(RxWiki News) With emerging viruses like bird flu and MERS in the news, many Americans may not give much thought to hepatitis C. But new research shows the illness still affects millions in the US.
A new study estimated the rate of chronic hepatitis C infection in the US for the years 2003 to 2010.
The researchers found that though the rate had dropped from previous surveys, an estimated 2.7 million people in the US had chronic hepatitis C infections during these years.
"Ask your doctor about getting tested for hepatitis C."
Hepatitis C is a viral infection that can cause inflammation in the liver. According to the Centers for Disease Control and Prevention (CDC), the infection can sometimes be short-lived, but in about 75 to 85 percent of cases, the infection becomes chronic and lingers for years or for a lifetime.
Chronic hepatitis C infection can lead to serious liver problems, including liver cancer or scarring of the liver (cirrhosis). CDC reported that the hepatitis C virus is typically spread through contact with the blood of someone who is infected.
"Today, most people become infected with the Hepatitis C virus by sharing needles or other equipment to inject drugs," explained CDC. "Before 1992, when widespread screening of the blood supply began in the United States, Hepatitis C was also commonly spread through blood transfusions and organ transplants."
According to the authors of this new study, led by Maxine M. Denniston, MSPH (Master of Science in Public Health), of CDC, although hepatitis C is treatable, many who are infected are not aware of their condition. Denniston and team explained that understanding the amount of chronic hepatitis C cases in the US is important for effective public health policy.
To update estimates for the rates of chronic hepatitis C in the US, these researchers utilized CDC's National Health and Nutrition Examination Survey (NHANES) for the years 2003 to 2010. From NHANES,, Denniston and team identified 30,074 participants who had all the data needed for this study.
These participants were asked about risk factors for the condition and potential exposures to hepatitis C and underwent blood tests and physical examinations. In total, 273 participants tested positive for chronic hepatitis C infection.
After analyzing the data, Denniston and team estimated that 1.0 percent of the US population aged 6 or older, or 2.7 million people, had a chronic hepatitis C infection at this time.
Denniston and team noted that the estimate of 2.7 million people with a chronic hepatitis C infection is about 500,000 people fewer than a similar estimate for the years 1999 through 2002, suggesting that perhaps rates of the infection have dropped in more recent years. However, the researchers noted that the drop in cases could be a reflection of an increase in deaths related to untreated chronic hepatitis C.
The researchers found that people with a chronic hepatitis C infection were more likely to be between the ages of 40 and 59 years old, male, non-Hispanic black and in lower income and education levels.
The risk factors strongly associated with a chronic hepatitis C infection were illicit drug use and receiving a blood transfusion before the year 1992. However, it is important to note that around half of people with a chronic hepatitis C infection did not report either risk factor.
"These data underscore the urgency of identifying the millions of persons who remain infected and linking them to appropriate care and treatment," wrote Denniston and team.
The survey did not include homeless people or jailed people, which might have affected the results.
The study was published March 3 by the Annals of Internal Medicine. No conflicts of interest were reported.