Significant features of the epidemiology of equine influenza in New South Wales, Australia, 2007.

This study investigates the properties and impact of an Equine Influenza (EI) outbreak that occurred in New South Wales, Australia in 2007. It analyses how the virus spread, the under-reporting levels, and assessments on horse movement regulations during the outbreak.

Background and Context

• The research focuses on the outbreak of Equine Influenza (EI), a highly infectious horse disease, that was spotted for the first time in the Australian horse population on 24 August 2007.
• The epicenter of the outbreak was identified as Centennial Park Equestrian Centre (CPEC) in Sydney, New South Wales (NSW), Australia. However, by the time diagnosis occurred, the virus had already spread significantly to properties in other parts of NSW and even southern Queensland.

Impact of the Outbreak

• The outbreak proved to be extensive, affecting approximately 6,000 premises housing about 47,000 horses in NSW alone. This suggests a considerable impact on the equine population, thus warranting a comprehensive analysis.

Research Approach and Findings

• The research was carried out by the epidemiology section, a separate unit within the planning section of the State Disease Control Headquarters.
• Different aspects of the outbreak were critically analyzed, including the attack risk on the affected properties – which refers to the likelihood of the disease infecting properties in its vicinity.
• Another crucial component of this research was identifying the level of under-reporting of affected properties. Under-reporting refers to instances where properties affected by EI were not reported, either due to lack of awareness, negligence, or deliberate efforts to avoid repercussions.
• A risk assessment related to the movement of horses out of the Special Restricted Area during the outbreak was also part of this study. This factors in the possibility that moving horses from these affected areas could have further propagated the spread of the virus.

Outcomes and Lessons

• The research provided crucial insights on the epidemiological features of the EI virus and its spread pattern in NSW and southern Queensland.
• Moreover, it highlighted the importance of addressing under-reporting during such outbreaks and the impact of horse movement on disease control.
• Findings from this research are expected to be useful in managing and mitigating future outbreaks of Equine Influenza or similar diseases.