Survey on bacterial contamination of bidet toilets and relation to the interval of scrubbing these units

We conducted a survey to investigate the distribution of bacteria recovered from the bidet toilets at a district hospital. The nozzle surface and spray water of 192 bidet toilets were sampled for contamination. Of the 192 toilets sampled, the nozzle surface of 167 (87%) and the spray water of 181 (94%) were found to be contaminated by one or more of the following organisms: Enterobacteriaceae, Enterococcus spp., Staphylococcus spp., non-glucose-fermenting rods, other Gram-negative bacteria, other Gram-positive bacteria, and Candida spp. An extended spectrum of β-lactamase producing Escherichia coli was found in one nozzle surface and one spray water. The frequency of colonization with 104 or more recovered from the nozzle surface was significantly greater in the toilets scrubbed every week than that in the units scrubbed every day, but that from the spray water was not significantly different between the groups. The nozzle surface and the spray water in the bidet toilets were contaminated with a wide range of bacteria. Because the interval of scrubbing the toilets did not have an influence on the contamination of the spray water, self-cleaning mechanisms of spray water should be developed to prevent patients' possible infections.