Effect ofDisinfectants on Pathogenic Free-Living Amoebae:in Axenic Conditions

duetotheuseofan indoor chlorinated swimming pool, stated that, "theconstant presence ofnumerous populations ofthelimaxgroupofamoebae cannotbeprevented evenunderthestrictest observations of allroutine safety measuresapplied towater systems ofswimming pools." In1972, Anderson andJamieson (2)reported a caseofprimary meningoencephalitis inSouthAustralia, thevictimhaving playfully submerged hisheadindomestic bathwater. Theyalsoreported that superchlorination to10mg-liter-' hadfailed to eradicate Naegleria fromacontaminated pool. Subsequently, Derreumaux etal.(11) demonstrated that0.5mgofHOCl,theactive disinfecting component ofchlorine disinfection, per liter wasabletoeradicate bothNaegleria and Acanthamoeba spp. DeJonckheere andvande Voorde(10) found thataninitial concentration ofchlorine between 0.5and1.0mg-liter-' was cysticidal forNaegleria spp. butthat Acanthamoebaculbertsoni cysts werenotinactivated by 40mg.liter-'. Thepresent study wasinitiated toassess the effectiveness ofchlorine, chlorine dioxide, ozone, anddeciquam 222against pathogenic andnonpathogenic species ofNaegleria andAcanthamoeba.