Worldwide rates of either HSV-1 or HSV-2 are between 60% and 95% in adults. HSV-1 is usually acquired during childhood. Rates of both increase as people age. Rates of HSV-1 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 worldwide (16% of the population) were infected with HSV-2 as of 2003 with greater rates among women and those in the developing world. Most people with HSV-2 do not realize that they are infected. The name is from Greek: ἕρπης herpēs which means "to creep", referring to spreading blisters. The name does not refer to latency.
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).
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.
Pain, sore lips, burning sensation, tingling, or itching occurs at the infection site before the sores appear. These are the early symptoms (prodrome). Sometimes these symptoms happen prior to the appearance of sores, bumps, pimple-like lesions, or blisters (herpes or herpetic stomatitis). Thereafter, clusters or groups of painful blisters (also termed fever blisters) or vesicles erupt or ooze with a clear to yellowish fluid that may develop into a yellowish crust. These blisters break down rapidly and appear as tiny, shallow gray ulcers on a red base. Fever blisters are smaller than canker sores. A few days later, they become crusted or scabbed and appear drier and more yellow.
Herpes “triggers” (determining exactly what leads to an outbreak) are highly individual, but with time, many people learn to recognize, and sometimes avoid, factors that seem to reactivate HSV in their own bodies. Illness, poor diet, emotional or physical stress, friction in the genital area, prolonged exposure to ultraviolet light (commonly for oral herpes, such as a beach trip or skiing weekend), surgical trauma, and steroidal medication (such as asthma treatment) may trigger a herpes outbreak.
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.
Do everything possible to prevent spreading it to other people. The virus cannot live long when it is not in contact with the skin, so door handles and towels are not likely to spread it. Do not share your personal belongings, like toothbrushes and combs. Wash your hands with soap and water often, and immediately if you touch the sores. This is important so as to minimize the chance of getting ocular herpes (herpes infection of the eye) which is a serious infection. Be especially careful around infants because their immune systems may not be fully developed. Little children often express affection with sloppy wet kisses. This is a common way to spread the herpes virus within the family.
Research has gone into vaccines for both prevention and treatment of herpes infections. Unsuccessful clinical trials have been conducted for some glycoprotein subunit vaccines. As of 2017, the future pipeline includes several promising replication-incompetent vaccine proposals while two replication-competent (live-attenuated) HSV vaccine are undergoing human testing.
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.
Human herpes virus 5 (HHV5) is the official name of cytomegalovirus (CMV). CMV is also a cause of mononucleosis. In people with healthy immune systems, the virus may not even cause any symptoms. It can be sexually transmitted, can cause problems to newborns, and can cause hepatitis. CMV can be transmitted through sexual contact, breast-feeding, blood transfusions, and organ transplants. CMV infection is one of the most difficult complications of AIDS. It may lead to diarrhea, severe vision problems including blindness, infections of the stomach and intestines, and even death. For a virus that barely causes a problem in most people with healthy immune systems, it can be amazingly nasty in people with damaged immune systems, such as people with AIDS.