Brucellosis questions and answers
Frequently asked question in relation to Brucellosis in Northern Ireland.
- What is an inner ring herd / outer ring herd?
- Why does the Department not take animals that give more than one doubtful reading?
- If I report an abortion will my herd be restricted?
- If my herd becomes infected with Brucellosis will it be bought out?
- If Brucella abortus was not isolated from the glands of my animal why is my herd not opened?
- What blood tests are used?
- If my herd is bought out what can I do with my silage?
- I am inner ring to a breakdown. Will my herd be restricted and how long do I have to test for?
- I am outer ring to a breakdown. Will my herd be restricted and how long do I have to test for?
- How long will it be before my reactor animal is taken?
- Why do I have so many doubtful animals?
- What is a forward traced animal?
- Why is compensation for reactors 75% of market value?
- How can Farmers protect themselves from the disease?
1. What is an inner ring herd / outer ring herd?
- As a general rule an inner ring herd marches the breakdown herd and an outer ring herd marches the inner ring herd. If the inner ring herd has an outfarm, the farms marching the outfarm may be considered to be outer ring to the breakdown herd.
2. Why does the Department not take animals that give more than one doubtful reading?
- The majority of these animals eventually become seronegative, that is negative to the blood test. Certain other bacteria and viruses can give readings to the tests commonly used for the detection of brucellosis. If the readings given on the blood test are getting worse, then due consideration will be given as to whether or not to take the animal as a reactor.
3. If I report an abortion will my herd be restricted?
- No. The aborted animal will be restricted until a clear test is obtained 21 days after the abortion. It is Department policy to test the animal when the abortion is reported and again at 21 days after the abortion.
4. If my herd becomes infected with Brucellosis will it be depopulated?
- This depends on several different factors and each case is looked at on an individual basis. The Veterinary Officer dealing with your breakdown will be the person who can best advise you on this matter. In some cases the herd may be depopulated.
5. If Brucella abortus was not isolated from the glands of my animal why is my herd not opened?
- There have been cases where the organism was not isolated from animals that gave positive readings to the blood test. This does not mean that these animals did not have Brucellosis. Each herd breakdown is looked at on an individual basis, and a decision as to when to derestrict a herd is made after taking several factors into account, for example the number of reactors, how high the readings were, whether the reactors were cows or maiden heifers, how long the reactors were in the herd and the number of breakdowns in the area.
6. What blood tests are used?
- There are currently three different laboratory blood tests that are used routinely in Northern Ireland. These are the SAT (serum agglutination test), the CFT (complement fixation test) and the EDTA (ethlyene diamine tetra acetic acid).
The SAT is used as the screening test for brucellosis. The CFT is regarded as one of the most sensitive for brucellosis and therefore any CFT reading at a test is regarded with great suspicion. The addition of EDTA to the SAT helps to distinguish cross-reactions to the SAT.
- The iELISA test has been introduced to some inconclusive tests and high risk tests in order to further increase the accuracy of the testing regime.
7. If my herd depopulated what can I do with my silage?
- Under current legislation the sale of silage from a breakdown herd is not prohibited. However, cleansing and disinfection should be carried out on the premises prior to movement of any silage, and cleansing and disinfection must be completed on the vehicles used to transport it prior to, and after, transportation. It would be good practice to feed this silage to bullocks only.
8. I am inner ring to a breakdown. Will my herd be restricted and how long do I have to test for?
- If you have not tested in the past 4 or 5 months your herd will be restricted until two clear herd tests have been carried out. This means that any inconclusive animals will have to be cleared also. Your herd will be tested until you complete one clear test after the breakdown herd has been opened.
9. I am outer ring to a breakdown. Will my herd be restricted and how long do I have to test for?
- Whenever there is a breakdown, a decision has to be made on risks to other herds. Based on the risk assessment Outer Ring Testing may or may not be required. If it is required the following will apply:
- If you have not tested in the past 4 months your herd will be restricted until one clear herd test has been carried out. This means that any inconclusive animals will have to be cleared also. Your herd will be tested until you complete one clear test after the breakdown herd has been opened.
10. How long will it be before my reactor animal is taken?
- It is Department policy to remove reactor animals within 15 working days of the blood test being taken.
11. Why do I have so many doubtful animals?
- A test can be interpreted under standard or severe interpretation depending on the perceived risk. If the herd is inner ring to a breakdown or it is considered that there is a large risk in the herd (for example a breakdown herd or a herd with several animals in it that have come from or through a breakdown herd), then the test is interpreted under severe interpretation. This means that any reading on the blood test is considered to be an inconclusive reading.
12. What is a forward traced animal?
- A forward traced animal is an animal that has come from or through a breakdown herd. These animals must be isolated as they may pose a risk to your herd. If these animals are females they are kept under restriction until they are slaughtered or have tested clear at 21 days after calving. Forward Traced High risk animals may be taken compulsorily as negative in contacts. In addition female progeny born in the two years prior to the dam being declared a reactor are bought and removed as negative-in-contact cattle. The reason for doing this is because female calves born to reactor animals may be latently infected with the disease i.e. silent carriers for an uncertain length of time.
- If bulls are forward traced they are kept under restriction until they are out of the breakdown herd for a least a year and have tested clear at that stage. Bulls and maiden heifers are tested at 3 monthly intervals whilst cows are tested at monthly intervals. However if a forward traced maiden heifer originates from a herd that is not bought out it may be derestricted after three tests where the final test takes place after the herd of origin has been derestricted.
- If the forward traced animal is dead and cannot be tested your herd will usually be subject to a herd test.
13. Why is compensation for reactors 75% of market value?
- The Brucellosis Control Order determines the compensation to be paid for Brucellosis reactors at 75% of the animal’s market value. The level of compensation reflects the fact that the animal is considered a reactor and a risk to animal health. Under the present arrangements, compensation is paid at 100% of market value for other animals slaughtered as a result of Brucellosis. During 2008/09, DARD plans to examine the existing arrangements for Brucellosis compensation in NI as well as looking at what scope there is for other possible areas for policy change that would impact on the cost of disease in NI.
14. How can Farmers protect themselves from the disease?
- Brucellosis is a serious disease in people which causes flu-like symptoms with fever, sweating and chills. There may also be aches and pains in the joints and headaches, fatigue, depression and weight loss.
- The infection usually enters the body by splashes to the eyes, inhalation, swallowing or through breaks in the skin. Farmers are especially at risk as they can become infected through handling aborted calves or infected material or by helping at calvings which appear to be normal.
Reducing the risks
At calving and abortions -
- Keep to a minimum those who assist or are present at calving.
- Cover all cuts and abrasions with waterproof dressings – the bacteria enter through uncovered wounds.
- Washable protective clothing, including arm-length gloves should be worn at all calvings/abortions to ensure that there is no skin contact with animal fluids, tissue or after-birth.
- Wear a visor if there is a risk of fluids or tissue being splashed on your face, lips or eyes. Matter can easily land on your face from a dirty tail.
- Wear a mask/respirator to prevent the organism being inhaled ( FFP3SL specification)
- Do not use mouth to mouth resuscitation for weak calves.
In general -
- Wash and remove protective clothing and gloves before entering the dwelling house.
- Wash hands and arms thoroughly after work and before eating, drinking or smoking.
- Do not drink raw unpasteurised milk.
- Keep children and the elderly away from calvings/abortions and those cows recently calved /aborted.
- Advice is given to herd owners at the time of breakdowns by the Department. Make yourself aware of the early symptoms and seek medical advice if you have any concerns.
- The Health and Safety Executive can be contacted through their helpline number 0800 0320 121
