HERPES SIMPLEX VIRUS (HSV)
Posted: under Herpes.
These infections can be caused by two serotypes: HSV-1 and HSV-2. Although HSV-1 more commonly infects the oral mucosa, it also causes up to 30% of genital infections. Almost all HSV-2 infection is sexually acquired.
Clinical FindingsIn one large study following HSV seronegative patients, approximately 70% of patients developed symptoms when they became infected with HSV-1, whereas about 40% of patients infected with HSV-2 developed symptoms. Clinicians should suspect HSV whenever an ulcerating genital lesion is noted. Most patients with symptomatic primary infections will have painful genital lesions, itching, and inguinal adenopathy. The classic presentation of genital HSV is a cluster of vesicles on an erythematous base. But these classic lesions are present in only 60% to 70% of symptomatic cases. About one half of patients will have fever, and one third will report photophobia and headache.
DiagnosisClinical diagnosis should not be relied upon because it is insensitive and nonspecific for serotype. Serotyping is important to properly counsel patients, since HSV-2 is much more likely than HSV-1 to recur. Tests that can distinguish serotypes include viral culture, direct fluorescent antibody tests, and serum antibody titers. Tzanck smears and some HSV antigen tests do not distinguish between serotypes of HSV. Viral culture becomes less sensitive as lesions heal, so false-negative results are common. Type-specific serologic testing should be considered in such cases. Antibodies to HSV develop within the several weeks of infection and persist indefinitely. Polymerase chain reaction may replace culture as the test of choice for herpes.
TreatmentTreatment with antiviral medications can minimize symptoms and shorten the course of both primary and recurrent episodes of herpes. Three drugs – acyclovir, famciclovir, and valacyclovir – have all been found to be effective therapy for HSV. The recommended regimens are different for primary and recurrent episodes.
RecurrenceAbout 90% of patients with HSV-2 infection will have at least one recurrence within 1 year. The median number of recurrences is four, and more than one third of patients will have more than six episodes per year. Frequent recurrence is more likely if the primary infection was severe. The recurrence rate is much lower in patients with HSV-1 infection. Infrequent recurrences can be treated by patient-initiated therapy. Patients should be given a supply of medication and instructed to start the medication within 1 day of lesion onset. Often, patients will notice a tingling or burning sensation 1 to 2 days before lesions appear.Frequent recurrences (more than five per year) can be treated using suppressive therapy. Suppression requires daily antiviral medication, but this can reduce recurrences by 70% to 80%. Patients taking suppressive therapy report an improved quality of life. Suppressive therapy lowers, but does not eliminate, viral shedding. It is unknown whether suppression affects HSV transmission.
CounselingThe psychological effect of herpes is often more substantial than the infection itself. Herpes is a lifelong, recurrent infection, and patients need time and guidance to deal with it properly. It is often helpful to counsel couples together. Abstinence or condom use during recurrences can help prevent transmission to partners. But patients should know that viral shedding and transmission also occur during asymptomatic phases. Pregnant women in their third trimester should avoid sexual contact with men who have a history of herpes.*147/348/5*
