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Epidemiology of hepatitis C in the United States
1Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
Insights
Hepatitis C virus (HCV) infection remains a significant public health concern in the US, with millions chronically infected and a substantial portion of liver disease linked to it. Early identification and prevention efforts are crucial to reduce transmission and HCV-related deaths.
Area of Science:
- Hepatology
- Infectious Diseases
- Public Health Epidemiology
Background:
- Hepatitis C virus (HCV) is the most common chronic blood-borne infection in the US.
- An estimated 3.9 million Americans have been infected with HCV, with 2.7 million chronically infected.
- HCV accounts for 40% of chronic liver disease and causes 8,000-10,000 deaths annually.
Purpose of the Study:
- To assess the prevalence and incidence of Hepatitis C virus (HCV) infection in the United States.
- To identify the primary risk factors and transmission routes for HCV.
- To highlight the potential increase in HCV-related mortality and the need for targeted interventions.
Main Methods:
- Utilized data from the Third National Health and Nutrition Examination Survey (NHANES III).
- Analyzed population-based studies to determine HCV prevalence and its association with chronic liver disease.
- Examined trends in HCV incidence since 1989 and identified current major risk factors.
Main Results:
- Annual incidence of new HCV infections decreased by over 80% since 1989, with approximately 36,000 new infections by 1996.
- 1.8% of the US population (3.9 million) were infected with HCV, and 2.7 million were chronically infected.
- Injection drug use is the predominant risk factor for acute HCV infection, while blood transfusions were significant before 1990.
Conclusions:
- A substantial number of Americans remain chronically infected with HCV, posing a risk for liver disease and mortality.
- The aging cohort with high HCV prevalence (ages 30-49) may lead to increased deaths from liver disease in the next 10-20 years.
- Effective prevention and control strategies must target high-risk groups and emphasize early detection of chronic HCV infections.
Abstract:
Although hepatitis C virus (HCV) infection is the most common chronic blood-bome infection in the United States, the annual incidence of new infections has decreased by more than 80% since 1989 to approximately 36,000 new infections by 1996. The Third National Health and Nutrition Examination Survey (NHANES III) revealed that an estimated 3.9 million US citizens (1.8%) have been infected with HCV. Of these, approximately 2.7 million persons are chronically infected with HCV. Population-based studies indicate that 40% of chronic liver disease is HCV related. Chronic hepatitis C results in an estimated 8,000 to 10,000 deaths each year. Because the prevalence of HCV infection is approximately threefold higher among persons now between 30 and 49 years of age, the number of deaths resulting from HCV-related liver disease could increase substantially during the next 10 to 20 years, as this cohort reaches the ages at which complications from chronic liver disease typically occur. Most people who develop chronic infection may not even be aware that they have been infected, because acute disease is commonly benign. However, infected persons can transmit the disease to others and are at risk for developing chronic liver disease. HCV is transmitted primarily through direct percutaneous exposures to blood. In the United States, blood transfusion accounted for a substantial proportion of HCV infections before 1990, when routine testing began, but now accounts for only a small percentage. Injection drug use is currently the major risk factor for acute HCV infection. Prevention and control of HCV infection in the United States must focus not only on reduction of transmission in groups at high risk of infection (e.g., injection drug users) but also on the early identification of persons with chronic infection.