Water and surface microbiological quality of point of use water filters: a comparative study FLORENTIN A.1,2, RIVIER A.4, LIZON J.1, ASENSIO E.3, FORIN J.1, RABAUD C.1, 1 – Operational Team of Hospital Hygiene, CHRU de Nancy, Vandoeuvre-lès-Nancy, France / 2 – EA 7298 INGRES, Lorraine University, Vandoeuvre-lès-Nancy, France / 3 – Technical services environmental department, CHRU de Nancy, Vandoeuvre-lès-Nancy, France / 4 – Laboratory of Environmental Biology, CHRU de Nancy, Vandoeuvre-lès-Nancy, France Introduction Methods We received POU filters from 4 manufacturers. We studied 8 facets and showers filters of 30 days of use, and 3 facets and 2 showers of 62 days of use. Each week, a water sample of 250mL and a surface swab were collected. We performed a 100mL filtrate of water sample (culture medium R2A / incubation temperature of 22°C). Swabs were spread on a petri dish (culture medium R2A / temperature 30°C). Each petri dish were enumerated at 7 days. Waterborne pathogens (WBP) such Legionella pneumophila and Pseudomonas aeruginosa are majors contributors to Hospital Acquired Infections (HAI). Point-of-use (POU) water filtration have demonstrated their benefits to prevent colonization/infection and interrupt outbreak implicating waterborne pathogens. In France, microbiological water quality are not routinely investigated if conditions of use are respected and controlled. The aim of our study was to compare in real conditions of use the water and surface microbiological quality of point of use water filters: facet and shower, 31 and 62 days of use. Results For facets and showers water filters with 31 days of use, respectively 37.5% and 34.4% of surface samples were positives and 0.3% of water samples were non-compliant. For facets and showers water filters with 62 days of use, respectively 29% and 81% of surface samples were positives and respectively 0% and 0.3% of water samples were non-compliant. Identified microorganisms were Staphylococcus sp., Penicillium sp. Acinetobacter haemoluticus Brevundimonas vesicularis, Bacillus sp., Micrococcus sp. and P. aeruginosa Water filters with 31 days of use W8 W0 W1 W2 W3 W4 W5 W6 W7 Water filters with 62 days of use Conclusion Our study showed that surface of POU water filters were often contaminated and sometimes with pathogenic microorganisms.