Where possible information will also be obtained about these people by interview, examining the medical records or discussion with their General Practitioners. Subjects will also be encouraged to attend the hospital in person where a clinical exam can be performed. If insufficient sera is stored further blood will be drawn at this time and examined for HCV, HIV and GBV-C related parameters as outlined in the tables below. A study specific questionnaire will be generated in which subjects will be asked to complete a confidential questionnaire that contains information related to demographic and behavioral factors that may contribute to the acquisition of GBV-C, HCV or HIV infection or various combinations of the above. Demographic variables will include age, sex, country of birth, and occupation. Information relevant to HIV infection including the use of HAART and the presence or absence of AIDS defining syndromes will be obtained. The questionnaire will attempt to identify the approximate time of acquisition of both HCV and HIV. In addition, the extent of liver disease will be assessed, alcohol consumption will be quantified and information will be gathered on previous treatment with Interferon and Ribavirin.