FRIDAY, Jan. 17, 2014 (HealthDay News) — Rates of hepatitis C infection vary widely among different Hispanic groups in the United States, and Puerto Rican Hispanics are much more likely to be infected than other groups, a new study shows.

Hepatitis C is a viral infection that causes inflammation of the liver. It’s transmitted from person to person through blood, often from sharing needles to inject drugs.

Researchers analyzed data collected from nearly 12,000 Hispanic adults in the Bronx, Miami, Chicago and San Diego as part of a U.S. National Institutes of Health-funded study. Hepatitis C infection rates ranged from 0.4 percent among men of South American background to 11.6 percent among men of Puerto Rican background.

Hepatitis C infection rates for men in other groups were: 1.9 percent in Mexicans, 1.5 percent in Dominicans, 1 percent in Central Americans and 0.8 percent in Cubans, according to the study published online Jan. 14 in the Journal of Infectious Diseases.

Hispanic women generally had lower infection rates than men, with Puerto Rican women having the highest rate (3.9 percent) among Hispanic women, the study authors noted in a news release from the Albert Einstein College of Medicine in New York City.

It’s not clear why men and women of Puerto Rican background have higher rates of hepatitis C infection than those in other Hispanic groups, the researchers said.

The overall rate of hepatitis C infection among men and women in the United States is 1.3 percent, according to the results of the U.S. National Health and Nutrition Examination Survey.

“Until now, national health surveys that assessed hepatitis C’s prevalence among U.S. Hispanics have looked only at Mexican Americans,” study author Mark Kuniholm, an assistant professor of epidemiology and population health at Albert Einstein College of Medicine, said in the news release. “As a result, no one knew whether the rates were higher or lower in other Hispanic populations.”

Kuniholm said these findings show “that it’s not appropriate to lump all U.S. Hispanics into a single, broad at-risk group.” The results highlight which Hispanic groups would gain the most benefit from increased hepatitis C testing and treatment.

More information

The U.S. National Institute of Allergy and Infectious Diseases has more about hepatitis C.