RESUMO
We report the first detection of Senecavirus A (SVA) in nine of 12 (75%) pigs in Thailand in 2016. The full-length genome demonstrated that Thai SVA isolates were closely related to the first Canada strain (11-55910-3) than the recent strains causing outbreaks in Brazil, the United States and China in 2015-2016.
Assuntos
Surtos de Doenças/veterinária , Infecções por Picornaviridae/veterinária , Picornaviridae/isolamento & purificação , Doenças dos Suínos/virologia , Animais , Genoma Viral/genética , Filogenia , Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/virologia , Suínos , Doenças dos Suínos/epidemiologia , Tailândia/epidemiologiaRESUMO
The O/Middle East-South Asia (ME-SA)/Ind-2001 lineage of foot-and-mouth disease virus (FMDV) is endemic in the Indian subcontinent and has been reported in the Middle East and North Africa, but it had not been detected in South-East Asia (SEA) before 2015. This study reports the recent incursions of this viral lineage into SEA, which caused outbreaks in Vientiane Capital of Lao People's Democratic Republic (PDR) in April 2015, in Dak Nong, Dak Lak and Ninh Thuan Provinces of Vietnam from May to October 2015, and in Rakhine State of Myanmar in October 2015. Disease investigations were conducted during the outbreaks and followed up after laboratory results confirmed the involvement of FMDV O/ME-SA/Ind-2001 sublineage d (O/ME-SA/Ind-2001d). Affected host species included cattle, buffalo and pig, and all the outbreaks resolved within 2 months. Animals with clinical signs were separated, and affected premises were disinfected. However, strict movement restrictions were not enforced, and emergency vaccinations were only implemented in Vientiane Capital of Lao PDR and Dak Nong and Ninh Thuan Provinces of Vietnam. Clinical samples were collected from each outbreak and examined by nucleotide sequencing of the FMDV viral protein 1 coding region. Sequence analysis revealed that the O/ME-SA/Ind-2001d isolates from Lao PDR and Vietnam were closely related to each other and similar to viruses previously circulating in India in 2013. Viruses collected from Myanmar were divergent from viruses of the same sublineage recovered from Lao PDR and Vietnam but were closely related to viruses present in Bangladesh in 2015. These findings imply that at least two independent introductions of O/ME-SA/Ind-2001d into SEA have occurred. Our study highlights the transboundary nature of foot-and-mouth disease (FMD) and reinforces the importance of improved FMD surveillance and promotion of safer cross-border trade in SEA to control the risk of introduction and spread of exotic FMDV strains.
Assuntos
Búfalos/virologia , Doenças dos Bovinos/virologia , Surtos de Doenças/veterinária , Vírus da Febre Aftosa/isolamento & purificação , Febre Aftosa/virologia , Doenças dos Suínos/virologia , Animais , Sudeste Asiático/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Febre Aftosa/epidemiologia , Febre Aftosa/transmissão , Vírus da Febre Aftosa/genética , Vírus da Febre Aftosa/imunologia , Geografia , Filogenia , Análise de Sequência de DNA/veterinária , Sorogrupo , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/transmissão , Vietnã/epidemiologiaRESUMO
Seasonal effects on post-partum ovarian activity, duration and intensity of sexual behaviour were determined for Holstein dairy cattle imported from a temperate climate into a tropical region. Animals were observed continuously during the cooler (temperature-humidity index (THI) < 25) and hotter (THI > 25) seasons for 2 years. They were restricted to a cement footing in the hotter season observation period in Year 1, but had access to both concrete and dirt footing during all other seasons. Sequential milk progesterone profiles provided an indication of when follicular phases occurred, and recorded sexual behaviour was compared with these to determine if oestrous signs accompanied ovulations. Most cows had normal ovarian cycles and ovulated regularly during both seasons, but quiet ovulations occurred with greater frequency during the hotter times of the year (P < 0.05). Demonstrations of sexual behaviour were affected by choice of footing rather than season. The actual time when cows stood passively and allowed herdmates to complete mounting ranged from 5.1 +/- 0.7 to 5.8 +/- 1 h with access to exercise yards and cement or dirt footing, but declined to only 1.3 +/- 1.1 h when animals were confined to cement (P < 0.05). Similarly, the total duration of oestrus and mean number of interactions were significantly (P < 0.05) reduced during the observation period conducted with cows confined to concrete footing. These findings further emphasize that the duration of oestrus in dairy cows in considerably shorter than the commonly quoted 18 h.