Contamination with Hepatitis B Virus DNA in Gastrointestinal Endoscope Channels: Risk of Infection on Reuse after On-Site Cleaning

Abstract

The incidence of viral contamination in the air, water and suction/accessory channels of gastrointestinal endoscopes was examined in order to evaluate the risk of infection. After endoscopic examinations, including biopsy procedures, in 17 patients who were positive for hepatitis B virus surface antigen and eight patients who were positive for hepatitis C virus antibody, the endoscopes were cleaned on site by suctioning and flushing the air and water channels with an enzyme detergent. First samples were then collected by flushing 5 ml of sterile water through each channel. After mechanical reprocessing, second samples were collected in the same way. Virological studies were carried out with real-time polymerase chain reactions for hepatitis B virus DNA and hepatitis C virus RNA. Hepatitis B virus DNA was detected in five of the first samples recovered from the suction/accessory channels of the endoscopes (titers of 1.3 x 10 (4) to 2.5 x 10 (5) copies/ml), while no contamination was detected after reprocessing ( P = 0.0445). The first samples from one water channel and three air channels were also positive for hepatitis B virus DNA, but were negative after reprocessing ( P > 0.5, P = 0.227, respectively). No hepatitis C virus RNA was detected in any of the samples. These results indicate that all of the channels were potential sources of viral infection.