[Usefulness of microbiological test in clinical decision making--from the view point of clinician].

During the last 50 years, there have been changes in the types of infectious diseases causing death in Japan. Endemic diseases have decreased and nosocomial infection during the therapeutic course of various diseases have increased. Progress of various new medical technology for cancer therapy and transplantation are supported by developed infection control, and the target of microbiological tests has changed from endemic organisms to resident organisms. To manage infectious diseases, clinicians collect considerable information. Microbiological tests are only one part and sometimes are used to assess therapeutic results. In this situation, microbiological tests sometimes only reconfirm or guide changes in therapeutic strategy if the initial empiric therapy was inappropriate. Then, well designed statistical data are necessary for appropriate empiric therapy. Surveillance of hospital infection is another important role of the microbiological laboratory. To improve the functioning of the microbiological laboratory, we need not only automatic and rapid systems, but also effective communication with clinicians to respond to their needs with clinically useful data.