The nature of the practice of infectious diseases

The practice of infectious diseases depends on the application of information, knowledge, skills, and judgment related to three areas, namely epidemiology, clinical medicine, and clinical microbiology. This book is intended to provide insights into infectious diseases in children, emphasizing the importance of these considerations.

The goal of clinical practice is to cure patients or, at least, to ameliorate their condition. The ultimate goal lies in a good or beneficial outcome, not only for the individual patient but also for the public. The outcome depends to a large extent on some kind of action being taken. For the individual this is usually therapeutic. For the public the action might entail tracing of exposed contacts, quarantining of exposed individuals, and providing vaccination or chemoprophylaxis. The action to be taken often, but not always, depends on an accurate diagnosis being made. It is important to remember that the ultimate goal does not lie in making an accurate diagnosis, nor in taking some action, but in obtaining a favorable outcome. There are circumstances in which the accurate diagnosis in an individual patient is not as important to that patient, for whom there may be no available therapy, as to the community.

Components of a diagnosis

Giving appropriate therapy often depends on making an accurate diagnosis. The diagnosis, like ancient Gaul, is divided into three parts (omnis diagnosis in tres partes divisa est):

1. Anatomic diagnosis, for example, the lung, the middle ear, the urinary tract.

2. Physiologic diagnosis. This describes functional disturbances, for example, respiratory failure, shock.