Stochastic estimation for seroprevalence of infections laryngotracheitis virus in broilers in Uruguay

Résumé

The objective of this study was to estimate the true seroprevalence of seropositive individual broilers against infectious laryngotracheitis virus in Uruguay using a Bayesian inference software based on Markov chain Monte Carlo technique. Seventeen farms were kept under investigation between 2008 and 2009. Each study flock was randomly selected at different farms recruited from the capital city Montevideo, Canelones and Lavalleja Departments. The required total sample size was determined by power analysis, and blood samples collected were analysed using a commercial ELISA for the detection of antibody to the pathogen mentioned above. The overall seroprevalence of the virus was estimated at 31.5% [95% Bayesian credible interval (16.8–49.2%); N = 1790]. Because none of the study broilers had been inoculated against the virus prior to sampling, most of these results could be ascribed to natural exposure by field viruses and/or vaccine viruses from neighbouring layers. It should be considered as further risk assessment for clarifying the suitable vaccines to prevent chicken population in Uruguay from the virus.