B Virus Information for Researchers

Cheryl S. Barbanel, MD, MBA, MPH, FACOEM 3/6/07

Cercopithecine Herpesvirus-1

What is B Virus?

B Virus (BV) is a common pathogen in monkeys of the genus Macaca including rhesus cynomolgus, bonnet and stump tail macaques.

BV in monkeys is similar to herpes simplex virus in humans.

BV in humans causes a rare but rapid ascending paralysis in humans with a 70% fatality rate.

All cases of B virus occur after exposure to monkeys, monkey tissues or bodily fluids from an infected person (one case). Symptoms typically appear five days to one month following exposure. Symptoms include “vesicular skin lesions at or near the exposure site; aching; chills and other flu–like symptoms; persistent fever; nausea; lethargy; chest pain and difficult breathing; and neurological symptoms such as itching or tingling at or near the exposure site, numbness, dizziness, double vision, difficult swallowing and confusion.” Other symptoms may occur as well. Treatment is critical, as coma, respiratory failure and death quickly result otherwise.

(from Nonhuman Primates in Biomedical Research: Biology and Management pp 395)

Human Incubation Period After an Identified Exposure to B Virus

2 days to 5 weeks most will be identified.

Most well described cases are identified in 5–21 days.

B Virus in Macaques

Primary infection is generally w/o symptoms

Latency in sensory nerves with reactivation with stress, illness, or in mating season

1–3% of infected macaques shed virus at any given time and may not have evidence of disease

Symptoms of BV in Humans

Variable and inconsistent

Usually occur within 1 month of exposure

Site of injury is related to the rapidity of onset due to the length of the nerve from the site of injury to the brain

Early Manifestations (within 10 days)

Vesicular eruption

Pain and itching or numbness at the exposure site

Regional lymphadenopathy (swollen glands)

Intermediate Manifestations (within 21 days)

Fever chillsProximally progressive paresthesia form the exposure siteFatigueConjunctivitisMyalgiaMuscle weakness in the exposed extremityDizziness

Late Manifestations

Neck stiffnessSevere headache lasting more than 24 hDouble visionDifficulty swallowing, loss of balance Difficulty walking or numbness on one sideAgitationRespiratory arrest

Potentially Infective Macaque Fluids and Tissues

Oral, ocular, genital secretionsCSFBrain tissueSensory gangliaPrimary monkey tissue culturesPossibly excreta

Well–Documented Cases of B Virus Infection in Humans (26)Monkey bite (10), Monkey scratch (2)Wound contamination with monkey saliva (1)Tissue culture–bottle cutsa (1)Needlestick injuryb (2)Possible aerosolc (2)Cleaned monkey skull (1)Needle scratch and monkey bite (1)Cage scratch (2)Possible reactivation of B virus (1)Human–to–human contactd (1)Mucosal splashe (1) AND Unknown (1)

Well–Documented Cases of B Virus Infection in Humans (26)Bottle cutsa (1)

a Cultures involved monkey kidney cellsNeedlestick injuryb (2)

b In one case, a needle had been used to inject the tissues around the eye, and, in the other case, a needle "may have been used previously to inject monkeys."

Possible aerosolc (2)c In one case, aerosol may have been generated

during autopsies performed on macaques, and, in the other case, the patient presented withrespiratory symptoms.

Well–Documented Cases of B Virus Infection in Humans (26)

Human–to–human contactd (1)d The patient applied cream to her husband's herpes vesicles and to areas of her own skin that were affected by contact dermatitis.

Mucosal splashe (1)e The patient was splashed in the eye with material, possibly feces, from a macaque.

MACAQUE MONKEY PROGRAM: POSSIBLE INFECTIOUS AGENTS AND THEIR CONTROL

AGENT WORKERS AT RISK

METHOD OF CONTROL COMMENTS

B Virus Macaque handlers, cage cleaners and necropsy technicians

See rules to prevent infection on next slide; Macaque monkeys shedding B virus (similar to shedding of herpes simplex virus by humans); Route: esp. through bite or scratch; infection through intact mouth or eye mucosa is possible;

Tuberculosis Macaque handlers and others who work in macaque rooms

TB skin test every 6-12 months to detect converters; all new employees should have the two step test as recommended by the CDC;

The monkeys are susceptible to TB. Once introduced by a human, the disease can spread quickly through the colony.

Measles Macaque handlers and others who work in macaque rooms

If born after 1/1/57, then a booster (MMR) is recommended; This is just a routine immunization practice.

Hepatitis A Macaque handlers and others exposed to fecal contamination

Personal protective equipment; good hand washing; offer hepatitis A vaccine;

Hepatitis A vaccine is now a routine immunization for travelers to parts of the world where hepatitis A is endemic.

Hepatitis B Macaque handlers Worker training regarding sharps; offer hepatitis B vaccine; Hepatitis B is now a routine part of childhood immunizations. It is also recommended to health care workers who have exposures to patients’ blood.

Tetanus Macaque handlers Booster every 10 years or give after tetanus prone wound sustained if more than 5 years;

This is just a routine immunization practice.

Bite wound infection

Macaque handlers Prevention of bites by using safe handling methods; consider treatment with Augmentin after deep bites;

Also consider debridement of any contused and nonviable tissue in the wound.

Rabies Macaque handlers Observe animal after bite; if becomes ill, then consider testing for rabies and beginning immunization of worker;

It is unlikely that these previously quarantined primates would contract rabies.

Rules to Prevent B Virus Infection in Primate Handlers

1. Know the safe methods for handling monkeys and sharps to prevent injuries.

2. Cleanse wounds thoroughly and without delay.3. Collect specimens from both worker and

monkey after an injury and ship promptly to the NIH B Virus Resource Laboratory.

4. Report all injuries and know the symptoms of B virus infection. The evidence from previous human infections suggests that patients survive if they are treated early before advanced symptoms develop.

5. Provide post–exposure prophylaxis if indicated, risk assessment and PEP.

Understanding Primate Behavior (1)

All monkeys are capable of scratching, biting or splashing humans.Yawning and display of canine teeth represent anxiety in macaques.Laboratory monkeys may try to attack humans to defend their territory or their infants.If an animal feels threatened by human approach, it may move out of visual range to avoid confrontation and physical contact.Direct stares are perceived as a threat by macaques.

Understanding Primate Behavior (2)

Sudden quick movements or increased activity by staff may trigger aggressive behavior accompanied by head bobs, ear flapping or raising and flashing eyebrows or eyelids.If threats are ignored macaques may become visibly tense and the tail held erect or rigid, shake the cage, bounce up and down and make abrupt changes in posture, glances or open–mouth threats.These behaviors are warning signals to care staff.

Understanding Primate Behavior (3)Aggression can be arrested by moving away from the animal.Monkeys can and will reach out of cages to grab unsuspecting personnel.Whenever your hand is anywhere near the cage your risk of a bite or scratch increases.Primates prefer predictability.Personnel should attempt to follow feeding, cleaning and research schedules to avoid anxiety for the primates.

Prevention of BV Infection

Use Appropriate Safety PrecautionsEngineering controls Administrative controls Personal protective equipmentPractice hygiene precautions

Follow First Aid Precautions after a potential exposure and follow–up an exposure with Occupational Health or the emergency department

Working with Macaques (1)Regard all macaques monkeys as infectedMinimize direct handling of macaque monkeysSqueeze–back cages permit physical restraint to facilitate the administration of anesthesiaKetamine anesthesia prior to procedures when possibleExtreme care must be taken when handling needles or sharps in a monkey environmentNo recapping needles

Working with Macaques (2)All hypodermic equipment must be discarded in appropriate “sharps” disposal units immediately after injection. All items contaminated by exposure to macaque blood or body fluids must be decontaminated as soon as possible after use. Cages and other equipment used for macaque housing or procedures are considered contaminated with B virus.The cages should be designed and maintained to avoid sharp edges to prevent scratches to personnel.

Working with Macaques (3)Personnel who transfer macaques from one cage to another must wear:

Long sleeved garment with no gaps between sleeves and gloves to prevent scratchesGoggles and a surgical mask or chin length wrap around face shield with top and side seals and a surgical mask to protect and surgical mask plus with side shields to prevent exposure of the eyes or mouth (mucous membranes) to monkey secretionsFull length arm bite protective gloves (leather or Kevlar) gloves should be worn while manipulating the cage during the animal transfer processLatex or vinyl gloves may be worn if the animal is immobilized

Working with Macaques (4)Access to all areas where macaques are maintained or used is restricted to workers who are properly trained and cleared by occupational health. All items contaminated by exposure to macaque blood or body fluids must be decontaminated as soon as possible after use. Contact with live macaques requires serum storage, 2–step TB test, measles immunity and clearance by Occupational Health.

Laboratory Hazards Working with Macaque Tissues or Body Fluids

Standard Precautions must be practiced at all times. Eye protection must be worn.Thorough hand washing should be done before and after gloving.BV is rarely transmitted by aerosol.BV may be present in abdominal and thoracic viscera and nerve tissues and cultures prepared from them, CSF, ocular, oral or genital fluid secretions.BV has never been cultured from blood.

Biosafety Levels for Work with Macaques Tissues or B Virus

Biosafety Level 2 practices and facilities are recommended for all activities involving the use manipulation of tissues, body fluids and primary culture materials derived from macaquesBiosafety Level 3 practices are recommended for the use or manipulation of any materials known or suspected to contain BV, including in vitro propagation of the virus Biosafety Level 4 practices and facilities are required for the propagation and manipulation of production quantities of BV

Personal Protective Equipment for Personnel Working with Non–Human Primates

Equipment Required For Entry

Required to handle cages or NHP

Lab coat, or surgical gown with long sleeves

overalls

2 pairs of Gloves

Face shield with splash protection from top and sides and SafetyGlasses and Surgical Mask

Shoe covers or dedicated monkey shoes.

RequiredDo you want to track monkey feces into your car or home?

Bouffant Hair Cover Required

AND

AND

Goggles with full splash protection anda surgical mask

OR

Personal Protective Equipmentfor NHP Handlers

Lab coat (long-sleeved) –required or overallsLong sleeves protect arms against scratches. There should be no gaps between the gloves and sleeves.

Goggles with a complete seal around the face and Surgical MaskGoggles are worn to protect against splash and must be worn to protect against eye exposure to B-virus if aerosols are likely to be generated, such as in dental cleaning of NHP

Surgical mask–requiredSurgical mask protects the monkeys from TBProtects you from inadvertently touching your mouth with contaminated hands.

Alternatives in some situations

Face shields and surgical maskFace shield must provide splash protection from top and sides.(Surgical masks with attached eye shields are NOT an acceptable substitute)

2 pairs of Gloves–required. Some situations may require arm length bite protection gloves when working with awake monkeys.

Shoe covers–requiredShoe covers or dedicated work shoesminimize the risk that you will track monkey feces home or into your car.

Bouffant hair cover –required

Taking off and disposing of the protective gear is part of biohazard containment

Remove: 1. face shield and goggles and safety glasses 2. the mask and head cover3. shoe covers 4. protective garments 5. gloves are the last items to come off Remove them so that they are inside out

Put these item in the proper container for disposal or decontamination, or laundering.

Frequent hand washing is important to protect yourself from hazards.

Examples of High Risk Activities that may result in Aerosols of NHP waste or body fluids

Hosing down animal rooms Dental work Tracheal intubationHandling (e.g. hand catching or restraining ) of an alert monkey, also requires arm length bite protective gloves

Lower Risk ActivitiesWorking with fully restrained animalsAnesthetized animal, although there is less risk working with anesthetized NHPs, Ketamine increases saliva production, a major source of B virus.Increased distance away from NHPs

Common NHP Procedures at BUMC and Required Eye and Face Protection

Procedure Eye/Face/Mucous Membrane Protection Alternative, if available

NHP cage changing goggles and surgical mask safety glasses, face shield and surgical mask

NHP dental cleaning goggles and surgical mask n/a

NHP live animal transport or removal to transport cage goggles and surgical mask safety glasses, face shield and surgical mask

Anesthetized NHP animal transport goggles and surgical mask safety glasses, face shield and surgical mask

NHP surgery on anesthetized animal using surgical

microscope

Safety Glasses (prescription if needed) with Surgical Loupes, Surgical Mask for Lead Surgeon, All surgical assistants in room should wear goggles

and surgical mask

Lead surgeon currently wearing prescription eyeglasses with side shields and surgical loupes

over the glasses with a surgical mask. Alternatively, surgical assistants can wear safety

glasses, face shield, and surgical mask

NHP surgery on anesthetized animal using surgical loupes

Safety Glasses (prescription if needed) with Surgical Loupes, Surgical Mask for Lead Surgeon, All surgical assistants in room should wear goggles

and surgical mask

Lead surgeon currently wearing prescription eyeglasses with side shields and surgical loupes

over the glasses with a surgical mask. Alternatively, surgical assistants can wear safety

glasses, face shield, and surgical mask

Tracheal tube intubation and removal during the beginning

and end of NHP Surgerygoggles and surgical mask safety glasses (prescription if needed), face shield

and surgical mask

Perfusion of NHP at termination surgery

Completed in Fume Hood by Lead Surgeon: Involves slicing of heart ventricles, NHP

anesthetized

Completed in Fume Hood by Lead Surgeon: Currently wears prescription eyeglasses and

surgical loupes and surgical mask

Magnetic resonance imaging of NHP anesthetized animal

Anesthetized animals in sealed micro isolator cage, safety glasses and surgical mask should be worn n/a

Risk Assessment for NHP Exposures

Four variable need to be assessed:

1. Source of the exposure2. First aid timeliness and adequacy 3. Type of wound or exposure4. Exposure to materials that have come in

contact with macaques.

Risk Assessment 1: Source of Exposure

Macaques are the only primates known to transmit B virus.Immunocomprimised macaques or ill animals, stressed animals, breeding animal and recently acquired animal that are in quarantine are more likely to be shedding virus.

Risk Assessment 2: First Aid Assessment for Timeliness and Adequacy

Was the wound cleaned within 5 minutes of the exposure and was the wound cleaned for a full 15 minutes?Mucosal splashes or wounds that are inadequately cleaned are more likely to become infected, because there is increased duration of exposure to infected material.

Risk Assessment 3: Type of Wound

Wound type, depth, and the location should be assessed.Infections that occur as a result of exposure to the head, torso, or neck may result in no signs of B virus until the CNS symptoms occur and are classified as high risk exposures.Bites (deep bites are hard to clean and are considered high risk).Scratches (superficial scratches can be more readily cleaned).

Risk Assessment 4: Exposure to materials that have had contact to Macaques

Contact with any of the below are considered high risk exposures:

Ocular, oral, or genital secretions Nervous system tissue, or Material contaminated by macaques(cages, or equipment, for example) Punctures with needles contaminated with ocular tissue, CNS, mucosal surfaces are high risk exposures.(Punctures from needles contaminated with peripheral blood from healthy monkeys is considered lower risk.)

Your health care provider will assist by determining if prophylaxis is indicated if you are potentially exposed to B

virus

First Aid Can Reduce the Risk

Prompt, appropriate first aid can reduce infectionsFirst aid should be initiated immediately at the work–site (within 5 minutes of injury)Skin is scrubbed with povidone iodine solution for 15 minutes, or chlorhexidine solution Mucous membranes should be flushed with water or normal saline for 15 minutes

Assisting First Aid – Wear Gloves!

After First Aid is Complete

After the full 15 minutes of First Aid WashingTake the BV information packet at the first aid station with you and….Report to Occupational Health or to Emergency Department (after hours, holidays and weekends) First Aid will be repeated and you will be evaluated and treated.Call Control Desk (8–4144) for severe injury requiring assistance or transport

Evaluation After First AidFirst aid is repeatedPost exposure prophylaxis is consideredBite Wounds or abrasions are cultured only aftercleaningAntibiotics are recommended if a bite (Augmentin or a Cephalosporin for 3–5 days)Initial serum is taken and you will be instructed to follow–up with Occupational Health on the next business dayInformation and a medical alert card is provided for your wallet

Clinical History at Visit

Time of injuryDetails of safety measures used at time of injuryType of fluid or tissue contactedType of injury, mucous membrane, skin or percutaneousCircumstances of the eventIdentity of NHP involved and state of health

Postexposure Prophylaxis Considerations – PROS

Initiation of acyclovir therapy within 24 h after exposure to B virus prevents death among animals Initiation of acyclovir therapy within hours of exposure may prevent or modify symptomatic B virus disease

Postexposure Prophylaxis Considerations – Cons

Infection with B virus is very rare relative to the number of possible exposuresThere are no controlled studies that document the ability of immediate empirical therapy to prevent infection or symptomatic B virus infection in humansAcyclovir therapy can suppress virus shedding and seroconversion, which may make diagnosis more difficult

PEP Recommended

Skin exposure with loss of skin integrity from a high risk sourceMucosal exposure (with or without injury) from a high risk sourceInadequately cleaned skin or mucosal exposureLacerations of the head, neck or torso

PEP Recommended(Continued)

Deep puncture biteNeedlestick associated with tissue or fluid from the nervous system, lesions suspicious for BV, eyelids or mucosaA post cleaning culture is positive for B virus

PEP Considered

Mucosal splash that has been adequately cleanedNeedlestick involving blood form and ill or immunocompromised macaquePuncture or laceration occurring after exposure to an object contaminated with body fluid (other than a lesion or potentially infected cell culture)

PEP Not Recommended

Skin exposures with skin intactExposures associated with non–macaque speciesMacaque Monkeys view at: http://www2.gsu.edu/~wwwvir/VirusInfo/macaque.html

Laboratory Testing of Exposed Worker (Culture)

Culture of material from the wound or site of exposure before cleansing is not recommended because:

Results in delay in cleansingMay force virus on the surface into the woundMay further contaminate the wound

Laboratory Testing of Exposed Worker (Culture)

Culture of material from the wound or site of exposure after cleansing is not recommended by some authorities because cultures after cleansing tend to be negative.Conversely, positive wound culture results or other exposure sites do not confirm infections with BVHowever, a positive culture or PCR result at a site not directly associated with the exposure or in a wound or at a site of exposure concurrent with symptom compatible with BV disease should be considered and infection and treated.

Laboratory Testing of Exposed Worker (Serologic Analysis)

Serum should be stored prior to working with NHPs.

Always notify BU Clinical Laboratory if you are sending a specimen for storage, before sending it, that an exposure has occurred.

Serum should be drawn at time of injury (day 1) and 14–21 days (2–3 weeks) after exposure and sent with initial sample to NIH B Virus Laboratory for testing.

Patients started on prophylaxis should have a second convalescent serum sent 4 weeks (1 month) after the cessation of prophylaxis.

If there is concern about any employee who works with non–human primates that has had an exposure and is having symptoms suggestive of B virus, serum should be drawn and sent to B Virus laboratory for testing and paired with a sample from their stored serum, if there is no serum at B virus laboratory from the time of injury.

Laboratory Testing of Exposed Worker (Serologic Analysis)

Asymptomatic seroconversion has not been reported in the literature.Seroconversion or a significant greater than or equal to 4 fold increase in titer is highly suggestive acute infection.Positive BV results should be confirmed with a Western blot or competition ELISA, because of the cross–reactivity of BV with herpes simplex

Schedule of Follow–Up after Exposure

Visit are scheduled at Occupational Health on next business day after exposure is evaluated in ED and end of week 1, 2 and 3 and 6. Any employee who fails to show–up for appointment must be contacted Occupational Health provider should evaluate the exposed person weekly for the first 3 weeks to assess the employees clinical statusExposed personnel on PEP should have their serum tested at 4 weeks and at 3 months if there are any concerns at that time

Follow–Up after Exposure

For Patients with positive post cleaning wound cultures additional cultures should be obtained from conjunctivae, oropharynx, and any unhealed skin lesions 1–2 weeks after d/c of antiviral medication.Draw serum if any potential symptoms of B virus on examination or history

Follow–Up after Exposure

Check the wound Check for signs and symptoms of BVDetermine compliance with medication if on PEPAnswer patient’s questionsCheck with supervisor if any corrective actions have been taken to prevent future exposuresDraw serum if indicated

Treatment of B Virus Disease

Presence of any signs or symptoms of disease orLaboratory confirmed culture result (not including positive post cleaning wound culture) thenTreat for BV disease

Summary of Recommendations:Post Exposure Prophylaxis and Treatment

Clinical Setting Drug of First Choice

Alternative Drug

Prophylaxis for BV Valacyclovir, 1 G po q8h for 14 days

Acyclovir, 800 mg po 5 times per day for 14 days

Treatment of BV

No CNS Symptoms Acyclovir, 12.5–15mg/kg iv q8ha

Ganciclovir, 5 mg/kg iv q12ha

Yes CNS Symptoms Ganciclovir 5mg/kg iv q12ha

http://www.journals.uchicago.edu/cgi-bin/resolve?CID020880PDF

Treatment Termination

Continue treatment until symptoms resolve and At least 2 cultures are negative for B Virus after 14 days of incubationMost experts change therapy to oral valacyclovir, famciclovir or acyclovir for 6 months–1 year

ResourcesQuestions on evaluation, prophylaxis, or treatment Julia Hilliard, Ph.D.National B Virus Resource CenterViral Immunology CenterGeorgia State UniversityP.O. Box 4118 Atlanta, Georgia 30302–4118404.651.0808Emergency: Dr. Julia Hilliard, Director: 404.358.8168bvirus@gsu.edujhilliard@gsu.edu

ReferencesCohen, JI, DS Davenport, JA Stewart, et al. 2002. Recommendations for prevention of and therapy for B virus (Cercopithecine Herpes–1). Clin. Infect. Dis. 35:1191–1203. National Research Council. Occupational Health and Safety in the Care and Use of Nonhuman Primates. 2003. National Academies Press.CDC–NIH. 1999. Biosafety in Microbiological and Biomedical Laboratories. HHS Publication No. CDC93–8395, 4th Edition. DC:US Government Printing Office.Julia Hilliard, Ph.D. and NIH B Virus Laboratory

SPECIAL THANKS TO:Nirah Shomer, D.V.M., Ph.D. and Lab. Animal

Technician, Dennis Noel for picture slide of personal protective equipment

James Ryan, MD, MPH for editing this project

Staff Boston University Occupational Health Center and Boston Medical Occupational & Environmental Medicine for assisting with this project and providing evaluations, training and care to personnel with potential B virus exposures