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.
At least 80 to 90 percent of people in the U.S. have already been exposed to the HSV-1 virus.sup style="font-size: 10px;">21 Meanwhile, around 3.7 billion HSV-1 infections were recorded in 2012 all over the world, according to the World Health Organization. Africa was home to the highest number of cases, with 87 percent of occurrences coming from this continent.22
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.
In all cases, HSV is never removed from the body by the immune system. Following a primary infection, the virus enters the nerves at the site of primary infection, migrates to the cell body of the neuron, and becomes latent in the ganglion. As a result of primary infection, the body produces antibodies to the particular type of HSV involved, preventing a subsequent infection of that type at a different site. In HSV-1-infected individuals, seroconversion after an oral infection prevents additional HSV-1 infections such as whitlow, genital herpes, and herpes of the eye. Prior HSV-1 seroconversion seems to reduce the symptoms of a later HSV-2 infection, although HSV-2 can still be contracted.
There’s herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). “HSV-1 and HSV-2 are different but closely related viruses,” says Dr. Christine Johnston, MPH, who is the Associate Medical Director of the Virology Research Clinic at the University of Washington. Johnston explains that both are transmitted through close mucosal or skin contact with infected secretions. HSV-1 primarily causes oral outbreaks, also known as cold sores, and HSV-2 usually causes genital outbreaks. But HSV-1 can also cause genital outbreaks through oral-to-genital contact, according to the CDC. According to Johnston, genital HSV-1 is less likely to recur than HSV-2, and there’s less asymptomatic shedding (transmitting the virus without realizing it) with HSV-1 than with HSV-2.
Herpes type 2 is one of two types of HSV (Herpes Simplex Virus). The virus is also known as HSV-2 and differs slightly from HSV-1. It is also called genital herpes or herpes genitalis, which is considered a harmless viral infection. Herpes genitalis is usually considered a sexually transmitted disease. However, it is not listed among notifiable diseases regulated under the Public Health Act.
Human herpes virus 6 (HHV6) is a recently observed agent found in the blood cells of a few patients with a variety of diseases. It causes roseola (a viral disease causing high fever and a skin rash in small children) and a variety of other illnesses associated with fever in that age group. This infection accounts for many of the cases of convulsions associated with fever in infancy (febrile seizures).
There are two types of herpes simplex virus, type 1 (HSV-1) and type 2 (HSV-2). HSV-1 more commonly causes infections around the mouth while HSV-2 more commonly causes genital infections. They are transmitted by direct contact with body fluids or lesions of an infected individual. Transmission may still occur when symptoms are not present. Genital herpes is classified as a sexually transmitted infection. It may be spread to an infant during childbirth. After infection, the viruses are transported along sensory nerves to the nerve cell bodies, where they reside lifelong. Causes of recurrence may include: decreased immune function, stress, and sunlight exposure. Oral and genital herpes is usually diagnosed based on the presenting symptoms. The diagnosis may be confirmed by viral culture or detecting herpes DNA in fluid from blisters. Testing the blood for antibodies against the virus can confirm a previous infection but will be negative in new infections.
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.
Primary orofacial herpes is readily identified by examination of persons with no previous history of lesions and contact with an individual with known HSV infection. The appearance and distribution of sores is typically presents as multiple, round, superficial oral ulcers, accompanied by acute gingivitis. Adults with atypical presentation are more difficult to diagnose. Prodromal symptoms that occur before the appearance of herpetic lesions help differentiate HSV symptoms from the similar symptoms of other disorders, such as allergic stomatitis. When lesions do not appear inside the mouth, primary orofacial herpes is sometimes mistaken for impetigo, a bacterial infection. Common mouth ulcers (aphthous ulcer) also resemble intraoral herpes, but do not present a vesicular stage.
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.
“Someone having HSV doesn't mean that they were reckless or irresponsible with their sex life,” says Sara, age 30. “I used condoms with all my partners, and I still caught it.” For Jamie, who contracted herpes from her husband three years into their monogamous relationship, he was her first and only sexual partner. And she says that he contracted it from one of his very first sexual encounters. No matter how and why someone contracted the virus, it doesn't erase their humanity and right to respect.
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.
According to Gina*, 21, “A herpes diagnosis is very shaking and it gives you the opportunity to look inward and really find what you love about yourself.” Gina says she has even better self-esteem than prior to finding out she had HSV. She explains, “You learn not to lower your standards, because you start to pick out who it is worth disclosing to and who isn't.”