Gallid herpesvirus 1
| Gallid herpesvirus 1 | |
|---|---|
| Virus classification | |
| Group: | Group I (dsDNA) |
| Order: | Herpesvirales |
| Family: | Herpesviridae |
| Subfamily: | Alphaherpesvirinae |
| Genus: | Iltovirus |
| Species: | Gallid herpesvirus 1 (GaHV-1) |
Gallid herpesvirus 1 (GaHV-1) (also known as Avian herpesvirus 1) is a virus of the family Herpesviridae that causes avian infectious laryngotracheitis. It was originally recognized as a disease of chickens in the United States in 1926.[1] The disease also occurs in pheasants.[2]
The disease is usually referred to as Infectious laryngotracheitis or simply LT in the poultry industry. It is widely viewed as one of the most contagious viruses that affect the poultry industry. A confirmed case will usually result in the establishment of a quarantine zone around the farm. Inside this quarantine zone, poultry workers will avoid poultry farms to prevent the spread of the virus.
GaHV-1 is shed in respiratory secretions and transmitted by droplet inhalation or via fomites. A previously unexposed flock will develop cases for two to eight weeks following introduction. The incubation period is two to eight days.[1]
Clinical signs and diagnosis
Symptoms include coughing, sneezing, head shaking, lethargy, discharge from the eyes and nostrils (sometimes bloody), and difficulty breathing. The name comes from the severe inflammation of the larynx and trachea. A diphtheritic membrane may form in the trachea, causing obstruction.
There may be problems in egg laying and the production of abnormal or thin-shelled eggs.
Mortality is typically less than 15 percent.[2]
Histopathology, PCR, ELISA, immunofluorescent staining and viral isolation are all possible methods of diagnosis.
Treatment and control
A vaccine is available (ATCvet code: QI01AD08 (WHO)), but it does not prevent latent infections. It can be used during an outbreak to decrease morbidity and deaths.
Biosecurity measure including quarantine, isolation and disinfection are very important in controlling the spread of an outbreak.
References
- 1 2 Fenner, Frank J.; Gibbs, E. Paul J.; Murphy, Frederick A.; Rott, Rudolph; Studdert, Michael J.; White, David O. (1993). Veterinary Virology (2nd ed.). Academic Press, Inc. ISBN 0-12-253056-X.
- 1 2 Carter, G.R.; Flores, E.F.; Wise, D.J. (2006). "Herpesviridae". A Concise Review of Veterinary Virology. Retrieved 2006-06-10.
External links
- Avian Infectious Laryngotracheitis, expert reviewed and published by WikiVet, accessed 07/10/2011
- Virus Pathogen Database and Analysis Resource (ViPR): Herpesviridae