A new government study has found new infections of the liver with hepatitis C virus being far less common in the US these days, compared to the early 1980s.

In the mid-1980s, the study by the researchers at the US Centres for Disease Control and Prevention (CDC) said around 70 of each million Americans developed acute hepatitis C each year. The rate was 90% lower between 1994 and 2006 i. e. only 7 per million per year.

CDC researchers in the Archives of Internal Medicine said over the years a growing proportion of cases have been accounted for by injection drug users, and their risk of infection remains an important public health issue.

Usually, new hepatitis C virus infections are not obvious, with no visible symptoms in some cases at first, hepatitis C quietly damages the liver for years until final diagnosis. However, two or there of every 10 newly infected patients have acute hepatitis. They suffer fever and nausea, and due to their liver not functioning properly, their skin turns yellow from jaundice, and they generally feel extremely sick.

Hepatitis C is transmitted via contact with infected blood, mostly from sharing tainted needles, with a small number of cases transmitted sexually or from mother to baby during childbirth.

Dr. John Ward, Director of the CDC’s Division of viral hepatitis said efforts to curb hepatitis C transmission has achieved some degree of success.

The risk of hepatitis C virus infection among people receiving transfusions steadily declined over time, with only five possible cases identified between 1994 and 2006.

According to CDS, the testing of all donated blood for hepatitis C in the US since 1992 has reduced the risk of receiving an infected donation now estimated to be one in 2 million.

There has also been a decline in the number of cases reportedly related to injection drug use, however, drug abuse accounted for a growing proportion of acute hepatitis C infections in the 1980s (32%) and least for the years 1994 through 2006 (46%).