The rapidity with which infectious diseases can spread throughout the world can be exemplified by the transmission of severe acute respiratory syndrome (SARS) through the international travel of infected individuals observed in 2003. In 2007 about 105 cases of Chikungunya (CHIK) fever, a viral disease transmitted by Aedes mosquitoes and occurring mainly in Africa and Asia, were identified in the Emilia-Romagna region of Italy. In the United States, West Nile Virus (WNV) was first identified in birds in New York State but an organ transplant recipient became the first reported human infection and the virus spread rapidly throughout North America. The epidemic outbreak of WNV and its association with blood transfusion resulted in the establishment of a public-private partnership between AABB (formerly the American Association of Blood Banks) and several government agencies to collaborate on response to this emerging public health disease threat. This AABB Inter-organizational Task Force carried out weekly monitoring of transfusion related cases, prevalence of reactive WNV NAT results and discussions of public health policy including reporting of outcomes.

A significant number of organ transplant-transmitted infections have been investigated by U.S. Public Health Authorities over the period 1985-2009, including HIV, HCV and WNV. The clinician’s role in identifying a problem was highlighted with the presentation of a specific case whereby two renal transplant patients from the same donor exhibited seizures and altered mental status within three weeks post-transplant. Investigations led to the finding that the young donor had Granulomatous amoebic encephalitis, which has only 150 described cases worldwide, and was the first transmission of a free-living amoeba via organ transplantation. 
The Centers for Disease Control and Prevention (CDC) has investigated dozens of transplant clusters of recipients with encephalitis-related illnesses (majority with fatal outcome) and likely many more left unidentified due to lack of recognition.