The Treatment of Post-Irradiation Infection

Abstract

This paper reviews the pertinent experimental studies which have contributed to the problem of post-irradiation infection and its treatment. It is well recognized that among the mammalian species studied an important result of total-body irradiation is lowered resistance to bacterial infection. Spontaneous infections may arise from those regions of the body which are normally inhabited by bacteria, particularly the gastrointestinal tract and the upper respiratory passages. It has been shown (1), at least in the case of the mouse irradiated with moderate doses (450 to 600 r), that these spontaneous infections give rise to fatal bacteremias which are an important cause of death during the second week post-irradiation. Most experimental work on the treatment of post-irradiation infection has been directed toward the control of these spontaneous infections. A few observations, however, have been made on the therapy of artificially induced infections. It must be borne in mind that antibiotic therapy is a temporary measure intended to prevent death from infection during the period when the animal's natural defenses are inadequate to combat bacterial invasion. Such treatment is effective therefore, only in those animals in which restoration of function of the defense mechanism can eventually occur. If, however, the defense mechanism has been irreparably damaged, control of infection by antibiotic therapy simply prolongs the survival time without preventing death. For this reason it is only in animals exposed to moderate doses of radiation that such treatment is able to bring about a real reduction in mortality. To anyone concerned with the problem of planning for the treatment of human casualties resulting from atomic warfare, it may seem unfortunate that so much work in this field has been done on small animals. The fact is that under the most rigorously standardized conditions experimental X-irradiation fails to produce