OK, so the majority of people have it. Just this year, the World Health Organization released a study that estimates two thirds of people in the world (67%) have the HSV-1 strain of the herpes simplex virus — that’s approximately 3.7 billion people worldwide. While HSV-1 typically refers to oral herpes infections, it also includes some genital infections. The new report estimates that half of the HSV-1 infections in people between the ages of 15–49 are actually genital infections transmitted via oral-to-genital contact. The Center For Disease Control (CDC) estimates that 1 in 6 people have genital herpes.
HSV-1 has been proposed as a possible cause of Alzheimer's disease. In the presence of a certain gene variation (APOE-epsilon4 allele carriers), HSV-1 appears to be particularly damaging to the nervous system and increases one's risk of developing Alzheimer's disease. The virus interacts with the components and receptors of lipoproteins, which may lead to its development.
Pain, sore lips, burning sensation, tingling, or itching occurs at the infection site before the sores appear. These are the early symptoms (prodrome). Sometimes these symptoms happen prior to the appearance of sores, bumps, pimple-like lesions, or blisters (herpes or herpetic stomatitis). Thereafter, clusters or groups of painful blisters (also termed fever blisters) or vesicles erupt or ooze with a clear to yellowish fluid that may develop into a yellowish crust. These blisters break down rapidly and appear as tiny, shallow gray ulcers on a red base. Fever blisters are smaller than canker sores. A few days later, they become crusted or scabbed and appear drier and more yellow.
Herpesviral encephalitis and herpesviral meningitis Herpes simplex encephalitis (HSE) is a rare life-threatening condition that is thought to be caused by the transmission of HSV-1 either from the nasal cavity to the brain's temporal lobe or from a peripheral site on the face, along the trigeminal nerve axon, to the brainstem. Despite its low incidence, HSE is the most common sporadic fatal encephalitis worldwide. HSV-2 is the most common cause of Mollaret's meningitis, a type of recurrent viral meningitis.
Worldwide rates of either HSV-1 and/or HSV-2 are between 60 and 95% in adults. HSV-1 is more common than HSV-2, with rates of both increasing as people age. HSV-1 rates are between 70% and 80% in populations of low socioeconomic status and 40% to 60% in populations of improved socioeconomic status. An estimated 536 million people or 16% of the population worldwide were infected with HSV-2 as of 2003 with greater rates among women and in those in the developing world. Rates of infection are determined by the presence of antibodies against either viral species.
Transmission of HSV-1 occurs by direct exposure to saliva or droplets formed in the breath of infected individuals. In addition, skin contact with the lesions on an infected individual can spread the disease to another individual. Although close personal contact is usually required for transmission of the virus, it is possible to transmit HSV-1 when people share toothbrushes, drinking glasses, or eating utensils.
Herpes is contracted through direct contact with an active lesion or body fluid of an infected person. Herpes transmission occurs between discordant partners; a person with a history of infection (HSV seropositive) can pass the virus to an HSV seronegative person. Herpes simplex virus 2 is typically contracted through direct skin-to-skin contact with an infected individual, but can also be contracted by exposure to infected saliva, semen, vaginal fluid, or the fluid from herpetic blisters. To infect a new individual, HSV travels through tiny breaks in the skin or mucous membranes in the mouth or genital areas. Even microscopic abrasions on mucous membranes are sufficient to allow viral entry.
In order to diagnose herpes, a health care provider can swab an area of visibly active herpes infection or, if symptoms aren’t active, a blood test can be given that measures the number of herpes antibodies present in the body. The antibodies don’t indicate herpes itself, but rather show the immune system’s response to the presence of the virus in the body. It’s important to note that sometimes a swab can give false negative results since herpes lesions need to be large enough to yield enough detectable virus and if the outbreak is already healing it also may not be detected in a swab. (6)
Herpes symptoms commonly show in or around the mouth. Sores may also occur at the back of the throat, causing the lymph nodes in the neck to swell. Mouth herpes is very common in children, as their parents or relatives can pass it on to them easily by a greeting or goodnight kiss. To get a better understanding of oral herpes, let us take a look at its causes.
If you have recently made it through a first episode that consisted of full-blown symptoms, you know something about signs and symptoms already. The good news is that the first episode is almost always the worst that HSV throws your way. Signs and symptoms of recurrent episodes (when they occur) tend to be milder and heal much more quickly, typically within two to twelve days.
Herpes type 2 (HSV-2) can cause genital herpes. This is one of the most common sexually transmitted infections (STIs) in the US. It causes sores or painful blisters on the penis, vagina, scrotum, anus and buttocks. Along with blisters, people with HSV-2 may experience tingling, itching or pain. Like HSV-1, HSV-2 infections are highly contagious. They can be spread easily through skin-to-skin contact. Sexual intercourse is the main route of transmission.
"Oral herpes is an infection found in the mouth, or on and around the lips, caused by the Herpes Simplex Virus (HSV)," Michael explains. "There are two types or strains of this virus called HSV1 and HSV2. Usually, the HSV1 strain infects the mouth and lips, and the HSV2 strain infects the genitals. It is however possible for HSV2 to infect your mouth and lips."