Reciprocal Interaction of Human Immunodeficiency Virus and Hepatitis C Virus Infections

Many individuals with hepatitis C virus (HCV) infection are coinfected with the human immunodeficiency virus (HIV). Since HCV and HIV are transmitted by parenteral exposure and both viruses have long clinical latent periods, persons with a history of illicit injection drug use and receipt of blood or blood products, such as factor VIII or IX, are commonly infected with both viruses. It has been estimated that 100,000 to 240,000 of the estimated 900,000 HIV-infected persons in the United States also are infected with HCV, and a similar proportion are coinfected in Europe (T. Benfield, 12th World AIDS Conf., abstr. 22261, 1998). Therefore, it is important to understand how these two viruses modify one another’s disease course and affect efforts to treat and prevent these common infections. HCV RNA LEVELS