The International Journal of Artificial Organs / Vol. 19/ no. 7,1996/ pp. 435-436 Letter to the Editor Effectiveness of universal precautions in limiting nosocomial transmission of hepatitis C virus in haemodialysis units Sir, In spite of the high prevalence of anti-HCV positive patients in haemodialysis units (1), there are conflicting results regarding the incidence rate and, consequently, the preventive strategies. Here we report our experience with a three-year follow-up: 88 patients on ROT for at least 6 months were enrolled in three dialysis units. Mean dura- tion of follow-up was 37.2 months. All patients enrolled were tested every 4 months with a 2nd generation anti- HCV test (Elisa, Ortho); confirmation of positive samples was performed with Riba test (Ortho), RT-nested PCR was used to detect HCV RNA sequence in serum. The prevention of nosocomial transmission was set up as follows. No segregation of anti-HCV positive patients was set up, no dedicated machines were used, and no dialyzer was reused. Utmost attention was paid in applying universal precautions for prevention of community acqui- red infection as in Center For Disease Control Recom- mendation (2). The disinfection protocol for dialysis monitors included a chemical disinfection with peracetic acid or hypoclorite solution after the last dialysis session of the day, while only a washing cycle was applied between dialysis ses- sions. Anti-HCV antibodies were initially detected in 32 subjects (35.2%); 56 patients were seronegative (Tab. I). The prevalence of anti-HCV positive patients ranged from 18.18% to 41.37%. During the follow-up five seroconver- sions were observed: 1 in the first, 2 in the second, 2 in the third year (3 in the hospital center, 1 for each outside centers). Thus, mean incidence of seroconversion was 2.79% / year. All seroconverted patients but one were PCR positive and all but one had a positive Riba 2° test (one was indeterminate); two patients received blood tran- sfusion. None of the seroconverted subjects were dialy- zing on single pass monitors; three were dialyzed on the same machines of an anti-HCV positive patients: one of these was also transfused 19 months before SC; one was dialyzed next to an anti-HCV positive patient, and the last had none of these risk conditions, but was transfused 15 months before SC (Tab. II). Up to now there is no agreement on applying a segre- gation protocol for anti-HCV positive and negative patients as has been done for hepatitis B. However, some authors have advocated the segregation of anti-HCV positive patients (3, 4). Should an isolation protocol be accepted, there will be many clinical and organizing problems: the delay between HCV infection and detection of anti-HCV antibodies; the great variability of HCV genomes (5); when isolation was performed SC rate decreased but did not disappear (6); on the other hand, there are organizing pro- blems: we will need up to four different facilities to dialyze patients with or without HBV and HCV infection or coinfec- TABLE I - HAEMODIALYSIS UNITS ENROLLED AND FOLLOW-UP unit patients antiHCV+ follow-up SC incidence (months) 1 58 24 (41.3%) 37.5 3 2.82% 2 19 6 (31.5%) 35 1 2.6% 3 11 2 (18.1%) 38 3.47% 88 32 (35.2%) 37.02 5 2.79% TABLE II - CLINICAL FEATURES AND RISK CONDITIONS OF SEROCONVERSIONS Elisa 2 Riba2 PCR ALT Blood transf. SC 1 pos pos pos ++ SC2 pos pos pos ++ SC3 pos pos pos ++ + SC4 pos pos pos ++ + SC5 pos ind pos + © by Wichtig Editore. 1996 Same monitor Dialyzing of HCV+ nextto an HCV+ no yes yes no yes no no no yes no 0391-3988/435-02 $01.00/0