Tattooing appears to be a major route of hepatitis C infection and is perhaps the biggest contributor to the spread of the disease -- even bigger than injection-drug use, according to a study in the March issue of Medicine.

Researchers from the University of Texas Southwestern Medical School in Dallas surveyed and tested 626 patients who sought medical treatment at an orthopedic spinal clinic.  Patients were surveyed and tested in 1991 and 1992, before widespread hepatitis C testing began.  Of the 113 patients who had a tattoo, 25 (22%) were infected with hepatitis C.  (Of the 513 patients who did not have tattoos, 18 [3.5%] were infected.)  Few of the tattoo-associated infections could be traced to injection-drug use, transfusions, or other known exposure sources.

The authors found that the hepatitis C risk was increased in people who had several tattoos or had ones that were large and complex. Tattoos acquired in commercial tattoo parlors were also associated with a higher risk of infection.  Hepatitis C and other infectious diseases can be spread by reuse of needles or dye and by inadequate sterilization technique.   The authors write that few states have laws addressing safe tattooing practices, and even fewer monitor and enforce the standards.

Nearly 4 million Americans have chronic hepatitis C infection, and an estimated 10,000 deaths occur each year from hepatitis-C related cirrhosis and liver cancer.