The word
herpes was coined from the Greek word
herpein meaning
to creep. Herpes Simplex Virus (
HSV)is about 180 - 200
nm in diameter and
icosahedral in shape. The virus has an envelope, making it more resistant to chemical and physical damage. Herpes Simplex Virus is typically classified under two distinct strains, Type I and Type II, each responsible for a group of symptoms but sharing several common features. The major difference between type I and type II is the site of infection, Type I causing orofacial lesions and Type II causing
genital lesions.
Features:
Infection
In the case of Type I, infection happens in about 80% of the population at a young age and usually causes no symptoms. This is referred to as a sub-clinical infection. The virus is spread by droplet infection. Type II infection is normally sexually transmitted.
HSV I affects the face, causing lesions around the
eye and
mouth, the latter being more common. Following infection, the virus migrates to the
trigeminal nerve and lies there in a
dormant state referred to as
latency. In the case of
HSV II, the virus resides in the
sacral area following infection. Stress such as
wind,
sunburn and fever cause the virus to migrate down to the skin surface such as the lips and multiply rapidly causing the lesions associated with the virus.
Cold sores are one such type of
clinical manifestation.
Treatment
Apart from symptomatic
treatment of
lesions,
antiviral treatment plays an important role in the control of such
HSV infection. While
eradication of the virus is difficult, drugs like
Acyclovir, famciclovir, valacyclovir and penvir are used to treat
HSV infection.