Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/57651
Title: Evaluation of actions of the official veterinary service to mitigate outbreaks of infectious laryngotracheitis and improve biosecurity on laying hen farms
Other Titles: Avaliação de ações do serviço veterinário oficial para bloqueio de foco de laringotraqueite infecciosa e melhoria da biosseguridade em granjas de postura
Keywords: Official Veterinary Service
Outbreaks
Infectious laryngotracheitis (ILT) - Control
Biosecurity
Hen farms
Surveillance
Layer hen
Epidemiology
Serviço Veterinário Oficial
Laringotraqueite infecciosa - Controle
Biosseguridade
Granjas de postura
Epidemiologia
Issue Date: Apr-2021
Publisher: Colégio Brasileiro de Patologia Animal - CBPA
Citation: HERGOT, I. G. et al. Evaluation of actions of the official veterinary service to mitigate outbreaks of infectious laryngotracheitis and improve biosecurity on laying hen farms. Pesquisa Veterinária Brasileira, Rio de Janeiro, v. 41, e06749, 2021. DOI: 10.1590/1678-5150-PVB-6749..
Abstract: Infectious laryngotracheitis (ILT), caused by an Alphaherpesvirus (Gallid herpesvirus-1; GaHV-1), has been noticed in the region of the Terras Altas da Mantiqueira, Minas Gerais. From 2010 to 2018, the “Serviço Veterinário Oficial” (SVO) of the “Instituto Mineiro Agropecuário” (IMA), implemented measures to prevent spread of the virus to other regions and control the disease in the area. Due to the close proximity and consequent epidemiological link among farms, the region was considered a unique epidemiological unit. To check the efficiency of the ILT control measures, we carried out: (1) a seroepidemiological survey, (2) questionnaires for evaluating biosecurity measures; and (3) an evaluation of the influence of farm population density on the occurrence of ILT. In 2016, 2017, and 2018, ILT was investigated using epidemiological and clinicopathological methods, along with GaHV-1 molecular detection. Serological survey was carried out on 24 farms in the quarantined region and on 13 farms from other regions of the state. In 2010 and 2018, questionnaires were applied to collect data and determine indicators of biosecurity practices in all farms of the quarantined area. The differences were then assessed (Wilcoxon’s p<0.05). The results indicated positive serology throughout the region, although only on four farms (16.6%) the chickens have clinical signs, macroscopic and histological lesions of ILT. The prevalence of viral infection increased from 2016 (27%) to 2017 (50%) and was higher in farms with a high stock density (p=0.033). No disease, virus or antibodies were detected in the farms outside of the quarantined area. Although the biosecurity indicators had improved on all farms in the quarantined area (p<0.05), the virus was active and circulating in the region. The contingency measures have contained the outbreak, but biosecurity practices are paramount in the control of new outbreaks. Official control will be maintained in the region, including surveillance of new cases and biosecurity procedures to mitigate the risk of the virus reaching other regions.
URI: http://repositorio.ufla.br/jspui/handle/1/57651
Appears in Collections:DMV - Artigos publicados em periódicos

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