The papers published herein comprise the presentations given at the eighteenth of an annual series of clinical symposia arranged under the auspices of the Eastern Pennsylvania Branch of the American Society for Microbiology. This symposium allowed approximately 200 persons to gather and exchange ideas on the rapid laboratory diagnosis of infectious diseases. The institution of the Diagnosis Related Group (DRG) method for reimbursement by both government agencies and private insurance carriers has provided a financial aspect to the established clinical reasons for rapid laboratory diagnosis. Now the health of the institution, as well as the patient, is dependent on a timely diagnosis and, hopefully, cure. Accordingly, the goal of this symposium was to present the latest developments in "same-day microbiology." In the face of stable or diminishing resources, the laboratory director is presented with many choices. Do nucleic acid probes, non instrumental ELISA techniques, or time-resolved fluorometry have a place in his or her laboratory? Should the laboratory test for newly described human pathogens such as human immunodeficiency virus or human papilloma virus? Can rapid techniques supplant conventional methods? Or are they merely adjunctive? This symposium attempted to assist in the formulation of informed decisions. Bruce Kleger Donald Jungkind Eileen Rinks Linda A. Miller vii ACKNOWLEDGEMENTS We would like to thank the Eastern Pennsylvania Branch of t e American Society for Microbiology for sponsoring this symposium and for making this publication possible. We especially thank the Symposium Committee for their diligent work in organizing an informative and successful symposium."