Acanthamoeba spp. in Dialysis Water: Assessing the Potential Risk of Transmission to Hemodialysis Patients.

PURPOSE: Acanthamoeba spp. can colonize various freshwater habitats. They are the causative agents of granulomatous amoebic encephalitis and can harbor many microorganisms. We studied the presence of Acanthamoeba spp. in the water system of a hemodialysis unit and assessed the potential for transmission to hemodialysis patients.

METHODS

Water samples collected from pretreatment and posttreatment water of the treatment station and from input and output water of the dialysis machines were cultured on non-nutrient agar supplemented with Escherichia coli. Blood samples from dialysis patients in the unit and from a control group in the same hospital were tested for anti-Acanthamoeba IgG antibodies.

RESULTS

Acanthamoeba spp. were found in posttreatment water. They were more commonly found in the input water samples (79.2%), than in the output water samples (16.7%) (p = 0.001). Anti-Acanthamoeba IgG antibodies were present in 32.9% of patients and were absent in the control group (p = 0.002). The duration of hemodialysis was significantly longer in seropositive patients than in seronegative patients (p = 0.008).

CONCLUSION

The study highlights the presence of Acanthamoeba spp. in the dialysis system. The relatively high prevalence of anti-Acanthamoeba IgG antibodies and the link between dialysis duration and seropositivity emphasize the importance of rigorous water monitoring.