We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Rapid Point-of-Care Identification of Aspergillus Species in Microbial Keratitis.
- Authors
Gunasekaran, Rameshkumar; Chandrasekaran, Abinaya; Rajarathinam, Karpagam; Duncan, Sheelagh; Dhaliwal, Kevin; Lalitha, Prajna; Prajna, N. Venkatesh; Mills, Bethany
- Abstract
This diagnostic study examines the diagnostic performance of a lateral-flow assay in detecting Aspergillus species in patients presenting with bacterial or fungal infection. Key Points: Question: Can microbial keratitis caused by Aspergillus species be diagnosed using a rapid lateral-flow device (LFD) from corneal scrape samples and a minimally invasive corneal swab sampling technique? Findings: In this diagnostic study of 198 participants in South India from whom scrape and swab samples were collected, high sensitivity and high specificity were achieved with an LFD identifying Aspergillus species. Meaning: Findings of this study suggest that a commercially available LFD along with a bespoke ratiometric analysis has high diagnostic accuracy and could be an alternative standard of care for the point-of-care diagnostics for microbial keratitis. Importance: Microbial keratitis (MK) is a common cause of unilateral visual impairment, blindness, and eye loss in low-income and middle-income countries. There is an urgent need to develop and implement rapid and simple point-of-care diagnostics for MK to increase the likelihood of good outcomes. Objective: To evaluate the diagnostic performance of the Aspergillus-specific lateral-flow device (AspLFD) to identify Aspergillus species causing MK in corneal scrape and corneal swab samples of patients presenting with microbial keratitis. Design, Setting, and Participants: This diagnostic study was conducted between May 2022 and January 2023 at the corneal clinic of Aravind Eye Hospital in Madurai, Tamil Nadu, India. All study participants were recruited during their first presentation to the clinic. Patients aged 15 years or older met the eligibility criteria if they were attending their first appointment, had a corneal ulcer that was suggestive of a bacterial or fungal infection, and were about to undergo diagnostic scrape and culture. Main Outcomes and Measures: Sensitivity and specificity of the AspLFD with corneal samples collected from patients with MK. During routine diagnostic scraping, a minimally invasive corneal swab and an additional corneal scrape were collected and transferred to aliquots of sample buffer and analyzed by lateral-flow device (LFD) if the patient met the inclusion criteria. Photographs of devices were taken with a smartphone and analyzed using a ratiometric approach, which was developed for this study. The AspLFD results were compared with culture reports. Results: The 198 participants who met the inclusion criteria had a mean (range) age of 51 (15-85) years and included 126 males (63.6%). Overall, 35 of 198 participants with corneal scrape (17.7%) and 17 of 40 participants with swab samples (42.5%) had positive culture results for Aspergillus species. Ratiometric analysis results for the scrape samples found that the AspLFD achieved high sensitivity (0.89; 95% CI, 0.74-0.95), high negative predictive value (0.97; 95% CI, 0.94-0.99), low negative likelihood ratio (0.12; 95% CI, 0.05-0.30), and an accuracy of 0.94 (95% CI, 0.90-0.97). Ratiometric analysis results for the swab samples showed that the AspLFD had high sensitivity (0.94; 95% CI, 0.73-1.00), high negative predictive value (0.95; 95% CI, 0.76-1.00), low negative likelihood ratio (0.07; 95% CI, 0.01-0.48), and an accuracy of 0.88 (95% CI, 0.73-0.96). Conclusions and Relevance: Results of this diagnostic study suggest that AspLFD along with the ratiometric analysis of LFDs developed for this study has high diagnostic accuracy in identifying Aspergillus species from corneal scrapes and swabs. This technology is an important step toward the provision of point-of-care diagnostics for MK and could inform the clinical management strategy.
- Publication
JAMA Ophthalmology, 2023, Vol 141, Issue 10, p966
- ISSN
2168-6165
- Publication type
Article
- DOI
10.1001/jamaophthalmol.2023.4214