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.
The risk of transmission from mother to baby is highest if the mother becomes infected around the time of delivery (30% to 60%), since insufficient time will have occurred for the generation and transfer of protective maternal antibodies before the birth of the child. In contrast, the risk falls to 3% if the infection is recurrent, and is 1–3% if the woman is seropositive for both HSV-1 and HSV-2, and is less than 1% if no lesions are visible. Women seropositive for only one type of HSV are only half as likely to transmit HSV as infected seronegative mothers. To prevent neonatal infections, seronegative women are recommended to avoid unprotected oral-genital contact with an HSV-1-seropositive partner and conventional sex with a partner having a genital infection during the last trimester of pregnancy. Mothers infected with HSV are advised to avoid procedures that would cause trauma to the infant during birth (e.g. fetal scalp electrodes, forceps, and vacuum extractors) and, should lesions be present, to elect caesarean section to reduce exposure of the child to infected secretions in the birth canal. The use of antiviral treatments, such as aciclovir, given from the 36th week of pregnancy, limits HSV recurrence and shedding during childbirth, thereby reducing the need for caesarean section.
Once a person is infected, there are no symptoms for anywhere between 2 days to 2 weeks. This is known as the incubation period and is the time during which the virus multiplies profusely. The first symptoms that are seen are the small fluid-filled blisters known as vesicles. This arises as the virus starts destroying cells at the site and causes intense localized inflammation. These small vesicles or sometimes the larger bullae may either burst resulting in ulcer or heal completely with no scarring. The virus may also travel from the site of infection and “hides” by the sensory dorsal root. Here it remains latent until is it is reactivated.
The HSV viruses multiply in the human cell by overtaking and utilizing most of the human cells functions. One of the HSV steps in multiplication is to take control of the human cell's nucleus and alter its structure. The altered nucleus (enlarged and lobulated or multinucleated) is what actually is used to help diagnose herpes simplex infections by microscopic examination. The reason sores appear is because as they mature the many HSV particles rupture the human cell's membrane as they break out of the cell.
To reduce the chance of acquiring HSV-1, avoid touching saliva, skin, or mucous membranes of people who have HSV-1 lesions. Prevention of genital HSV may be accomplished by latex condoms, but protection is never 100%. Spermicides do not protect against HSV. Some clinicians recommend using dental dams (small latex squares) during oral sex, but like condoms, they are not 100% protective.
^ 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.
These herpes viruses enter the body through small cuts, abrasions, or breaks in the skin or mucous membranes. The incubation period for herpes simplex infections is about three to six days. Transmission (spread) of the virus is person to person and more likely to occur if blisters or lesions are present. The majority enter after an uninfected person has direct contact with someone carrying the virus (either with or without noticeable lesions). Simply touching an infected person is often the way children get exposed. Adolescents and adults frequently get exposed by skin contact but may get their first exposure by kissing or sexual contact (oral and/or genital contact), especially for HSV-2. Statistical studies suggest that about 80%-90% of people in the U.S. have been exposed to HSV-1 and about 30% have been exposed to HSV-2. Usually, the contagious period continues until lesions heal. Some people (estimated from 30%-50%) occasionally shed herpes virus while having few or no associated symptoms or signs.
Signs and symptoms of dehydration usually warrant going to a hospital's emergency department. Infants, especially under 6 weeks of age or if the infant appears to slow urine output or decrease fluid intake, should be evaluated by their pediatrician or in an emergency center if oral sores appear. Individuals with immune suppression (for example, patients undergoing chemotherapy, HIV patients, or cancer patients) should contact their doctors if they suspect a HSV-1 infection.
Primary Infection: This is the first stage wherein the contagion reproduces upon entering from the mucous membrane or skin. Typical symptom is the appearance of oral lesions which may not be present initially resulting in an asymptotic infection. In this case due to lack of symptoms one will be unaware of the presence of an infection. The sores usually takes 21 days to form and become visible, then the blisters will persist up to 10 days before beginning to heal.
No method eradicates herpes virus from the body, but antiviral medications can reduce the frequency, duration, and severity of outbreaks. Analgesics such as ibuprofen and paracetamol (acetaminophen) can reduce pain and fever. Topical anesthetic treatments such as prilocaine, lidocaine, benzocaine, or tetracaine can also relieve itching and pain.
Stage 3 -- Recurrence: When people encounter certain stresses (also termed triggers), emotional or physical, the virus may reactivate and cause new sores and symptoms. The following factors may contribute to or trigger recurrence: stress, illness, ultraviolet light (UV rays including sunshine), fever, fatigue, hormonal changes (for example, menstruation), immune depression, and trauma to a site or a nerve region where previous HSV infection occurred.
Herpes sores usually appear as one or more blisters on or around the genitals, rectum or mouth. The blisters break and leave painful sores that may take a week or more to heal. These symptoms are sometimes called “having an outbreak.” The first time someone has an outbreak they may also have flu-like symptoms such as fever, body aches, or swollen glands.
Human herpes virus 3 (HHV3) is also called varicella-zoster virus. HHV3 causes chickenpox. It can also cause a recurrent virus infection of the skin, which is called herpes zoster or shingles. Shingles occurs when dormant varicella-zoster virus from an initial bout of chickenpox becomes reactivated. Like its close relative, HHV1, herpes zoster likes to infect skin cells and nerve cells. This virus may also recur along nerve fibre pathways, causing multiple sores where nerve fibres end on skin cells. Because an entire group of nerve cells is often affected, shingles is generally much more severe than a recurrence of herpes simplex. The lesions generally appear in a band-like or belt-like pattern occurring on one side of the body and are often accompanied by itching, tingling, or even severe pain. Healing usually occurs in 2 to 4 weeks, and scars may remain. Postherpetic neuralgia is a complication of shingles where the pain associated with the infection can persist for months and even years. Most people who experience shingles once do not experience it again.
HSV asymptomatic shedding occurs at some time in most individuals infected with herpes. It can occur more than a week before or after a symptomatic recurrence in 50% of cases. Virus enters into susceptible cells by entry receptors such as nectin-1, HVEM and 3-O sulfated heparan sulfate. Infected people who show no visible symptoms may still shed and transmit viruses through their skin; asymptomatic shedding may represent the most common form of HSV-2 transmission. Asymptomatic shedding is more frequent within the first 12 months of acquiring HSV. Concurrent infection with HIV increases the frequency and duration of asymptomatic shedding. Some individuals may have much lower patterns of shedding, but evidence supporting this is not fully verified; no significant differences are seen in the frequency of asymptomatic shedding when comparing persons with one to 12 annual recurrences to those with no recurrences.
Oral herpes, commonly referred to as mouth herpes, is a viral infection of the mouth and gums primarily by the Herpes simplex virus type 1 (HSV-1) but may also be due to the genital variant (HSV-2). It is also known as recurrent herpetic stomatitis or acute herpetic gingivostomatitis. The infection of the mouth typically causes small fluid-filled blisters known as vesicles on the roof of the mouth (palate), inside of the cheeks (buccal muscosa), tongue, gums and even the lips (herpes labialis). It may also occur on the skin around the mouth and extend to the nose and into the nasal cavity.
Not every person with a herpes infection actually experiences breakouts of cold sores throughout his or her lifetime or even after initially becoming infected. How often someone has a herpes cold sore outbreak, how severe the outbreaks are, how contagious someone is after infection and how long the sores take to heal all depend on someone’s individual immune response.
"When you are having an outbreak of oral herpes, symptoms usually start with a burning, itching or tingling sensation on your lips," Michael says. "This will intensify until a small rash, and then blisters, appear. These sores are commonly called 'cold sores'. The blisters are usually filled with a clear or slightly yellow liquid. Over a short time, these blisters will burst leaving a painful, raw area. These will then dry and scab over. The scabs will generally fall off after a week or two, leaving fresh clear skin beneath."