Hepatitis B reactivation in an Irish dialysis unit, 2005

In April 2005, a case of reactivation of hepatitis B virus (HBV) infection occurred in a patient undergoing haemodialysis in an Irish hospital. This incident potentially affected patients attending hospitals throughout the country, so a national incident team was set up coordinate the response to the incident. A total of 306 dialysis patients, attending 17 different dialysis centres (14 in Ireland), were identified as having been potentially exposed to HBV as a result of this incident. A programme of HBV serological testing and HBV vaccination was instituted. There was no evidence that any patient acquired HBV infection as a result of cross-infection from the index patient, although 11 patients (3.6%) had evidence of past infection (anti-HBc positive, HBsAg negative). The majority of patients in this cohort were of unknown HBV vaccination status (62.7%), 13.4% were fully vaccinated, 4.6% partially vaccinated and 15.7% unvaccinated. Of 239 tested for anti-HBs, 183 (76.6%) had a titre <10 mIU/ml. Local incidents in dialysis units can have national implications due to the frequent patient transfer between units. This incident highlighted serious deficiencies in current structures and practices, and a lack of appropriate guidelines. However, there were positive outcomes from this incident. The majority of Irish dialysis patients have now been vaccinated against HBV, and lessons learned have been used to develop national guidelines on HBV vaccination and testing and on the management of incidents of blood-borne viral infections in dialysis units.