THE PREVENTION OF INFECTIONThe control of infection is largely based on three concepts:
1. The host is separated from the parasite. The oldest known public health measures employed isolation of the infected patient (source isolation) which remains an extremely important method of preventing the spread of infection, including that occurring in hospital. Isolation is carried to its its most sophisticated development in pathogen free units (protective isolation) for the care of patients who are particularly prone to infection, e.g. those suffering from leukaemia under treatment with cytotoxic and corticosteroid drugs. The elimination of a disease from community by finding, treating and isolating the sources of infection is an ideal which should always be vigorously pursued and it has met with considerable success in health campaigns against smallpox and tuberculosis.