Herpes simplex

Definition

Herpes is an infection caused by a herpes simplex virus 1 or 2, and it primarily affects the mouth or genital area.

Description

There are two strains of herpes simplex viruses. Herpes simplex virus type 1 (HSV-1) is usually associated with infections of the lips, mouth, and face. It is the most common herpes simplex virus among the general population and is usually acquired in childhood. Herpes simplex virus 2 (HSV-2) is sexually transmitted and is usually associated with genital ulcers or sores. Individuals may harbor HSV-1 and or HSV-2 and not have developed any symptoms.

Transmission

HSV-1 causes lesions inside the mouth that are often referred to as cold sores or fever blisters, and it is transmitted by contact with infected saliva. By adulthood, up to 90 percent of the population has antibodies to HSV-1. HSV-2 is sexually transmitted and not everyone develops symptoms when they have it. Up to 30 percent of adults in the United States have antibodies against HSV-2. Cross infection of type 1 and 2 viruses may occur from oral-genital contact. Herpes viruses can be transmitted to a newborn during vaginal delivery in mothers infected with herpes viruses, especially if the infection is primary (first occurrence) and is active at the time of delivery. The virus can lead to complications such as meningoencephalitis, which is an infection of the lining of the brain and the brain itself. It can also cause eye infections, in particular, of the conjunctiva and cornea.

Demographics

The prevalence of herpes simplex in the United States is as follows:

• Seventy to ninety percent of adults test seropositive (present in blood serum) for HSV-1.
• Up to 30 percent of adults test seropositive for HSV-2.
• The highest incidence of HSV-1 is in children six months to three years of age.
• The highest incidence of HSV-2 is in young adults between the age of 18 and 25 years.
• HSV-2 antibodies are present in approximately 20 percent of Caucasians and about 65 percent of African-American adults.

Causes and symptoms

A primary infection of HSV-1 typically occurs between six months and five years of age and is systemic (affecting the whole body). Transmission is generally via respiratory droplets (HSV-1) or direct contact (HSV-1 and HSV-2). The virus enters the body through mucosal surfaces, replicates in the cell nucleus, and then kills the host cell. The initial infection is self-limiting, but the immune system does not destroy the virus. The virus migrates along nerves to an area of regional ganglia (nerve centers) and then typically enters into a latent (sleeping) phase. Reactivation of the virus occurs in 50 percent of patients within five years, and it can be triggered by various factors:

• fatigue
• stress
• trauma
• immunocompromise (lack of normal immune response)
• illness, such as a cold
• fever
• sunburn
• menstruation
• sexual intercourse

The symptoms of a herpes infection can vary tremendously. Many infected individuals have few, if any, noticeable symptoms. Those who do have symptoms usually notice them from two to 20 days after being exposed to someone with HSV infection. Symptoms can last for several weeks, but the first episode of herpes is usually worse than subsequent outbreaks. The predominant symptom of herpes is the outbreak of painful, itching blisters filled with fluid on and around the external sexual organs or, for oral herpes, on or very near the lip. Females may have a vaginal discharge and experience flu-like symptoms with HSV2 outbreaks, including fever, headache , muscle aches, and fatigue. There may be painful urination, and swollen and tender lymph glands in the groin. More often than not the blisters disappear without treatment in two to 10 days, but the virus remains in the body, lying dormant among clusters of nerve cells until another outbreak is triggered.

Many people are able to anticipate an outbreak when they notice a warning sign (a tingling sensation, called a prodrome) of the approaching illness. It is when they feel signs that an outbreak is about to start that they are particularly contagious, even though the skin still appears normal. Most people with genital herpes have five to eight outbreaks per year, but not everyone has recurrent symptoms. In time, the number of outbreaks usually decreases. Oral herpes can recur as often as monthly or only one or two times each year. Sores typically come back near the site of the first infection, but there are fewer sores with recurrences that heal faster and are less painful.

When to call the doctor

Anyone who has a history of herpes infection and current lesions should notify the physician if the lesions do not resolve after seven to ten days or if a condition exists that weakens the immune system. Children with a herpes infection most commonly have sores in the mouth usually caused by HSV-1. This infection causes fever, irritability, pain , decreased appetite, and ulcers in the mouth. The most common complication is dehydration secondary to a refusal to drink fluids because of mouth pain and difficulty swallowing. Treatment is usually not required, and symptoms generally improve in three to five days. If, however, the child does not improve, develops a fever, and becomes lethargic, the pediatrician should be called immediately.

Herpes infections that spread throughout the body in a newborn are usually more serious, but fortunately less common than the other types of neonatal infections. They typically occur in the first week of life, with symptoms including fever, difficulty breathing, seizures, lethargy, and irritability. Since many infants in the first month of life can have a herpes infection and not have skin lesions, it takes a great deal of time and effort to diagnose and treat these infections early. Herpes should be considered in any acutely ill newborn, especially if bacterial cultures are negative and the baby is not improving after two to three days. Parents should be informed to watch the baby closely if either one of them has a history of herpes infections.

Diagnosis

Testing for neonatal herpes infections may include special smears and/or viral cultures, blood antibody levels, and polymerase chain reaction (PCR) testing of spinal fluid. Cultures are usually obtained from skin vesicles, eyes, mouth, rectum, urine, stool, and blood. For older children and adults, if there is a question as to the cause of a sore, a tissue sample or culture can be taken to determine what type of virus or other microorganism is responsible. For herpes, it is preferable to have this test done within the first 48 hours after symptoms first show up for a more accurate result.

Treatment

There are three drugs proven to treat genital herpes symptoms: acyclovir, sold under the brand name Zovirax, Famvir, and Valtrex. These are all taken in pill form. Formulas applied to the surface of the skin provide little benefit, and they are not recommended. Drug therapy is not a cure, but it can make living with the condition easier. For an initial outbreak with symptoms such as sores, a doctor should begin a brief course of antiviral therapy to relieve the symptoms or prevent them from getting worse. Seven to ten days of treatment is recommended but if the lesions do not heal, a longer period of time may be required. Following the initial outbreak there are two options to consider for further outbreaks. One is intermittent treatment, which involves the physician prescribing an antiviral drug to keep on hand in case an individual has a flare-up. The pills can be taken for three to five days as soon as sores are noticed or when an outbreak tingling sensation occurs. Sores heal and disappear on their own, but taking the drugs helps to alleviate the symptoms. For individuals who have frequent outbreaks, a suppressive treatment may work better. This treatment involves taking an antiviral drug every day. For example, someone who typically has more than six outbreaks a year, suppressive therapy reduces the number of outbreaks by 70 to 80 percent. Moreover, many who take the antiviral drugs daily have no outbreaks at all.

In the early 2000s herpes vaccines are being investigated, and an effective vaccine may be available in before 2010. Vaccines will only function to prevent the infection in new patients. Those who already have the simplex virus disease will probably not benefit.

Nutritional concerns

Diet is a very important factor in keeping herpes in remission. It has been found that foods high in arginine may cause herpes outbreaks. Supplementation with free-form lysine has shown to be beneficial in controlling herpes along with a diet high in lysine and low in arginine. The amount of lysine required to control herpes varies from case to case, but a typical adult dose to maintain remission is 500 mg daily, and active herpes requires 1–6 g between meals to induce healing.

Prognosis

There is no cure for herpes simplex. Once it is contracted, it is always in a person's system. However, with treatment therapies, the problems previously encountered are lessened considerably.

Prevention

Whereas it is almost impossible to keep a baby or child from being exposed to herpes simplex due to its universal presence, there are conditions that can be used to prevent its transmission. Hand washing is one of the biggest factors in the transmission of all diseases, and it is especially true of herpes simplex since it is spread by respiratory droplets through mucosal membranes. In terms of genital herpes, education regarding the use of condoms is the best tool. Young adults should also be reminded that herpes simplex can be transferred from oral-genital contact. Since many teenagers do not consider oral or anal sex as sexual intercourse per se, it is imperative to spell out exactly what, when, and how these viruses can be spread.

Parental concerns

It is important that the pediatrician discusses the possibility of herpes infections with new parents, particularly if they have a history of genital herpes. Signs and symptoms need to be gone over, i.e., lethargy, fever, as well as the fact that there may or may not be lesions present. A newborn's own immune system begins to function around the third month, and if a mother is breast-feeding, she is passing antibodies to her baby. The primary concern is that a herpes infection does not become systemic. Thus, if the child seems to be getting sicker instead of better, parents should call the doctor immediately.

KEY TERMS

Conjunctiva —Plural, conjunctivae. The mucous membrane that covers the white part of the eyes (sclera) and lines the eyelids.

Cornea —The clear, dome-shaped outer covering of the eye that lies in front of the iris and pupil. The cornea lets light into the eye.

Ganglion —Plural, ganglia. A mass of nerve tissue or a group of neurons.

Latent virus —A nonactive virus that is in a dormant state within a cell. The herpes virus is latent in the nervous system.

Lesion —A disruption of the normal structure and function of a tissue by an injury or disease process. Wounds, sores, rashes, and boils are all lesions.

Meningoencephalitis —Inflammation of the brain and its membranes; also called cerebromeningitis or encephalomeningitis.

Mucosal —Refers to the mucous membrane.

Seropositive —Showing a positive reaction to a test on blood serum for a disease; exhibiting seroconversion.

Virus —A small infectious agent consisting of a core of genetic material (DNA or RNA) surrounded by a shell of protein. A virus needs a living cell to reproduce.

Resources

BOOKS

Ebel, Charles, and A. Wald. Managing Herpes: How to Live and Love with a Chronic STD. Durham, NC: American Social Health Association, 2002.

The Official Patient's Sourcebook on Genital Herpes. San Diego, CA: Icon Group International, 2002.

Spencer, Judith V., et al. Herpes. Langhorne, PA: Chelsea House Publishers, 2005.

Westheimer, Ruth K. Dr. Ruth's Guide to Talking about Herpes. New York: Grove/Atlantic Inc., 2004.

ORGANIZATIONS

American Social Health Association. PO Box 13827, Research Triangle Park, NC 27709. Web site: <www.ashastd.org/hrc/>.

Linda K. Bennington, MSN, CNS

Herpes simplex

Description

Herpes simples virus (HSV, or herpesvirus) is a virus that causes infection of skin and mucous membrane and rarely infects other parts of the body. However, in the immunosuppressed patient, HSV may cause pneumonia and other more severe infections. When the infection occurs in the mouth it is commonly referred to as cold sores. An outbreak of HSV infection can be very painful. There are two distinct types of HSV: type 1 and type 2. It was believed that HSV-1 mostly caused oral herpes (herpes labialis), while HSV-2 generally caused genital herpes that typically affects the penis, vulva, and rectum. This is not completely true. Both type 1 and type 2 can cause herpes lesions on the lips or genitals. The first symptoms occur within 2-20 days after contact with an infected person.

Symptoms of the primary infection are usually more severe than those of recurrent infections. The primary infection can cause symptoms like those experienced in other viral infections, including lack of energy, headache, fever , and swollen lymph nodes in the neck. The first sign of infection is formation of fluid-filled blisters that may last up to two weeks. However, the pain in the area may last much longer. Once HSV enters the body it spreads to nearby mucosal areas through nerve cells. Once it infects the body the virus remains latent for the life of that individual. During the period of latency there are no symptoms. At times the infected person may shed the virus, even in the absence of visible symptoms, and infect others. Individuals infected with the virus can have recurrent infections; however, normally, recurrent infections are milder and shorter. However, cancer patients can have severe recurrences.

Typically, 50-80% of persons with oral herpes experience a prodrome (symptoms of oncoming disease) of pain, burning, itching , or tingling at the site where blisters will form. This prodrome stage may last anywhere from a few hours to one to two days. The herpes infection prodrome occurs in both the primary infection and recurrent infections.

Causes

Everyone with cancer has a higher risk of catching viral infections of any type. This is because the cancer itself, and the methods used to treat it, affect the immune defense mechanisms that fight infection. Normally the mucous membrane is one of the first lines of defense against infectious organisms. However, chemotherapy and radiation can damage this very important barrier. The barrier that skin provides is also compromised because of needles used for drawing blood or injecting drugs. Radiation and chemotherapy also suppress the immune system. Certain cancers like Hodgkin's disease , lymphoma, and T-cell leukemia cause defects in cellular immunity, which is a primary defense mechanism against viral infections. Thus cancer patients, especially those who are undergoing chemotherapy or radiation treatments, are at greater risk of primary and secondary herpes infections.

Oral herpes simplex infections are more common in children than adults following chemotherapy. Patients who have the virus latent in the system have a higher chance of recurrent infection. Primary infection generally causes gingivitis (inflammation of the gums, vesicles on the mucosa (blisters on the lining of the mouth), and a coated tongue (white covering on tongue). Women with genital herpes can have severe recurrence following chemotherapy because of immunosuppression.

Treatment

There is no cure for HSV infection although there are antiviral drugs available that have some effect in lessening the symptoms and decreasing the length of herpes outbreaks. There is evidence that some of these drugs may also prevent future outbreaks. For the best results drug treatment should begin during the prodrome stage before blisters are visible. Depending upon the length of the outbreak, drug treatment could continue up to 10 days.

Acyclovir (Zovirax) is the drug of choice for herpes infection and can be given intravenously or taken by mouth. It can be applied directly to sores as an ointment but is not very useful in this form. A liquid form for children is also available. Acyclovir is effective in treating both the primary infection and recurrent outbreaks. When taken by mouth to prevent an outbreak, acyclovir reduces the frequency of herpes outbreaks.

Alternative and complementary therapies

A number of steps can relieve the symptoms of herpes infections. It is important to keep the blisters or sores clean and dry with an agent like cornstarch. One should avoid touching the sores, and wash hands frequently. Local application of ice may relieve the pain. Over-the-counter medication for fever, pain, and inflammation— such as aspirin, acetaminophen, or ibuprofen—may help. Children should never be given aspirin. Sexual intercourse should be avoided during both the active stage and the prodrome stages. During an outbreak of cold sores salty foods, citrus foods (oranges etc.), and other foods that irritate the sores should be avoided. Over-the-counter lip products that contain the chemical "phenol" (such as Blistex Medicated Lip Ointment) and numbing ointments (such as Anbesol) help to relieve the pain of cold sores. A bandage may be placed over the sores to protect them and prevent spreading the virus to other sites on the lips or face.

A diet rich in the amino acid lysine may help prevent recurrences of cold sores. Foods that contain high levels of lysine include most vegetables, legumes, fish, turkey, and chicken. Oral lysine supplements in the amount of 1000 mg per day may help sores heal faster. There is a belief that foods with high lysine-to-arginine ratio will help prevent outbreaks of herpes simplex. That has not been proven, and it is important to include foods that have a low lysine-to-arginine ratio also, such as nuts, onion, garlic, and green vegetables. It is also suggested that the amount of arginine in the diet be limited as there is a belief that arginine is needed for herpesvirus growth. This amino acid is found in peanuts, beer, chocolate, gelatin, and raisins.

Resources

BOOKS

Noskin, Gary A. Management of Infectious Complications in Cancer Patients. Norwell: Kluwer Academic Publishers, 1998.

PERIODICALS

Whitley, Richard J., and Bernard Roizman. "Herpes Simplex Virus Infections." The Lancet 357 (12 May 2001) 1513.

ORGANIZATIONS

American Herpes Foundation. (201) 342-4441. <http://www.herpes-foundation.org>.

Belinda M. Rowland, Ph.D.

Malini Vashishtha, Ph.D.

herpes simplex , an acute viral infection of the skin characterized by one or more painful, itching blisters filled with clear fluid. It is caused by either of two herpes simplex viruses: Type 1, herpes labialis, which generally involves the lip (producing what are commonly known as cold sores) or the mouth area (producing canker sores), but can involve the genital area or, in the case of herpes gladiatorum, parts of the body that have been exposed to the virus through skin-to-skin contact in sports; and Type 2, herpes genitalis, which involves the genitals, but may involve the mouth. It is believed that invasion of Type 1 herpes occurs in most persons during infancy and childhood, either as a systemic or severe local infection. Type 2 herpes, or genital herpes, is a sexually transmitted disease that became epidemic in the United States in the late 1960s. Newborns exposed to active herpes in the mother's birth canal can contract a serious form of the disease. The herpes simplex virus can be spread by an infected but asymptomatic person.

Outbreaks of both types of herpes simplex alternate with periods when the virus lies dormant in the nerve cells. The reappearance of blisters may be triggered by such factors as fever, infectious diseases, exposure to sunlight, menstruation, or pregnancy. The blisters usually last from 10 to 14 days. Treatment for recurrent herpes includes elimination of the precipitating conditions, local antibiotic treatment to prevent bacterial infection, and treatment with antiviral drugs such as acyclovir, although some resistant strains (see drug resistance ) have developed. There is no cure. The herpes simplex virus is also the cause of a form of viral encephalitis .

See also herpes zoster (shingles).

herpes (her-peez) n. inflammation of the skin or mucous membranes caused by herpesviruses and characterized by collections of small blisters. Treatment is with antiviral drugs (e.g. aciclovir). genital h. a sexually transmitted disease, usually caused by herpes simplex virus (HSV) type II, that is characterized by painful blisters in the genital region. It may be recurrent and is extremely contagious as the blisters burst to release viruses that infect the sexual partner. h. simplex (cold sore) herpes that affects the lips or surrounding area, caused by HSV type I. h. zoster (shingles) herpes caused by the varicella-zoster virus, which also causes chickenpox. Following an attack of chickenpox, the virus lies dormant in the spinal cord and later migrates down a sensory nerve to affect the skin in a band. One side of the face or an eye (ophthalmic zoster) may be involved. Shingles may be chronically painful, especially in the elderly.

herpesvirus One of a group of complex DNA-containing viruses causing infections in humans and most other vertebrates that tend to recur. The group includes herpes simplex, the agent of cold sores; herpes varicella/zoster, the virus causing chickenpox and shingles; Epstein–Barr (EB) virus, the causal agent of glandular fever and also implicated in the cancer Burkitt's lymphoma; and the cytomegalovirus.

her·pes / ˈhərpēz/ • n. any of a group of viral diseases caused by herpes viruses, affecting the skin (often with blisters) or the nervous system. DERIVATIVES: her·pet·ic / hərˈpetik/ adj.

herpesvirus (her-peez-vy-rŭs) n. one of a group of DNA-containing viruses causing latent infections in humans and animals. The herpesviruses are the causative agents of herpes and chickenpox. See also cytomegalovirus, Epstein-Barr virus.

herpesvirus any of the family (Herpesviridae) of common DNA-containing viruses, many of which are associated with human disease. See cytomegalovirus ; Epstein-Barr virus ; herpes simplex ; herpes zoster .

her·pes sim·plex • n. a viral infection, caused by a group of herpes viruses, that may produce cold sores, genital inflammation, or conjunctivitis.

herpes XVII. — L. herpēs — Gr. hérpēs shingles, lit. ‘creeping’, f. hérpein creep.

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