NEW YORK (Reuters Health) - People who become infected with the hepatitis C virus when getting a tattoo may be less likely to develop obvious symptoms than people who become infected in other ways, according to Texas researchers.

In a small study, both people with tattoos and those with a history of injection-drug use were more likely than others to be infected with hepatitis C.

But unlike people who had injected drugs, individuals who had a tattoo were not more likely to develop acute hepatitis symptoms, such as jaundice, vomiting and fatigue.

The hepatitis C virus causes chronic infection and disease in over 70 percent of infected people, but only 10 to 15 percent of people with the virus are believed to develop acute symptoms soon after infection.

According to Dr. Robert W. Haley, the lead author of the study, a tattoo needle carries a smaller amount of virus and does not inject the virus directly into the bloodstream, as opposed to needles used to inject drugs.

As a consequence, in the case of tattooing, it takes longer for the disease-causing agent to enter the bloodstream and make its way to the liver and cause symptoms, Haley, a professor of internal medicine and chief of epidemiology at the University of Texas Southwestern Medical Center in Dallas, told Reuters Health in an interview.

But Dr. Miriam Alter, the associate director for science in the division of viral hepatitis at the Centers for Disease Control and Prevention (CDC) in Atlanta, told Reuters Health that Haley "misinterpreted" the data. According to Alter, the risk of being infected with hepatitis C from a tattoo needle is small. "Overall we would not recommend that people who get tattooed get tested for hepatitis C because they are unlikely to have a higher rate of infection than anyone else in the general population," said Alter. In an interview, Alter also disputed Haley's contention that those people getting a smaller dose of the virus were less likely to develop acute symptoms of HCV.

To minimize one's risk of contracting and spreading a blood-borne pathogen, both Alter and Haley advise making sure that any procedure that pierces the skin is performed safely. For instance, needles, gloves and towels should be used once and then either discarded or sterilized.

In the study, Haley and a colleague, Dr. R. Paul Fischer of Presbyterian Hospitals of Dallas, re-analyzed data collected in the early 1990s on 626 patients seeing a physician for back problems. Patients were asked about risk factors for hepatitis C, and were screened for the virus after the interview.

The latest results were published in the journal Archives of Internal Medicine.

Researchers found that those who had a tattoo had an almost 7-fold higher risk of testing positive for hepatitis C. However, they were not at greater risk of having experienced acute hepatitis symptoms, according to the report.

In contrast, people with a history of IV drug use were 7 times more likely to be infected with the hepatitis C virus and 6 times more likely to have experienced acute hepatitis symptoms. In the interview, Haley urged regulation and inspection of tattoo parlors to reduce the risk of hepatitis infection from tattoos.

SOURCE: Archives of Internal Medicine 2003;163:1095-1098.