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Avian Paramyxovirus Type 2 |
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Sunday, 29 June 2008 |
| | | | Avian Paramyxovirus Type 2 | | Uncomplicated infections of chickens or turkeys with avian paramyxovirus type 2 (PMV-2) probably result in only mild respiratory disease. However, much more serious disease may ensue due to exacerbation by other organisms. Etiology and Epidemiology: PMV-2 viruses have been shown to infect not only chickens and turkeys but also feral birds, particularly passerine species; they have also been isolated from caged psittacine species. PMV-2 viruses have been isolated from feral birds, mainly passerines, in Europe, Africa, Central America, and Asia and from poultry in North and Central America, Europe, Asia, and the Middle East. The assumed primary introduction to poultry is via contact with feral birds. The method of transmission to chickens or turkeys is unclear. Clinical Findings:PMV-2 viruses have been associated with mild to severe respiratory and egg production problems in chickens and turkeys. Mortality may be increased. Associated disease has usually been more severe in turkeys than in chickens. Virus isolation or the presence of antibodies (or both) have also confirmed the presence of PMV-2 viruses in chicken and turkey flocks that have experienced no clinical disease. It is probable that the clinical outcome of infections of domestic poultry with PMV-2 viruses depends on exacerbation by other organisms or environmental conditions. Experimental infections of laying turkeys showed that egg production and hatchability were adversely affected although fertility was not. Diagnosis:PMV-2 infections have usually been diagnosed by serology or virus isolation. Antibodies to PMV-2 may be detected by hemagglutination inhibition tests, and there is little or no cross-reaction with other paramyxovirus serotypes. PMV-2 viruses can be isolated from tracheal or fecal swabs or tissue samples from infected birds by inoculation of 8- to 10-day-old embryonating chicken eggs via the allantoic cavity. Confirmation of the virus as PMV-2 can be done by hemagglutination inhibition tests with specific antiserum. Prevention and Control:There are no vaccines available for PMV-2. The risk from PMV-2 virus may be minimized by prevention of introduction of virus by bird-proofing poultry houses and general good hygiene practices. Treatment of exacerbating secondary bacterial infections with antibiotics has had some success. | | | | | |
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