It is recommended to perform virus isolation also in case of previous confirmation of classical swine fever by other methods.

In order that the manner of introduction of classical swine fever virus into an infected holding and the length of time elapsed since its introduction may be established, when pigs are killed on a holding following confirmation of an outbreak in accordance with Article 5(1)(a) of Directive 2001/89/EC, blood samples for serological tests must be taken at random from the pigs when they are killed.

This test is for confirmation of the diagnosis of Ralstonia solanacearum and for the assessment of the virulence of the cultures identified as Ralstonia solanacearum.

Virus isolation and identification by HAD are recommended as a reference test for the confirmation of positive results of a prior ELISA, PCR or DIFT. They are also recommended when ASF has already been confirmed by other methods, particularly in case of a primary outbreak or case of ASF.

In order that the manner of introduction of the ASF virus into an infected holding and the length of time elapsed since its introduction may be established, when pigs are killed on a holding following confirmation of an outbreak in accordance with Article 5(1)(a) of Directive 2002/60/EC, blood samples for serological tests must be taken at random from the pigs when they are killed.

Pursuant to Decision 2002/106/EC of 1 February 2002 approving a Diagnostic Manual establishing diagnostic procedures, sampling methods and criteria for evaluation of the laboratory tests for the confirmation of classical swine fever fn, no suitable discriminatory tests are available to distinguish vaccinated pigs from pigs naturally infected with classical swine fever virus.

In the case of confirmation of the presence of classical swine fever in holdings which consist of two or more separate production units and in order that fattening of pigs may be completed, the competent authority may decide to derogate from the provisions of Article 5(l)(a) as regards healthy pig production units on a holding which is infected provided that the official veterinarian has confirmed that the structure, size and distance between these production units and the operations carried out there are such that the production units provide completely separate facilities for housing, keeping and feeding, so that the virus cannot spread from one production unit to another.

Confirmation of Newcastle-disease virus would again be by inhibition in haemagglutination inhibition tests with monospecific chicken antisera.

Virus isolation and identification by HAD are recommended as a reference test for the confirmation of positive results of a prior ELISA, PCR or DIFT.

Such monoclonal antibodies should be obtained by the Community reference laboratory as referred to in Article 14 and supplied to the national laboratories to enable confirmation of the isolation of vaccinal viruses.

When the presence of swine vesicular disease virus in a holding is suspected as clinical signs of disease have been observed, appropriate samples from representative groups of pigs showing these signs must be collected for disease confirmation and differential diagnosis with foot-and-mouth disease.

Otherwise, at the earliest possible occasion, the National Laboratory must send a sample of virus from the primary case to the Community Reference Laboratory for confirmation and further characterisation, including advice on the antigenic relationship of the field strain to vaccine strains in the Community antigen and vaccine banks.