The document summarizes information about Herpes Simplex Virus (HSV). There are two types of HSV, HSV-1 which causes oral herpes/cold sores and HSV-2 which causes genital herpes. HSV are DNA viruses that enter host cells and replicate in the cell nucleus. HSV can cause painful blisters or sores on the skin or mucous membranes and has no cure, though antiviral drugs can reduce symptoms. Transmission occurs via direct contact with infected secretions.

1. Presentation by:
A.Abinaya Kalyani,
III B.Sc Microbiology,
HERPES SIMPLEX VIRUS

2. Herpes Simplex Viruses:
The herpes simplex virus, also known as HSV, is an
infection that causes herpes. Herpes can appear in various
parts of the body, most commonly on the genitals or
mouth. The term “herpes” means “to creep” (easily
spreading nature).
There are two types of the herpes simplex virus.
HSV-1: Also known as oral herpes, this type can cause cold
sores and fever blisters around the mouth and on the face,
This can spread by contact with infected saliva.
HSV-2: This type is generally responsible for genital herpes
outbreaks. This type can transmitted Sexually.

3. Herpes viruses are large enveloped DNA Viruses.
Virion is spherical, 150-200nm in diameter.
It has a icosahedral capsid.
Its genome is linear double stranded DNA,
124-235kbp
More than 35 proteins are present in the virion.
Replication occurs in the nucleus of the host cell.
Genome is large enough to code for atleast 100
proteins.
Structure of virus:

4. HSV 1:
HSV-1 is the virus that causes cold sores or fever
blisters, it may start with a tingling, itching, or
burning on the skin, usually on the lips
Tiny blisters show up and quickly break open,
causing a painful sore which eventually scabs over.
It’s most common to have outbreaks 2-3 times a
year. A sore can take a week or two to heal without
medication.
Herpes is contagious, but it's possible for one person
in a family to have it, while the others don't.
Herpes is spread through direct skin to skin contact
like kissing.

5. HSV 2: Genital herpes is a common sexually transmitted
infection caused by the herpes simplex virus.
There's no cure for genital herpes, but medications
can ease symptoms and reduce the risk of infecting
others.
The symptoms may begin about 2 to 12 days after
exposure to the virus.
Women are more likely to have genital herpes than
are men. The virus is sexually transmitted more
easily from men to women than it is from women to
men.
Babies born to infected mothers can be exposed to
the virus during the birthing process. This may result
in brain damage, blindness or death for the
newborn.
Vaginal area Penis
External genitals Scrotum
Cervix
Symptoms

6. Replication process of HSV

7. Clinical Manifestation:
The symptoms can be quite severe and may include:
blisters and ulceration on external genitalia, in the vagina, or on the cervix
vaginal discharge
pain and itching
tender, enlarged lymph nodes
pain when urinating
high temperature (fever)
malaise (feeling unwell)
cold sores around the mouth
red blisters on the skin
In most cases, the ulcers will heal, and the individual
will not have any lasting scars.

8. Infection of other Organs:
Herpetic Whitlow Herpes Gladiatorum Eczema Herpeticum

9. Pathogenesis:
Primary Infection:
 Man is the only natural host to HSV, the virus is spread by contact, the
usual site for the implantation is skin or mucous membrane.
HSV undergoes replication in the parabasal and intermediate epithelial
cells, which lyse and invoke inflammatory response.
The incubation period of primary genital herpes is 3-7 days.
Constitutional symptoms include fever, headache, malaise, and myalgia
(prominent in the first 3-4 days).
Local symptoms include pain, itching, dysuria, vaginal and urethral
discharge, and tender lymphadenopathy.

10. Pathogenesis:
Reactivation:
It is well known that many triggers can provoke a recurrence. These include;
 Stress - physical or psychological.
Pneumococcal infection.
Meningococcal infection.
Fever
Irradiation including sunlight.
Menstruation
Others.

11. Laboratory Diagnosis:
Specimen collection:
Vesicular and hepatic lesions of skin, cornea or brain,
throat washings, CSF and Stool.
Light Microscopy:
Cells from the base of the lesion, or wiped from a
mucous surface, or biopsy material, may reveal intranuclear
inclusions (Lipschutz inclusion bodies). Infected cells may
show ballooning and fusion.

12. Isolation of Virus:
The specimen are transported through viral transport
medium and inoculated into tissue culture. HSV has a wide host
range, so many cell culture systems are susceptible. The
appearance of typical cytopatheic effects in cell culture in 2-3
days suggests the presence of HSV.
Serology:
Several methods have been developed for rapid diagnosis.
Antibodies appear in 4-7 days after infection. Neutralization
test, CF, ELISA, RIA and Immunofluorescence can quantitate
antibodies.
Laboratory Diagnosis:

13. Epidemiology:
Herpes Simplex viruses are worldwide in
distribution. No animal reservoirs are
involved in human infection transmission.
Transmission is by infected secretions.
Prevention:
Currently there is no effective therapy for the
prevention of HSV infection.
 Avoidance of direct contact with lesion or
infected secretions is the primary means of
prophylaxis.
Vaccination for Herpes would be the ideal
preventive measure.

14. Treatment:
There is no cure for herpes. But medicines can help. Medicines
such as acyclovir and valaciclovir fight the herpes virus. They
can speed up healing and lessen the pain of herpes for many
people. They can be used to treat a primary outbreak or a
recurrent one.
If the medicines are being used to treat a repeat outbreak,
they should be started as soon as you feel any tingling, burning,
or itching. They can also be taken every day to prevent
recurrences.
Most of the drugs used for the treatment of HSV, inhibit the
DNA synthesis.
Vidarabine triphosphate inhibits DNA polymerase.