An Outbreak of Influenza (H1N1) in Turkey Breeder Hens

SUMMARY. Outbreaks of influenza were diagnosed in two turkey breeder flocks on the same premises in eastern North Carolina during the "dark-out" period of recycling for a second lay. Clinical history included increased mortality from acute death with no apparent predisposing illness. Mortality attributed to the disease was 4.5% in one flock and 3.3% in the other. Necropsy findings included severe diffuse congestion and edema of both lungs, with little or no pleural exudate. Spleens were moderately to markedly enlarged and mottled, and kidneys were swollen and congested. Microscopic lesions included moderate to severe serofibrinous pneumonia with severe pulmonary congestion. Splenic changes included fibrin deposition and severe congestion, and severe congestion was noted in kidneys. Influenza virus (HlN1) was isolated from pools of tissues including lung, spleen, liver, and kidney, and both flocks seroconverted to influenza (H1N1) virus. RESUMEN. Reporte de Caso-Un brote de influenza (H1N1) en pavas reproductoras. Se diagnosticaron brotes de influenza en dos parvadas de pavas reproductoras localizadas en la misma granja en el oriente del estado de Carolina del Norte, E.U.A. El brote ocurri6 durante el periodo de muda forzada o reciclaje para un segundo periodo de postura. La historia clinica incluia un aumento de mortalidad aguda sin aparente enfermedad predisponente. La mortalidad atribuida a la enfermedad fue de 4.5% en un lote y 3.3% en el otro. A la necropsia se observ6 severa congesti6n difusa y edema de ambos pulmones, sin presencia de exudado pleural o con pequefias cantidades del mismo. Los bazos estaban ligera o excesivamente aumentados de tamano y moteados. Los rifiones estaban inflamados y congestionados. Las lesiones microsc6picas incluyeron neumonia serofibrinosa moderada o severa y fuerte congesti6n pulmonar. Se encontr6 deposici6n de fibrina en el bazo y congesti6n severa en este 6rgano y en el rifi6n. Se aisl6 un virus de influenza (H1N1) a partir de varios tejidos incluyendo el pulm6n, bazo, higado y riii6n. Ambos grupos mostraron seroconversi6n al virus de la influenza (H1N1).