Detection of viral antigens in cerebrospinal fluid of rabbits with experimental herpes simplex virus type 1 encephalitis.

We investigated several methods for the rapid diagnosis of herpes simplex virus induced encephalitis in a rabbit model. The corneas of twenty-two rabbits were infected with herpes simplex virus type 1 (HSV-1) and diagnosis of Herpes encephalitis was made by virus isolation, immunofluorescent and peroxidase staining of brain biopsies, demonstration of anti-HSV IgM in cerebrospinal fluid (CSF) and by an indirect enzyme-linked immunosorbent assay (ELISA), designed for detection of viral antigens. With the last method we were able to demonstrate viral antigens in cerebrospinal fluid six days post infection, before clinical signs of encephalitis appeared. In three rabbits this was before anti-HSV IgM appeared in the CSF. Virus was isolated from brain samples of 67 per cent of the animals which died from Herpes encephalitis. Nine rabbits received cortisone before infection, resulting in markedly lower antibody titers and a higher lethality, 77 per cent, as compared to 46 per cent in nontreated rabbits. For rapid diagnosis of Herpes encephalitis in rabbits, demonstration of herpes simplex virus antigens in CSF by means of an indirect ELISA is superior to the other methods investigated.