The following article, “Microbiological Hazards Related to Xenotransplantation of Porcine Organs in Man” inaugurates this section of the Journal, which will focus on the interface between the world of emerging infectious diseases and the delivery of healthcare. Emerging infectious diseases, that is, diseases of infectious origin whose incidence in humans has increased within the past 2 decades or threatens to increase in the near future, are of great importance to hospital epidemiologists and infection control practitioners. Many of the diseases in this category, eg, Clostridium difficile colitis, infections caused by methicillin-resistant Staphylococcus aureus or van-comycin-resistant enterococci, and legionellosis, are well-recognized causes of nosocomial infections. Others, such as hepatitis C virus, human immunodeficiency virus, and Ebola virus, are potential threats to healthcare workers in certain occupational settings. Still others, group B streptococcal infections in neonates, for example, may be prevented by implementation of strategies that infection control programs can promote.