Newcastle Disease Risk Profile For Estonia

Abstract

Newcastle disease (ND) is an acute highly contagious virosis of birds caused by avian paramyxovirus 1. The outbreaks of the disease may cause serious economic losses. In the current risk profile the pathways of introduction of ND to Estonian domestic bird populations and factors favouring the spread of the disease are described.The APMV-1 infection was assumed to be endemic among Estonian wild bird populations (pigeons). The probability of spread of the virus from wild to domestic birds was considered and evaluated.The release assessment has revealed three main scenarios of introduction of NDV to Estonian domestic birds: • Import of NDV infected domestic birds; • Import of NDV contaminated food and food waste; • Entry of a NDV contaminated vehicle. The probability of introduction is very low in case of all these pathways assuming there are no outbreaks of ND in neighbouring countries. Exposure assessment shows that the probability of exposure of a local bird population is very high in case of introduction of NDV by introducing infected domestic birds into poultry farms. The probability of exposure of poultry to a local infected wild bird population is also very high for small holdings, where the birds are kept outside during the summer. The exposure of poultry flocks through indirect contacts to initial outbreaks and the likelihood of the spread of the infection in the poultry population are moderate. The probability of infection is smaller in vaccinated herds, thus the small holdings are more threatened (vaccination is not compulsory). The consequence analysis shows that the NDV outbreak of any scale among poultry would have at least serious economic consequences for Estonia causing an export ban of live birds and products. In case of wider spread of ND the economic consequences would be severe. The adequacy of risk management measures to minimize the likelihood of NDV introduction should be improved where necessary.