Hepatitis B virus (HBV) infection is a serious global health problem, with 2 billion people infected worldwide, and 350 million suffering from chronic HBV infection. The 10th leading cause of death worldwide, HBV infections result in 500 000 to 1.2 million deaths per year caused by chronic hepatitis, cirrhosis, and hepatocellular carcinoma; the last accounts for 320 000 deaths per year. In Western countries, the disease is relatively rare and acquired primarily in adulthood, whereas in Asia and most of Africa, chronic HBV infection is common and usually acquired perinatally or in childhood. More efficacious treatments, mass immunization programs, and safe injection techniques are essential for eliminating HBV infection and reducing global HBV-related morbidity and mortality. Safe and effective vaccines against HBV infection have been available since 1982. The implementation of mass immunization programs, which have been recommended by the World Health Organization since 1991, have dramatically decreased the incidence of HBV infection among infants, children, and adolescents in many countries. However, not all countries have adopted these recommendations and there remains a large number of persons that were infected with HBV prior to the implementation of immunization programs. Antiviral treatment is the only way to reduce morbidity and mortality from chronic HBV infection. Conventional interferon alfa and lamivudine have been the primary treatments to date. Conventional interferon alfa produces a durable response in a moderate proportion of patients but has undesirable side-effects and must be administered subcutaneously three times per week. Lamivudine also produces a response in a modest proportion of patients and causes few side-effects. However, prolonged treatment is often necessary to prevent relapse on cessation of therapy, and continuous treatment can lead to the development of lamivudine resistance. Promising emerging new treatments include adefovir, entecavir and peginterferon alfa-2a (40 kDa).

Hepatitis C is of concern both to industrialized and developing countries. Preliminary unpublished estimates of the global burden of disease (GBD) attributable to HCV-related chronic liver disease seem to be substantial. Therefore, the reduction of global mortality and morbidity related to chronic hepatitis C should be a concern to public health authorities, and primary, secondary and tertiary prevention activities should be implemented and monitored in each country, with precise targets set to be reached. In order to decide on national health policies, there is a need to estimate the burden of disease, globally, regionally and nationally. To evaluate the GBD, three components have to be assessed: 1) The global, regional and national burden of morbidity and mortality associated with HCV infection, based on prevalence, incidence, transmission and economics; 2) The natural history of HCV infection, including 'healthy individuals'; and 3) The areas for which more research is needed. A working group was created to assist the World Health organization (WHO) in estimating the GBD associated with HCV infection.

John C Martin Foundation.

More than 20 years after the discovery of the hepatitis C virus (HCV), it is now well established that HCV is of global importance affecting all countries, leading to a major global health problem that requires widespread active interventions for its prevention and control. Chronic hepatitis C was linked to the development of cirrhosis and hepatocellular carcinoma in many areas of the world. Current epidemiological assessments have identified complex patterns with highly variable local prevalence rates between countries and within countries. HCV infection patterns have not significantly changed in most parts of the world since 1997, when first analyzed, partly due to the lack of new and more accurate data. The assessment of the national HCV prevalence and transmission modes should be completed to enable national authorities to prioritize preventive measures and to make the most appropriate use of available resources. The 'patchy' epidemiological situation in some areas will continue to complicate the task of the establishment of global, regional and national base line data. The present assessment finds a global prevalence of 2.35%, affecting 160 million chronically infected individuals. There is an urgent need for more accurate Information on the costs and burden of HCV to society. Twenty-one year after the discovery of HCV, the assessment is far from being complete and little progress has been made in the past 10 years in many countries. In some countries significant increases have been reported and this may also apply to countries were insufficient data exist. A safe and efficient vaccine against HCV is urgently needed.

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