Hepatitis C virus (HCV) infection is a major global health issue. Previous global burden of disease estimates published by the World Health Organization (WHO) include only burden from acute HCV infection.1 Available estimates indicate that worldwide there were 54,000 deaths and 955,000 disability adjusted life-years associated with acute HCV infection. The major burden from HCV infection comes from sequelae from chronic infection.2 Estimates indicate that three to four million persons are newly infected each year, 170 million people are chronically infected and at risk of developing liver disease including cirrhosis and liver cancer, and 350,000 deaths occur each year due to all HCV-related causes.2 Antibodies to HCV (anti-HCV) are a commonly available marker of HCV infection. The prevalence of anti-HCV from population-based studies is used to compare HCV infection levels globally. Historically, countries in Africa and Asia have the highest reported anti-HCV prevalence, whereas industrialized countries in North America, Western Europe, and Australia are known to have lower prevalence.3-6 Without an effective vaccine, primary prevention against hepatitis C focuses on reducing risks of infection through safe injections and blood safety. With new and promising drugs recently available and more in the pipeline, hepatitis C is now considered curable in up to 70% of treated patients. Although therapy for hepatitis C can be instrumental in the prevention of advanced liver disease, lack of knowledge and of skill to deliver treatment among providers, and the high costs of HCV genotyping and drugs, make access to treatment a major global problem.7 Secondary prevention of advanced liver disease from chronic HCV infection through screening for early detection and promoting and aiding cessation of alcohol intake remain key public health strategies.7-9 Proper planning and public health investments are necessary to ensure that preventive measures can be implemented.
To facilitate evidence-based policymaking and prudent resource allocation, it is essential to estimate the burden of HCV infection globally, regionally, and nationally. Additional epidemiological measures typically included in a generic disease model, such as incidence and excess mortality, are difficult to obtain because HCV infections are rarely clinically apparent. Limitations of available assays to distinguish acute and chronic infections6 and poor surveillance systems worldwide for HCV infection further impede efforts to usefully quantify HCV burden. However, recent developments in modeling allow the seroprevalence of anti-HCV to be used to estimate the burden of disease for HCV infections. The Global Burden of Diseases, Injuries, and Risk Factors 2010 (GBD2010) Study is an international collaborative effort to estimate the burden of disease using available parameters.
This systematic review used the GBD Study operations guidelines, which divide the world into 21 regions based on geography and epidemiological profiles.10 The purpose of this study was to estimate the age-specific anti-HCV seroprevalence in each of the 21 world regions in 1990 and in 2005 through a systematic review and meta-analysis of primary national data sources and articles published for peer review between 1980 and 2007. The seroprevalence was modeled using the age-averaging random effects generalized negative binomial spline model from DisMod III,11 the latest iteration of the generic disease modeling system for model-based meta-analysis for descriptive epidemiology, developed by the Institute of Health Metrics and Evaluation (IHME) at the University of Washington. The results of this meta-analysis and the estimates produced by the models identify regions and age groups with high prevalence, and predict prevalence in areas where data are sparse or not available. The anti-HCV seroprevalence estimated in this systematic review is the first step towards modeling the global burden of disease for HCV infection.