Four million infected with hepatitis C in US

NEW YORK, May 16 (Reuters) Findings from a nationwide study suggest that 4.1 million people in the US have been infected with hepatitis C virus (HCV), and most of these individuals have chronic infection.

However, the current rate of infection, 1.6 per cent, is actually slightly lower than a decade ago when the rate was 1.8 per cent.

HCV, which attacks the liver, is typically spread through contact with contaminated blood products. Injection drug users are at particularly high risk for picking up the virus. Chronic hepatitis C is the leading reason for liver transplantation and up to 5 per cent of people with chronic disease will die.

The new findings are based on analysis of data for 15,079 participants in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2002. In addition to answering detailed questions about their health and lifestyles, the subjects submitted blood samples for HCV testing and liver enzyme analysis.

The new findings build on those from the previous NHANES, conducted between 1988 and 1994, according to the report in the Annals of Internal Medicine.

As noted, the rate of HCV infection was 1.6 per cent, and 1.3 per cent of all subjects had chronic HCV infection, lead author Dr Gregory L Armstrong, from the Centers for Disease Control and Prevention in Atlanta, and colleagues report.

People in their 40s had the highest rate of infection -- 4.3 per cent, the researchers point out.

The biggest risk factor for HCV infection was injection drug use: nearly half of infected subjects between 20 and 59 years of age reported injecting drugs. The majority of infection drug users said they had not used drugs for at least 1 year prior to being surveyed.

Blood transfusion before 1992 was also significant risk factors for HCV infection, as was having 20 or more lifetime sexual partners, the report indicates.

In a related commentary, Dr Jules L Dienstag, from Harvard Medical School in Boston, comments that ''the new data build on those reported previously to paint a vivid portrait of hepatitis C in the US. A self-limited epidemic of injection drug use over several decades amplified the transmission of HCV, and we are now seeing the delayed, bitter harvest of chronic liver disease.'' REUTERS SI SSC1102