HCV moves from patient to worker to five patients

Ross RS, Viazov S, Gross T, et al. Transmission of hepatitis C virus from a patient to an anesthesiology assistant to five patients. N Engl J Med 2000; 343:1,851-1,854.

An anesthesia assistant with occupationally-acquired hepatitis C virus transmitted the pathogen to at least five surgical patients via an uncovered hand wound, the authors of this German study report.

"Our findings suggest that an anesthesiology assistant contracted HCV from a chronically infected patient and subsequently transmitted the virus to five other patients," they report. "Our conclusion is supported by both epidemiologic and molecular evidence. The five patients had no known risk factors for HCV infection, and there were no evident contacts among them — a fact that excludes the possibility of patient-to-patient transmission. On the other hand, the anesthesiology assistant was the only staff member infected with HCV and could be identified as the sole common denominator in all six cases."

The worker tested negative for serum HCV antibodies approximately eight weeks before a patient with HCV underwent surgery on April 28, 1998. The worker was apparently occupationally infected by the patient and began showing symptoms of acute hepatitis C six weeks after this operation. However, in the interim, other patients were apparently minimal and invisible amounts of the assistant’s blood or wound secretions directly through mucosal lesions caused by intubation or through indwelling venous and arterial cannulas.

None of the other patients had a history of hepatitis, nor were they aware of any history of hepatitis in their families. All reported no other risk factors for HCV infection, including tattooing or body piercing, intravenous drug use, or high-risk sexual behavior.

The operations were performed in two rooms. There was no known contact between the patients either before or during their hospitalizations, which were in different parts of the hospital.

Besides occupational exposure, the anesthesiology assistant had no known risk factors for HCV infection. Intravenous drug abuse was ruled out by extensive drug screening and numerous interviews.

The assistant was almost entirely responsible for the administration of general anesthesia, including the preparation of narcotic drugs, the placement of venous and arterial catheters, the intubation of the patients, and the subsequent artificial respiration.

The anesthesia worker usually did not wear gloves, claiming that they impaired his work by diminishing his sense of touch.

On questioning, he reported that during the time under investigation he had a wound on the third finger of his right hand, sustained in April 1998 when he opened a box containing infusion solutions.

The wound was initially the size of a thumbnail and bled repeatedly. He used a bandage for three or four days but not thereafter, although the wound was still weeping. The assistant admitted that this was negligent behavior, but at the time, he already considered the open wound to be an old injury and was not aware that such an attitude might be risky for him as well as for his patients.

In addition, inspections and interviews with staff members indicated that numerous breaches of general infection-control practices had taken place. For instance, needles were frequently recapped after use, and gloves were not always worn in settings in which exposure was likely. Multidose vials for flushing solutions, saline, local anesthetic drugs, and heparin were often used in the operating rooms, although the solutions were changed every second day.

Phylogenetic analysis confirmed that the assistant and all six patients were infected with the same HCV isolate.

"The only identifiable condition that might have caused the spread of the virus was the wound on the assistant’s right hand," the authors conclude. "Given the high plasma levels of HCV RNA in both patient one and the assistant, and given that the assistant usually did not wear gloves in the operating room, it is possible that a fraction of a microliter of blood or wound secretions might have transmitted HCV from patient one to the assistant and subsequently from him to the five other patients."