Snowshoe Hare Virus Agent Information Sheet

Boston University
Research Occupational Health Program (ROHP)


Snowshoe Hare virus is a member of the California encephalitis subgroup of Bunyviridae.  It was first identified in Montana in 1958.  Its distribution includes Canada, Alaska, and Eastern Asia.


Snowshoe Hare virus symptoms can include flu like illness, headache, nausea, vomiting, seizure, and confusion (encephalitis type symptoms).


A bunya virus present in mosquitoes, and rarely infect humans.

Biosafety Information

Risk Group/ABSL
Risk Group 2

Modes of Transmission
Transmitted by mosquitoes, wild mammals infected.

Skin Exposure (Needlestick, bite, or scratch):Accidental parenteral inoculation or exposure to non-intact skin
Mucous Membrane Splash to Eye(s), Nose or Mouth:Direct or indirect contact with mucous membranes
Inhalation:Unlikely unless aerosolized
Ingestion:Unlikely in laboratory setting

Host Range/Reservoir
Mosquitoes and vertebrates      

Snowshoe Hare virus symptoms can include flu like illness, headache, nausea, vomiting, seizure, and confusion (encephalitis type symptoms).  Can develop elevated white blood count and protein, and low sugar in cerebrospinal fluid.

Incubation Period

Susceptible to 70% alcohol, 1% sodium hypochlorite, and 2% glutaraldehyde

Survival Outside Host

Information for Lab Workers

Laboratory PPE

BSL-2 precautions – lab coat, gown, and gloves.  Wear eye protection if splash risk.


BSL-2 and ABSL-2 practices

In Case of Exposure/Disease

  • For injuries in the lab which are major medical emergencies (heart attacks, seizures, etc…).
    • Medical Campus: call or have a coworker call the Control Center at 617-414–4144.
    • Charles River Campus: call or have a coworker call campus security at 617-353-2121.

    You will be referred to or transported to the appropriate health care location by the emergency response team.

  • For lab exposures (needle sticks, bite, cut, scratch, splash, etc…) involving animals or infectious agents, or for unexplained symptoms or illness call the ROHP 24/7 hour number (1-617-358-ROHP (7647); or, 8-ROHP (7647) if calling from an on-campus location) to be connected with the BU Research Occupational Health Program (ROHP) medical officer. ROHP will refer you to the appropriate health care location.
  • Under any of these scenarios, always inform the physician of your work in the laboratory and the agent(s) that you work with.
  • Provide the wallet-size agent ID card to the physician.


There is no vaccination available

Information for First Responders/Medical Personnel

Public Health Issues

After exposure:  No human to human transmission.

In case of illness:  Standard precautions

PPE:  Standard precautions


Diagnosed by PCR or 4 times rise in acute and convalescent serum specimens on blood serology – IgM and IgG response (EIA)

First Aid/Post Exposure Prophylaxis

Perform one of the following actions:

Skin Exposure (Needlestick or scratch):Immediately go to the sink and thoroughly wash the wound with soap and water for 15 minutes. Decontaminate any exposed skin surfaces with an antiseptic scrub solution.
Mucous Membrane Splash to Eye(s), Nose or Mouth:Exposure should be irrigated vigorously.
Splash Affecting Garments:Remove garments that may have become soiled or contaminated and place them in a double red plastic bag.


There is no treatment other than supportive care.  Interferon may be effective in animals.


Fauvel M et al.  California group virus encephalitis in three children from Quebec: clinical and serologic findings.  Canadian Medical Association Journal, Vol. 122, 1/12/80, 60-4.


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