Contaminated radioistopes cause hepatitis C infections

A contaminated radioisotope used in cardiac stress tests has been blamed for more than a dozen cases of hepatitis C contracted by patients in Maryland, according to a report released Monday by the Maryland Department of Health and Mental Hygiene.

The investigation by the DHMH found that 16 individuals were exposed to the hepatitis C virus on Oct. 15, 2004, when they were given technetium-99m-labeled sestamibi prepared by a nuclear pharmacy owned by Cardinal Health in the central Maryland city of Timonium.

By December, all 16 patients had developed clinical or laboratory evidence of hepatitis C, the report said.

Some reports have indicated that one person died as a result of the hepatitis C infection, but Maryland authorities and Cardinal Health refused to confirm or deny the assertion. Although 16 patients were contaminated, the DHMH report lists follow-up data on only 15.

The DHMH investigation did not specify the mechanism for contamination, but it appears possible there was cross-contamination between a blood-labeling procedure and the preparation of the radioisotope. A patient whose labeled leukocytes were prepared at the pharmacy on Oct. 14 had been previously diagnosed with the hepatitis B and C viruses as well as HIV.

Staff at the pharmacy told Maryland health investigators that, at certain points in the preparation procedure, this patient's blood or blood components could have been processed in the same work area or with the same equipment used some hours later during preparation of the radiolabeled product.

DHMH health officials said that during an inspection of the pharmacy, they noted that the pace of the work appeared to be hurried and sloppy. Their report quoted the pharmacist as saying the rapid work pace was required to prepare a large number of doses with short expiration periods and exacerbated by the need to transport the doses to clinics.

The DHMH probe was conducted a month after the Oct. 15 contamination date and did not draw a firm conclusion as to mechanism of contamination.

The report stated that the work areas in the pharmacy were poorly defined, no policy existed for cleaning the containers used to transport the doses to clinics and to return the empty syringes to the pharmacy, and syringes were scattered about the counters and sitting in cups.

Cardinal Health will reevaluate the physical layout of its pharmacies, paying special attention to the proximity of the aseptic processing to the sterile compounding, said spokesperson Jim Mazzola. The company also is reevaluating and strengthening its training protocols.

Cardinal Health shut down the pharmacy in November when it was notified of the problem, and it remains closed today. The company is planning to build a new pharmacy in the Baltimore area that will incorporate the latest design standards, Mazzola said.