Although the cause is unknown, outbreaks are often associated with periods of weakened immune systems, skin wounds, menstruation, fever, nerve damage, tissue damage from surgery, or exposure to extreme climate situations. A genital herpes outbreak or episode occurs when the HSV-1 or HSV-2 virus is reactivated from its dormant stage. Genital herpes is an incurable disease, and once you contract it, you may experience outbreaks throughout your lifetime. Those who are experiencing their first herpes episode of genital herpes can expect to have several (typically four or five) outbreaks within a year. Over time these recurrences usually decrease in frequency and severity. The first outbreak of herpes is often the longest outbreak experienced. After that, short and inconsistent episodes can be managed and treated with antiviral medication.
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.
Following active infection, herpes viruses establish a latent infection in sensory and autonomic ganglia of the nervous system. The double-stranded DNA of the virus is incorporated into the cell physiology by infection of the nucleus of a nerve's cell body. HSV latency is static; no virus is produced; and is controlled by a number of viral genes, including latency-associated transcript.
HSV-2 is commonly referred to as genital herpes because it usually causes cold sores to erupt around the genitalia. In fact, genital herpes is the No. 1 cause of genital ulcers worldwide, according to the Centers for Disease Control and Prevention (CDC), and affects up to 1 in 3 adults (although most who are infected don’t even know it). (5) Both types of herpes viruses are highly contagious, and both can cause cold sores in either area of the body (or sometimes both).
However, asymptomatic carriers of the HSV-2 virus are still contagious. In many infections, the first symptom people will have of their own infections is the horizontal transmission to a sexual partner or the vertical transmission of neonatal herpes to a newborn at term. Since most asymptomatic individuals are unaware of their infection, they are considered at high risk for spreading HSV.
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 simplex viruses -- more commonly known as herpes -- are categorized into two types: herpes type 1 (HSV-1, or oral herpes) and herpes type 2 (HSV-2, or genital herpes). Most commonly, herpes type 1 causes sores around the mouth and lips (sometimes called fever blisters or cold sores). HSV-1 can cause genital herpes, but most cases of genital herpes are caused by herpes type 2. In HSV-2, the infected person may have sores around the genitals or rectum. Although HSV-2 sores may occur in other locations, these sores usually are found below the waist.
As with almost all sexually transmitted infections, women are more susceptible to acquiring genital HSV-2 than men. On an annual basis, without the use of antivirals or condoms, the transmission risk of HSV-2 from infected male to female is about 8–11%. This is believed to be due to the increased exposure of mucosal tissue to potential infection sites. Transmission risk from infected female to male is around 4–5% annually. Suppressive antiviral therapy reduces these risks by 50%. Antivirals also help prevent the development of symptomatic HSV in infection scenarios, meaning the infected partner will be seropositive but symptom-free by about 50%. Condom use also reduces the transmission risk significantly. Condom use is much more effective at preventing male-to-female transmission than vice versa. Previous HSV-1 infection may reduce the risk for acquisition of HSV-2 infection among women by a factor of three, although the one study that states this has a small sample size of 14 transmissions out of 214 couples.
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.
Herpes virus type 5 is also known as cytomegalovirus. It is the major cause of mononucleosis. Mononucleosis causes symptoms similar to infectious mononucleosis. It is spread via blood transfusion, breast-feeding, organ transplants, and sexual contact. The virus causes diarrhea, or severe vision problems and even leads to AIDS. People with weakened immune systems are more susceptible to these diseases.
HSV-1 and HSV-2 are transmitted by direct physical contact with a sore on an infected person. Facial or lip herpes is most often contracted by kissing someone with a cold sore. Genital herpes is most often contracted during sexual intercourse with a person who has an active genital sore. Genital herpes can also be contracted during or genital sex if a partner has labial herpes.
Varicella-zoster is transmitted though the mucosa of the respiratory system, specifically the upper respiratory tract, or the conjunctiva of the eye. Initial replication takes place in the regional lymph nodes, and then the virus spreads and replication begins in the liver and spleen. The virus is then transported to the skin where the rash develops. The incubation period of varicella is about 10 to 21 days.
Herpes infection can be passed from you to your unborn child before birth but is more commonly passed to your infant during delivery. This can lead to a potentially deadly infection in your baby (called neonatal herpes). It is important that you avoid getting herpes during pregnancy. If you are pregnant and have genital herpes, you may be offered anti-herpes medicine towards the end of your pregnancy. This medicine may reduce your risk of having signs or symptoms of genital herpes at the time of delivery. At the time of delivery, your doctor should carefully examine you for herpes sores. If you have herpes symptoms at delivery, a ‘C-section’ is usually performed.