[From the Mailing List SIN: Epidemic of infections caused by 'aquatic' bacteria in patients undergoing hemodialysis via central venous catheters].

UNLABELLED: Bacteremia due to central venous catheter (CVC) infection is the most frequent complication of CVC use as vascular access for hemodialysis (HD). We report a case of an epidemic of CVC infections caused by 3 strains of unusual bacteria: Ralstonia pickettii (Rp), Leifsonia xyli/Leifsonia aquatica (Lxa), Tsuckamurella strandjordae (Ts). From 20/8/01 to 30/9/01, 23 of 35 patients dialyzed via CVCs experienced intra-HD pyrogenic reactions. Their hemocultures were positive for: Rp (14 pts), Lxa (3 pts), Rp+Lxa (5 pts) and Rp+Ts (1 pt). The hemocultures of 12/35 asymptomatic pts were positive for: Rp 2 pts, Lxa 2 pts, Rp+Lxa 2 pts, Ts 1 pt, Rp+Ts 1 pt. The epidemiological and microbiological analyses of environmental samples failed to identify the source of the epidemic. Actions taken were: a) replacement of the batches of disposable materials; b) removal of CVCs in cases where possible to prepare a different access; c) treatment of the infections with intra-CVC antibiotic lock therapy. No relapses were recorded until April 2002, when 8 pts had again pyrogenic reactions due to Rp. After quick substitution of the CVC and repetitions of the action a), no relapses of pyrogenic reactions were observed.
CONCLUSIONS: 1) given the characteristics of Rp, Lxa and Ts, saprophytes of moist environments, the most plausible source of the epidemic was a low-charge contaminated solution that was not identified due to low sensitivity of environmental sample culturing methods; 2) antibiotic lock therapy is a viable option for the conservative treatment of CVC infections.