Biology of Sexually Transmitted Herpes Viruses

Abstract

There are five human herpesviruses that are transmitted by intercourse and by other routes of intimate contact: Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), cytomegalo-virus (HCMV), Kaposi’s sarcoma-associated herpesvirus (KSHV or HHV-8), and Epstein-Barr virus (EBV). Among them only HSV-2 and less frequently HSV-1 cause primary and recurrent genital disease (herpes genitalis). Intrapartum, the newborn may be infected and suffer from a life-threatening herpes neonatorum generalisatus. Sexually transmitted and ascending HCMV may prenatally infect and damage the fetus in utero, usually in the second and third trimester of pregnancy or ­intrapartum. Occult damages of the brain may lead to mental retardation. HHV-8 and EBV are (also) sexually transmitted and are responsible for oncologic diseases (lymphomas etc.) and other disorders of the lymphatic systems. For EBV infection, sexually transmission is of minor relevance. Herpesvirus infections persist –life-long by establishing a proviral latency in distinct body cells and by special immune escape mechanisms. 90, 80, 50, 20 and <1% of young adults in Europe have acquired EBV, HSV-1, HCMV, HSV-2, and HHV-8 infections. They are reactivated and spread during deficiency of the cell-mediated immunity causing opportunistic, partially life-threatening infectious diseases. Vaccination is not currently available, but antivirals can be successfully applied against HSV and HCMV. HHV-8 (and EBV) infection is stopped by natural or therapeutic immunoreconstitution. Laboratory diagnosis is fully developed with all kinds of virus (antigen/ nucleic acid) and antibody detection.