Confirmation of genital herpes simplex viral infection by an immunoperoxidase technique.

Over the 12-month period from April 1984 to April 1985, 512,000 gynecologic (Papanicolaou) smears were examined in the Provincial Screening Program in British Columbia. During this time, 307 patients were found to have smears that contained cells consistent with, or suggestive of, a herpes simplex viral (HSV) infection. The Papanicolaou-stained smears from these 307 cases were subsequently restained, without prior destaining, using an immunoperoxidase technique specific for type 2 HSV (HSV-2) and cross reactive with HSV-1. Of the 205 smears containing cells considered to be consistent with a herpes infection, 187 were positive using the immunoperoxidase technique. Of the 102 smears showing reactive cell changes though unlikely to be causes by an HSV infection, only 5 were positive using the immunoperoxidase technique. The results show that the immunoperoxidase technique is a rapid and reliable method of confirming a suspected diagnosis of herpetic infection and that it is particularly useful in those patients in whom the Papanicolaou smear findings are equivocal.