Advisory group meets to manage bacterium outbreak

Advisory group meets to discuss options for managing bacterium outbreak

The first meeting of the Technical Advisory Group (TAG) set up to consider the response to a disease outbreak in goats and cattle in the Waikato was held today. Officials from the Ministry of Agriculture and Forestry met for several hours with Dairy, Meat, and Goat industry representatives, along with Massey University veterinary experts.

MAF exotic disease response programme co-ordinator Matthew Stone said that it was unlikely a decision on the long term response to the outbreak of Mycoplasma mycoides subspecies mycoides (large colony (MmmLC) in goats and cattle would be reached until the end of November.

However, he wished to reassure people that the bacterium does not pose a human health hazard, also it is deactivated by pasteurisation.

He also emphasised the distinction of MmmLC from a related bacterium, Mycoplasma mycoides subspecies mycoides small colony (MmmSC) that causes a serious disease in cattle, called contagious bovine pleuropneumonia.

“Although that bacterium and the disease it causes are different from what we are seeing in New Zealand, some misunderstandings have arisen, with some trading partners mistakenly thinking we have the more serious MmmSC-related disease,” he said.

Dr Stone said that the TAG group would consider of different issues, including response options, their technical feasibility and cost, the economic impact associated with the presence of MmmLC in New Zealand.

Today’s meeting was mainly about building a framework and work plan to address these issues,” he said.

A recommendation on a long-term response objective, and the means of achieving this objective will be made by the Director of Animal Biosecurity taking into account recommendations from the TAG.

The TAG will probably meet again in late November to review the situation and finalise a recommended course of action.

In the interim, containment measures will be kept in place on the eight properties where exposure is known to have occurred. This includes three goat properties and four cattle properties in the Waikato and one cattle property in South Canterbury. A further Waikato goat property has been placed under movement restrictions as of today, as a result of a high-risk tracing of animal movements.

Five of these properties have been confirmed as infected and MAF hopes to have lab results for the remaining four properties in the next two weeks.

Surveillance and tracing measures put in place by MAF have located 27 high-risk movements, with expectations that all but six of these will have been followed up by the end of the week. Next week tracing, surveillance and processing samples through the laboratory will continue.

Consumption of unpasteurised goats’ milk from an infected dairy goat herd on July 25 caused the first exposure of calves on a large Waikato dairy cattle property.

The disease outbreak on these properties began with cases in kids on 25 July, and continued through August and September. During that period 34 cases in kids and 39 cases in calves occurred.

Six kids and 10 calves either died or were put down. The disease outbreak on these properties is now over, although recovered and exposed animals may be carrying the infection.

To alleviate the pressure imposed upon the large dairy cattle farm through restricted movement, MAF is urgently seeking a grazing block to rear exposed calves until they attain a killable weight.

In view of possible trade implications MAF will set up a Trade Group. The group will consist of representatives from MAF and key trade stakeholders and will consider implications the export of live animals and products, including the process of re-negotiating export certificates that have to had to be revoked.

Transmission of MmmLC can occur through a number of different routes although it is present in highest numbers in milk of infected animals and is passed from doe to kid. Herd to herd spread can be caused by the introduction of an infected animal.

MmmLC is found in Europe, Africa, North America and Australia, where it causes sporadic outbreaks of arthritis, conjunctivitis, and mastitis in goats, and in some countries, sheep.

At the present time MAF has not identified the time and route of introduction of the organism into goats in New Zealand. It is probable that the organism was introduced through imports of live goats. It is also possible that the organism was introduced several years ago but has escaped detection till now. Clarification of this will be a key issue for MAF's response and the decision on long-term response objectives.

The bacterium causes polyarthritis in goats, which is characterised by painful swelling of several joints. It also causes mastitis and conjunctivitis in goats. Signs in cattle have been polyarthritis and focal pneumonia (only apparent at post mortem).

If farmers suspect there life stock have become infected with the bacterium they can call 0800 809966

For further information contact: Philippa White Communications Adviser, 025 223 1875

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