Hantaviruses are RNA viruses that are harbored by specific rodent species and are transmitted to man via inhalation of virus-contaminated rodent feces and urine. In the Americas, several hantaviruses are now recognized as etiological agents of hantavirus cardiopulmonary syndrome (HCPS), which has a high case- fatality ratio. Etiologic agents of HCPS are Category A bioweapon threats. Andes virus-associated HCPS in Chile and Argentina is unique among hantaviruses in that it can be transmitted person-to-person. Hantavirus disease was first recognized in the Western Hemisphere in 1993, so there is an urgent need to build expertise in the Americas in rodent ecology, virology, clinical care, and clinical research as it relates to hantavirus infections in the Americas. Our group of U.S. and Chilean investigators has collaborated in hantavirus research, training and technology transfer since 1997, and multiple members of the team contributed to expansion of our research and training to Panama when it experienced its first outbreak of HCPS in 2000. We have had an ICIDR program project grant and a Fogarty ABC training program since 1999, with a track record of successful short- and long-term training of students at multiple levels. In 2004 we obtained supplemental funding through the Global Infectious Disease Research Training Program for a post- doctoral fellowship, and the ICIDR program project grant has been renewed through 2010. In this competitive renewal, our specific aims are to: 1) provide long-term training, including Ph.D., MPH, infectious diseases and critical care and post-doctoral fellowship training at the University of New Mexico, the University of Alabama and Southern Research Institute in areas that will increase the research capacity of the collaborating academic centers in Chile and Panama, 2) provide short-term training at the University of New Mexico, the University of Alabama at Birmingham, the Johns Hopkins University School of Public Health, Catholic University in Santiago, Chile and Universidad del Desarrollo in Santiago, Chile to address specific training needs for the UNM/Chile/Panama ICIDR program, and 3) conduct an annual research and training meeting, jointly supported by this training grant and UNM/Chile/Panama, for team building, to review progress in the research and training activities, for trainees and investigators to report on their projects, and to plan future research and training activities.