<i>Notes from the Field: Acanthamoeba</i> Keratitis Cases — Iowa, 2002–2017

Scruggs, Brittni A.; Quist, Tyler S.; Salinas, Jorge; Greiner, Mark A.

doi:10.15585/mmwr.mm6819a6

Cited by 23 publications

(23 citation statements)

References 7 publications

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“…An increase in AK incidence was discussed in several international studies 20 , 24 – 26 . In our study population, we observed a peak in first presentations during the summer months, especially the month of August.…”

Section: Discussionmentioning

confidence: 99%

“…The aim of this study was to analyse AK cases in our department between 1997 and 2018 and compare the characteristics, treatment strategies, results and outcomes with other studies. www.nature.com/scientificreports/ An increase in AK incidence was discussed in several international studies 20,[24][25][26] . In our study population, we observed a peak in first presentations during the summer months, especially the month of August.…”

Section: Discussionmentioning

confidence: 99%

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Evaluation of Acanthamoeba keratitis cases in a tertiary medical care centre over 21 years

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Glatz

Riedl

et al. 2021

Sci Rep

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To report on Acanthamoeba keratitis cases in a tertiary university eye-hospital in Graz, Austria, over a 21-year period. Retrospective study. Parameters included demographics, diagnostics, clinical courses, medical therapies, surgical interventions, secondary complications, and best spectacle-corrected visual acuity (BSCVA). Patient records for 44 eyes of 42 patients were analysed; 2 bilateral infections. Mean age at presentation was 31 ± 13 (16–65) years; contact lenses were used in 41 of 44 eyes (93.2%). Symptoms at initial presentation were mainly pain (41/43, 95.3%) and photophobia (16/43, 37.2%). Most frequent morphological findings were stromal infiltrates (30/44, 68.2%). Diagnosis was mainly confirmed by smears (40/42, 95.2%) and polymerase chain reaction (8/42, 19%). Antiamoebic treatment comprised biguanides and diamidines. Penetrating keratoplasty was performed in 10/44 (22.7%) eyes. Median time from symptom onset to initial visit was 2 (0–26) weeks; median follow-up was 30 (2–1008) weeks. BSCVA improved in 23/36 (63.9%) eyes, remained unchanged in 6/36 (16.7%) eyes and deteriorated in 7/36 (19.4%) eyes. Acanthamoeba keratitis predominantly occurs in young contact lens wearers. Diagnosis should be considered in patients with pain and stromal infiltrates. In the majority of cases, BSCVA can be improved. Early diagnosis and adequate treatment should be implemented to prevent complications.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Evaluation of Acanthamoeba keratitis cases in a tertiary medical care centre over 21 years

List

Glatz

Riedl

et al. 2021

Sci Rep

View full text Add to dashboard Cite

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“…Outbreaks of Acanthamoeba keratitis in the United States in 2007 [ 2 ] and the United Kingdom beginning in 2010 [ 3 ] have led to hundreds of infected patients, as well as the products or disinfectants associated with those outbreaks being recalled or phased out [ 2 , 3 , 4 , 5 ]. Critically, within populations of infected patients, as many as 41% of AK sufferers have become blind due to corneal damage [ 6 ]. Following this, the differences in Acanthamoeba disinfection between CLC products available to consumers, largely due to the biocides used in each product, continues to be a risk factor for the development of AK.…”

Section: Introductionmentioning

confidence: 99%

Evaluating Alternate Methods of Determining the Antimicrobial Efficacy of Contact Lens Care Products against Acanthamoeba Trophozoites

2021

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Acanthamoeba keratitis (AK) is a serious ocular infection caused by a ubiquitous free-living amoeba, Acanthamoeba. This infection often results in extensive corneal damage and blindness, and is notoriously difficult to cure. While Acanthamoeba is an abundant organism, AK is most associated with contact lens hygiene noncompliance and inadequate contact lens care (CLC) disinfection regimens. Thus, accurate and timely antimicrobial efficacy testing of CLC solutions is paramount. Published methods for antimicrobial efficacy testing of Acanthamoeba trophozoites requires 14 days for results. Presently, alternate and/or rapid methods for evaluating CLC products rarely demonstrate equivalent results compared to commonly-reported methods. Propidium iodide is a cellular stain that can only bind to cells with damaged outer membranes. We evaluated propidium iodide staining as an alternative method for determining the relative antimicrobial efficacy of 11 different CLC products against Acanthamoeba trophozoites. Following exposure to a CLC product, the fluorescence intensity of propidium iodide in an Acanthamoeba population demonstrated a strong correlation to the log reduction determined by established, growth-based Acanthamoeba testing used to evaluate the antimicrobial efficacy of CLC products. Thus, propidium iodide was found to be an effective rapid tool for determining cell death in Acanthamoeba trophozoites following exposure to CLC solutions.

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“…They have an active trophozoite form, approximately 15–35 μm in size with specialized pseudopodia and no descript shape, and a dormant cyst stage, approximately 10–20 μm in size, encased in a double-cellulose cell wall that provides increased protection from environmental stressors ( Khan, 2006 ; Garajová et al, 2019 ). Globally, increasing cases of Acanthamoeba -associated infections have been documented, prompting significant concerns from a clinical perspective ( Carnt et al, 2018 ; Randag et al, 2019 ; Scruggs et al, 2019 ; Höllhumer et al, 2020 ). These amoebae can be viewed as opportunistic parasites, ordinarily free living yet capable of causing severe infections under suitable circumstances.…”

Section: Introductionmentioning

confidence: 99%

Paradigms of Protist/Bacteria Symbioses Affecting Human Health: Acanthamoeba species and Trichomonas vaginalis

et al. 2021

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Ever since the publication of the seminal paper by Lynn Margulis in 1967 proposing the theory of the endosymbiotic origin of organelles, the study of the symbiotic relationships between unicellular eukaryotes and prokaryotes has received ever-growing attention by microbiologists and evolutionists alike. While the evolutionary significance of the endosymbiotic associations within protists has emerged and is intensively studied, the impact of these relationships on human health has been seldom taken into account. Microbial endosymbioses involving human eukaryotic pathogens are not common, and the sexually transmitted obligate parasite Trichomonas vaginalis and the free-living opportunistic pathogen Acanthamoeba represent two unique cases in this regard, to date. The reasons of this peculiarity for T. vaginalis and Acanthamoeba may be due to their lifestyles, characterized by bacteria-rich environments. However, this characteristic does not fully explain the reason why no bacterial endosymbiont has yet been detected in unicellular eukaryotic human pathogens other than in T. vaginalis and Acanthamoeba, albeit sparse and poorly investigated examples of morphological identification of bacteria-like microorganisms associated with Giardia and Entamoeba were reported in the past. In this review article we will present the body of experimental evidences revealing the profound effects of these examples of protist/bacteria symbiosis on the pathogenesis of the microbial species involved, and ultimately their impact on human health.

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Notes from the Field: Acanthamoeba Keratitis Cases — Iowa, 2002–2017

Cited by 23 publications

References 7 publications

Evaluation of Acanthamoeba keratitis cases in a tertiary medical care centre over 21 years

Evaluation of Acanthamoeba keratitis cases in a tertiary medical care centre over 21 years

Evaluating Alternate Methods of Determining the Antimicrobial Efficacy of Contact Lens Care Products against Acanthamoeba Trophozoites

Paradigms of Protist/Bacteria Symbioses Affecting Human Health: Acanthamoeba species and Trichomonas vaginalis

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