VIRAL HAEMORRHAGIC SEPTICAEMIA IN THE UNITED STATES OF AMERICA
in Esox masquinongy
Immediate notification report
Information received on 26 January 2006 from Dr Peter Fernandez, Associate Administrator, Animal and Plant Health Inspection Service (APHIS), United States Department of Agriculture (USDA), Washington, DC:
Report date: 13 January 2006.
Reasons for immediate notification: occurrence in a new host species.
Identification of agent: North American strain of the viral haemorrhagic septicaemia virus (VHSV).
Affected species: muskellunge( Esox masquinongy ).
This is the first confirmed diagnosis of this pathogen in this species of pike(1), and the first known detection of the pathogen in this area of the Great Lakes.
Date of first confirmation of the event: 18 December 2005.
Date of start of the event: 20 May 2005 (date of sampling).
Clinical disease: yes.
Nature of diagnosis: clinical diagnosis and advanced laboratory tests.
Details of occurrence:
First administrative division (State): Michigan; Type of epide-miolo-gical unit: lake; Name of the location: Lake St. Clair; Date of start of the outbreak: 20 May 2005*(*date of sampling); Species: fau; Number of animals in the occurrence - susceptible:
Affected population: wild fish in fresh water.
Diagnosis: the fish were collected from wild stock during routine surveillance activities within Lake St. Clair, Michigan. Although the samples from wild-caught fish were obtained in May 2005, the samples were frozen and testing was completed in December 2005.
Laboratories where diagnostic tests were performed:
Aquatic Animal Health Laboratory, Michigan State University; Species examined: Esox masquinongy; Diagnostic tests used: - electron microscopy; - culture on FHM cell line; Date: June 2005; Results: presence of a rhabdovirus
Western Fisheries Research Center - USGS, Seattle, State of Washington; Species examined: Diagnostic tests used: - - - PCR(2); - gene sequencing; Date:
Results: sequence similarities to VHSV North American strain
Source of occurrence or origin of infection: unknown or inconclusive.
Control measures to be undertaken:
- surveillance within containment and/or buffer zone;
- surveillance outside containment and/or buffer zone.
Treatment of infected animals: no.
Other details/comments: vaccine against VHSV is not used in wildlife.
Final report: yes.
(1) Esox masquinongy is not listed in the Aquatic Animal Health Code as a species susceptible to VHS virus (see Chapter 2.1.5. of the Aquatic Animal Health Code ).
(2) PCR: polymerase chain reaction