Zosteriform Spread of Herpes Simplex Virus Type 2 Genital Infection in the Guinea-pig

A model of herpes simplex virus type 2 (HSV-2) infection was developed in the guinea-pig that permits investigation of the role of neural spread of virus in the pathogenesis of genital skin disease. After HSV-2 inoculation of an abraded area lateral to the external genital skin, virus was first detected in the ipsilateral (to the inoculation site) peripheral nerves or genital skin on day 2 or 3 post-inoculation followed by detection in the ipsilateral dorsal root ganglia and spinal cord on day 3 or 4. Virus also spread to the contralateral dorsal root ganglia, contralateral peripheral nerves and contralateral genital skin on day 4 or 5 although lesions were only rarely detected on the contralateral side. Genital skin lesions first developed on day 5 and were followed by the development of lesions along the medial aspect of the ipsilateral hindlimb. Virus was first detected in the vaginal vault on day 4 or 5. The development of lesions appeared to be unrelated to vaginal virus replication but was associated with the recovery of virus from peripheral nerves. Recurrent genital skin lesions were seen more commonly on the inoculated side than the contralateral side. Since the development of skin lesions appeared to result from virus emerging from nerve endings, an event similar to the terminal event that is believed to be involved in the development of recurrent lesions, we now have a model which may be useful in further exploring the pathogenesis of herpetic disease.