Health care workers are at higher than average risk of infection with the hepatitis C virus, a research review suggests.

Compared to the general population, health workers had 60 percent greater odds of getting hepatitis C, and those who worked directly with blood had almost triple the risk, according to the analysis in Occupational and Environmental Medicine.

Hepatitis C is usually spread when blood from an infected person enters the body of someone who isn’t infected. These days, most people infected with the virus get it from sharing needles or equipment to inject drugs, but it can also be transmitted during sex, and until a test for it was developed in the early 1990s, people could acquire hepatitis C through blood transfusions.

“Contact with blood, for example, from needle stick injuries, is associated with a risk of infection and continues to be the major threat to the health of health care workers,” said lead study author Claudia Westermann of the University Medical Center Hamburg-Eppendorf in Germany by email.

“Exposure to blood cannot completely be avoided when using `safe’ instruments, as they reduce the risk of needle stick injuries but do not completely prevent them,” Westermann added. “Therefore blood borne virus infections will remain a threat to health care workers for some time to come.”

To assess the prevalence of hepatitis C among health care workers, Westermann and colleagues analyzed data from 44 previously published studies.