How the Herpes Simplex Virus Works

How the Herpes Simplex Virus Works
Herpes Simplex Virus Infection and Recurrence
By Heather Brannon, MD, About.com
Updated: May 21, 2007
About.com Health's Disease and Condition content is reviewed by the Medical Review Board
The herpes virus is one of the most difficult viruses to control. Scientists study how the virus works in order to understand how to combat it. It is also important for the general public to understand how this virus works because 85 percent of the world has been infected with one of the herpes simplex viruses.
The Herpes Simplex Virus
The word "herpes" is taken from the Greek word "herpein" which means "to creep." The herpes simplex viruses are double-stranded DNA viruses that only infect humans. There are two types of herpes simplex viruses:
• Herpes simplex virus type 1 (HSV-1)
• Herpes simplex virus type 2 (HSV-2)
Herpes Simplex Virus Infections
A person can be infected with one or both herpes viruses. It has generally been believed that HSV-1 infections occurred in the mouth and HSV-2 infections occur in the genital area. Now it has been shown that either type of virus can infect either site.
How the Herpes Simplex Virus Works
• The virus comes in contact with broken skin or the lining of the mouth, vagina, or anus.
• The virus goes to the nuclei of the cells and tries to reproduce itself, or replicate.
• Though the cells are infected, most people do not get symptoms.
• Sometimes the virus's replication process destroys the cells it has invaded causing blisters or ulcers to form on the skin.
• The blisters or ulcers crust over and heal without scarring.
• The virus is transported back through the nerve to important nerve branching points called ganglia deep in the body.
• The virus stays in the ganglia in an inactive, or latent, form. During this time, the virus does not replicate. It stays in this latent form for varying amounts of time.
• Certain triggers may cause the virus to travel back down the nerve to the skin and cause symptoms again. This is known as recurrence.
• Pictures of Herpes Simplex Virus Infections
Causes of Herpes Simplex Virus Recurrences
Even with a normal immune system, recurrences can happen. Sometimes the recurrence occurs spontaneously. However, the following are known triggers that can stimulate a recurrence:
• Physical stress
• Poor emotional coping style
• Persistent stressors for greater than 1 week
• Anxiety
• Fever
• Exposure to ultraviolet light
• Nerve damage
• Tissue damage
• A suppressed immune system
• Heat
• Cold
• Menstruation
• Other infections
• Fatigue
Sources:
CDC. "Sexually Transmitted Diseases Treatment Guidelines, 2006." Morbidity and Mortality Weekly Report. 55(2006): 16-20.
Habif, Thomas. "Warts, Herpes Simplex, and Other Viral Infections." Clinical Dermatology, 4th Edition. Ed. Thomas Habif, MD. New York: Mosby, 2004. 381-388.
Yeung-Yue, Kimberly. "Herpes simplex viruses 1 and 2." Dermatologic Clinics 20(2002): 1-21.