Quest Diagnostics , the world's leading provider of diagnostic information services, today announced that it will collaborate with the Centers for Disease Control and Prevention to identify trends in screening, diagnosis and treatment for four strains of viral hepatitis in the United States, based on insights revealed by analysis of Quest's national testing database. Under terms of the multi-year contract, Quest Diagnostics will provide CDC researchers with analytics expertise and access to the company's national Quest Diagnostics Health Trends database of de-identified clinical testing hepatitis data.