Humans are the only natural host for the herpes simplex viruses, HSV-1 and HSV-2. Transmission occurs through direct contact with infected body fluids. Several common herpetic illnesses occur, including herpes labialis, or cold sores; ocular, or eye herpes; herpes stomatitis, or mouth herpes; and genital herpes. HSV-1 and HSV-2 can cause any of these infections. HSV-2 predominates in sexually transmitted infections. Different ways to get the herpes virus involve varying routes of direct contact with the virus.
Oral Contact
Initial herpes simplex infection of the mouth occurs with direct or indirect contact with the saliva of someone with HSV. People with active cold sores are most likely to transmit HSV to others through a kiss or sharing a drinking glass or eating utensils. The medical reference text "Principles and Practice of Infectious Diseases" explains that although HSV transmission is most likely when an active sore exists, people with a history of cold sores but no active lesions are also able to transmit the virus to others.
Sexual Contact
Sexual transmission of HSV can occur with vaginal intercourse, anal intercourse or oral sex. Females infected through vaginal intercourse develop lesions of the vulvar skin. Infected males develop lesions on the penis and surrounding genital skin. HSV infection contracted through anal sex causes lesions near the anus. The American Academy of Dermatology points out that initial infection with HSV can be asymptomatic or mild enough to remain unrecognized. Thus, people may not realize they have HSV and can unknowingly transmit the virus to others.
Oral-anal, oral-vulvar and oral-penile contact with an infected person can lead to HSV transmission. A person with cold sores can transmit HSV to the anus, vulva or penis of another person. Similarly, a person with HSV infection in these body areas can transmit the virus to the mouth of a partner performing oral sex. Touching the genitals or anus of someone with HSV and then touching the eyes or mouth can also serve as a route of transmission.
Hand Contact
"Principles and Practice of Infectious Diseases" notes that herpetic whitlow--an HSV infection of the fingers--may occur in medical, dental and allied health-care personnel who inadvertently contact the virus while working with patients infected with HSV. Children with oral HSV may infect their hands by sucking the thumb or putting the fingers in the mouth. Hand-genital sexual contact with an infected person may also cause herpetic whitlow.
Mother-to-Child Transmission
Children's Hospital Boston reports that a mother with HSV can transmit the virus to her baby at the time of delivery. This route of transmission most commonly occurs with vaginal births. The likelihood of transmission increases if the mother is experiencing an initial genital herpes outbreak at the time of delivery. Uncommonly, babies may be infected with HSV while in the womb or after delivery.
References
- "Principles and Practice of Infectious Diseases" Sixth Edition; Gerald L. Mandell, M.D., et al., Editors; 2004
- Centers for Disease Control and Prevention: How Do People Get Genital Herpes?
- American Academy of Dermatology: Herpes Simplex
- Children's Hospital Boston: Congenital Herpes Simplex
- University of Maryland Medical Center: Herpes Simplex Risk Factors
