Antimicrobial Therapy in the Immunocompromised Patient [antikvár]

INTRODUCTION This monograph considers the prevention and management of infection in the immunocompromised subject. Since the initial management of patients with infection and immunocompromise is largely empirical, the patients have been divided not according to their primary disorder or nature of their immune defect, but on the basis of whether they are considered to be mildly, moderately or severely immunocompromised. Several causes of mild immunocompromise may be regarded as non-specific; in other words, they do not affect primarily one particular aspect of the immune part of the host defence system. However, as immunocompromise becomes more severe, fewer of its causes are non-specific and more of them are found to produce specific abnormalities of the immune system. Furthermore, as an individual moves from mild to severe immunocompromise, the organisms which could cause an infection increase in number and variety; hence, in mildly immunocompromised subjects the infection is nearly always with an organism expected to infect a normal host, whereas in severely immunocompromised patients the infection may well be due to an opportunistic organism which is part of the commensal flora of the normal subject, or exists in large numbers in the environment without causing clinical infection in normal subjects. Within this broad trend from moderate to severe immune deficiency, some clue regarding the infecting organism may be gained by considering: (a) The primary disorder which has caused the immune compromise. (b) The nature of the immune defect caused. (c) Whether the infection in question is a presenting one or a superinfection which occurred during the course of therapy for an earlier infection episode. It must be emphasised that, as in normal subjects, even in severely immunocompromised patients a presenting or primary infection is almost always with a bacterium. It is in second and subsequent infections, when antibacterial therapy has already been used, that fungi, viruses or protozoa become increasingly frequent causes.