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.
At the other end of the spectrum, there is a possibility of a herpetic flare up taking a sinister turn and leading to herpetic encephalitis. It is estimated to affect at least 1 in 500,000 individuals per year. The mechanism of this is not fully understood, but it is believed that the infection occurs through direct transmission of the virus via nerves from other parts of the body to the brain. In such cases, a person may complain of fever, headache, and lethargy, followed by confusion or delirium. In some cases, some people even develop seizures. This requires immediate medical attention and treatment.
Although it's rare, pregnant women can pass on the herpes infection to their child. This can result in a serious and sometimes deadly infection in the baby. That's why taking steps to prevent an outbreak at time of delivery is recommended starting at 34 weeks into the pregnancy. If you have signs of an active viral infection when it's time to deliver, your doctor will likely recommend a cesarean section for delivery.
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.
Herpes is transmitted via skin-to-skin contact, not through blood or saliva. Cullins explains that someone with HSV can be shedding the herpes virus without having an outbreak (known as asymptomatic virus shedding), and infect somebody that way. Suppressive antiviral medications, like acyclovir or valacyclovir, inhibit HSV replication, which decreases shedding but does not completely eliminate it, says Johnston.
When herpes flares up again, it is called a "recurrence" or "outbreak." Herpes does not always recur, and if it does recur, the timing and severity are different from person to person. Some people rarely have recurrences. Others have them often. Herpes is most likely to recur in the first year after infection. Recurrences may be more frequent for people with weakened immune systems.
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.
Some people have recurrent outbreaks with the so-called “classic” blister-like herpes lesions that crust over, or with painful sores. In recurrent herpes, however, this process usually takes about half the time it does in first episodes. In addition, many people have very subtle forms of recurrent herpes that heal up in a matter of days. And lastly, herpes is capable of reactivating without producing any visible lesions (asymptomatic reactivation).
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.
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)