risk of hepatitis b virus infection following upper gastrointestinal endoscopy: a prospective study in an endemic area

background: it is thought that the transmission of hepatitis b virus (hbv) through the endoscopic procedures is a very rare event. the aim of this study is to evaluate the effect of the standard disinfection procedure of the endoscopes and accessories versus conventional disinfection in the transmission of hbv. materials and methods: a prospective survey, comprising 520 consecutive upper gastrointestinal endoscopies was carried out simultaneously at three endoscopy centers in iran, without altering the routine procedures. at center 1, the standard disinfection procedure (manual brushing of internal channel of the endoscope followed by 20 minutes exposure to 2% glutaraldehyde before the start of endoscopy sessions and at center 2, conventional disinfection (exposure of the endoscope to 2% glutaraldehyde for 4 minutes) was performed. hepatitis b surface antigen (hbsag) was tested for all patients; and a questionnaire was lfilled by the patients to obtain information regarding the risk factors for hbv infection. six months later, hbsag testing was repeated, and a new questionnaire about hbv risk factors was completed by the patients. results: a total of 520 patients (273 men and 247 women, mean age 48.35 years) were enrolled. 311 patients in the standard disinfection groups and 209 patients in the conventional disinfection group underwent upper gastrointestinal endoscopy. 19 patients (10 in the conventional disinfection group, and 9 in the standard disinfection groups) were hbsag positive (3.7%). on survey for the risk factors of hbv, 14 patients (73.7%) had a history of dental procedures, 2 (10.5%) had positive familial history of hbv, and 2 (10.5%) had a history of blood transfusion. six months later, the patients were retested for hbsag. of those with negative hbsag, one patient in the conventional disinfection group became hbsag positive. conclusion: the probability of transmission of hbv by the endoscope in the conventional disinfection system is very low. in order to document that standard disinfection is preferable over the conventional one, a very large multicenter study is needed.