Safety and Extraneous Agents Testing for Veterinary Vaccines", Annecy, France, 25-27 October 2005.], 38(3):381-388. http://www.sciencedirect.com/science/journal/10451056

Ou SC; Giambrone JJ; Macklin KS, 2012. Comparison of a TaqMan real-time polymerase chain reaction assay with a loop-mediated isothermal amplification assay for detection of Gallid herpesvirus 1. Journal of Veterinary Diagnostic Investigation, 24(1):138-141.

Rashid S; Naeem K; Ahmed Z; Saddique N; Abbas MA; Malik SA, 2009. Multiplex polymerase chain reaction for the detection and differentiation of avian influenza viruses and other poultry respiratory pathogens. Poultry Science, 88(12):2526-2531. http://www.poultryscience.org

Tadese T; Potter AE; Fitzgerald S; Reed WM, 2007. Concurrent infection in chickens with fowlpox virus and infectious laryngotracheitis virus as detected by immunohistochemistry and a multiplex polymerase chain reaction technique. Avian Diseases, 51(3):719-724. http://avdi.allenpress.com/avdionline/?request=get-abstract&doi=10.1637%2F0005-2086(2007)51%5B719:CIICWF%5D2.0.CO%3B2

Tripathy DN, 1998. Infectious laryngotracheitis. In:Laboratory Manual for the Isolation and Identification of Avian Pathogens, edition 4. Pennsylvania, USA: American Association of Avian Pathologists, 111-115.

Vagnozzi A; Zavala G; Riblet SM; Mundt A; García M, 2012. Protection induced by commercially available live-attenuated and recombinant viral vector vaccines against infectious laryngotracheitis virus in broiler chickens. Avian Pathology, 41(1):21-31. http://www.tandfonline.com/loi/cavp20

Watrach AM; Hanson LE; Watrach MA, 1963. The structure of infectious laryngotracheitis virus. Virology, 21:601-608.

Williams RA; Bennett M; Bradbury JM; Gaskell RM; Jones RC; Jordan FTW, 1992. Demonstration of sites of latency of infectious laryngotracheitis virus using the polymerase chain reaction. Journal of General Virology, 73(9):2415-2420; 27 ref.

Williams RA; Savage CE; Jones RC, 1994. A comparison of direct electron microscopy, virus isolation and a DNA amplification method for the detection of avian infectious laryngotracheitis virus in field material. Avian Pathology, 23(4):709-720; 22 ref.

Winterfield RW; So IG, 1968. Susceptibility of turkeys to infectious laryngotracheitis. Avian Diseases, 12:191-202.

York JJ; Fahey KJ, 1988. Diagnosis of infectious laryngotracheitis using a monoclonal antibody ELISA. Avian Pathology, 17:173-182.

Distribution Maps

Top of page
You can pan and zoom the map
Save map