Human herpesvirus 4, also known as Epstein-Barr virus (EBV), is one of the most common human viruses that infects B cells and epithelial cells. It was first discovered in 1964 in cultured tumor cells from a patient with Burkitt's lymphoma in Uganda. EBV has a double-stranded DNA genome enclosed in proteins and enters host cells via glycoproteins in its envelope. The virus can cause either a lytic infection, actively replicating and producing new virus particles, or establish a latent infection that can last a lifetime with only limited gene expression. There is no vaccine to protect against EBV infection, so prevention focuses on avoiding contact with saliva and practicing good hand hygiene.

1. HUMAN HERPESVIRUS 4
- is a member of the herpes virus
family. It is one of the most common
human viruses. EBV is found all over
the world. Most people get infected
with EBV at some point in their lives.
Has double-stranded DNA enclosed by
proteins. The virus's envelope has
glycoproteins, essential for attachment
and entry into the host cells (B cells
and epithelial cells). Target B cells use
their molecular machinery to replicate
the viral genome. The virus causes B
cells to differentiate into memory B
cells, which then can move into the
circulatory system or become latent
until a trigger causes reactivation.
HISTORY
-first discovered in cultured tumor cells
derived from a biopsy of a Burkitt’s
lymphoma (BL) patient in 1964 FROM
UGANDA, AFRICA.In 1963, a specimen
was sent from Uganda to Middlesex
Hospital to be cultured. Virus particles
were identified in the cultured cells.
Cell lines were sent to Werner and
Gertrude Henle, who developed
serological markers at the Children's
Hospital of Philadelphia. In 1967, a
technician in their laboratory
developed mononucleosis, and they
could compare a stored serum sample,
showing that antibodies to the virus
developed. Yu, H, & Robertson, E.S
(2023)
LIFE CYCLE
-consists of two phases: lytic infection
and latent infection.
During lytic infection, active replication
and the production of numerous
progeny virions.
In Latent infection-During this time,
the viral genome remains in the nuclei
of the cells but only expresses a few
genes and does not replicate. The
latent phase can last for years or the
entire lifetime of the infected
individual. The latent phase comes
after the active phase.
PORTAL OF ENTRY
-Oral-through saliva
-Genital secretions via semen
ROUTE OF TRANSMISSION
 spread by saliva through:
• Kissing, Sharing drinks and food.
• Using the same cups, eating
utensils, or toothbrushes; having contact
with toys that children have drooled on
ORGANS AFFECTED
-Throat
-Spleen

2. -Liver
EPIDEMIOLOGY, PREVALENCE,
&INCIDENCE.
In the United States, children and
adolescents between the ages of 6 to 19
years had an EBV prevalence of 66.5%.
Children between 6-8 years of age had
a prevalence of approximately 54%,
while adolescents 18-19 had a
prevalence of 82.9%. More females
than males were infected, but the
difference was minimal. Children and
adolescents who identified as Mexican
American had a higher prevalence of
Epstein-Barr virus than non-Hispanic
Blacks and Whites. Hoover K,
Higginbotham K (2022).
MORBIDITY AND MORTALITY RATE.
-The mortality rate was significantly
higher in seropositive patients for EBV
patients than in seronegative patients
(62.5% vs 20.0%).
-According to CDC, US-50 % of
children ages and adults experience
EBV during their lifetime.
SIGNS AND SYMPTOMS
- symptoms about four to six weeks after
exposure to the virus.
• Fatigue
• Fever
• Inflamed throat
• Swollen lymph nodes in the neck
• Enlarged spleen.
• Swollen liver and rash
TREATMENTS
There is no specific treatment for EBV.
However, some things can be done to help
relieve symptoms, including:
• Drinking fluids to stay hydrated.
• Getting plenty of rest; and taking over-
the-counter medications for pain and
fever, such as Tylenol and ibuprofen.
PREVENTION AND CONTROL
According to CDC, there is no vaccine to
protect against EBV infection. You can help
protect yourself by avoiding kissing or
sharing drinks, food, or personal items,
like toothbrushes, with people who have
EBV infection.
 Practice hand washing.
 Drink plenty of fluids to prevent
dehydration.
 Avoid sports that can hurt the
spleen.