Kararehe Kino — Vertebrate Pest Research Issue 27
March 2016 — Eradicating Bovine Tuberculosis
In this issue
Editorial — The Benefits of Applied Research
Over the past years there has been much excellent research targeted at TB in New Zealand, particularly on the role that possums and other feral animals play in the spread of this disease.
Making TB science available to end users
The control and eradication of bovine tuberculosis (TB) from New Zealand wildlife has been based on strong scientific foundations. However, often this science has only been appreciated by a small group of TB managers and researchers.
Controlling possums to manage TB
Since the early 1970s, possums have been controlled in New Zealand as part of an ongoing strategy to manage bovine tuberculosis (TB) in livestock. The frequency and intensity of such control is driven by a requirement to reduce populations to very low levels, then to hold them at or below this level for 5–10 years to ensure the disease is eradicated.
How does chronic TB affect possum movements?
Significant new insight into the movement of possums in relation to their role as vectors of bovine tuberculosis (TB) has been revealed in recent research by Graham Nugent and his colleagues.
Bovine TB infection at Karamea – why is TB persisting there?
The decline of TB-infected cattle and deer herds across New Zealand from 1700 in the mid-1990s to less than 40 in 2015 is a disease management success story. However, in the Karamea district in Westland, reduction in infected herd numbers has proven harder to achieve and progress has been considerably slower than elsewhere.
Livestock as sentinels for TB in possums
Substantial research effort over several decades has gone into improving surveillance techniques for assessing the status of TB (caused by Mycobacterium bovis) in New Zealand wildlife. Important advances have been made in diagnostics and in understanding the behavioural ecology of host species and multi-species epidemiological dynamics.
Lesion resolution may contribute to TB persistence in the face of control
Recent trials to directly measure the rate at which infected possums transmit TB to uninfected possums in free-living populations have raised more questions than they have answered.
The main host of TB is …possum!
It has recently been suggested (both through media and by an MP) that possums are ‘not the single most important vector [of bovine tuberculosis (TB)] . In stark contrast, Graham Nugent and his colleagues use much of the same TBfree New Zealand data as strong evidence that major progress is being made in locally eliminating TB from possums and other wildlife.
Ghost hosts: Deer, pigs, and TB eradication
Possums are the main wildlife vector of bovine tuberculosis (TB) in New Zealand, but pigs and deer are spillover hosts of the disease. Replicated large-scale field trials show that greatly reducing possum densities but not deer or pig densities results in the prevalence of TB in deer and pigs falling towards zero.