Is Epstein-Barr virus (EBV) a Human Herpesvirus (HHV)?

From the Guidelines

Yes, Epstein-Barr virus (EBV) is indeed a herpes virus, specifically classified as human herpesvirus 4 (HHV-4). It belongs to the Herpesviridae family and more specifically to the subfamily Gammaherpesvirinae 1. Like other herpes viruses, EBV establishes lifelong latent infection after initial exposure, with the ability to reactivate periodically. This virus is extremely common worldwide, with most people becoming infected at some point in their lives. EBV is primarily known for causing infectious mononucleosis (often called "mono" or "glandular fever"), but most infections are asymptomatic, especially in children. The virus primarily targets B lymphocytes and epithelial cells, and after the initial infection, it remains dormant in memory B cells. This ability to establish latency is a characteristic feature of all herpes viruses, allowing them to persist in the host for life while evading immune detection during periods of dormancy.

Key Characteristics of EBV

• EBV is one of eight known human herpesviruses 1
• It is etiologically linked to human malignancies such as endemic Burkitt lymphoma (BL) and undifferentiated nasopharyngeal carcinoma (NPC) 1
• EBV association with various etiologically unknown diseases has been widely documented due to the presence or increase of viral genomes in affected lesions 1
• The virus can cause chronic active EBV infection, which is characterized by persistent or intermittent fever and lymphadenopathy 1

Diagnosis and Latency

• New diagnostic methods for EBV infection have been developed, including the detection of EBV variants, distinct target cell populations associated with different viral gene expressions, and various abnormalities of immune surveillance 1
• EBV establishes latency in memory B cells, allowing it to persist in the host for life while evading immune detection during periods of dormancy 1
• The virus can reactivate periodically, leading to various clinical manifestations, including infectious mononucleosis and chronic active EBV infection 1

Clinical Implications

• EBV infection is extremely common worldwide, with most people becoming infected at some point in their lives 1
• Most infections are asymptomatic, especially in children 1
• However, EBV can cause severe diseases, including chronic active EBV infection and EBV-associated malignancies 1
• Accurate diagnosis and management of EBV infection are crucial to prevent long-term complications and improve patient outcomes 1

From the Research

Classification of Epstein-Barr Virus

• Epstein-Barr virus (EBV) is classified as a member of the order herpesvirales, family herpesviridae, subfamily gammaherpesvirinae, and the genus lymphocytovirus 2.
• EBV is also termed as human herpesvirus 4 (HHV4) due to its exclusive human pathogenicity 2.
• The virus belongs to the Herpesviridae family, which includes other herpesviruses 3.

Characteristics of Epstein-Barr Virus

• EBV is a double-stranded DNA virus with a lymphoid tropism and transforming capacities using different oncogenic viral proteins 3.
• The virus has two replication cycles: a lytic cycle mainly occurring during primary infection and a latent cycle allowing viral persistence into host memory B cells 3.
• EBV infects B lymphocytes, leading to their immortalization, with persistence of the EBV genome as an episome 4.

Relationship with Herpesviruses

• EBV is a type of herpesvirus, and its classification and characteristics are consistent with those of the Herpesviridae family 3, 2.
• The virus shares some features with other herpesviruses, despite having no sequence homology to other herpesviral genomes 5.