Both HSV-1 and HSV-2 infections are acquired from direct contact with someone who carries the virus. The infectious secretions that pass on HSV-1 or HSV-2 live on oral, genital or anal mucosal surfaces. They’re passed through skin-to-skin transmission, and any form of direct contact with sores on the mouth, buttocks or genitals can cause the virus to be passed.
Antibodies that develop following an initial infection with a type of HSV prevents reinfection with the same virus type—a person with a history of orofacial infection caused by HSV-1 cannot contract herpes whitlow or a genital infection caused by HSV-1. In a monogamous couple, a seronegative female runs a greater than 30% per year risk of contracting an HSV infection from a seropositive male partner. If an oral HSV-1 infection is contracted first, seroconversion will have occurred after 6 weeks to provide protective antibodies against a future genital HSV-1 infection. Herpes simplex is a double-stranded DNA virus.
^ Xu, Fujie; Fujie Xu; Maya R. Sternberg; Benny J. Kottiri; Geraldine M. McQuillan; Francis K. Lee; Andre J. Nahmias; Stuart M. Berman; Lauri E. Markowitz (2006-10-23). "Trends in Herpes Simplex Virus Type 1 and Type 2 Seroprevalence in the United States". JAMA. 296 (8): 964–73. doi:10.1001/jama.296.8.964. PMID 16926356. Archived from the original on 2010-04-24.
Prodrome: Early in the phase of reactivation (also called an outbreak), many people experience an itching, tingling, or painful feeling in the area where their recurrent lesions will develop. This sort of warning symptom – called a “prodrome” – often comes a day or two before lesions appear. To be on the safe side, it’s best to assume virus is active (and, therefore, can be spread through direct skin-to-skin contact) during these times.
Oral herpes is also known commonly as cold sores and fever blisters but is different entity from oral canker sores although canker sores may sometimes be associated with HSV infection. Canker sores occur solely inside the mouth. Oral herpes occurs inside and around the mouth. Most of the time HSV-1 causes mouth symptoms and in a minority of cases it may also be responsible for genital symptoms. The opposite is true for HSV-2 – it causes genital symptoms in the majority of cases while only a few cases of HSV-2 infection will result in mouth symptoms. HSV-1 infection may be seen in all ages, including children, but when genital herpes is seen in children, sexual abuse needs to be a consideration.
Cullins explains that the first, or initial, outbreak is usually the worst, and “over time when you have recurrent episodes, you may not have systemic symptoms” or frequent symptoms. But everyone’s body and immune system reacts to the virus differently; while some people may never have many outbreaks, other people may be more chronically symptomatic. The National Institutes of Health indicate that infrequent outbreaks, around one or two per year, are not uncommon.