Influenza Virus - A Multicenter Registry

The investigators purpose is to prospectively characterize influenza infections over a 3 year period in transplant patients using a registry system. The investigators plan to generate robust data on clinical features of upper and lower respiratory disease, antiviral therapy and its effects on disease outcome, as well as quantitative virologic data on shedding and antiviral resistance. The investigators also will study the long term sequelae of influenza infections and look at development of rejection.