The review of all the Centers for Disease Control and Prevention's investigations over the past 10 years of healthcare-associated viral hepatitis outbreaks appears in the journal Annals of Internal Medicine.

"This report is a wake-up call," said Dr. John Ward, director of CDC's division of viral hepatitis. "Thousands of patients are needlessly exposed to viral hepatitis and other preventable diseases in the very places where they should feel protected. No patient should go to their doctor for healthcare only to leave with a life-threatening disease."

In the United States, transmission of hepatitis B and C while receiving healthcare has been considered uncommon; however, a review of CDC outbreak information revealed a total of 33 identified outbreaks outside of hospitals in 15 states, during the past decade: 12 in outpatient clinics, six in hemodialysis centers and 15 in long-term care facilities.

Reuse of syringes and blood-contamination of medications, equipment and devices were identified in the study as common factors in these outbreaks.

CDC officials say the report shows the need for ongoing professional education for healthcare providers, as well as consistent state oversight in detecting and preventing the transmission of blood-borne pathogens in healthcare settings.