Abstract
Objective: To estimate the frequency of Hepatitis B surface antigen (HBsAg) in patients on hemodialysis and to study the association of various risk factors in the acquisition of Hepatitis B infection.
Materials and Methods: All patients on long-term hemodialysis in nephrology unit of Shifa International Hospital, Islamabad between January 2002 to June 2003 were studied. Their medical records were reviewed for presence of HBsAg. Any risk factors were noted from the patient’s records and from the history of those patients who were regularly attending the dialysis unit. All data was fed and analyzed using SPSS v 10.0.
Results: A total of 97 patients on hemodialysis were included in the study. Out of these, 12 (12.4%) were found to be HBsAg positive. The mean age of study participants was 54.93 ± 15.09 years. The mean age of HBsAg positive patients was significantly lower than those who were HBsAg negative HBsAg positive patients (n=12) were compared with HBsAg negative patients (n=85) with regards various risk factors such as history of dialysis more than 2 years, history of transplant, history of transfusion and history of injections. HBsAg positive group had significantly greater proportion of patients with a history of dialysis more than 2 years (58.3% versus 16.5%), with an un-adjusted p-value of 0.003. When adjusted for the confounding risk factors the adjusted p-value obtained was 0.007. No significant association of any other risk factor with HBsAg positivity was found.
Conclusion: Patients on hemodialysis in our unit had 12.4% positivity of HBsAg and history of dialysis more than 2 years was noted to be a significant risk factor for acquisition of infection in these patients.

Key words: Hemodialysis, HBsAg, and hepatitis B