Question 1: Who are the persons at risk for complicated or severe varicella zoster virus infections?

After having defined the severe varicella tester virus infections, the vari ous risks groups' identification was available via a review of the french a nd english speaking literature for the last fifteen years. For the immunoco mpetent subject, it means the foetus (congenital varicella), the new-born ( neonatal varicella), the adult (varicella pneumonia preferentially occuring to the smoker and the pregnant) and the old subject (post herpetic neuralg ia). Then, the outbreak of severe cases are enhanced by cellular immunosupp ression (leukemia, lymphoma, cancer, either bone marrow transplantation, co rticotherapy and HIV infection). So, these high risk subjects are susceptib le to be suggested preventive and curative therapy.