An improved method for detection of ganglionic latency in herpes simplex virus type-1 infected guinea pigs

A simple method was developed which increased the sensitivity and reliability of detecting latent herpes simplex virus type-1 (HSV-1) in trigeminal ganglia of guinea pigs. Animals were infected with the Shealey strain of HSV-1 immediately following scarification of the cornea and maintained for 30-40 days to ensure that true latency was established. Viral latency was defined as the appearance of infectious virus in ganglia only upon cultivation in vitro. Thus, ganglia from similarly infected animals, homogenized immediately upon removal, did not contain infectious virus. Excised ganglia were incubated intact in high glucose medium and yielded maximal positive results (90-100%) by the twelfth day of incubation. This method was compared with the standard cocultivation technique in which minced fragments of ganglionic tissue were explanted onto Vero cell cultures. Cocultivation yielded a considerably lower latency rate and was more variable (29-57%) than the whole ganglion culture method.