Experts at the Ministry for Primary Industries are more confident they can eradicate Mycoplasma bovis now than they were in the middle of last year.

Photo: RNZ / Rebekah Parsons-King

And they are gratified at the comparatively small number of new infections they are finding.

But they still face a long hard road.

They said they needed better testing of cleansed farms that were now back in business to make sure the disease did not reappear.

They also needed improved testing methods, as well as a proper definition of what it meant to be disease free.

This would include not just a statement that the disease was absent but a programme of surveys to be carried out regularly in the future, with, for example, a 95 percent probability of accuracy.

These were some of the findings contained in the latest report by the Ministry's TAG, or Technical Advisory Group.

Other findings confirmed Mycoplasma bovis was of recent origin, late 2015 to early 2016, and that there was one source.

The report mentioned some grounds for optimism.

It said there was a low number of dairy herds newly infected by last Spring after six rounds of testing.

While the rate of infection within beef herds remained unknown, it was likely to remain low.

But there was an urgent need to undertake a risk analysis of transmission between the dairy and beef sectors and vice versa.

However, based on the evidence presented, eradication remained technically feasible.

The report also discussed progress so far in fighting M Bovis.

It said at this rate, the majority of infected dairy herds would have been detected by June 2020.

But at least five years of ongoing surveillance would be needed to confirm that they remained free of the disease.

It went on to discuss the merits of different testing, that looking for antibodies was working better than looking for the bacteria that caused the disease.

An extra problem was an overloaded system, with fatigue of staff, resulting in slow or poor decision making.

It said this led to concerns by some farmers around the timeliness and transparency of decision-making, which could affect compliance and trust amongst the farming community.

Clear and timely communication with herd owners and other stakeholders was of critical importance.