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Herpesvirus B Biological Agent Reference Sheet (BARS)

Last revised 03/05/2024

Disclaimer: Risk group, biosafety level, and all other precautions noted here are subject to change after a risk assessment by EHS.

This information has been prepared to align with the NIH B Virus Resource Program guidelines and recommendations. 


Agent Type Risk Group Biosafety Level Animal Housing Biosafety Level



No propagation or work with viral isolates is permitted at Cornell.

BSL-3 containment practices are required for work with diagnostic materials suspected for CHV-1.

BSL-2 practices and facilities are suitable for all activities involving the use or manipulation of tissues, cells, blood, or serum from macaques with appropriate personal protective equipment
No experimental infection or work with CHV-1-virus-infected animals is permitted at Cornell.

Synonym or Cross Reference: Herpes simiae virus, herpesvirus simiae, B virus, herpes B virus, herpes B, monkey B virus, W virus, monkey herpes infection, simian herpesvirus B infection, and B virus infection, Macacine alphaherpesvirus 1, McHV-1, Macacine herpesvirus 1

Agent Characteristics 

Description: CHV-1 belongs to the subfamily Alphaherpesvirinae, genus Simplexvirus, closely related to herpes simplex virus-1 and -2. CHV-1 is the only non-human primate herpesvirus shown to infect humans. In the natural host, the virus exhibits pathogenesis similar to human cold sores. In humans, zoonotic infection with B virus can cause severe encephalitis, leading to permanent neurological dysfunction or death. Untreated cases have an approximately 80% case fatality rate.

The genome structure, genetic makeup, and unique features of Cercopithecinae herpes virus 1 (B virus) are studied extensively. For detailed genetic information, refer to the NIH B Virus Resource Program.

Host Range: Humans, macaque monkeys (including M. artoides, M. nemestrina, M. fuscata, M. radiate, M. cyclopis), with M. mulatta and M. fascicularis as the main natural reservoirs. All macaques should be considered potentially infected. Experimental hosts include rabbits, dogs, mice, and guinea pigs.

Host Shedding: Bodily fluids of infected monkeys. CHV-1 is not present in blood or serum in healthy infected macaques.

Route of Exposure to Humans: Mucous membranes, skin breaks.

Infectious Dose: Unknown

Incubation Period: The reported range is two days to 5 weeks, though most cases become apparent in 21 days or less.

Health Hazards

Asymptomatic CHV-1 virus shedding is the primary transmission mode among monkeys and human workers. Exposure via mucous membranes or skin breaks provides access to the new host. Transmission occurs through bites, scratches, splashes, and contaminated surfaces. Cercopithecinae herpes virus 1 is a hazard in facilities where macaque monkeys are present or with cell cultures and CNS tissue. Mucosal secretions (saliva, genital, conjunctival) are primary risk for transmission. Zoonoses have been reported after exposure to monkey cell cultures and CNS tissue. Barrier precautions should be observed with confirmed cases as there are no effective vaccines or curative therapeutics for humans.

All macaques, regardless of their origin, should be considered potentially infected. Animals with no detectable antibody are not necessarily CHV-1-free.

Agent Viability 

Survival Outside Host Disinfection Inactivation
Storage of CHV-1 in tissue culture medium (pH 7.2, 4°C) resulted in a slight loss in viability after 8 weeks. A single episode of freezing at either -20°C or -72°C resulted in an initial loss of 2 logs of infectivity of tissue culture medium stored specimens. All infectivity of CHV-1 is lost after storage in tissue culture media at 40°C for 2 weeks.

CHV-1 is susceptible to fresh 0.25% hypochlorite solution, povidone-iodine, and chlorhexidine

Heat inactivated by 56ºC for 30 minutes or longer. 

For more guidance on disinfection, see disinfectant selection.

Laboratory Hazards 

  • High energy-creating activities (centrifugation, sonication, high-pressure systems, vortexing, tube cap popping) 
  • Handling of sharps (needles, scalpels, microtome blades, broken glass, etc.) 
  • Splash/droplet-creating activities (shaking incubators, liquid culturing, mechanical pipetting) 
  • Equipment contamination
  • Exposed skin/uncovered wounds 

Laboratory Acquired Infection (LAI) History: The first human case of CHV-1 was reported in a laboratory researcher in 1932, who was bitten on the finger by an apparently healthy rhesus macaque and died of progressive encephalomyelitis 15 days later. There have been approximately 50 reported cases of Herpes B virus (CHV-1) infections in laboratory workers globally. These infections often result from exposures such as needlestick injuries, mucous membrane contact, and broken skin coming into contact with virus-containing materials. Mortality from exposure is approximately 80%.

Laboratory Handling Guidelines 

Laboratory Biosafety Level (BSL): No work with CHV-1 isolates at Cornell. Work with the agent and infected animals requires BSL-4 or ABSL-4 containment practices.

Work with diagnostic samples at BSL-3 containment.

Work with samples from animals tested regularly and found negative may occur using BSL-2 containment practices. All materials must be handled inside primary containment, such as biosafety cabinets. Centrifugation of samples must use centrifuges with safety cups or sealed rotors loaded and unloaded inside biosafety cabinets. Processes like homogenization or vortexing must occur inside biosafety cabinets.

Attenuated Strain Alternatives: None known.

Training Lab Engineering Controls Personal Protective Equipment

Lab safety training, including BSL-2 training, and annual training for CHV-1 hazards, including exposure modes, transmission, and emergency response.

See EHS Biosafety Training Curriculum

  • Biosafety cabinet (BSC)

  • Centrifuge lids or safety cups; samples are loaded/unloaded inside the BSC

  • Use of safety-engineered sharps

Safety glasses, lab coat, gloves; face shield for procedures with splash or spray hazards (consult with EHS).

Waste Management: Regulated Medical Waste (RMW)

Shipping Guidance: Refer to EHS Biological Materials Shipping Shipment of the virus has explicit permitting requirements from CDC and USDA. Shipment of animal-derived materials may require permitting from the USDA, including domestic shipments.

Animal Vivarium Guidance

Animal Housing Biosafety Level (ABSL): No experimental infection or work with CHV-1-virus-infected animals is permitted at Cornell.

Exposure and Spill Procedures 

Exposure to B-virus and materials derived from macaques can occur through various means. Direct contact of macaque materials or the agent with mucous membranes (such as eyes, nose, and mouth) or broken skin can lead to exposure. Accidental cuts, stabs, or punctures with objects contaminated by macaque materials also pose a significant risk. It is crucial to note that all macaques should be considered potentially infected, and caution is advised when handling samples.


Risk Level


Neurological tissues, including the spinal cord


High viral load; significant risk of B-virus transmission

Adrenal glands


Moderate viral load; substantial risk of transmission

Salivary glands, saliva


Moderate viral load; potential risk through bites.

Lymphoid tissues


Moderate viral load; potential risk of transmission

Blood and serum


Lower viral load; lower risk of transmission

Call or contact EHS Biosafety for additional guidance.

Mucous Membranes: Flush eyes, mouth, or nose for 15 minutes at an eyewash station. See: responding to exposures.

Other Exposures: Thoroughly wash and scrub the area or wound with soap, a concentrated solution of detergent, povidone-iodine, or chlorhexidine, or 0.25% sodium hypochlorite (5% household bleach) and water for 15-20 minutes. Then, irrigate the washed area with running water. Seek medical evaluation.

Medical Treatment and Surveillance:

Employees and students go to Cayuga Medical Center’s emergency department, located at 101 Dates Dr, Ithaca, NY 14850, or the nearest emergency department. Give a copy of this sheet to the physician so they understand that you may have just been exposed to Cercopithecinae herpes virus 1 (or herpes B virus), and this is a medical emergency.

Physician Information:

This is not herpes zoster – this is a potentially life-threatening disease. Herpes B virus is one of the highest-risk pathogens in humans, belonging to the risk group 4 of pathogens. Contact Cornell University Biosafety or Cornell University Occupational Medicine for additional information.

Perform the following specimen collection:

  • Irrigate wounds,
  • Flush mucous membranes,
  • Repeat cleansing
  • Debride as necessary
  • Collect
    • (2) serum separator (SST) blood collection tubes.
    • Viral swab(s) of the affected area in commercially prepared viral transport media (VTM), if appropriate, based on the nature of exposure.
    • The employee should be evaluated for treatment with oral valacyclovir 1 gram 3 times per day for 14 days, or oral acyclovir 800 mg 5 times/day for 14 days, or another comparable chemoprophylaxis. Refer to the recommendations outlined in Recommendations for Prevention of and Therapy for Exposure to B Virus (Cercopithecine Herpesvirus 1)

Small Spills:

  1. Notify Others: Inform colleagues working in the lab about the spill.
  2. PPE: Wear appropriate personal protective equipment (lab coat, gloves, and safety glasses).
  3. Containment: Cover the spill area with absorbent materials (e.g., paper towels) to absorb the spilled material.
  4. Clean-Up: Carefully clean the spill area using an appropriate disinfectant solution recommended for BSL-2 or BSL-3 labs, depending on the facility's biosafety level. Dispose of contaminated materials in a biohazard waste bag.
  5. Decontamination: Decontaminate surfaces and equipment that came into contact with the spill using an appropriate disinfectant.

Large Spills:

  1. Notify Others: Inform colleagues, evacuate the area, and restrict access.
  2. Evacuation: Evacuate the laboratory area immediately to prevent exposure to potentially aerosolized contaminants.
  3. PPE: Wear appropriate personal protective equipment (lab coat, gloves, safety glasses, and a face shield).
  4. Containment: Cover the spill area with absorbent materials and apply a suitable disinfectant.
  5. Clean-Up: Trained professionals or EHS personnel should handle large spills. Follow established spill cleanup procedures with extreme caution.

You may request aid from EHS by calling CUPD dispatch. Call 911 from a campus phone or 607-255-1111 from a mobile phone. Ask for a biological safety hot page.

Incident Reporting: Immediately report the incident to the supervisor and complete the EHS online injury/illness report as soon as possible.

Medical Follow-Up:

  • Seek a medical evaluation with an infectious disease specialist for care at 1, 2, 4 weeks. Serological testing should occur at week 4 follow-up. Cornell Health does not see employees for post-exposure care.
  • Emergencies: Call 911 from a campus phone or 607-255-1111 from a mobile phone.

More Information


Cohen, Jeffrey I., et al. Recommendations for Prevention of and Therapy for Exposure to B Virus (Cercopithecinae herpes virus 1). Clinical Infectious Diseases 2002; 35:1191-1203.

Holmes, et. al. Guidelines for the Prevention and Treatment of B-virus Infections in Exposed Persons. Clinical Infectious Diseases 1995; 20:421-439.

Biosafety in Microbiological and Biomedical Laboratories 6th edition

Centers for Disease Control and Prevention (CDC). 1987. Guidelines for the Prevention of Herpesvirus simiae (B Virus) Infection in Monkey Handlers. Morbidity and Mortality Weekly Report (MMWR) 36 (41): 680-682, 687-689; October 23, 1987.

Cercopithecine herpesvirus 1 (B Virus) infection resulting from ocular exposure. NOISE, May 1999. Publication No. 99-100. Reviewed 11/27/02. Revised: 6/19/07, 7/08

CME Resource. Zoonotic Diseases. Prevention and Nursing Care. January 2001, Vol 73, No.2.

“People at High Risk for Infection for Herpes B Virus.” Centers for Disease Control and Prevention, 31 Jan. 2019,

Johnson, R. K., Gilden, D. H., Ellerbrock, T. V., & Herndon, R. M. (2018). B virus (herpes B): a historical and clinical review. Viruses, 10(5), 266.

Mandell, G. L., J. E. Bennett, et al. (2010). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Philadelphia, PA, Churchill Livingstone/Elsevier.