North East Valley Division of General Practice, Victoria, Australia.

Genital Herpes (herpesvirus 2)
see also herpes on net

DEFINITION

A sexually-transmitted viral infection that is characterised by repeated episodes of developing an eruption of small and usually painful blisters on the genitals.

CAUSES, INCIDENCE, AND RISK FACTORS

Genital herpes is caused by two viruses belonging to the Herpes virus hominus group and known as herpes simplex virus type 2(HSV-2) and by herpes simplex virus type 1 (HSV-1). HSV-1 is responsible for approximately 5 to 10% of genital herpes although in recent years the incidence of genital herpes type 1 has increased significantly.

Both viruses are transmitted by sexual contact. Cross-infection of type 1 and 2 viruses is thought to occur during oral-genital sex.(Note: HSV-1, the virus responsible for common cold sores, can be transmitted through oral secretions during kissing, and by eating and drinking from contaminated utensils.)

Initial oral herpes infection usually occurs in childhood and is not classified as a sexually-transmitted disease. Eighty per cent of the adult population is thought to carry HSV-1 and to have acquired it in a non-sexual manner. However in recent years there has been a decline in the levels of immunity to herpes type 1 in the general population (60% in adolescents) and this goes part way to explain the increased incidence of genital herpes type 1.

The overall incidence of genital herpes is thought to be 1 out of 1,000 people.

For people with no prior contact with HSV 1 or 2, the initial infection is characterised by systemic (whole body) as well as local symptoms and signs.

Since the virus is transmitted by virus-containing secretions from the oral or genital mucosa, the primary lesion is at the primary site of infection. Common sites of infection include the shaft and head of the penis, scrotum, inner thighs, and anus in men; and the labia, vagina, cervix, anus, and inner thighs in women.

The mouth can also be a site of infection in both sexes.

Systemic symptoms

include fever, malaise, generalised achiness (myalgia), and decreased appetite.

Localised symptoms

Prior to the appearance of blisters, the infected individual can experience increased skin sensitivity, tingling, burning, or pain at the site where the blisters will appear. The skin becomes reddened and multiple small blisters (vesicles) filled with a clear straw-colored fluid appear. The blisters break leaving shallow painful ulcers which eventually crust over and slowly heal over a period of 7 to 14 days.

The outbreak may be accompanied by enlargement and tenderness of the lymph nodes in the groin or inguinal fold. Women may develop vaginal discharge and painful urination (dysuria). Men may have dysuria if the lesion is near the opening of the urethra (meatus).

Once a person is infected, the virus finds a hiding place within nerve cells where antibodies, the body's normal infection fighters, cannot reach. Within the nerve cells the virus may remain dormant, a period called "latency", for an extended period of time then suddenly the infection becomes reactivated and the individual has another attack of pain and blistering. Recurrent attacks may be rare, occurring only once per year or so frequent that the symptoms seem continuous. Recurrent attacks may be triggered by many things including mechanical irritation, menses, fatigue, sunburn, and so on. Recurrent infections in men are generally milder and of shorter duration than those experienced by women.

Research suggests that the virus can be transmitted even in the absence of clinical disease, so that a sex partner without obvious genital herpes may still transmit the illness. Asymptomatic spread may actually contribute more to the spread of genital herpes than does active disease.

For the pregnant women, the presence of either HSV-1 or HSV-2 on the genitalia or in the birth canal is a threat to the infant. Infection in the newborn infant can lead to herpetic meningitis, herpetic viraemia, chronic skin infection and even death. Pregnant women with the herpes simplex infection should receive weekly viral cultures of the cervix and external genitalia as the delivery date approaches. At the time of delivery, if active lesions are present, or if the viral culture is positive for herpes, a caesarean delivery is recommended to avoid infecting the newborn.

The herpes infection also poses a serious problem for the immunocompromised person (someone with AIDS, undergoing chemotherapy, radiation therapy, or taking high dose cortisone preparation).

PREVENTION

Prevention is difficult since the virus can be spread to others even when the infected person has no evidence of a current outbreak. However, avoiding direct contact with an open lesion will lower the risk of infection.

People with genital herpes should avoid sexual contact when active lesions are present. People with known genital herpes but without current clinical symptoms should inform their partner that they have the disease. This will allow both parties to use barrier protection (condoms) to prevent the spread of the illness.

Condoms remain the best protection against acquiring genital herpes when sexually active. CORRECT and CONSISTENT use of a condom will help prevent the transmission of the disease.

TREATMENT

Treatment of genital herpes does not cure the disease but can relieve the symptoms. Treatment can rapidly decrease the pain and discomfort associated with an outbreak and shorten the healing time.

Oral acyclovir (Zovirax) does not cure the infection, but it reduces the duration and severity of the symptoms in primary infection, and to a lesser extent in secondary attacks. It also reduces viral shedding, which affects the duration of contagiousness. It may be used in the first episode and for recurrence. For maximum benefit during recurrences, therapy should be started as soon as the tingling, burning, or itching (sensations before the blisters) starts, or as soon as the blisters are noticed.

Topical acyclovir (Zovirax cream soon to be released in Australia) is also effective.

Warm baths may relieve the pain associated with genital lesions. Gentle cleansing in a warm salt bath may be soothing. Sometimes ice applied directly to the sores may help. Also antiseptic or drying agents are recommended.(to prevent secondary infection of open ulcers). If secondary infection of the skin lesions occur, a topical antibiotic such as Neomycin and Polymyxin B ointment can be used, or sometimes oral antibiotics are needed.

Acyclovir-resistant strains of herpes virus are appearing. If symptoms are not rapidly relieved by acyclovir, further evaluation by a physician is indicated.

Support groups:

The stress of illness can often be helped by joining a support group where members share common experiences and problems.

EXPECTATIONS

Once infected, the virus stays in the body for the rest of a person's life. Some people never have another episode, and some have frequent recurrences throughout the year. Subsequent infections tend to occur after sexual intercourse, exposure to the sun, and after stressful events.

In individuals with normal immune systems, genital herpes remains a localised and bothersome infection but seldom a life-threatening infection.

Further Patient Information Sheets & Updates at:- http://www.nevdgp.org.au/