Tuesday, 14 August 2018 14:55

Finding the last M. bovis farm

Written by  Pam Tipa
Andy McFadden, MPI. Andy McFadden, MPI.

Most farms infected with Mycoplasma bovis may already have been detected but you must be confident you have got the last one, says MPI veterinarian epidemiologist Andy McFadden.

Studies at this stage also indicate that the M. bovis incursion is a one-off that occurred in late 2015. 

Personally he is confident not many infected properties are yet to be found, he told the NZ Institute of Primary Industry Management conference in Hamilton. 

Asked for his personal opinion on what stage the eradication process had reached, he sounded notes of caution and patience.

“When you are talking about eradication you have to find the last farm, and even that is a simplification. If the last farm is a dead-end host all the animals [will be] going to the slaughterhouse and it is not a forward risk. 

“But in talking about the last farm where there is a risk of forward transmission… it is not a case of ‘we’ve got 99% of the infected properties’ because we’ve got to find that last farm.”

Being confident you have found the last one is the difficult bit, he says. Work on improving testing for the disease is ongoing.  “At the end of the response we are going to have more tests and more confidence that in fact we are free.”

To be asked what stage the eradication process is at is a difficult question because it is not linear, he says.

McFadden suggests we have a ‘social media instant-gratification’ approach to eradication -- wanting to get rid of a problem in a very short time. Disease control programmes, such as hydatids, have historically taken decades but NZ has succeeded in eradication when other countries haven’t. 

“We still have a difficult disease; the tests are time consuming. It needs working through over time and we need patience.”

Earlier he told the conference that the infected farms are well and truly connected. Understanding an infection network in an outbreak is almost unheard of at this level of detail. 

“In this particular outbreak they are almost all connected and we have an understanding of how that connection has occurred.”

A group of individuals got together from government and industry to try to work through where the M. bovis came from. A number of scenarios were looked at and genetic testing of the bug was carried out. This testing ruled out imported cattle from Australia as a pathway.

Germplasm is the most likely pathway, but none of seven pathways looked at seemed particularly likely. He referred participants to the pathway report on the MPI website.

They are assuming a one-off event that has resulted in this outbreak.  Looking at the rate of mutation and the different strains they can work out how long it is likely to have been here. All the information supports that late M. bovis first arrived in late 2015. 

It all points to change

On very large farms with different ownership models today many veterinarians have limited contact with the animals, says McFadden.

That affects our surveillance ability: “What worked in the past – an eye on new incursions – won’t work now. We need to understand that and work out other solutions.”

He suggested legislation may be needed for greater oversight of animal welfare and a review of veterinary contact with farms and biosecurity risk behaviours.

More like this

MPI defends cost of new biosecurity lab

The head of the Ministry for Primary Industries (MPI) biosecurity operation, Stuart Anderson, has defended the cost and the need for a Plant Healht and Environment Laboratory (PHEL) being built in Auckland.

Bikinis in cowshed

OPINION: An animal activist organisation is calling for an investigation into the use of dairy cows in sexuallly explicit content posted on social media and adult entertainment subscription site OnlyFans.

Featured

US removes reciprocal tariff on NZ beef

Red meat farmers and processors are welcoming a US Government announcement - removing its reciprocal tariffs on a range of food products, including New Zealand beef.

India-New Zealand free trade agreement (FTA) dairy outcomes

OPINION: As negotiations advance on the India-New Zealand FTA, it’s important to remember the joint commitment made by Indian Prime Minister Narendra Modi and New Zealand Prime Minister Christopher Luxon at the beginning of this process in March: for a balanced, ambitious, comprehensive, and mutually beneficial agreement.

Honesty vital in flood insurance claims, says IFSO

As New Zealand experiences more frequent and severe flooding events, the Insurance & Financial Services Ombudsman Scheme (IFSO Scheme) is urging consumers to be honest and accurate when making insurance claims for flood damage.

National

Machinery & Products

New pick-up for Reiter R10 merger

Building on experience gained during 10 years of making mergers/ windrowers, Austrian company Reiter has announced the secondgeneration pick-up on…

» Latest Print Issues Online

Milking It

Remembering Bolger

OPINION: Is it now time for the country's top agricultural university to start thinking about a name change - something…

Time for action

OPINION: If David Seymour's much-trumpeted Ministry for Regulation wants a serious job they need look no further than reviewing the…

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter