Herpes simplex - not as simple as you think

Herpes labialis

Cold sores are the commonly known form of oral herpes, though herpes is best known as its genital form. Both are caused by the herpes simplex virus. No cure is available for herpes simplex infection because it hibernates in the nerve cells. A weakened immune system puts an individual at greater risk for infection.

HSV-1 and HSV-2 can both cause oral or genital lesions, and can be spread by symptomatic or asymptomatic individuals via body fluids. When spread by an individual who lacks sores or symptoms, the transmission is called asymptomatic viral shedding. After initial infection, outbreaks can be triggered by stress, menstruation, sun exposure, fever, and illness.

Read more about types of herpes simplex virus below the jump, and then protect yourself.

 

Herpes simplex viruses are icosahedral, enveloped DNA viruses that cause herpes, an infection that appears as sores on the affected area. Cold sores are the commonly known form of oral herpes, though herpes is best known as its genital form. No cure is available for herpes simplex infection because it hibernates in the nerve cells. Herpes simplex virus is characterized as two types.

Herpes simplex virus type 1

HSV-1 causes most cases of the oral form of herpes. The American Academy of Dermatology (AAD) recognizes several names for this infection: oral herpes, cold sores, fever blisters, mouth herpes, and herpes simplex labialis. According to the AAD, most people are exposed to HSV-1 as infants or children, who are infected by skin to skin contact with adults, such as a kiss on the cheek, sharing utensils, and sharing a towel. Herpes simplex viruses are very common pathogens, with the University of Maryland Medical Center estimating that 90 percent of American adults are infected with the oral virus.

Herpes simplex virus type 2

HSV-2 causes most cases of the genital form of herpes, which is most often known simply as herpes. The University of Maryland Medical Center estimates that 20 percent of American adults are infected with HSV-2. Most infections occur in women (1 in 4 are infected, compared to 1 in 8 men), individuals who have had several sexual partners, individuals who had sex at an early age, individuals with a history of sexually transmitted diseases, and individuals with a weakened immune system, such as HIV-positive patients. HSV-2 is most commonly spread by sexual contact, including via oral sex, causing oral herpes (non-HSV-1).

Commonalities among the herpes types

Common symptoms of herpes simplex virus infection are tingling in the affected area, fever, small blisters in the affected area, and swollen lymph nodes (neck for HSV-1 and groin for HSV-2). To become infected, the virus has to be able to enter through a break in the skin. A weakened immune system puts an individual at greater risk for infection. HSV-1 and HSV-2 can both cause oral or genital lesions, and can be spread by symptomatic or asymptomatic individuals via body fluids. When spread by an individual who lacks sores or symptoms, the transmission is called asymptomatic viral shedding. After initial infection, outbreaks can be triggered by stress, menstruation, sun exposure, fever, and illness.

For a visualization of the virus structure and infectious actions, see Dr. Edward Wagner’s resource at the University of California Irvine.