Desarrollo de un análisis de riesgo de entrada y un modelo de difusión potencial del virus de Newcastle en la República Argentina

Resum

The overall objective of this thesis is to evaluate and quantify the risk and consequences of a potential entry and spread of Newcastle disease (ND) in Argentina. To do this a semiquantitative risk analysis model and a deterministic diffusion model have been developed. Moreover, we characterized and analyzed patterns of movements among commercial poultry farms using social network analysis methodology and the graph theory. Argentina has a highly developed poultry industry of great economic importance which represents the second largest production of live animals after cattle. Currently the country is the 7th largest producer and 5th largest exporter of poultry products. For that reason, the potential introduction and spread of infectious diseases such as ND, could cause severe socio-economic consequences. The ND is worldwide considered as one of the major diseases affecting the poultry industry due to the high mortality that can produce and to the socio-economic impacts from trade restrictions in the affected countries that can arise. Because of its importance and because it is a highly contagious disease, is included in the list of reportable diseases by the World Organization for Animal Health (OIE), being endemic in many countries of America, Middle East, Africa and Asia. Since July 1997, OIE considers Argentina as free from ND. To evaluate and quantify the risk and consequences of the potential entry of ND, a semiquantitative risk analysis model has been developed, according to the guidelines recommended by OIE. Up to the present no risk analysis model adapted to the characteristics of Argentina to estimate the risk of ND has been found in the literature. The analyzed pathways to assess the risk of potential entry of ND in Argentina were the most important ones and those with enough information to be evaluated. Specifically, the selected pathways for the analysis were the imports of live poultry, poultry products and fertile eggs. To perform this analysis we collected information from both national databases (such as volume of birds, hatching eggs, poultry products and imported products recorded from 2001 to 2010) and international scientific publications. The steps followed in this study focused specifically on hazard identification and risk assessment (which included the risk estimate of release and exposure and the estimate of the total risk). The results of the semiquantitative risk analysis indicated that the total relative risk associated with the importation of pigeons and chickens was high, being United States the country that represents the highest relative risk of release associated to pigeons and United States and Brazil regarding to chickens. Ducks, turkeys and psittacines had a medium total relative risk ...