Guidance on Containment for Work with Eastern Equine Encephalitis virus

The Federal Select Agent Program is providing this guidance on the containment facilities and practices that registered entities working with Eastern Equine Encephalitis virus (EEE) should follow.

The fifth edition of the Biosafety in Microbiological and Biomedical Laboratories (BMBL) states the following:
"Diagnostic and research activities involving clinical material, infectious cultures and infected animals or arthropods should be performed under BSL-3 practices, containment equipment, and facilities. Due to the high risk of aerosol infection, additional personal protective equipment, including respiratory protection, should be considered for non-immune personnel. Animal work with VEE virus, EEE virus and WEE virus should be performed under ABSL-3 conditions. HEPA filtration is required on the exhaust system of laboratory and animal facilities using VEE virus."

It is recommended that entities conducting diagnostic procedures which involve the potential for isolation and subsequent identification of EEE virus, but do not involve the manipulation of the virus, work under BSL-3 containment. However, if BSL-3 containment is not available this work may be authorized at BSL-2 under the following conditions:

1. Strict adherence to BSL-2 safety practices, safety equipment, and facility requirements, as described in the BMBL, must be maintained. Personnel protective equipment should, at a minimum, consist of gloves and laboratory coat.
   
   
2. Work with specimens suspected of containing EEE virus must be performed in a certified biological safety cabinet (BSC).
   
   
3. Centrifugation of material containing EEE virus, or suspected of containing EEE virus, must be done in a sealed rotor that can be removed and opened in a BSC.
   
   
4. For assays that do not require viral replication, protocols should be developed to achieve inactivation of the virus as an initial step to reduce the risk of exposure.
   
   
5. The risk assessment associated with this work should address the need for eye and/or respiratory protection.

Note: For the purpose of this policy the term manipulation refers to the isolation of EEE from a specimen followed by application of identification testing procedures that do not require propagation of the EEE to obtain additional EEE (i.e. protein or nucleic-acid based diagnostic tests). The term propagation refers to the isolation of EEE from a specimen and followed by sub-culturing or the culturing of stock EEE to obtain additional EEE for diagnostic research, or archival purposes. For work conducted under BSL-2 conditions as specified above, HEPA filtration of the room where the work is performed is not required.

Entities that conduct diagnostic or research procedures involving the propagation and manipulation of EEE virus are required to conduct this work in BSL-3 containment. Respiratory protection, gloves, shoe covers, and solid front gowns are recommended. The air in the room where the work is performed is not required to be exhausted through HEPA filtration as long as the exhaust air does not circulate to other areas of the building and is vented away from public areas and supply air intake vents.

Entities that conduct work with EEE virus that results in an aerosol, or that has the potential to cause an aerosol, are required to conduct this work under BSL-3 containment. The aerosol work must be conducted in a BSC, Class III cabinet or in a bubble chamber that is HEPA filtered if the air is exhausted into the room. Personnel protective equipment should consist of respiratory protection (N95/N100 or Powered Air Purifying Respirator (PAPR)) gloves, a solid front gown, scrubs or Tyvek suit and shoe covers.

Entities that conduct work with EEE virus involving animals are required to use ABSL-3 containment. HEPA filtration of exhaust air is required. Animal manipulation must be conducted in a BSC or Class III cabinet. HEPA filtered containment cages may be required depending on animal host. Personnel protective equipment must be N95/N100 masks or Powered Air Purifying Respirator (PAPR), gloves a solid front gown, scrubs or Tyvek suit, and shoe covers.

Entities that conduct work with arthropods and EEE virus are required to use ACL-3 containment. Appropriate filter/barriers are required to prevent the escape of arthropods.

Vaccination for EEE is not currently available.