The herpes simplex virus is probably the most well-known virus of the herpes family, and it is just as contagious. Herpes simplex infects epithelial cells and remains latent in neurons. HSV-1 causes recurrent oropharyngeal lesions, commonly known as “fever blisters" or "cold sores.” It is also the primary cause of sporadic encephalitis (inflammation of the brain), gingivostomatitis (inflammation of the gums and mucous lining of the mouth), and keratoconjunctivitis (severe dryness of the eye that involves the cornea) and dendritic corneal ulcers (also called HSV keratitis) in which the cornea becomes affected by herpetic lesions that look like the dendrites of neurons in the brain.
Cullins explains that even if you’ve never had an outbreak, if you’ve been exposed to herpes, it lies dormant in your body. A blood test could reveal antibodies for HSV-1 and/or HSV-2, which means that you have been exposed to the infection in your past, you have been infected, and you have developed antibodies because your body has or is fighting the infection.