The role of surgery in transmitting "post-transfusion hepatitis".

The role of surgery as an additional risk in transmitting "post-transfusion" hepatitis was investigated in a retrospective study on acute hepatitis occurring in 77 transfused patients, 293 transfused and operated patients and 243 hepatitis cases with history of surgery without transfusion. Hepatitis A patients admitted to the same centres in the same period were utilized as controls. In transfused patients the percentage of NANB hepatitis was higher than that of type B (61.0% vs. 36.4%), while in the operated not transfused group the percentage of type B was twice that of type NANB (63.4% vs. 32.5%). In transfused and operated cases intermediate values were observed. The age-adjusted measures of association between exposures and the different hepatitis types showed a lack of effect of transfusion and a dominant role of surgery in transmitting type B hepatitis. In contrast, NANB "post-transfusional" cases were actually a mixture of post-transfusional and post-surgical cases, since both these exposures were found to be significantly associated with the disease. Our results suggest that studies on the incidence and the etiology of post-transfusion hepatitis should take into account the risk of surgical exposure which might have occurred.