HUMAN HERPESVIRUS 6
Actually, Human Herpesvirus-6 (HHV-6) is neither vector-borne nor a zoonotic agent. Often the case is that one of the local reference facilities requests a product they are having trouble obtaining. Such is the case with HHV-6 IFA slides and it turns out they are fun to work with. There is also quite a lot of research going on with the pathology of HHV-6, expanding the list of associated diseases.
Our IFA slide substrate contains cells at different stages, demonstrating both early antigens (diffuse cytoplasmic) and late antigens (compacted inclusions), much like EBV. As with EBV, also, titers of early antigen titers are higher than generally described in the literature due to insensitive assays and, thus, they persist longer.
EPSTEIN-BARR VIRUS (HHV-4)
Epstein-Barr virus (EBV) is also neither vector-borne nor a zoonotic agent, although we have continuously manufactured a full range of EBV assays for local testing laboratories for over 25 years. The virus is specifically a human herpesvirus (HHV-4) and, as described above for HHV-6, there are several useful diagnostic assays available.
Infection with EBV is most often an early childhood occurance, with the earliest diagnostic antibody being directed against early antigens (EA) and the viral capsid (VCA). IgM class antibody against the viral capsid antigens is diagnostic for acute disease and rising IgG and IgA titers to these antigens can be seen in acute/convalescent pairs. In early convalescence another antibody is first seen and is directed against the EBNA-1 protein. Seroconversion of this specificity is also diagnostic.