Herpes Serology can be unreliable therefore viral detection via one of the following specimens is recommended:
1. CSF (Herpes Encephalitis) 2. Viral Transport Swab of vesicle material (cold sore or disseminated herpes) 3. Viral Transport Swab of corneal or conjuntival specimens (herpes kerato-conjuntivitis)
Application: Very limited usefulness in the diagnosis of primary oral or genital herpes. If testing is indicated clinically, viral antigen detection is the preferred test (see Herpes PCR).
Interpretation: A four-fold rise in titre between acute and convalescent samples supports the diagnosis of primary herpes infection. Antigenic cross reactivity occurs between HSV-1 and HSV-2. Recurrent infections often do not stimulate a significant increase in antibody titre. Viral culture and direct antigen detection performed on vesicle fluid or material scraped from the base of a vesicle/ulcer are more rapid and reliable methods to diagnose both primary and recurrent HSV-1 or HSV-2 infection. Antibody testing has not been of value in herpes encephalitis, although the presence of IgM antibodies in CSF may support a presumptive diagnosis. Virus Detection (HSV PCR)is the preferred test for the diagnosis of HSV encephalitis.
Reference: Arvin AM and Prober CG. In: Murray PR et al eds. Manual of Clinical Microbiology, 6th ed. ASM Press 1995. Nahmias AJ et al. J Infect Dis 1982; 145: 829-836.