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Back to Brucellosis Homepage
24 February 2003
Update on UK outbreak of Brucellosis
Tina Vernon BVSc MRCVS
Strathearn Farm & Equine Practice, Crieff, Perthshire
Tel: 07889 044 169
E-mail: tina.vernon@tesco.net
(Filed 24/02/03)
Brucellosis was diagnosed last week
near Forfar, Angus.
This is the first case in Scotland since 1973.
Background
Thrity six heifers born in Spring 2000 were imported
into Scotland in May/June 2002. On arrival in the UK they tested
negative for brucella, and again at a check test 60 days later.
The herd of origin in Republic of Ireland suffered a brucellosis
breakdown at the end of 2002. These thirty six animals, on five
farms across Scotland, have been under restriction since.
An aborted foetus from one of the heifers, on
a farm near Forfar, tested positive for Brucella
abortus last week.
In a separate incident last week, five cattle
imported from Northern Ireland in September 2002 have also been
placed under restrictions. Again this was following a brucellosis
breakdown in the exporting herd. Four of these went to a farm near
Middlesborough, and one to a farm in Scotland.
What is brucellosis?
Brucellosis is a disease caused by the bacteria
Brucella abortus. In cattle
it causes abortion in late pregnancy and often subsequent poor fertility.
It is an important zoonosis and can be spread
to man by contact with blood, urine, aborted foetus or discharges,
or by drinking unpasteurised milk. When the disease was prevalent
in cattle in Britain many farmers, butchers, vets and others were
affected. The disease can cause a range of problems in people, but
perhaps the most common is a recurrent cyclical fever which may
persist throughout life (sometimes known as Undulant Fever).
How was it eradicated?
The importance to both human health and cattle
productivity meant an intensive programme was set up to eradicate
brucellosis from the UK. This involved regular screening of all
cattle for antibody indicating exposure to the disease, and the
use of vaccine to offer protection in the interim period.
Since eradication in the 1970’s the situation
has been monitored continually by:
- Regular sampling of the bulk milk tanks from
dairies
- Blood sampling all beef cows, breeding bulls
& dairy & beef heifer replacements
- Screening all cattle abortions for brucella
How come these cattle tested negative when they were imported?
This is still being investigated. However, the
most likely explanation is that they were infected as calves, or
in utero, on the farm of origin.
Once infected the bacteria goes into dormancy
in the animal until she becomes pregnant. It then resurges &
causes the typical signs of abortion. The calves may have had antibody
to brucella for the first few months of life, either from their
own body response, or from colostrum from an infected dam. This
wanes quickly and they would then test negative until the disease
resurged in pregnancy.
This is a well known problem with brucellosis,
hence the need for continual screening and surveillance. It is also
the means by which most new herd outbreaks are transmitted.
What is happening now?
All the imported cattle have been traced and both
they and any contacts are in isolation and under movement restrictions.
The advice is to cull all these imported cattle and any offspring.
Contacts will be monitored regularly for evidence
of spread.
It appears that the first abortion was not reported,
so the risk to others in the herd may be increased.
What do farmers need to do?
It is essential (and a legal obligation) to report
any calvings/abortions at less than 271 days after service or 265
days after embryo transfer – even if the calf survives.
The aborted animal must be isolated until the
results of testing indicates all clear.
Remember the potential zoonotic risk and take
sensible precautions to minimise the risk to human health.
Any imported animals need to be blood tested just
after first calving, and the Divisional Veterinary Officer (DVO) should
be informed of when they calve.
Keep good movement records. Records have allowed
tracing of all the cattle imported in both incidents, and thus appropriate
action has been taken to minimise risk to the national herd.
Review sources for replacement heifers. The upsurge
of both brucellosis and tuberculosis recently in both Northern Ireland
and the Republic of Ireland makes it difficult to recommend importing
heifers at the moment.
When looking for alternative sources within Britain,
it is wise to consult the local animal health office for the herd
of origin with regards tuberculosis and other cattle diseases in
the area.
It would also be wise to look carefully at the
herd health status for diseases such as Johnes and bovine viral
diarrhoea (BVD).
Should the public be worried?
No. The herd in Angus where the bacteria has been
isolated (as opposed to just a dangerous contact, or antibody response
on a blood test) is a mixed beef and sheep farm. There is therefore
no risk from drinking milk.
The only danger is to attending stockmen, vets
and others who may have been exposed to discharges from the heifers.
To keep updated on the situation see www.defra.gov.uk
or www.scotland.gov.uk
24/02/03
Tina Vernon BVSc MRCVS
Strathearn Farm & Equine Practice, Crieff, Perthshire
Tel: 07889 044 169 E-mail: tina.vernon@tesco.net
Further Reading Recommended by Land-Care
DEFRA News release, 20th February 2003. Cull of Livestock in the
light of brucellosis cases in Scotland.
(Filed 21 February 2003, www.land-care.org.uk,
click
here to view).
Scottish Executive Press Release, 20th February 2003. Bovine brucellosis
cases confirmed.
(Filed 21 February 2003, www.land-care.org.uk,
click
here to view).
DEFRA (2001). Brucellosis: A reminder for all Cattle Farmers.
(Filed 21 February 2003, www.land-care.org.uk,
download
PDF).
Centers for Disease Control. Division of Bacterial and Mycotic Diseases:
Disease Information - Brucellosis (www.cdc.gov/ncidod/dbmd/diseaseinfo/brucellosis_g.htm).
(Filed 21 February 2003, www.land-care.org.uk,
click
here to view).
Arbuckle, Andrew (2003). Action Demanded as Brucellosis Found in
Angus. Dundee Courier, 21 February 2003.
(Filed 21 February 2003, www.land-care.org.uk,
click
here to view).
Uhlig, Robert (2003). Cull planned as cattle disease returns. Daily
Telegraph,
Friday 21 February 2003.
(Filed 24 February 2003, www.land-care.org.uk,
click here to view).
Cultybraggan Farm Diary (2002). Routine testing of Cultybraggan
cattle for Tuberculosis and Brucellosis, November 2002: All results
negative.
(Filed 26 November 2002, www.land-care.org.uk,
click
here to view).
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