What most refer to as herpes is actually family of socially transmitted diseases caused by the herpes simplex viruses type 1 (HSV-1 cold sores) and type 2 (HSV-2 genital herpes). Other types of the virus are commonly known as shingles and the Epstein-Barr virus. Most people who carry the virus have no or only minimal signs of an infection. Because of this, many people are unaware that they have the virus. Telling signs of an infection include one or more blisters on the face or genitals that break and leave small ulcers that may take 2 to 4 weeks to heal initially. The blisters recur periodically over time, typically about 5 times per year. The frequency of outbreaks usually reduces over time.
For most healthy people it is harmless. Rare severe cases of HSV-1 on the head or face may lead to serious conditions. Extra precautions for pregnant women at the time of delivery are needed to prevent genital herpes transmission to the baby which can sometimes be fatal to infants.
The disease is very common. In the US about 20% of adults are have the infection. Because the symptoms can often be mild, most people do not know they have the disease or mistake it for other causes like insect bites. About 1 million new cases are reported every year. Millions more likely go unreported.
