ANNEXMANUAL OF DIAGNOSTIC PROCEDURES, SAMPLING METHODS AND CRITERIA FOR THE EVALUATION OF THE RESULTS OF LABORATORY TESTS FOR THE CONFIRMATION AND DIFFERENTIAL DIAGNOSIS OF SWINE VESICULAR DISEASE

CHAPTER XSwine vesicular disease reference sera

Reference serum

Origin

Comment8

1

Normal pig serum (NPS)

Negative control serum.

2

Serum collected 21 days post infec- tion (dpi) from a pig infected with swine vesicular disease virus strain UKG 27/72 (neat)

Strong positive control serum.

3

A 1:10 dilution in NPS of a serum collected five dpi from a pig infected with swine vesicular disease strain Italy 8/94

A low-positive serum from a pig soon after infection with a recent European isolate of swine vesicular disease virus. The serum has been diluted to give a low positive result in ELISA and VNT.

4

A 1:40 dilution of a serum collected 21 dpi from a pig infected with swine vesicular disease virus strain UKG 27/72

A low-positive serum defining the lowest level of antibodies that EU National Reference Laboratories should consistently score positive by ELISA and virus neutralisation.

Equivalent to serum RS 01-04-949

5

Serum collected four dpi from a pig infected with swine vesicular disease virus strain UKG 27/72 (neat)

A low-positive serum from a pig soon after infection.

6

Serum collected five dpi from a pig infected with swine vesicular disease virus strain UKG 27/72 (neat)

A low-positive serum from a pig soon after infection.

These comments relate to the testing of individual pigs. For sero-surveillance the sensitivity of the test used should be taken into account.

i.e. a serum with a titre sufficiently greater than the cut-off that it should always score positive by ELISA and VN test in repeated testing.