Epstein-Barr virus: Infectious substances pathogen safety data sheet

Section I – Infectious agent

Name

Epstein-Barr virus

Agent type

Virus

Taxonomy

Family

Orthoherpesviridae

Genus

Lymphocryptovirus

Species

humangamma4^{Footnote 1}

Synonym or cross-reference

Also known as human gammaherpesvirus 4 (HuGHV4) and human herpesvirus 4 (HHV-4)^{Footnote 1Footnote 2}. Causative agent of infectious mononucleosis (IM) or glandular fever (commonly known as mono or kissing disease); associated with Burkitt lymphoma (BL), nasopharyngeal carcinoma (NPC), Hodgkin's lymphoma (HL), peripheral natural killer/T cell lymphoma, and gastric carcinoma (GC)^{Footnote 3Footnote 4}.

Characteristics

Brief description

Epstein-Barr virus (EBV) virions are large, multilayered particles, 150–170 nm in diameter, and each containing more than 30 different capsid, tegument, and envelope proteins^{Footnote 3Footnote 5}. The genome consists of a linear, double-stranded DNA molecule, 172 kbp in size, and is enclosed within an icosahedral capsid surrounded by a layer of tegument proteins and a lipid envelope composed of several unique glycoproteins^{Footnote 3Footnote 4}.

Properties

EBV targets epithelial cells and B cells of the oropharynx upon entry^{Footnote 5} and establishes a lifelong infection in its host^{Footnote 6}. The EBV life cycle consists of latent and lytic states and establishes asymptomatic infection in memory B cells^{Footnote 6}. EBV can be cultured in lymphoblastoid cell lines^{Footnote 7}.

Section II – Hazard identification

Pathogenicity and toxicity

Most EBV infections are acquired during childhood and are asymptomatic^{Footnote 3Footnote 8}. Clinically overt disease is similar to other hemophagocytic syndromes^{Footnote 9}. However, several benign and malignant diseases have been associated with EBV infection in both immunocompetent and immunocompromised individuals^{Footnote 3Footnote 4Footnote 7Footnote 10Footnote 11Footnote 12Footnote 13Footnote 14}.

Infectious mononucleosis (IM) is an acute, self-limiting febrile illness in adolescents and young adults^{Footnote 3}. IM is associated with primary EBV infection and typically develops in 35-50% of the human population one month after infection^{Footnote 3}. IM is typically characterized by fever, sore throat, splenic rupture, hepatitis, airway obstruction, abdominal discomfort, pharyngitis, tonsillitis, generalized lymphadenopathy, palatal petechiae, and periorbital edema^{Footnote 3Footnote 15}. Some patients also present with maculopapular rash, splenomegaly, hepatomegaly, and jaundice. Rashes are almost always present in patients who were given ampicillin or amoxicillin^{Footnote 3Footnote 8Footnote 14}. The acute phase of IM can last from 1 to 4 weeks^{Footnote 3Footnote 8Footnote 14Footnote 16}. Malaise and exhaustion are the most persistent symptoms and relapses may occur during 6 months to 1 year^{Footnote 14}. Various complications, including prolonged fatigue, hypersomnia, short depressive disorders, autoimmune hemolytic anemia, splenic rupture, hemophagocytic lymphohistiocytosis, airway obstruction, myocarditis, cardiac arrhythmia, liver failure, secondary bacterial infection, thrombocytopenia, and neurological complications have also been associated with IM^{Footnote 3Footnote 8Footnote 17}. Death from IM is rare but can occur as a result of its associated complications^{Footnote 17}.

Burkitt lymphoma (BL) may be endemic, sporadic, or immunodeficiency-associated^{Footnote 3}. BL arises due to an early infection with EBV resulting in B cell infection^{Footnote 7Footnote 13}. Endemic BL frequently affects the facial bones, particularly the jaw, maxilla, and orbit in young children^{Footnote 13}. Sporadic BL arises in the lymphoid tissues of the gut and the upper respiratory tract^{Footnote 13}.

Other malignant diseases in immunocompetent hosts include various B-cell or T-cell lymphomas and epithelial or mesenchymal carcinomas, such as classical Hodgkin's lymphoma (HL) and nasopharyngeal carcinoma (NPC)^{Footnote 11Footnote 12Footnote 18}.

In acquired immunodeficiency syndrome (AIDS) or otherwise immunocompromised patients, many EBV-associated diseases may occur, such as oral hairy leukoplasia, interstitial lymphocytic pneumonia, B-cell or T-cell lymphomas, and mesenchymal lymphomas (e.g., leiomyosarcoma)^{Footnote 3Footnote 4Footnote 7Footnote 12}. In transplant patients, early and late onset lymphoproliferative diseases are often caused by EBV.

EBV infection has been strongly associated with the onset of multiple sclerosis, although further evidence is required for corroboration^{Footnote 19Footnote 20}.

Epidemiology

EBV infection is very prevalent, occurring in more than 90% of individuals during the first two decades of life worldwide^{Footnote 3Footnote 21}. The combined global incidence of EBV-attributed BL, HL, NPC, and gastric carcinoma (GC) in 2017 was an estimated 265,000 cases, including 164,000 deaths, representing a 36% increase in incidence and 19% increase in mortality from 1990^{Footnote 22}. There are two EBV subtypes, namely type-I EBV (EBV-1), which occurs worldwide, and type-II EBV (EBV-2), which only occurs in parts of Africa and New Guinea^{Footnote 4}. These subtypes do not show specific disease associations^{Footnote 17}.

In developing countries, primary infection occurs mainly in young children and is often asymptomatic^{Footnote 14}. In developed countries, primary EBV infection mainly manifests as IM and affects adolescents and young adults^{Footnote 14}. Endemic BL occurs frequently in young children in the equatorial regions of Africa and Papua New Guinea and has an incidence of 50–100 cases per 1,000,000 individuals^{Footnote 12}. In contrast, EBV-associated sporadic lymphoma occurs in children and young adults and has no specific geographic distribution, with an incidence of 2–3 cases per 1,000,000 individuals^{Footnote 12}. Endemic BL is associated with EBV infection in 95% of cases, whereas association of sporadic BL with EBV infection is lower (15–20% of cases)^{Footnote 3Footnote 12Footnote 23}. NPC is most common in southern China and accounts for approximately 20% of all adult cancers^{Footnote 11}. NPC is extremely rare in Europe and North America, with an incidence rate is <1 per 100,000 individuals^{Footnote 11}.

EBV reactivation can occur due to external stress stimuli and by co-infection with certain viruses, including human simplex virus 1, human immunodeficiency virus (HIV), hepatitis viruses, and novel SARS-CoV-2, and may result in complications such as BL, HL, and other types of cancer^{Footnote 6}. Immunocompromised individuals are particularly at risk^{Footnote 6}.

Host range

Natural host(s)

Humans^{Footnote 24}.

Other host(s)

Experimentally infected hosts include rabbits, non-human primates, and humanized mice^{Footnote 25}.

Infectious dose

The infectious dose for humans is unknown. However, in experimental settings, 1 × 10³ TD₅₀  of EBV administered intravenously caused lymphoproliferative disorder in humanized mice, and ≤1 × 10¹ TD₅₀ resulted in persistent asymptomatic infection^{Footnote 26}.

Incubation period

The incubation period for IM is 30-50 days^{Footnote 8Footnote 14}.

Communicability

Transmission of EBV primarily occurs by contact of infected saliva or other bodily fluids with mucous membranes^{Footnote 17Footnote 27Footnote 28}. Inhalation of respiratory droplets is also a possible route of transmission^{Footnote 29}. Transmission via blood transfusion has also been reported^{Footnote 17}. Human-to-human transmission can occur via intimate direct contact with infected saliva or breast milk, as well as by organ transplantation and blood transfusion^{Footnote 17Footnote 30}. Indirect contact via fomites (e.g., toothbrushes, drinking glasses) may also pose a risk of transmission, although there is no definitive evidence of fomite-mediated transmission^{Footnote 31}.

Peaks in transmission occur between 1-6 and 14-20 years of age and over 95% of adults are asymptomatic carriers of EBV^{Footnote 32}. Shedding decreases during the year following infection but persists throughout life^{Footnote 33}.

Section III – Dissemination

Reservoir

Humans^{Footnote 7}.

Zoonosis

None.

Vectors

None.

Section IV – Stability and viability

Drug susceptibility/resistance

Nucleoside analogues, such as acyclovir, ganciclovir, penciclovir, valacyclovir, valganciclovir, famciclovir, cidofovir, and pyrophosphate analogues (e.g., foscarnet) can inhibit viral replication^{Footnote 3Footnote 7Footnote 34}.

Susceptibility to disinfectants

EBV is inactivated by standard disinfectants, and non-ionic detergents solubilize the viral envelope^{Footnote 35}. Most herpesviruses are susceptible to 30% ethanol and 20% isopropanol, 2000 ppm sodium hypochlorite, 0.12 % orthophenyl phenol, and 0.04% glutaraldehyde^{Footnote 36}.

Physical inactivation

EBV is inactivated by heating at 50–60°C for 30 minutes^{Footnote 35}. It is also inactivated by UV light and gamma irradiation^{Footnote 35}, although effective parameters specific to EBV are not available. Herpesviruses have generally been shown to be inactivated by 5000-10,000 mJ/cm UV radiation^{Footnote 37}.

Survival outside host

EBV can survive at room temperature for a few days, at refrigeration temperature for 2-3 days, and at -70°C for many years^{Footnote 35}.

Section V – First aid/medical

Surveillance

Monitor for clinical symptoms^{Footnote 7}. Direct detection of the viral antigen can be done by staining for EBV nuclear antigen 1 (EBNA1) using anti-complement immunofluorescence. Viral RNA or DNA can be identified using in situ hybridization, dot-blot hybridization, nucleic acid amplification testing (NAAT), and southern blotting^{Footnote 3}. Tests for heterophile antibodies in mononucleosis, antibodies against viral capsid antigen (VCA), or anti-EBNA1 antibodies can also be used^{Footnote 3Footnote 4Footnote 7}. An EBV DNA load ≥10,000 IU/mL in whole blood is proposed as a diagnostic cut-off value for chronic active EBV disease^{Footnote 38}. High EBV DNA loads are also observed in patients with other EBV-related diseases.

Note: The specific recommendations for surveillance in the laboratory should come from the medical surveillance program, which is based on a local risk assessment of the pathogens and activities being undertaken, as well as an overarching risk assessment of the biosafety program as a whole. More information on medical surveillance is available in the Canadian Biosafety Handbook.

First aid/treatment

Treatment of IM is mainly supportive^{Footnote 7}. Viral replication can be inhibited by nucleoside analogues which can reduce or terminate viral shedding, but have no effect on symptoms^{Footnote 3Footnote 7}. Airway obstruction is treated with a high dose of corticosteroids and a nasopharyngeal airway^{Footnote 3Footnote 7Footnote 14}. Interferon gamma treatment has been shown to be effective for patients lacking this interferon^{Footnote 3}. Lymphoproliferative disorders associated with EBV can be treated with anti-CD20 monoclonal antibodies and EBV-specific cytotoxic T lymphocytes along with antiviral drugs^{Footnote 3}.

Note: The specific recommendations for first aid/treatment in the laboratory should come from the post-exposure response plan, which is developed as part of the medical surveillance program. More information on the post-exposure response plan can be found in the Canadian Biosafety Handbook.

Immunization

No vaccine is currently available to prevent EBV-associated infection and/or disease; however, a glycoprotein gp350-based vaccine is in clinical trials^{Footnote 3Footnote 6Footnote 39}.

Note: More information on the medical surveillance program can be found in the Canadian Biosafety Handbook, and by consulting the Canadian Immunization Guide.

Prophylaxis

There is currently no known pre- or post-exposure prophylaxis. Nonetheless, the development of a prophylactic vaccine targeting a combination of EBV envelope proteins (gL, gB, and gp350) shows promise for future development^{Footnote 40}.

Note: More information on prophylaxis as part of the medical surveillance program can be found in the Canadian Biosafety Handbook.

Section VI – Laboratory hazard

Laboratory-acquired infections

No cases of laboratory-acquired infection with EBV have been reported.

Note: Please consult the Canadian Biosafety Standard and Canadian Biosafety Handbook for additional details on requirements for reporting exposure incidents.

Sources/specimens

Blood, saliva, breast milk, and throat specimens^{Footnote 3Footnote 7Footnote 17}.

Primary hazards

Exposure of mucous membranes to infectious material is the primary hazard associated with exposure to EBV, although ingestion of infectious material, autoinoculation with infectious material, and inhalation of airborne or aerosolized materials may also be important exposure hazards to consider^{Footnote 17Footnote 27Footnote 28Footnote 29Footnote 30}.

Special hazards

None.

Section VII – Exposure controls/personal protection

Risk group classification

EBV is a Risk Group 2 Human Pathogen and Risk Group 1 Animal Pathogen^{Footnote 41}.

Containment requirements

Containment Level 2 facilities, equipment, and operational practices outlined in the Canadian Biosafety Standard for work involving infectious or potentially infectious materials, animals, or cultures.

Protective clothing

The applicable Containment Level 2 requirements for personal protective equipment and clothing outlined in the Canadian Biosafety Standard are to be followed. The personal protective equipment could include the use of a labcoat and dedicated footwear (e.g., boots, shoes) or additional protective footwear (e.g., boot or shoe covers) where floors may be contaminated (e.g., animal cubicles, post mortem rooms), gloves when direct skin contact with infected materials or animals is unavoidable, and eye protection where there is a known or potential risk of exposure to splashes.

Note: A local risk assessment will identify the appropriate hand, foot, head, body, eye/face, and respiratory protection, and the personal protective equipment requirements for the containment zone and work activities must be documented.

Other precautions

A biological safety cabinet (BSC) or other primary containment devices to be used for activities with open vessels, based on the risks associated with the inherent characteristics of the regulated material, the potential to produce infectious aerosols or aerosolized toxins, the handling of high concentrations of regulated materials, or the handling of large volumes of regulated materials.

Use of needles and syringes are to be strictly limited. Bending, shearing, re-capping, or removing needles from syringes are to be avoided, and if necessary, performed only as specified in standard operating procedures (SOPs). Additional precautions are required with work involving animals or large-scale activities.

For diagnostic laboratories handling primary specimens that may contain EBV, the following resources may be consulted:

• Human Diagnostic Activities Biosafety Guideline
• Local Risk Assessment Biosafety Guideline

Section VIII – Handling and storage

Spills

Allow aerosols to settle. Wearing personal protective equipment, gently cover the spill with absorbent paper towel and apply suitable disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time with disinfectant before clean up (Canadian Biosafety Handbook).

Disposal

All materials/substances that have come in contact with the regulated materials to be completely decontaminated before they are removed from the containment zone or standard operating procedures (SOPs) to be in place to safely and securely move or transport waste out of the containment zone to a designated decontamination area / third party. This can be achieved by using decontamination technologies and processes that have been demonstrated to be effective against the regulated material, such as chemical disinfectants, autoclaving, irradiation, incineration, an effluent treatment system, or gaseous decontamination (Canadian Biosafety Handbook).

Storage

The applicable Containment Level 2 requirements for storage outlined in the Canadian Biosafety Standard are to be followed. Primary containers of regulated materials removed from the containment zone to be labelled, leakproof, impact resistant, and kept either in locked storage equipment or within an area with limited access.

Section IX – Regulatory and other information

Canadian regulatory information

Controlled activities with EBV require a Pathogen and Toxin licence issued by the Public Health Agency of Canada.

The following is a non-exhaustive list of applicable designations, regulations, or legislations:

• Human Pathogens and Toxins Act and Human Pathogens and Toxins Regulations
• Transportation of Dangerous Goods Act and Transportation of Dangerous Goods Regulations

Last file update

April 2024

Prepared by

Centre for Biosecurity, Public Health Agency of Canada.

Disclaimer

The scientific information, opinions, and recommendations contained in this Pathogen Safety Data Sheet have been developed based on or compiled from trusted sources available at the time of publication. Newly discovered hazards are frequent and this information may not be completely up to date. The Government of Canada accepts no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information.

Persons in Canada are responsible for complying with the relevant laws, including regulations, guidelines and standards applicable to the import, transport, and use of pathogens in Canada set by relevant regulatory authorities, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment and Climate Change Canada, and Transport Canada. The risk classification and related regulatory requirements referenced in this Pathogen Safety Data Sheet, such as those found in the Canadian Biosafety Standard, may be incomplete and are specific to the Canadian context. Other jurisdictions will have their own requirements.

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