title: Acanthamoeba keratitis: the persistence of cases following a multistate outbreak.
abstract: OBJECTIVE
  To describe the trend of Acanthamoeba keratitis case reports following an outbreak and the recall of a multipurpose contact lens disinfection solution. Acanthamoeba keratitis is a serious eye infection caused by the free-living amoeba Acanthamoeba that primarily affects contact lens users.
  
  
  METHODS
  A convenience sample of 13 ophthalmology centers and laboratories in the USA, provided annual numbers of Acanthamoeba keratitis cases diagnosed between 1999-2009 and monthly numbers of cases diagnosed between 2007-2009. Data on ophthalmic preparations of anti-Acanthamoeba therapies were collected from a national compounding pharmacy.
  
  
  RESULTS
  Data from sentinel site ophthalmology centers and laboratories revealed that the yearly number of cases gradually increased from 22 in 1999 to 43 in 2003, with a marked increase beginning in 2004 (93 cases) that continued through 2007 (170 cases; p < 0.0001). The outbreak identified from these sentinel sites resulted in the recall of a contact lens disinfecting solution. There was a statistically significant (p ≤ 0.0001) decrease in monthly cases reported from 28 cases in June 2007 (following the recall) to seven cases in June 2008, followed by an increase (p = 0.0004) in reported cases thereafter; cases have remained higher than pre-outbreak levels. A similar trend was seen in prescriptions for Acanthamoeba keratitis chemotherapy. Cases were significantly more likely to be reported during summer than during other seasons.
  
  
  CONCLUSIONS
  The persistently elevated number of reported cases supports the need to understand the risk factors and environmental exposures associated with Acanthamoeba keratitis. Further prevention efforts are needed to reduce the number of cases occurring among contact lens wearers.
authors: Centers for Disease Control and Prevention. jyoder@cdc.gov
authors: Jonathan S
authors: JS
authors: Yoder
authors: Jennifer
authors: J
authors: Verani
authors: Nancy
authors: N
authors: Heidman
authors: Joan
authors: J
authors: Hoppe-Bauer
authors: Eduardo C
authors: EC
authors: Alfonso
authors: Darlene
authors: D
authors: Miller
authors: Dan B
authors: DB
authors: Jones
authors: David
authors: D
authors: Bruckner
authors: Roger
authors: R
authors: Langston
authors: Bennie H
authors: BH
authors: Jeng
authors: Charlotte E
authors: CE
authors: Joslin
authors: Elmer
authors: E
authors: Tu
authors: Kathryn
authors: K
authors: Colby
authors: Emily
authors: E
authors: Vetter
authors: David
authors: D
authors: Ritterband
authors: William
authors: W
authors: Mathers
authors: Regis P
authors: RP
authors: Kowalski
authors: Nisha R
authors: NR
authors: Acharya
authors: Ajit P
authors: AP
authors: Limaye
authors: Charles
authors: C
authors: Leiter
authors: Sharon
authors: S
authors: Roy
authors: Suchita
authors: S
authors: Lorick
authors: Jacquelin
authors: J
authors: Roberts
authors: Michael J
authors: MJ
authors: Beach
mesh_terms: D015823:Acanthamoeba Keratitis / Q000453:epidemiology* / Q000469:parasitology; D018639:Contact Lens Solutions; D003261:Contact Lenses / Q000469:parasitology; D004196:Disease Outbreaks; D004340:Drug Contamination; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D056736:Drug Recalls; D006801:Humans; D018571:Sentinel Surveillance; D014481:United States / Q000453:epidemiology
chemical_list: D018639:Contact Lens Solutions