West Nile Virus (June 2001, Revised June 2003)

Biosafety Advisory

We are providing you with the following biosafety advisory regarding the laboratory manipulation of the West Nile (WN) virus and handling of potentially infectious clinical specimens.

Precautions for the field collection of dead birds and other animals:

Persons involved in collecting dead birds and other animals should follow the recommendations of the Occupational Health Advisory West Nile Virus, Revised May 29, 2003:

  • precautions for mosquito avoidance (i.e. wearing long sleeved shirts, full length trousers, socks, light coloured clothing, high boots) and the use of repellants (i.e. 20-30% DEET) should be implemented
  • when possible, minimize outdoor activities where and when (e.g. dusk, night, dawn) mosquitoes are likely to be encountered
  • bare-handed contact should be avoided when handling dead animals and birds and precautions should be taken to avoid direct contact with excretions
  • rubber/nitrile/latex/vinyl/PVC gloves and double plastic bags turned inside out over hands can be used to collect dead birds
  • cut-resistant gloves can be worn under rubber/nitrile/latex/vinyl/PVC gloves to avoid cuts or puncture wounds from bills, claws, or instruments during handling and dissection of birds and other animals
  • hands should be washed after handling dead birds

Precautions for the handling of suspect specimens in animal necropsy suites:

  • where practical, animal carcasses should be manipulated in a certified biological safety cabinet (BSC)
  • larger carcasses should be manipulated using equivalent protective measures (e.g. splash protection on eyes, protective solid-front gowns with tight fitting wrists, rubber/latex/vinyl/PVC gloves, and respiratory protection1 (NIOSH certified N-95 to N-100 respirator filter mask, half or full face, depending on splash protection)

Precautions for the handling of human and animal (including avian) suspect clinical specimens:

  • potentially infected human and animal clinical specimens (e.g. blood, serum, CSF, tissues) may be handled in a Containment Level 2 facility2 using Containment Level 3 operational practices2 as outlined below
  • blood collection should be carried out using standard universal precautions3 (e.g. wearing gloves, hand washing, avoiding needle sticks)
  • sorting of mosquitoes for species identification, where possible and practical, may be performed in a Containment Level 2 facility2
  • certified biological safety cabinets should be used for laboratory manipulations of suspect clinical specimens
  • centrifugation of clinical specimens (e.g. for serum separation) should be carried out using sealed centrifuge cups or rotors that are loaded and unloaded in a biological safety cabinet
  • aliquots used for serology should be heat inactivated at 56° C for 30 minutes
  • PCR testing may be performed in a Containment Level 2 facility1 using Containment Level 3 operational practices2

Precautions for virus isolation and laboratory manipulation of the WN virus:

  • virus isolation and propagation should be performed in a Containment Level 3 facility2 using Containment Level 3 operational practices2
  • animal studies should be performed in a Containment Level 3 animal facility1 using Containment Level 3 operational practices1
  • studies involving infected mosquitos should be performed in a Containment Level 3 facility2 using Containment Level 3 operational practices2

Dead birds and sera to be tested (eg. sera collected from sentinel chickens) should be packaged adequately and labelled and shipped as "Diagnostic Specimen".

Shipping, packaging and transport of the WN virus and suspect clinical specimens and sera should follow the Transportation of Dangerous Goods Regulations, Transport Canada.

  1. Further biosafety information may be obtained from the Office of Laboratory Security, Public Health Agency of Canada, at (613) 957-1779 or fax (613) 941-0596.

  2. Further occupational health and safety information is available in the Occupational Health Advisory, Occupational Health and Safety Agency, June 24, 2003.


  1. Containment Standards for Veterinary Facilities, Agriculture and Agri-Food Canada, Publication No. 1921, July 1996.
  2. Laboratory Biosafety Guidelines, 3rd Edition, Public Health Agency of Canada.
  3. Preventing the Transmission of Bloodborne pathogens in Health Care and Public Service Settings, Canada Communicable Diseases Report - Supplement Vol. 23S3, May 1997.

Material Safety Data Sheet - West Nile Virus

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