EPIZOOTIC HAEMATOPOIETIC NECROSIS IN FINLAND
(Disease never reported before in Finland).
Information received by OIE on 4 November 2002 from Dr Jaana Husu-Kallio, Delegate of Finland to the OIE:
Report date: 4 November 2002.
Nature of diagnosis: clinical and laboratory.
Date of initial detection of animal health incident: 1 November 2002.
Estimated date of first infection: 19 April 2002.
Location province of Southern Finland
No. of outbreaks 1 farm
The farm is situated in south-eastern Finland, near the border with Russia, lower part of the large watercourse of Vuoksi, which flows via Lake Ladoga (Russia) to the Gulf of Finland in the Baltic Sea.
Description of affected population: sheatfish (Silurus glanis) imported from a European country in April 2002. No other susceptible species listed in the International Aquatic Animal Health Code are present at the farm.
Total number of animals in the outbreak:
species: pis, susceptible: 2,600 , cases: 50, deaths: 50, destroyed: 0, slaughtered: ....
Diagnosis: the virus was isolated from dead one-year-old sheatfish collected soon after their arrival at the farm. Mortality at the farm has been very low.
A. Laboratory where diagnosis was made: National Veterinary and Food Research Institute. The virus isolate was sent to the European Union Reference Laboratory in Denmark for confirmation.
B. Diagnostic tests used: virus isolation. Diagnosis was performed according to the Diagnostic Manual for Aquatic Animal Diseases, 3rd edition, 2000.
C. Causal agent: European sheatfish virus (ESV). According to the Diagnostic Manual for Aquatic Animal Diseases, ESV is one of the three iridovirus types considered as agents of epizootic haematopoietic necrosis.
A. Source of agent / origin of infection: the virus was isolated from sheatfish newly imported from a European country.
B. Other epidemiological details:
- The farm uses re-circulated, ozone-treated lake water heated by waste heat from a paper and pulp mill factory. Effluent water from the farm runs through the sewage treatment plant of the factory. Therefore the risk of virus spread to other farms and natural water is very limited.
- Sheatfish do not occur at other farms or natural waters in Finland.
- no virus was isolated in samples taken in September 2002.
- Movement restrictions on live fish are in place at the farm. Live fish have not been transported to other farms or natural waters since the arrival of the sheatfish.
- To eradicate the disease, sheatfish will be slaughtered for human consumption in such a way as to prevent any spread of virus to natural waters.
(Source: Disease Information , Vol 15 No. 45, 8 November 2002)