Herpes simplex viruses 1 and 2.

An increased understanding of the pathogenesis and transmission of HSV infections and the development of sensitive type-specific diagnostic tests have helped develop effective prophylactic and therapeutic antiviral drug regimens. Effective medications have been available for quite some time, but the most optimal regimens are still under investigation. Advances in the treatment of atypical presentations of HSV infection (such as the use of cidofovir gel for the treatment of acyclovir-resistant HSV) are promising. Newer treatments, such as resiquimod, actually may alter the course of HSV infection, reducing the severity and frequency of recurrences. Vaccines are being explored as preventive and therapeutic measures against HSV.