[Virus infections in man during immunodepression (author's transl)]

The authors review virus infections observed in patients undergoing immunosuppressive treatment. The herpes virus, in particular the cytomegalovirus, are the most important cause. However, the role of the virus itself in an unfavourable course is variously assessed. The mechanism of the virus infection is discussed, whether primary infection, exogenous or endogenous re-infection. The latter seems to be the most frequent, at least in the case of the herpes viruses.