Chicago ? Patients who got hepatitis from contaminated syringes and medicine vials are joining infection control advocates to warn Americans about a problem they say is more common than people think.

A recent federal report suggests they are right.

It found more than 60,000 people were exposed to hepatitis, and at least 400 people were infected with it in 33 outbreaks linked with blatant safety violations. The report covered the period from 1998 to 2008.

Many involved reuse of syringes: Health workers likely thought they were being safe by discarding the syringes’ used needles and snapping on sterile ones. They were apparently unaware that the plastic barrel part of a syringe can become contaminated, too. Reusing it even with a fresh needle also can contaminate the medicine vial.

Army officials announced Thursday they are investigating evidence that a similar unsanitary practice, reuse of insulin-injecting devices, may have occurred at a Texas Army hospital. More than 2,100 diabetic patients treated at William Beaumont Army Medical Center in El Paso may be at risk for hepatitis or HIV, although no cases have been confirmed.

Authorities believe many infections from such incidents go unreported. The lack of care and cleanliness that has been uncovered in medical clinics and doctors’ offices is disturbing.

The most publicized cases in recent years occurred in Nevada, Nebraska and New York; one of the most recent outbreaks was in Illinois.

But they have happened in other states and in hospitals, too.

The federal report published last month says the cases it highlights “probably represent a much wider problem.”