RESUMO
In March 2014, avian influenza in poultry in Laos was caused by an emergent influenza A(H5N6) virus. Genetic analysis indicated that the virus had originated from reassortment of influenza A(H5N1) clade 2.3.2.1b, variant clade 2.3.4, and influenza A(H6N6) viruses that circulate broadly in duck populations in southern and eastern China.
Assuntos
Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Vírus Reordenados , Animais , Embrião de Galinha , Testes de Inibição da Hemaglutinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Laos/epidemiologia , Dados de Sequência Molecular , Neuraminidase/genética , Filogenia , Aves Domésticas , Proteínas Virais/genéticaRESUMO
Avian influenza viruses (H5N1) of clades 2.3.4.1, 2.3.4.2, and 2.3.2.1 were introduced into Laos in 2009-2010. To investigate these viruses, we conducted active surveillance of poultry during March 2010. We detected viruses throughout Laos, including several interclade reassortants and 2 subgroups of clade 2.3.4, one of which caused an outbreak in May 2010.
Assuntos
Galinhas/virologia , Surtos de Doenças , Patos/virologia , Virus da Influenza A Subtipo H5N1 , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/virologia , Laos/epidemiologia , Filogenia , Aves Domésticas , Doenças das Aves Domésticas/virologia , Vigilância de Evento Sentinela/veterinária , Análise de Sequência de DNARESUMO
Significant global efforts have been directed towards understanding the epidemiology of highly pathogenic avian influenza (HPAI) across poultry production systems and in wild-bird reservoirs, yet understanding of disease dynamics in the village poultry setting remains limited. This article provides a detailed account of the first laboratory-confirmed outbreak of HPAI in the south-eastern provinces of Lao PDR, which occurred in a village in Sekong Province in October 2018. Perspectives from an anthropologist conducting fieldwork at the time of the outbreak, clinical and epidemiological observations by an Australian veterinarian are combined with laboratory characterization and sequencing of the virus to provide insights about disease dynamics, biosecurity, outbreak response and impediments to disease surveillance. Market-purchased chickens were considered the likely source of the outbreak. Observations highlighted the significance of a-lack-of pathognomonic clinical signs and commonness of high-mortality poultry disease with consequent importance of laboratory diagnosis. Sample submission and testing was found to be efficient, despite the village being far from the national veterinary diagnostic laboratory. Extensively raised poultry play key roles in ritual, livelihoods and nutrition of rural Lao PDR people. Unfortunately, mass mortality of chickens due to diseases such as HPAI and Newcastle disease (ND) imposes a significant burden on smallholders in Lao PDR, as in most other SE Asian countries. We observed that high mortality of chickens is perceived by locals as a new 'normal' in raising poultry; this sense of it being 'normal' is a disincentive to reporting of mortality events. Establishing effective people-centred disease-surveillance approaches with local benefit, improving market-biosecurity and veterinary-service support to control vaccine-preventable poultry diseases could all reduce mass-mortality event frequency, improve veterinary-producer relationships and increase the likelihood that mortality events are reported. Priority in each of these aspects should be on working with smallholders and local traders, appreciating and respecting their perspectives and local knowledge.