The epidemic behavior of the hepatitis C virus

Abstract

Hepatitis C virus (HCV) is a leading worldwide cause of liver disease. Here, we use a new model of HCV spread to investigate the epidemic behavior of the virus and to estimate its basic reproductive number from gene sequence data. We Þnd signiÞcant differences in epidemic behavior among HCV subtypes and suggest that these differences are largely the result of subtype-speciÞc transmission patterns. Our model builds a bridge between the disciplines of population genetics and mathematical epidemiology by using pathogen gene sequences to infer the pop-ulation dynamic history of an infectious disease. An estimated 170 million people world-wide are at risk of liver cirrhosis and liver cancer due to chronic infection with HCV (1). The virus is responsible for 10,000 deaths per year in the United States, and this rate is expected to increase substantial-ly in the next two decades (2). HCV is