title: Resistance of Acanthamoeba cysts to disinfection in multiple contact lens solutions.
abstract: Acanthamoebae are free-living amoebae found in the environment, including soil, freshwater, brackish water, seawater, hot tubs, and Jacuzzis. Acanthamoeba species can cause keratitis, a painful vision-threatening infection of the cornea, and fatal granulomatous encephalitis in humans. More than 20 species of Acanthamoeba belonging to morphological groups I, II, and III distributed in 15 genotypes have been described. Among these, Acanthamoeba castellanii, A. polyphaga, and A. hatchetti are frequently identified as causing Acanthamoeba keratitis (AK). Improper contact lens care and contact with nonsterile water while wearing contact lenses are known risk factors for AK. During a recent multistate outbreak, AK was found to be associated with the use of Advanced Medical Optics Complete MoisturePlus multipurpose contact lens solution, which was hypothesized to have had insufficient anti-Acanthamoeba activity. As part of the investigation of that outbreak, we compared the efficacies of 11 different contact lens solutions against cysts of A. castellanii, A. polyphaga, and A. hatchetti (the isolates of all species were genotype T4), which were isolated in 2007 from specimens obtained during the outbreak investigation. The data, generated with A. castellanii, A. polyphaga, and A. hatchetti cysts, suggest that the two contact lens solutions containing hydrogen peroxide were the only solutions that showed any disinfection ability, with 0% and 66% growth, respectively, being detected with A. castellanii and 0% and 33% growth, respectively, being detected with A. polyphaga. There was no statistically significant difference in disinfection efficacy between the 11 solutions for A. hatchetti.
authors.affiliation: Division of Parasitic Diseases, Centers for Disease Control and Prevention, Public Health Service, US Department of Health and Human Services, Atlanta, GA 30341-3724, USA. sjohnston@cdc.gov
authors.forename: Stephanie P
authors.initials: SP
authors.lastname: Johnston
authors.forename: Rama
authors.initials: R
authors.lastname: Sriram
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Qvarnstrom
authors.forename: Sharon
authors.initials: S
authors.lastname: Roy
authors.forename: Jennifer
authors.initials: J
authors.lastname: Verani
authors.forename: Jonathan
authors.initials: J
authors.lastname: Yoder
authors.forename: Suchita
authors.initials: S
authors.lastname: Lorick
authors.forename: Jacquelin
authors.initials: J
authors.lastname: Roberts
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Beach
authors.forename: Govinda
authors.initials: G
authors.lastname: Visvesvara
mesh_terms: D000048:Acanthamoeba / Q000187:drug effects* / Q000302:isolation & purification*; D015823:Acanthamoeba Keratitis / Q000469:parasitology*; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D018639:Contact Lens Solutions / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D006801:Humans
chemical_list: D000981:Antiprotozoal Agents; D018639:Contact Lens Solutions