Blood-borne virus infections in dialysis units--a review.

Hepatitis outbreaks in haemodialysis unit patients and staff were reported in the late 1960s. In 1972, the Rosenheim report in the UK established guidelines which included routine tests for hepatitis B surface antigen and isolation facilities for dialysing patients with hepatitis B virus which resulted in a dramatic fall in cases of hepatitis. However, since these guidelines were introduced, other blood-borne viruses, notably HCV and HIV have been discovered, and failures of infection control practices still lead to outbreaks of HBV in haemodialysis units. The prevalence of HCV in dialysis patients varies considerably throughout the world, with reported prevalence ranging from 3.9% to 71%. The number of blood transfusions and the length of time on dialysis have consistently been associated with HCV prevalence. Several reports provide evidence of patient-to-patient HCV transmission with environmental blood contamination the most significant factor in intra-unit transmission. There is no evidence that HCV has been transmitted by re-use of dialysis machines but being dialysed next to an HCV positive patient is associated with a significant risk of HCV acquisition. Several studies have shown that dialysing HCV positive patients in a separate unit or in a defined sector of a dialysis unit significantly reduces nosocomial HCV infection. HGV is prevalent in dialysis units where there is evidence of transmission to patients but no evidence of associated symptoms. HIV is infrequently transmitted in dialysis units and several units treating many HIV-positive patients have shown no evidence of transmission. Careful attention needs to be paid to infection control procedures and regular virological testing.