Classical Swine Fever
Thorough investigations for classical swine fever in two Danish holdings.
The Lithuanian veterinary authorities has based on results of investigations on the national laboratory confirmed an outbreak of classical swine fever the 11 July 2009.
As these pigs originally came from two Danish holdings in the southern part of Jutland, the Danish Veterinary and Food Administration (DVFA) decided to carry out a thorough investigation in the two Danish holdings to rule out the possibility that the infection came from Denmark.
The investigations were carried out although the pigs from the Danish holdings were delivered to Lithuania in February 2009, more than three months earlier, which is the time limit given by the World Organisation for Animal Health (OIE) for how long an animal has to be kept in one country, before it no longer has the health status of the originally country.
The investigation was carried out in cooperation with the Danish National Veterinary Institute.
In connection with national surveillance of classical swine fever in holdings with breeding animals in Denmark, 30 blood samples from each holding were tested in June 2009. All tests were negative.
30 samples taken by the DVFA in connection with the clinical surveillance of the two holdings were also negative.
Also test done on 30 samples from each month March to May from each herd were negative for classical swine fever.
Additionally a large number of boars delivered from the two holding to semen collection centres in Denmark have been tested for classical swine fever with negative result.
In order to finally acquitting the Danish pig herds for being the source of the classical swine fever infection in Lithuania, the DVFA decided to conduct an additional sampling at the farms within a sampling frame of detecting 1 % prevalence with a confidence level of 95 %. This sampling took place on the 5-6 July and focussed on sows having given birth to the pigs exported to Lithuania, litter mates left in the herds and an appropriate number of other pigs from the herds.
The number of animals tested at each herd appears from the table below.
Holding 1:
|
Sampling date
|
Test number
|
Test result
|
|
23-03-2009
|
101
|
31-03-2009 Negative
|
|
15-06-2009
|
302
|
02-07-2009 Negative
|
|
02-07-2009
|
303
|
03-07-2009 Negative
|
|
March-May 2009
|
904
|
04-07-2009 Negative
|
|
06-07-2009
|
3905
|
07-07-2009 Negative
|
Holding 2:
|
Sampling date
|
Test number
|
Test result
|
|
03-03-2009
|
101
|
17-03-2009 Negative
|
|
03-06-2009
|
302
|
02-07-2009 Negative
|
|
02-07-2009
|
303
|
03-07-2009 Negative
|
|
March-May 2009
|
904
|
04-07-2009 Negative
|
|
04-07-2009
|
2735
|
07-07-2009 Negative
|
1 Routine quarterly CSF test
2 Surveillance samples for SPS surveillance incl. CSF test
3 DFVA samples
4 Recovered surveillance samples for SPS surveillance
5 Additional DFVA samples
All samples has been analysed on The Danish Veterinary Institute and all were negative for classical swine fever.
Denmark has remained free from classical swine fever since 1933.
Contact
Animal Health Division -
1kontor@fvst.dk