Development of the New Zealand strategy for local eradication of tuberculosis from wildlife and livestock.

We describe the progressive development of New Zealand's national strategy for control of tuberculosis (TB) in its agricultural sector over the last four decades. The strategy is globally unique, reflecting the need for effective and co-ordinated management of TB in a wildlife maintenance host, the brushtail possum (Trichosurus vulpecula), in addition to controlling infection in cattle and farmed deer herds. Since the early 1990s, the strategy has been developed by the Animal Health Board (AHB), formed to empower the farming industry to take the leadership role in funding of TB control, policy development and administration. The AHB became the first non-government organisation to develop and gain acceptance by the funders (farming industry and government) of a National Pest Management Strategy (NPMS) under the Biosecurity Act 1993. A key outcome of the NPMS for TB control was the development and inclusion of very challenging objectives that provided direction for management, research and possum control. This paper describes the process whereby the NPMS was revised twice, following achievement of each successive set of strategy objectives within budget. Success was based on firstly, reorganisation of the AHB and its operational systems to achieve increased efficiency; secondly, improved efficiency through contracting possum and disease control, and thirdly research delivering effective and practical applications, while also providing a scientific basis for setting directions for future control strategies. The last revision of the NPMS was implemented in 2011, and included objectives to eradicate Mycobacterium bovis-infected wildlife populations over 2.5 million hectares by 2026. This ambitious objective was adopted only after extensive forecast modelling enabled stakeholders to identify and select the most cost-effective long-term solution for the management of M. bovis-infected possum populations. The accomplishment of New Zealand's TB control programme, in meeting successive sets of demanding NPMS objectives, has seen a 95% decrease in the number of infected cattle and deer herds since they peaked at 1,694 in 1994, and the eradication of TB from infected possum populations from 830,000 hectares. Provided the current level of funding continues, New Zealand is positioned to achieve national eradication of TB well in advance of the 40-50-year timeline forecast 3 years ago.

Toward eradication: the effect of Mycobacterium bovis infection in wildlife on the evolution and future direction of bovine tuberculosis management in New Zealand.

New Zealand's bovine tuberculosis (TB) control programme has greatly reduced the burden of tuberculosis on the farming industry, from 11% of mature cattle found with TB at slaughter in 1905 to <0.003% in 2012/13. New Zealand implemented TB control measures in cattle from the mid-twentieth century, and later in farmed deer. Control was based on established methods of tuberculin testing of herds, slaughter of suspect cases, and livestock movement control. Unexplained regional control failures and serious disease outbreaks were eventually linked to wildlife-vectored infection from the introduced Australian brushtail possum (Trichosurus vulpecula), which also triggered a wildlife disease complex involving a range of introduced species. This paper reviews the progressive elucidation of the epidemiology of Mycobacterium bovis in New Zealand's wildlife and farmed livestock, and the parallel development of research-led, multi-faceted TB control strategies required to protect New Zealand's livestock industries from damaging infection levels. The adoption of coordinated national pest management strategies, with increasingly ambitious objectives agreed between government and industry funders, has driven a costly but very successful management regime targeted at controlling TB in the possum maintenance host. This success has led to initiation of a strategy designed to eradicate TB from New Zealand's livestock and wildlife, which is considered a realistic long-term prospect.

A strategic approach to eradication of bovine TB from wildlife in New Zealand.

A review and amendment of New Zealand's National Pest Management Strategy for bovine tuberculosis (TB) has led to adoption of new strategy objectives for localized eradication of disease from the principal wildlife maintenance host and infecting vector for farmed cattle and deer, the brushtail possum Trichosurus vulpecula. Historic programmes have been based on management of disease within herds and control of wildlife directed towards reducing infected herd prevalence. From July 2011, the TB strategy has been redirected towards eradication of TB from possums and other wildlife over a total area of at least 2.5 million hectares over a 15-year period. The amended strategy is intended to provide large-scale proof of concept, using two extensive bush areas, that TB can be eradicated from wildlife in New Zealand in the longer term, leading to eventual savings in control programmes needed to protect cattle and deer herds from infection. Achievement of strategy objectives will be supported by major research together with technical and managerial improvements in wildlife TB control and surveillance, and these are reviewed.

Techniques for identifying the epidural space: a survey of practice amongst anaesthetists in the UK.

A postal survey of all UK members of the Obstetric Anaesthetists' Association was carried out to ascertain their preferred method for identifying the epidural space in obstetric and non-obstetric patients. Over 1200 questionnaires were returned (79.3% response rate). In obstetric patients, the single most common technique (used by 58% of anaesthetists) was continuous advancement of the epidural needle and loss of resistance with saline, followed by intermittent needle advancement with air (21%). A minority of respondents used other variants, including intermittent advancement with saline (16%) and continuous advancement with air (4%). Consultant anaesthetists showed greater variety in techniques used than did trainees (p < 0.001). Less than 5% of respondents used a paramedian approach, and these were almost exclusively senior staff. Only 48% of anaesthetists said they would try an alternative if they experienced difficulty with their preferred technique. A similar pattern was seen for lumbar epidurals in non-obstetric surgical patients (89% used the same technique as in obstetrics), although for thoracic epidurals, 23% used a different technique to that which they would use for obstetrics, and the paramedian approach was more popular (21%). When inserting lumbar epidurals to supplement general anaesthesia in surgical patients, 18% of anaesthetists said they usually performed the block with the patient asleep, whereas for thoracic epidurals, this figure fell to 14%.

Regionalization: a strategy that will assist with bovine tuberculosis control and facilitate trade.

It is expected that the revised chapter on bovine tuberculosis in the Terrestrial Animal Health Code of the Office Internationale des Epizooties (OIE) will embrace regionalization as a functional means of assisting countries, states or regions to meet the requirements for freedom from tuberculosis and to facilitate trade. The benefits and applications of regionalization, which comprises zoning and compartmentalisation, are discussed. Regionalization requires that a country's veterinary administration is able to implement transparent and auditable biosecurity measures that will ensure that the tuberculosis-free status of a subpopulation of cattle is maintained despite the presence of infection in another cattle subpopulation, or in other domestic or wild animal species. Zoning, which requires cattle subpopulations to be separated by geographic boundaries, provides a practical basis whereby countries, states or regions, can progress towards freedom from tuberculosis, regardless of the source of infection for defined cattle subpopulations. Compartmentalisation however, requires that husbandry or management practices will be used to prevent a tuberculosis-free cattle subpopulation from contacting interspecific and intraspecific sources of infection. This will be difficult to achieve except for specialised cases such as artificial breeding centers.