Abstract

VIRAL HAEMORRHAGIC SEPTICAEMIA IN THE UNITED KINGDOM/GREAT BRITAIN

( Date of previous outbreak of viral haemorrhagic septicaemia in the United Kingdom/Great Britain reported to the OIE: 1994).

Immediate notification report
Information received on 16 and 20 June 2006 from Dr Debby Reynolds, Director General for Animal Health and Welfare, Department for Environment, Food and Rural Affairs (DEFRA), London:

Report date: 20 June 2006.

Reason for immediate notification: first occurrence or re-occurrence in a country or zone /compartment of the country, if the country or zone/compartment of the country was previously considered to be free of that particular disease.

Identification of agent: viral haemorrhagic septicaemia virus genotype 1a.

Date of first confirmation of the event: 26 May 2006.

Date of start of the event: 28 March 2006.
Clinical disease: yes.
Nature of diagnosis: laboratory.
Details of occurrence:
Lower administrative division: North Yorkshire;
Type of epidemiological unit: river (Ouse Catchment);
Name of the location: Nidderdale trout farm;

Date of start of the occurrence: 28 March 2006;

Species: pis;

Animals (in kg) in the occurrence - susceptible: 300,699; cases: 94,000; deaths: 64,599; destroyed: 236,100; slaughtered: 0

Description of affected population:
rainbow trout( Oncorhynchus mykiss ).

Diagnosis:

Laboratory where diagnostic tests were performed: Centre for Environment, Fisheries and Aquaculture Science (CEFAS), national reference laboratory, Weymouth;

Species examined: pis;

No of animals examined: 20;

Diagnostic tests used: - cell culture / - ELISA(1) / - RT-PCR(2);

Results: - cytopathic effect / - positive / - positive

Date: 26 May 2006;

Source of occurrence or origin of infection: unknown or inconclusive.

Control measures

A. Undertaken:
- tracing forward;
- tracing back;
- surveillance within containment and/or buffer zone;
- surveillance outside containment and/or buffer zone;
- official destruction of clinically diseased aquatic animals;
- official disposal of carcasses, by-products and waste;
- control of wildlife reservoirs;
- stamping out;
- within-country movement controls.

B. To be undertaken:

- decontamination of premises/disinfection;
- zoning.

Other details/comments: deaths on the farm started on 28 March but were not notified to the official services until 17 May 2006 because the private fish health services considered it likely that they were due to a bacterial infection. VHS had not been suspected. The farm was inspected by the official services on 22 May 2006 and a sample of 20 moribund fish taken for diagnostic tests.

Final report: no.

(1) ELISA: enzyme-linked immunosorbent assay
(2) RT-PCR: reverse transcriptase - polymerase chain reaction