Newer trends in the management of genital herpes.(Review Article)(Report)

Byline: Amiya. Nath, Devinder. Thappa

Management of genital herpes is complex. Apart from using the standard antivirals, an ideal management protocol also needs to address various aspects of the disease, including the psychological morbidity. Oral acyclovir, valacyclovir or famciclovir are recommended for routine use. Long-term suppressive therapy is effective in reducing the number of recurrences and the risk of transmission to others. Severe or disseminated disease may require intravenous therapy. Resistant cases are managed with foscarnet or cidofovir. Genital herpes in human immunodeficiency virus-infected individuals usually needs a longer duration of antiviral therapy along with continuation of highly active anti retroviral therapy (HAART). Genital herpes in late pregnancy increases the risk of neonatal herpes. Antiviral therapy and/or cesarean delivery are indicated depending on the clinical circumstance. Acyclovir appears to be safe in pregnancy. But, there is limited data regarding the use of valacyclovir and famciclovir in pregnancy. Neonatal herpes requires a higher dose of acyclovir given intravenously for a longer duration. Management of the sex partner, counseling and prevention advice are equally important in appropriate management of genital herpes. Vaccines till date have been marginally effective. Helicase-primase inhibitors, needle-free mucosal vaccine and a new microbicide product named VivaGel may become promising treatment options in the future.

Introduction

Genital herpes is the most common cause of ulcerative sexually transmitted infection in the world.[sup] [1] Appropriate management of genital herpes is complex. The most important aspect of the management revolves around the judicious use of antiviral agents.[sup] [1] As the results of various randomized studies come to light, treatment protocols for the management of genital herpes under different clinical circumstances undergo constant update.

Many patients with genital herpes may have atypical manifestations.[sup] [2] Therefore, the sensitivity and the specificity of a clinical diagnosis is unacceptably low (39% sensitivity at best with a 20% false-positive diagnosis).[sup] [3] It should also be borne in mind that undiagnosed cases are the most common source of new transmission.[sup] [3] Hence, clinical diagnosis of genital herpes should be confirmed by laboratory testing.

Investigations

Investigations should be routinely utilized to improve the diagnostic accuracy of genital herpes. They are especially useful when the manifestations of genital herpes are atypical or when met with special circumstances like neonatal herpes.[sup] [3],[4],[5]

Tzanck smear can be helpful in the rapid diagnosis of genital herpes lesions (by identifying multinucleate giant cells), but it is less sensitive than viral culture.[sup] Immunofluorescence staining increases the sensitivity and specificity of a Tzanck smear preparation.

Histopathology is occasionally required in chronic herpes infection in human immunodeficiency virus (HIV)-infected individuals wherein morphology and clinical course are atypical.

Viral culture is the 'gold standard' for herpes simplex virus (HSV) diagnosis. Cytopathic effects appear in 2-3 days after inoculation in human diploid fibroblast cultures or green monkey kidney cell cultures. Sensitivity of the tissue culture depends on the stage of clinical lesions - isolation is successful in about 80% of primary infections and in 25-50% of recurrent infections. Viral isolation is least successful in lesions that have begun to heal.[sup]

HSV direct detection tests include electron microscopy, HSV antigen detection (immunoperoxidase tests, immunofluorescence, enzyme immunoassay), HSV-DNA detection (DNA hybridization) and HSV-PCR.

Immunofluorescence

Direct fluorescent antibody test (DFA) is used for the detection of HSV antigen in smear, tissues or culture. The sensitivity of the DFA test for the detection of HSV in genital specimens varies between 70 and 90% of culture-positive specimens.

Rapid assay

HSV antigen is extracted from the clinical specimen with a buffered solution. The extract is added to a test device and any antigen present is immobilized on a membrane. When treated peroxidase-labeled anti-HSV monoclonal antibody with substrate is added, a colored spot is obtained on the membrane. The sensitivity of this test is slightly lower than that of enzyme-linked immunosorbent assay (ELISA).

HSV-PCR

PCR is more sensitive (four times) and faster than viral culture. Because the type of HSV infection affects prognosis and subsequent counseling, type-specific testing to distinguish HSV-1 from HSV-2 is recommended. Although PCR has …