These viruses look identical under the microscope, and either type can infect the mouth or genitals. In the 1960's, the distinction was made that HSV-1 occurs above the waist, and HSV-2 below, but genital HSV-1 infections are increasing.
Herpes Simplex Type 1 (HSV-1) is the virus usually responsible for oral herpes or cold sores. If you receive unprotected oral sex from someone who has (HSV-1) cold sores, you can get genital herpes, or HSV-1 on your genitals.
Herpes Simplex Type 2 (HSV-2) or genital herpes is usually below the waist, but if you perform oral sex on someone who has HSV-2 genital sores, you can get HSV-2 on your face and mouth area.
HSV can also infect other parts of the body. Some other areas could be the eyes and the brain. Herpes Encephalitis is herpes in the brain. Very rare, and only affecting 2 per million, encephalitis is very dangerous and can cause a sore throat, headache, fever, vomitng, coma, and even death if left untreated.
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Prevention of this disease, which is contagious before and during an outbreak, is important. If tingling, burning, itching or tenderness -- signs of a recurrence -- occur in an area of the body where there was a herpes infection, then that area should be kept away from other people. With mouth lesions, one should avoid kissing and sharing cups or lip balms. For persons with genital herpes, this means avoiding sexual relations and oral and/or genital contact during the period of symptoms or active lesions. Towels should not be shared nor clothing exchanged.