Microbial contamination of contact lens cases in the west of Scotland.

Devonshire, Penny; Munro, F.A.; Abernethy, C. Scott; Clark, Brian J.

doi:10.1136/bjo.77.1.41

Cited by 128 publications

(76 citation statements)

References 27 publications

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“…Acanthamoeba thrive on bacterial colonies in culture, particularly on Gram-negative rods, and may reflect combined infection of the lenses or cases. 17,19,20 This sequence of events seems most likely where bacteria were isolated only days after the first symptoms were experienced. However, the cor neal ulceration seen in later-presenting acanthamoebal infection is a recognised risk factor for bacterial super infection.…”

Section: Discussionmentioning

confidence: 99%

A review of 72 consecutive cases of Acanthamoeba keratitis, 1984–1992

Bacon¹,

Frazer²,

Dart³

et al. 1993

Eye

252

159

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Section: Discussionmentioning

confidence: 99%

A review of 72 consecutive cases of Acanthamoeba keratitis, 1984–1992

Bacon¹,

Frazer²,

Dart³

et al. 1993

Eye

252

159

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“…Since Acanthamoeba species access ocular tissue by first attaching to the contact lens, identifying this organism from a contact lens or within lens fluids may be suggestive of involvement of this pathogen, which could therefore assist with a diagnosis in conjunction with clinical findings. However, it should be noted that isolating a pathogen in non-clinical material is not direct evidence for its role in the disease process, as shown by Devonshire et al (1993) who demonstrated Acanthamoeba species from 3.3% of contact lens cases in asymptomatic contact lens wearers. Advantages of testing contact lenses and/or contact lens fluid are the ease of sampling, which might be preferable for certain patients, and greater sample volume.…”

Section: Pcr Detectionmentioning

confidence: 99%

Acanthamoeba keratitis: improving the Scottish diagnostic service for the rapid molecular detection of Acanthamoeba species

Alexander

Coyne

Jones

et al. 2015

Journal of Medical Microbiology

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Acanthamoeba species are responsible for causing the potentially sight-threatening condition, Acanthamoeba keratitis, which is commonly associated with contact lens use. In this report, we highlight the challenges faced using conventional laboratory identification methods to identify this often under-reported pathogen, and discuss the reasons for introducing the first national service in Scotland for the rapid and sensitive molecular identification of Acanthamoeba species. By comparing culture and molecular testing data from a total of 63 patients (n580 samples) throughout Scotland presenting with ocular eye disease, we describe the improvement in detection rates where an additional four positive cases were identified using a molecular assay versus culture. The testing of a further ten patients by confocal imaging is also presented. This report emphasizes the importance of continuing to improve clinical laboratory services to ensure a prompt, correct diagnosis and better prognosis, in addition to raising awareness of this potentially debilitating opportunistic pathogen. INTRODUCTIONAcanthamoeba keratitis is an uncommon but sightthreatening disease of the cornea caused by free-living protozoan amoebae belonging to the genus Acanthamoeba (Lorenzo- Morales et al., 2013). This painful, often unilateral eye disease may eventually progress to blindness and is associated with contact lens use but can also be diagnosed in non-contact lens wearers. Acanthamoeba species can be found in a variety of different environments including recreational and drinking water, soil and air (Gianinazzi et al., 2009;Legarreta et al., 2013;Rivera et al., 1991). Trophozoites and highly robust cysts can persist for years and are often resistant to drug treatments.Global increases of Acanthamoeba keratitis occurred during the 1970s and 1980s with links to contact lens use in over 85% of cases, which is consistent with recent data from America and Canada (Stehr-Green et al., 1989;Fraser et al., 2012;Page & Mathers, 2013). In addition, noncommercial saline solutions have been implicated as potential risk factors (Newton et al., 1986). The UK experienced an increase in cases during the 1990s which coincided with increased use of soft contact lenses (Illingworth et al., 1995).There is a lack of recent robust data on the prevalence of Acanthamoeba keratitis in Scotland, but based on a study by Seal et al. (1999), the incidence was 149 per million soft contact lens wearers compared with much lower incidence rates of around 18 to 21 per million in the rest of the UK (Radford et al., 2002). Presently, there are approximately 3.7 million contact lens wearers in the UK (British Contact Lens Association, http://www.bcla.org.uk/).An early, accurate diagnosis is crucial for achieving a better prognosis. However, conventional techniques to detect Acanthamoeba species may lack sensitivity, which is likely to result in the true prevalence being underestimated. The challenges of an early diagnosis are compounded by the ability of Acanthamoeba to mimic non-...

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“…Riboprinting (see below) and mitochondrial DNA restriction fragment length polymorphism (RFLP) were used to show that storage case isolates had similar genetic characterisation to keratitis-causing strains and are thus potential pathogens for the cornea. The authors were able to analyse 43 isolates of Acanthamoeba from lens storage cases, which far exceeds the numbers isolated in Scotland, where the contamination rate was found to be approximately 2% 10,13 at the time of our highest incidence figures of Acanthamoeba keratitis in 1994/95. In Hong Kong, Acanthamoeba spp were isolated from the used lens storage cases of three out of 116 (2.6%) asymptomatic CLW control volunteers.…”

Section: Incidencementioning

confidence: 99%