Royston, I. and L. Aurelian (Dept. Laboratory Animal Medicine and Microbiology, Johns Hopkins Univ. School of Medicine, Baltimore, Md. 21205). The association of genital herpesvirus with cervical atypia and carcinoma in situ. Amer. J. Epid., 1970, 91: 531–538.—A neutralization test (multiplicity analysis) using an artificial mixture of two strains of herpes simplex virus, a prototype of the genital strain and a laboratory strain designated HSV-MP, was used to differentiate antibodies to the genital and facial strains (types 1 and 2) of herpes simplex virus in sera of patients with cervical neoplasia. The prevalence of antibody to the genital strain in women without cancer was found to increase both with increasing age and with decreasing socioeconomic class. The frequency of antibody among women with cervical neoplasia was uniformly high and thereby independent of age and socioeconomic class. Antibody was detected in 98% of 110 patients with cervical carcinoma at any stage of the disease, in 55% of the matched control women and 50% of those women with malignancies at sites other than the cervix. Statistically significant differences (p <.0005) were observed between antibodies to genital herpesvirus in patients with preinvasive carcinoma (atypia 95%t carcinoma in situ 100%) and a matched control population, differences which do not exist with regard to two other venereally transmitted diseases, trichomoniasis and syphilis. The data support the hypothesis that genital herpesvirus may be responsible for the induction of squamous neoplasia in the human cervix; however, further studies are required to determine whether the association is a causal one.