LATENT HERPES-SIMPLEX VIRUS REACTIVATION IN THE GUINEA-PIG - AN ANIMAL-MODEL FOR RECURRENT DISEASE

The purpose of this investigation was to establish an animal model by which latent herpetic disease could be mechanically reactivated, yielding an adequate number of recurrent clinical lesions in the guinea pig. To determine strain virulence, hairless guinea pigs were inoculated with three different strains of herpes simplex virus (HSV) using a springloaded multiple puncture apparatus. HSV-1 strains SC-16 and McKrae produced an average of 21 and 8 lesions per infected area, respectively. The HSV-2 strain (333) produced the lowest number at an average of 3 lesions per site. Following the determination of strain virulence, a large number of guinea pigs, Hartley and hairless, were inoculated with the same HSV strains in a similar fashion as previously described. The primary infection was evident from 6 to 12 hours postinfection (Pl) by the initial appearance of small pustules, which peaked by day 2, seen as dome-shaped fluid-filled sacs. These initial lesions burst, crusted (day 6 Pl), and had resolved and flattened between days 9 and 12 Pl. At 4-6 weeks Pl the inoculated areas were stripped 6 times per area with cellophane tape. Recurrent lesions were seen in the majority of the stripped areas (89-100%). The best results were achieved with the HSV-1 (SC-16) strain in hairless guinea pigs, which peaked on day 3 poststripping, producing an average of 12.25 lesions per area. The hairless guinea pig is ideal for this type of experiment because its use eliminates the trauma associated with denudation, a procedure necessary when using haired (Hartley) animals. Using our model for recurrent cutaneous HSV, the number of lesions produced allows this method to be suitable for quantitive analysis.