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.
The annual incidence in Canada of genital herpes due to HSV-1 and HSV-2 infection is not known (for a review of HSV-1/HSV-2 prevalence and incidence studies worldwide, see Smith and Robinson 2002). As many as one in seven Canadians aged 14 to 59 may be infected with herpes simplex type 2 virus and more than 90 per cent of them may be unaware of their status, a new study suggests. In the United States, it is estimated that about 1,640,000 HSV-2 seroconversions occur yearly (730,000 men and 910,000 women, or 8.4 per 1,000 persons).
You should stop having sexual contact as soon as you feel warning signs of an outbreak. Warning signs may include a burning, itching, or tingling feeling on the genitals or around the mouth. Do not have vaginal, anal, or oral sex — even with a condom — until seven days after the warning signs stop or the sore heals. The virus can spread from sores not covered by the condom. It can also spread in sweat or vaginal fluids to places the condom doesn't cover.
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.
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.
Human herpes virus 8 (HHV8) was recently discovered in the tumours called Kaposi's Sarcoma (KS). These tumours are found in people with AIDS and are otherwise very rare. KS forms purplish tumours in the skin and other tissues of some people with AIDS. It is very difficult to treat with medication. HHV8 may also cause other cancers, including certain lymphomas (lymph node cancers) associated with AIDS. The fact that these cancers are caused by a virus may explain why they tend to occur in people with AIDS when their immune systems begin to fail. The discovery also provides new hope that specific treatments for these tumours will be developed that target the virus.
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.
During stage 1, the virus comes in contact with the skin, enters through cracks or breaks, and reproduces. In this phase, symptoms like fever might occur. The incubation period for oral herpes is between 2 to 12 days. The symptoms last for about 3 weeks. The symptoms may be mild or serious, and occur within the first three weeks after contracting the infection. These symptoms include;
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.
A doctor will base a presumptive diagnosis on information provided by the patient and on the physical examination. The characteristic appearance of the herpes sores leaves little doubt about the diagnosis, so the typical appearance of the sores is key to the diagnosis. This appearance helps distinguish oral herpes from oral thrush, shingles, gonorrhea, and syphilis. In addition, chapped or sunburned lips can resemble oral herpes, but the tissue stain (Tzanck smear, see below) shows no virus-induced cell changes. Further testing is usually not necessary but is sometimes done.