HSV-1 & HSV-2 Herpes simplex virus (HSV) types 1 and 2 are common infections worldwide. However, the majority of infected individuals remain undiagnosed because they are asymptomatic.
HSV-1 is usually transmitted during childhood through contact with oral secretions (cold sores). Seroprevalence studies indicate about 60% of adults in the United States are infected with this virus. HSV-2 is usually spread by sexual contact (genital herpes). Consequently this infection usually occurs later in life and the seroprevalence rates vary dramatically by geographic region. Both HSV-1 and HSV-2 establish a lifelong, latent infection in the nervous system and there is no cure. Antiviral medications can reduce the frequency, duration and severity of outbreaks and over a period of several years, many infected individuals experience less severe symptoms and fewer outbreaks, although they are still contagious to others. The greatest risk of an HSV infection is in neonates and infants, when an infected mother passes it to her fetus in utero or during delivery. A neonatal HSV infection can be devastating to an infant and 70- 85% of these infections are caused by HSV-2. Many infants infected with HSV are born prematurely and approximately 4% can develop congenital HSV which has serious consequences including death.
HERPES SIMPLEX VIRUS
CONGENITAL HERPES SIMPLEX
DIAGNOSIS Mother and baby are usually tested simultaneously if herpes is suspected. Diagnostic methods include serological tests such as ELISA and IFA, as well as PCR blood tests and cell culture. Due to a high degree of genetic similarity between HSV-1 and HSV-2, most viral proteins induce a cross-reactive antibody response that hampers the discrimination between HSV-1 and HSV-2 infections using serological approaches. Since the discovery of the serologically distinct HSV viral envelope glycoproteins gG-1 (HSV-1) and gG-2 (HSV-2), new type-specific immunoassays have been developed that are capable of discriminating between HSV-1 and HSV-2 infections. Since antibodies may take several weeks to reach detectable levels after primary infection, negative results should be confirmed by repeat testing 4 to 6 weeks after a suspected early infection. In most cases, babies contract congenital herpes in the birth canal during delivery (especially if the mother has an active outbreak of genital herpes at the time of delivery). In rare circumstances, it is possible to be infected in the uterus or immediately after birth (from being kissed or having other contact with someone who has herpes mouth sores). Congenital HSV is a serious condition and affects about 1 out of every 3,000-20,000 live births. Detection and prevention is difficult because the infected mother is typically asymptomatic. Congenital herpes symptoms usually appear within the first month of the infant’s life and antiviral treatments such as vidarabine and acyclovir have proven helpful to reduce the severity of the disease. However, infants with systemic herpes or encephalitis often do poorly, despite antiviral medications and early treatment.
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ToRCH & Childhood Diseases- Reagents for Assay Development
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