Elementary bodies of varicella and herpes zoster

A study of herpes zoster particularly in its relationship to chickenpox

The results of a field survey of herpes zoster over a period of 18 months are described and the difficulties of such a survey mentioned.

A total of 246 patients with herpes zoster, only 16% of whom had attended hospital, is reported. It is calculated that the yearly incidence in the population was approximately 2 per 1000.

Full investigation and ‘follow up’ was undertaken in 184 cases. These are classified according to the site of the zoster—the dorsal, supra-orbital and cervical regions being affected in almost 90%, the dorsal region alone accounting for 53·3%.

Herpes generalisatus occurred in 7, or 38%, of the cases, recurrent herpes zoster in 6, or 3·3%, while there was one case of motor paralysis affecting lower limb.

The majority of patients were apparently well at the onset of the zoster, but 27 had some associated disease; 5 gave a history of trauma prior to the onset and 2 were related to pregnancy.

The seasonal and geographical distribution is given and, while the numbers are too small for statistical analysis, the disease in 1947 showed two peaks of higher incidence, the one in May and the other in October. Crowding or density of population did not appear to be important, and the disease occurred sporadically rather than in epidemic form.

There was a higher proportion of female cases, but when related to the population as a whole no sex differentiation was observed. Of the patients 60% were over 45 years of age.

There was no evidence that housing conditions or occupation were of aetiological significance or that the disease was more common among any particular section of the community.

Eleven patients had been associated with other cases of herpes zoster before developing the disease, while 3 gave a suggestive history of prior contact with chickenpox.

A condition indistinguishable from chickenpox occurred among the contacts of 10 patients, 12 individuals being affected, and there was one instance of concurrent herpes zoster and chickenpox. Other infections such as mumps, measles and rubella, while as common in association with the onset of herpes zoster, were not so frequently found as the chickenpox condition amongst contacts of the disease.

The results of the survey as regards the relationship of chickenpox and herpes zoster are discussed. It is considered that the evidence does not favour a significant association with chickenpox prior to the onset of herpes zoster, but that the facts are consistent with the view that a condition indistinguishable from chickenpox may follow contact with herpes zoster. It is suggested, however, that this may be a generalized manifestation of the virus of zoster rather than true chickenpox.

Interactions among structural proteins of varicella zoster virus

Varicella zoster virus tegument components include the regulatory proteins IE4, IE62, IE63 and the ORFI0 protein, a protein kinase (ORF47) and an abundant protein encoded in ORF9 which is the homolog of HSV VP22. The kinase is able to phosphorylate IE62 and the ORF9 protein specifically in viral particles. We show that interactions among these proteins are, at least in part, dependent on the presence or absence of phosphate groups and we suggest models for tegument formation and for its dissolution in the infected cell.

The etiologic agents of varicella and herpes zoster; serologic studies with the viruses as propagated in vitro

The preparation of antigenic materials capable of specific fixation of complement in the presence of convalescent phase sera from patients with varicella and herpes zoster is described. Satisfactory antigens were obtained by the repetitive harvest and subsequent concentration of the pooled nutrient fluids from bottle cultures of human embryonic skin-muscle tissue or of monkey kidney tissue infected with varicella or herpes zoster viruses. Specific fixation of complement was also demonstrated with antigens prepared from extracts of the infected cell sheets harvested from bottle cultures. In individuals with varicella, complement-fixing antibody usually appeared in the serum 4 or 5 days after the development of the exanthem and further significant increases in titer were characteristically observed during the 2nd week of illness. The complement-fixing antibody response in herpes zoster tended to follow the same pattern as in varicella, with the exception that in sera from some individuals relatively high titers were present in the acute phase specimen. Complement-fixing antigens prepared from varicella strains or from a zoster strain reacted to essentially the same degree with convalescent sera from the homologous and the heterologous clinical entities. The varicella-zoster antigens did not fix complement in the presence of paired sera obtained from a limited number of individuals with primary infections due to herpes simplex virus or from individuals with generalized vaccinia infection. Specific inhibition in vitro of the focal cytopathic process produced by the varicella-zoster viruses was demonstrated. This was accomplished by the incorporation of the sera under test as constituents of nutrient media of the cultures, either prior to or at the time of their inoculation with virus. The neutralization of focal cytopathogenicity thus obtained was relative in degree and never absolute; it was therefore assayed by repetitive counts of the number of focal lesions per culture in the various test groups. Inhibition of varicella-zoster viral cytopathogenicity occurred in the presence of convalescent serum from either clinical entity. The results of the immunologic studies with the viruses of herpes zoster and varicella as propagated in vitro are considered as providing further evidence in support of the concept of the close relationship and probable identity of the two agents.