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An outbreak of equine influenza (EI) in Australia was confirmed by the New South Wales Department of Primary Industries on 24 August 2007 in Sydney. Also known as "horse flu" and "A1 influenza", the rapid outbreak was of the Influenza A virus strain of subtype H3N8. While the virus is highly contagious, it rarely kills adult horses but the performance of thoroughbred racing horses can be affected for several weeks. It can be fatal to young foals and debilitated horses. Because of strict quarantine procedures to reduce the risk of exotic pests and diseases entering Australia, this was the first outbreak of equine influenza in Australia. Horses in Australia had not been exposed to the virus and, not being vaccinated, were fully susceptible. A combination of control measures was successful in combating the outbreak. The last new infected property was identified on 22 December 2007. The zones which had been instituted to permit and restrict movements according to risk were progressively lifted from areas of New South Wales and Queensland. Following the provisional declaration of EI-free status for New South Wales and Queensland, ongoing surveillance and tracking measures are required until the international community recognises that the disease has been eradicated from Australia. == Outbreak == Four Japanese racing stallions had arrived at Eastern Creek Quarantine Station earlier in August 2007, soon after an outbreak of EI in Japan. By Tuesday 21 August, several horses at Eastern Creek showed symptoms of a viral infection and subsequently tested positive for equine influenza. On the same day, several recreational horses at Centennial Parklands Equestrian Centre also displayed symptoms of infection. There was no direct contact between horses at Eastern Creek and horses at Centennial Park and investigations are underway. The first case of EI in Australia was confirmed in a stallion at Eastern Creek on 24 August. The positive test resulted in the lockdown of approximately 60 horses at the Eastern Creek and Spotswood quarantine stations (in Sydney and Melbourne respectively). 16 horses at Eastern Creek and at Centennial Parklands tested positive for EI virus while another six exhibited symptoms. By the next day, there were over 80 suspected cases. All horses were isolated and a 72-hour national standstill on the movement of horses was declared. By 26 August 161 of the 165 horses at Centennial Parklands and other horses at Parkes, Moonbi, Berry, Wilberforce, Cattai and Wyong were confirmed as being infected. Most of the infected horses at Centennial Park were found to have been together at a One Day Event at Maitland the previous week. On 26 August 2007 about 300 horses were released from the Narrabri Showground where campdraft competitions were held. By 27 August, more than 400 horses on 50 properties in New South Wales had been quarantined after showing symptoms. A horse trials event at the Morgan Park Equestrian Centre near Warwick in Queensland was locked down after 20 infections were confirmed. Horses at Gatton tested positive on 27 August. Also on 27 August, New South Wales police confirmed that six police horses had tested positive and the police stables were placed under quarantine for two months. Police horses were suspected of being infected after some police riders attended the Maitland gymkhana. Infections were confirmed and quarantine zones established at Mount Hunter, Moree, Aberdeen and Anambah. On 29 August, a racecourse at Hamilton in Victoria went into lockdown when a horse began to exhibit signs of influenza however, the flu tests were negative. Additional quarantine zones were declared at Lake Macquarie, Terry Hie Hie, East Maitland, Warwick, Timbumburi, Eagleton (near Raymond Terrace) and some areas of Kenthurst following further positive flu tests. On 30 August, a thoroughbred racehorse at Randwick Racecourse returned a preliminary positive test for EI, although did not have any symptoms of infection. Track work was cancelled and the stables were locked down. Tests confirmed that eight race horses in the stable had EI and the racecourse was quarantined for two months. This brought the number of confirmed infections to 488 on 41 properties, plus another 1,646 suspected infections on 100 properties. The first infection in Brisbane was confirmed, increasing the number of quarantine zones in Queensland to five. On 5 November 2007 it was announced that a new outbreak of EI has occurred about south of Walcha. By early December, the number of new cases had declined and it appeared that the outbreak had been effectively contained. On 22 December a substantial part of the New South Control one was promoted to a provisionally free status. By mid February 2008 it was increasingly clear that the outbreak had been successfully controlled and, on 28 February, the NSW Government declared victory against EI, lifting most of the remaining movement restrictions on horses. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「2007 Australian equine influenza outbreak」の詳細全文を読む スポンサード リンク
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