Chapter 96 : Herpes Simplex Viruses and Herpes B Virus

Abstract:

This chapter focuses on the herpes simplex viruses (HSV) and herpes B virus, describing their transmission, clinical significance, and detection mechanisms. Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), formally designated human herpesvirus 1 and human herpesvirus 2, respectively, are members of the family Herpesviridae. Primary infection with HSV-1 or HSV-2 is followed by the establishment of latency in the dorsal root ganglia, typically the trigeminal ganglia for orolabial disease and the lumbosacral ganglia for genital disease. Immunostaining methods to detect antigen require less expertise than cytopathic effect (CPE)-based culture methods and are usually less expensive than culture. Polymerase chain reaction (PCR) provides the best sensitivity of the direct detection approaches. Tests based on crude antigen mixtures are still marketed, but they have unacceptably low sensitivity and specificity, especially for detecting new HSV-2 infections in those with prior HSV-1 infection. The HSV Western blot assay used by the University of Washington laboratory uses nitrocellulose blots prepared with human diploid fibroblast-infected cell proteins. Western blotting detects antibodies to multiple viral proteins, including those to the type-specific glycoproteins gG-1 and gG-2. Simple gG-based lateral-flow assays are available that are designed for point-of-care testing. Type-specific serology is critical for identifying pregnant women with new HSV infections. Serodiagnosis of herpes B virus infections has been complicated by extensive cross-reactivity with HSV-1 and HSV-2. Serologic testing can be useful for evaluation of potentially infected animals involved in human exposures and for screening of research animals.