Epidemiology of a Bluetongue outbreak in a sheep flock in Brazil

• Autor(a) principal: Ana Carolina Diniz Matos
• Data de Publicação: 2016
• Outros Autores: Mario Felipe Alvarez Balaro, Maria Isabel Maldonado Coelho Guedes, Erica Azevedo Costa, Júlio César Câmara Rosa, Aristóteles Gomes Costa, Felipe Zandonadi Brandão, Zélia Inês Portela Lobato
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFMG
• Texto Completo: http://hdl.handle.net/1843/61606; https://orcid.org/0000-0003-3175-2590; https://orcid.org/0000-0002-8198-7964; https://orcid.org/0000-0002-6734-0216; https://orcid.org/0000-0002-5396-3818; https://orcid.org/0000-0003-0189-7828; https://orcid.org/0000-0003-4027-5562; https://orcid.org/0000-0002-9399-3691
• topic: Bluetongue; Brazil; Clinical signs; Epidemiology; Outbreak; Serology; Sheep; Surveillance; Bluetongue; Brasil; Sinais e sintomas; Epidemiologia; Surtos de doenças; Sorologia; Doenças dos ovinos

In January 2013, an outbreak of Bluetongue (BT) affecting a Lacaune sheep flock occurred in Vassouras, Rio de Janeiro state, Brazil. From March to August 2013, blood samples collection and clinical examination were performed monthly, in order to monitor the epidemiological profile of Bluetongue virus (BTV) circulation and clinical disease in the flock. Agar gel immunodiffusion (AGID) and reverse transcription polymerase chain reaction (RT‑PCR) targeting BTV segment 10 were used as diagnostic assays. Additionally, insect trapping was conducted in the farm from May to July 2013. The flock serological prevalence to BTV was 80% since the first month of monitoring, with a variation in the serological rate depending on the sheep age categories. The number of susceptible lambs increased with time, probably due to the decrease of passive immunity. Viral RNA was detected in blood samples, demonstrating viral circulation, prolonged viraemia, and potential source for virus transmission in the region, even in a dry and cool season. The presence of Culicoides pusillus and Culicoides insignis was confirmed in the farm. The emergence of this outbreak in a Brazilian endemic area for BTV emphasises an urgent need of animal surveillance and BTV epidemiological studies.