Herpesvirus Type 2 Infection (Herpes Genitalis, Herpes Simplex Virus)

HERPESVIRUS TYPE 2 INFECTION (HERPES GENITALIS, HERPES SIMPLEX VIRUS)

Herpes genitalis is a recurrent, life-long viral infection that causes herpetic lesions (blisters) on the cervix, vagina, and external gen-italia. It is an STD but may also be transmitted asexually from wet surfaces or by self-transmission (ie, touching a cold sore and then touching the genital area). The initial infection is usually very painful and lasts about 1 week, but it can also be asymptom-atic. Recurrences are less painful and usually produce minor itch-ing and burning. Some patients have few or no recurrences, whereas others have frequent bouts. Recurrences are often asso-ciated with stress, sunburn, dental work, or inadequate rest or nu-trition. The incidence of herpes infection has increased fivefold since the late 1970s among Caucasian teenagers and adults in their 20s. At least 50 million persons in the United States have genital herpes infection; most of them have not been diagnosed (Centers for Disease Control & Prevention, 2002). The prevalence of other STDs has decreased slightly, possibly due to increased con-dom use, but herpes can be transmitted by contact with skin not covered by a condom. Transmission is possible even when the carrier does not have symptoms (subclinical shedding). Lesions increase vulnerability to HIV infection and other STDs. Vaccines for this virus are in clinical trials.

Pathophysiology

Of the known herpesviruses, six affect humans: (1) herpes sim-plex type 1 (HSV-1), which usually causes cold sores of the lips; (2) herpes simplex type 2 (HSV-2), or genital herpes; (3) varicella zoster, or shingles; (4) Epstein-Barr virus; (5) cytomegalovirus; and (6) human B-lymphotrophic virus. HSV-2 appears to be the cause of about 80% of genital and perineal lesions; HSV-1 may cause about 20%.

There is considerable overlap between HSV-1 and HSV-2, which are clinically indistinguishable. Close human contact by the mouth, oropharynx, mucosal surface, vagina, or cervix ap-pears necessary to acquire the infection. Other susceptible sites are skin lacerations and conjunctivae. Usually, the virus is killed at room temperature by drying. When viral replication dimin-ishes, the virus ascends the peripheral sensory nerves and remains inactive in the nerve ganglia. Another outbreak may occur when the host is subjected to stress. In pregnant women with active her-pes, babies delivered vaginally may become infected with the virus. There is a risk for fetal morbidity and mortality if this oc-curs; therefore, a cesarean delivery may be performed if the virus recurs near the time of delivery.

Clinical Manifestations

Itching and pain accompany the process as the infected area be-comes red and swollen (edematous). The vesicular state often ap-pears as a blister, which later coalesces, ulcerates, and encrusts. In women, the labia are the usual primary site, although the cervix, vagina, and perianal skin may be affected. In men, the glans penis, foreskin, or penile shaft is typically affected. Influenza-like symptoms may occur 3 or 4 days after the lesions appear. Inguinal lymphadenopathy (swollen lymph nodes in the groin), minor tem-perature elevation, malaise, headache, myalgia (aching muscles), and dysuria (pain on urination) are often noted. Pain is evident during the first week and then decreases. The lesions subside in about 2 weeks unless secondary infection occurs.

Rarely, complications may arise from extragenital spread, such as to the buttocks, upper thighs, or even the eyes as a result of touching lesions and then touching other areas. Patients should be advised to wash their hands after contact with lesions. Other potential problems are aseptic meningitis and severe emotional stress related to the diagnosis.

Medical Management

There is currently no cure for HSV-2 infection, but treatment is aimed at relieving the symptoms. Management goals are pre-venting the spread of infection, making the patient comfortable, decreasing potential health risks, and initiating a counseling and education program. Acyclovir (Zovirax), valacyclovir (Valtrex), and famciclovir (Famvir) are antiviral agents that can suppress symptoms and shorten the course of the infection. Other antivi-ral agents are also available. All of them are effective at reducing the duration of lesions and preventing recurrences. Resistance and long-term side effects do not appear to be major problems. Recurrent episodes are much milder than the initial episode.