Pathogenic free-living amoebae in swimming pools: survey in Belgium.

During a short term investigation, 1 outdoor and 15 indoor swimming pools were examined for the presence of amoebae. Of all isolates from 13 pools, 43.6% belonged to the genus Acanthamoeba. The genus Naegleria accounted for 7.3% of the isolates, but none belonged to the pathogenic N. fowleri. A high percentage (70%) of the Acanthamoeba strains tested showed virulence for mice.