Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2TMPRSS2 cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention.

OBJECTIVE: To estimate 22-year trends in the prevalence and incidence of scleritis, and the associations of scleritis with infectious and immune-mediated inflammatory diseases (I-IMIDs) in the UK. METHODS: The retrospective cross-sectional and population cohort study (1997-2018) included 10,939,823 patients (2,946 incident scleritis cases) in The Health Improvement Network, a nationally representative primary care records database. The case-control and matched cohort study (1995-2019) included 3,005 incident scleritis cases and 12,020 control patients matched by age, sex, region, and Townsend deprivation index. Data were analyzed using multivariable Poisson regression, multivariable logistic regression, and Cox proportional hazards multivariable models adjusted for age, sex, Townsend deprivation index, race/ethnicity, smoking status, nation within the UK, and body mass index. Incidence rate ratios (IRRs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: Scleritis incidence rates per 100,000 person-years declined from 4.23 (95% CI 2.16-6.31) to 2.79 (95% CI 2.19-3.39) between 1997 and 2018. The prevalence of scleritis per 100,000 person-years was 93.62 (95% CI 90.17-97.07) in 2018 (61,650 UK patients). Among 2,946 patients with incident scleritis, 1,831 (62.2%) were female, the mean ± SD age was 44.9 ± 17.6 years (range 1-93), and 1,257 (88.8%) were White. Higher risk of incident scleritis was associated with female sex (adjusted IRR 1.53 [95% CI 1.43-1.66], P < 0.001), Black race/ethnicity (adjusted IRR 1.52 [95% CI 1.14-2.01], P = 0.004 compared to White race/ethnicity), or South Asian race/ethnicity (adjusted IRR 1.50 [95% CI 1.19-1.90], P < 0.001 compared to White race/ethnicity), and older age (peak adjusted IRR 4.95 [95% CI 3.99-6.14], P < 0.001 for patients ages 51-60 years versus those ages ≤10 years). Compared to controls, scleritis patients had a 2-fold increased risk of a prior I-IMID diagnosis (17 I-IMIDs, P < 0.001) and significantly increased risk of subsequent diagnosis (13 I-IMIDs). The I-IMIDs most strongly associated with scleritis included granulomatosis with polyangiitis, Behçet's disease, and Sjögren's syndrome. CONCLUSION: From 1997 through 2018, the UK incidence of scleritis declined from 4.23 to 2.79/100,000 person-years. Incident scleritis was associated with 19 I-IMIDs, providing data for rational investigation and cross-specialty engagement.

SIGNIFICANCE: Think Tank 2019 affirmed that the rate of infection associated with contact lenses has not changed in several decades. Also, there is a trend toward more serious infections associated with Acanthamoeba and fungi. The growing use of contact lenses in children demands our attention with surveillance and case-control studies. PURPOSE: The American Academy of Optometry (AAO) gathered researchers and key opinion leaders from around the world to discuss contact lens-associated microbial keratitis at the 2019 AAO Annual Meeting. METHODS: Experts presented within four sessions. Session 1 covered the epidemiology of microbial keratitis, pathogenesis of Pseudomonas aeruginosa, and the role of lens care systems and storage cases in corneal disease. Session 2 covered nonbacterial forms of keratitis in contact lens wearers. Session 3 covered future needs, challenges, and research questions in relation to microbial keratitis in youth and myopia control, microbiome, antimicrobial surfaces, and genetic susceptibility. Session 4 covered compliance and communication imperatives. RESULTS: The absolute rate of microbial keratitis has remained very consistent for three decades despite new technologies, and extended wear significantly increases the risk. Improved oxygen delivery afforded by silicone hydrogel lenses has not impacted the rates, and although the introduction of daily disposable lenses has minimized the risk of severe disease, there is no consistent evidence that they have altered the overall rate of microbial keratitis. Overnight orthokeratology lenses may increase the risk of microbial keratitis, especially secondary to Acanthamoeba, in children. Compliance remains a concern and a significant risk factor for disease. New insights into host microbiome and genetic susceptibility may uncover new theories. More studies such as case-control designs suited for rare diseases and registries are needed. CONCLUSIONS: The first annual AAO Think Tank acknowledged that the risk of microbial keratitis has not decreased over decades, despite innovation. Important questions and research directions remain.

ABSTRACT: Protecting nurses in healthcare facilities from SARS-CoV-2 infection is essential for maintaining an adequate nursing force. Foundational guidelines, consistently utilized, protect the nursing staff from infection. This article describes guidelines designed to reduce acute infection and associated morbidity and mortality among nursing staff and improve compliance with infection prevention protocols.

PURPOSE: To investigate a cluster of corneoscleral rim cultures positive for Achromobacter species over a 6-month period at Massachusetts Eye and Ear. METHODS: An increased rate of positive corneal donor rim cultures was noted at Massachusetts Eye and Ear between July and December 2017. Positive cultures were subjected to identification and antimicrobial susceptibility testing by phenotypic (MicroScan WalkAway) and genotypic (16S rDNA sequencing) methods. Samples of the eye wash solution (GeriCare) used in the eye bank were also evaluated. Antimicrobial activity of Optical-GS against Achromobacter spp. at 4°C and 37°C was assessed by time-kill kinetics assay. RESULTS: Of 99 donor rims cultured, 14 (14.1%) grew bacteria with 11 (78.6%) due to uncommon nonfermenting Gram-negative bacilli. These had been identified by standard automated methods as Achromobacter (n = 3), Alcaligenes (n = 3), Ralstonia (n = 2), Pseudomonas (n = 2), and Stenotrophomonas (n = 1). Eight of these 11 isolates were subsequently available for molecular identification, and all were identified as Achromobacter spp. Six bottles of eyewash solution were evaluated and were positive for abundant Achromobacter spp. (3.4 × 105 ± 1.1 CFU/mL). Optisol-GS had no bactericidal activity against Achromobacter spp. at 4°C after 24-hour incubation but was bactericidal at 37°C. None of the patients who had received the contaminated corneas developed postoperative infection. CONCLUSIONS: An eyewash solution arising from a single lot was implicated in the contamination of donor rims by Achromobacter spp. The isolates were able to survive in the Optisol-GS medium at the recommended storage temperature. This highlights the need to continue improving protocols for tissue preparation and storage.

BACKGROUND: Community-genotype methicillin-resistant Staphylococcus aureus (CG-MRSA) emerged in the 1990s as a global community pathogen primarily involved in skin and soft tissue infections (SSTIs) and pneumonia. To date, the CG-MRSA SSTI burden in Latin America (LA) has not been assessed. OBJECTIVE: The main objective of this study was to report the rate and genotypes of community-genotype methicillin-resistant Staphylococcus aureus (CG-MRSA) causing community-onset skin and soft tissue infections (CO-SSTIs) in LA over the last two decades. In addition, this research determined relevant data related to SSTIs due to CG-MRSA, including risk factors, other invasive diseases, and mortality. DATA SOURCES: Relevant literature was searched and extracted from five major databases: Embase, PubMed, LILACS, SciELO, and Web of Science. METHODS: A systematic review was performed, and a narrative review was constructed. RESULTS: An analysis of 11 studies identified epidemiological data across LA, with Argentina presenting the highest percentage of SSTIs caused by CG-MRSA (88%). Other countries had rates of CG-MRSA infection ranging from 0 to 51%. Brazil had one of the lowest rates of CG-MRSA SSTI (4.5-25%). In Argentina, being younger than 50 years of age and having purulent lesions were predictive factors for CG-MRSA CO-SSTIs. In addition, the predominant genetic lineages in LA belonged to sequence types 8, 30, and 5 (ST8, ST30, and ST5). CONCLUSION: There are significant regional differences in the rates of CG-MRSA causing CO-SSTIs. It is not possible to conclude whether or not CG-MRSA CO-SSTIs resulted in more severe SSTI presentations or in a higher mortality rate.

is a multidrug resistant, opportunistic human pathogen and a leading cause of hospital acquired infections. Recently, isolates have been recovered from the air and surfaces onboard the International Space Station (ISS). Pangenomic and functional analyses were carried out to assess their potential impact on astronaut health. Genomes of each ISS isolate, and both clinical and commensal reference strains, were evaluated for their core and unique gene content, acquired antibiotic resistance genes, phage, plasmid content, and virulence traits. In order to determine their potential survival when outside of the human host, isolates were also challenged with three weeks of desiccation at 30% relative humidity. Finally, pathogenicity of the ISS strains was evaluated in the model organism At the culmination of this study, there were no defining signatures that separated known pathogenic strains from the more commensal phenotypes using the currently available resources. As a result, the current reliance on database information alone must be shifted to experimentally evaluated genotypic and phenotypic characteristics of clinically relevant microorganisms.

Many of the risk factors for developing severe coronavirus disease 2019 (COVID-19) are also risk factors for eye diseases such as age-related macular degeneration (AMD). During the past decades, macrophages and the complement pathway (as a part of the innate immune system) have been identified as important contributors to the development of AMD, and we suggest that these mechanisms are of similar importance for the clinical course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Based on the experience with AMD, we discuss how behavioral factors such as diet, smoking and higher body mass index, as well as genetic determinants such as the complement and immune pathway genes may lead to the overactive inflammatory phenotypes seen in some patients with COVID-19, and may in part explain the heterogeneity of disease manifestations and outcomes. Based on this experience, we discuss potential genetic research projects and elaborate on preventive and treatment approaches related to COVID-19.

Objective: To describe and evaluate a secure video call system combined with a suite of iPad vision testing apps to improve access to vision rehabilitation assessment for inpatients. Design: Retrospective. Setting: Two acute care inpatient rehabilitation hospitals and 1 long-term acute care (LTAC) hospital. Participants: Records of inpatients seen by the vision service. Interventions: Records from a 1-year telemedicine pilot performed at acute rehabilitation (AR) hospital 1 and then expanded to AR hospital 2 and LTAC hospital during coronavirus disease 2019 (COVID-19) were reviewed. In the virtual visits, an occupational therapist measured the patients' vision with the iPad applications and forwarded results to the off-site Doctor of Optometry (OD) for review prior to a video visit. The OD provided diagnosis and education, press-on prism application supervision, strategies and modifications, and follow-up recommendations. Providers completed the telehealth usability questionnaire (10-point scale). Main Outcome Measures: Vision examinations per month at AR hospital 1 before and with telemedicine. Results: With telemedicine at AR hospital 1, mean visits per month significantly increased from 10.7±5 to 14.9±5 (=.002). Prism was trialed in 40% of cases of which 83% were successful, similar to previously reported in-person success rates. COVID-19 caused only a marginal decrease in visits per month (=.08) at AR1, whereas the site without an established program (AR hospital 2) had a 3-4 week gap in care while the program was initiated. Cases at the LTAC hospital tended to be more complex and difficult to manage virtually. The telehealth usability questionnaire median category scores were 7 for , 8 for , 6 for , and 9 for . Conclusions: The virtual vision clinic process improved inpatient access to eye and visual neurorehabilitation assessment before and during the COVID-19 quarantine and was well accepted by providers and patients.

Purpose: During the COVID-19 pandemic, there is growing concern that patients are forgoing necessary care. Emergency departments (ED) represent an important site of eye care. We analyzed patterns of ED visits at an eye-specific ED since the declaration of the public health crisis. Materials and Methods: In this retrospective, cross-sectional single center study, medical records of 6744 patients who presented to the Massachusetts Eye and Ear ED between March 1st and April 30th in 2018, 2019, and 2020 were studied. The primary outcome measures were total volume of ED visits, proportion of urgent ED visits, and proportion of surgical visits. Results: Overall, the median number of daily visits to the ED decreased by 18 visits per day since the declaration of public health guidelines (interquartile range, 9-24, p < 0.001). This accounted for a 32% decrease in the total volume of ED visits in 2020 compared to prior years during the study period (p < 0.001). There was a 9% increase in the proportion of primary diagnoses considered urgent (p = 0.002). The proportion of visits requiring urgent surgery increased by 39% (p = 0.004). Conclusion: The total number of eye-specific ED visits dropped compared to prior years while the proportion of urgent visits increased. Patients were likely more reluctant to seek eye care, deferring less urgent evaluation.

PURPOSE: To critically evaluate the potential impact of the coronavirus disease (COVID-19) pandemic on global ophthalmology and VISION 2020. DESIGN: Perspective supplemented with epidemiologic insights from available online databases. METHODS: We extracted data from the Global Vision Database (2017) and Global Burden of Disease Study (2017) to highlight temporal trends in global blindness since 1990, and provide a narrative overview of how COVID-19 may derail progress toward the goals of VISION 2020. RESULTS: Over 2 decades of VISION 2020 advocacy and program implementation have culminated in a universal reduction of combined age-standardized prevalence of moderate-to-severe vision impairment (MSVI) across all world regions since 1990. Between 1990 and 2017, low-income countries observed large reductions in the age-standardized prevalence per 100,000 persons of vitamin A deficiency (25,155 to 19,187), undercorrected refractive disorders (2,286 to 2,040), cataract (1,846 to 1,690), onchocerciasis (5,577 to 2,871), trachoma (506 to 159), and leprosy (36 to 26). Despite these reductions, crude projections suggest that more than 700 million persons will experience MSVI or blindness by 2050, principally owing to our growing and ageing global population. CONCLUSIONS: Despite the many resounding successes of VISION 2020, the burden of global blindness and vision impairment is set to reach historic levels in the coming years. The impact of COVID-19, while yet to be fully determined, now threatens the hard-fought gains of global ophthalmology. The postpandemic years will require renewed effort and focus on vision advocacy and expanding eye care services worldwide.

The enterococci, which are among the leading causes of multidrug-resistant (MDR) hospital infection, are notable for their environmental ruggedness, which extends to intrinsic antibiotic resistance. To identify genes that confer this unique property, we used Tn-seq to comprehensively explore the genome of MDR strain MMH594 for genes important for growth in nutrient-containing medium and with low-level antibiotic challenge. As expected, a large core of genes for DNA replication, expression, and central metabolism, shared with other bacteria, are intolerant to transposon disruption. However, genes were identified that are important to that are either absent from or unimportant for and fitness when similarly tested. Further, 217 genes were identified that when challenged by sub-MIC antibiotic levels exhibited reduced tolerance to transposon disruption, including those previously shown to contribute to intrinsic resistance, and others not previously ascribed this role. is one of the few Gram-positive bacteria experimentally shown to possess a functional Entner-Doudoroff pathway for carbon metabolism, a pathway that contributes to stress tolerance in other microbes. Through functional genomics and network analysis we defined the unusual structure of this pathway in and assessed its importance. These approaches also identified toxin-antitoxin and related systems that are unique and active in Finally, we identified genes that are absent in the closest nonenterococcal relatives, the vagococci, and that contribute importantly to fitness with and without antibiotic selection, advancing an understanding of the unique biology of enterococci. Enterococci are leading causes of antibiotic-resistant infection transmitted in hospitals. The intrinsic hardiness of these organisms allows them to survive disinfection practices and then proliferate in the gastrointestinal tracts of antibiotic-treated patients. The objective of this study was to identify the underlying genetic basis for its unusual hardiness. Using a functional genomic approach, we identified traits and pathways of general importance for enterococcal survival and growth that distinguish them from closely related pathogens as well as ancestrally related species. We further identified unique traits that enable them to survive antibiotic challenge, revealing a large set of genes that contribute to intrinsic antibiotic resistance and a smaller set of uniquely important genes that are rare outside enterococci.

PURPOSE: To report a case series of patients with treatment-resistant Acanthamoeba keratitis (AK) using oral miltefosine, often as salvage therapy. DESIGN: Descriptive, retrospective multicenter case series. METHODS: We reviewed 15 patients with AK unresponsive to therapy who were subsequently given adjuvant systemic miltefosine between 2011 and 2017. The main outcome measures were resolution of infection, final visual acuity, tolerance of miltefosine, and clinical course of disease. RESULTS: All patients were treated with biguanides and/or diamidines or azoles without resolution of disease before starting miltefosine. Eleven of 15 patients retained count fingers or better vision, and all were considered disease free at last follow-up. Eleven of 15 patients had worsening inflammation with miltefosine, with 10 of them improving with steroids. Six patients received multiple courses of miltefosine. Most tolerated oral miltefosine well, with mild gastrointestinal symptoms as the most common systemic side effect. CONCLUSIONS: Oral miltefosine is a generally well-tolerated treatment adjuvant in patients with refractory AK. The clinician should be prepared for a steroid-responsive inflammatory response frequently encountered during the treatment course.

In a serosurvey of asymptomatic people from the general population recruited from a clinical laboratory in May 2020 in Addis Ababa, Ethiopia, three of 99 persons tested positive for SARS-CoV-2 IgG (3.0%, 95% binomial exact confidence interval: 0.6-8.6%). Taking into account pretest probability and the sampling scheme, the range of plausible population prevalence values was approximately 1.0-8.4%. These results suggest that a larger number of people have been infected than the counts detected by surveillance to date; nevertheless, the results suggest the large majority of the general population in Addis Ababa currently is susceptible to COVID-19.

The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has had an enormous impact on society worldwide, threatening the lives and livelihoods of many. The effects will continue to grow and worsen if economies begin to open without the proper precautions, including expanded diagnostic capabilities. To address this need for increased testing, we have developed a sensitive reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay compatible with current reagents, which utilizes a colorimetric readout in as little as 30 min. A rapid inactivation protocol capable of inactivating virions, as well as endogenous nucleases, was optimized to increase sensitivity and sample stability. This protocol, combined with the RT-LAMP assay, has a sensitivity of at least 50 viral RNA copies per microliter in a sample. To further increase the sensitivity, a purification protocol compatible with this inactivation method was developed. The inactivation and purification protocol, combined with the RT-LAMP assay, brings the sensitivity to at least 1 viral RNA copy per microliter in a sample. This simple inactivation and purification pipeline is inexpensive and compatible with other downstream RNA detection platforms and uses readily available reagents. It should increase the availability of SARS-CoV-2 testing as well as expand the settings in which this testing can be performed.

Enterococci are commensals that proliferated as animals crawled ashore hundreds of millions of years ago. They are also leading causes of multidrug-resistant hospital-acquired infections. While most studies are driven by clinical interest, comparatively little is known about enterococci in the wild or the effect of human activity on them. Pharmaceutical pollution and runoff from other human activities are encroaching widely into natural habitats. To assess their reach into remote habitats, we investigated the identity, genetic relatedness, and presence of specific traits among 172 enterococcal isolates from wild Magellanic penguins. Four enterococcal species, 18 lineage groups, and different colonization patterns were identified. One lineage, sequence type 475 (ST475), was isolated from three different penguins, making it of special interest. Its genome was compared to those of other sequence types (ST116 and ST242) recovered from Magellanic penguins, as well as to an existing phylogeny of isolated from diverse origins over the past 100 years. No penguin-derived strains were closely related to dominant clinical lineages. Most possessed intact CRISPR defenses, few mobile elements, and antibiotic resistances limited to those intrinsic to the species and lacked pathogenic features conveyed by mobile elements. Interestingly, plasmids were identified in penguin isolates that also had been reported for other marine mammals. Enterococci isolated from penguins showed limited anthropogenic impact, indicating that they are likely representative of those naturally circulating in the ecosystem inhabited by the penguins. These findings establish an important baseline for detecting the encroachment of human activity into remote planetary environments. Enterococci are host-associated microbes that have an unusually broad range, from the built hospital environment to the guts of insects and other animals in remote locations. Despite their occurrence in the guts of animals for hundreds of millions of years, we know little about the properties that confer this range or how anthropogenic activities may be introducing new selective forces. Magellanic penguins live at the periphery of human habitation. It was of interest to examine enterococci from these animals for the presence of antibiotic resistance and other markers reflective of anthropogenic selection. Diverse enterococcal lineages found discount the existence of a single well-adapted intrinsic penguin-specific species. Instead, they appear to be influenced by a carnivorous lifestyle and enterococci present in the coastal sea life consumed. These results indicate that currently, the penguin habitat remains relatively free of pollutants that select for adaptation to human-derived stressors.

PURPOSE: To provide an overview of the current knowledge on the Human Immunodeficiency Virus (HIV)-associated retinopathies. METHODS: A PubMed search was performed, using the key terms "HIV Retinopathy OR Retinitis" and "HIV AND Retinitis" to find manuscripts published within the last ten years. RESULTS: If left untreated, HIV infection causes a progressive immunodeficiency caused by depletion of CD4-positive T lymphocytes. Noninfectious HIV retinopathy, clinically manifested by cotton wool spots. Once the CD4 count drops below 200 c/μl, immunodeficiency creates a vulnerability for systemic opportunistic infections. Within the posterior segment of the eye, cytomegalovirus (CMV) retinitis has to be distinguished from infections with other members of the herpes virus family, as well as from toxoplasmosis, tuberculosis, and syphilis. Upon restoration of the immune system, immune recovery uveitis may manifest in one third of CMV affected eyes. CONCLUSION: Targeted antiviral treatment and secondary recurrence prophylaxis prevent vision loss of the retina prior to immune recovery.

Purpose: This systematic review aimed to determine currently reported clinical and prodromal ocular symptoms in patients with coronavirus disease 2019 (COVID-19). Methods: An online article search was performed in PubMed and EMBASE. Altogether 15 studies (retrospective, prospective, or case studies) involving 1533 patients with COVID-19, reporting on ocular symptoms, and with outcome data available were identified. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines were followed. Study-specific estimates (incidence rates of ocular symptoms in patients with COVID-19) of cases were combined using one-group meta-analysis in a random-effects model. Results: Of all included studies, 11.2% (95% confidence interval, 5.5-16.9; 78/1526 cases) reported ocular symptoms. The most common ocular finding was conjunctivitis. Prodromal ocular symptoms occurred in 12.5% (13/104 cases) of patients with COVID-19. Positive real-time polymerase chain reaction results were obtained for 16.7% (10/60 cases) of conjunctival samples and 0% (0/17 cases) of tear samples. Twelve ocular conjunctival swab samples tested positive for SARS-CoV-2. Ten cases were from subjects showing ocular symptoms (16.7%, 10/60 cases), and the remaining two cases were from subjects without ocular manifestation (1.8%, 2/113 cases). Limitations included the short study period, small sample size, findings were limited to the Asian population, only seven articles included ophthalmologic examination details, and there is currently no consensus on COVID-19 management. Conclusions: Ocular symptoms may occur in the presymptomatic phase as a prodromal symptom (12.5%, 13/104 cases), suggesting the possibility of viral transmission from the conjunctiva.

Since the new coronavirus known as 2019-nCoV (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) has widely spread in Wuhan, China, with severe pneumonia, scientists and physicians have made remarkable efforts to use various options such as monoclonal antibodies, peptides, vaccines, small-molecule drugs and interferon therapies to control, prevent or treatment infections of 2019-nCoV. However, no vaccine or drug has yet been confirmed to completely treat 2019-nCoV. In this review, we focus on the use of potential available small-molecule drug candidates for treating infections caused by 2019-nCoV.

PURPOSE: To report a case of microsporidia (Encephalitozoon hellem) keratoconjunctivitis acquired through avian transmission in an immunocompetent adult, diagnosed by metagenomic deep sequencing (MDS), and confirmed by polymerase chain reaction. METHODS: A case report. RESULTS: An 18-year-old woman was referred with unilateral keratoconjunctivitis unresponsive to topical and systemic therapy after exposure to birdcage debris. Slit-lamp examination of the left eye revealed a follicular papillary reaction of the palpebral conjunctiva and multiple corneal punctate epithelial opacities that stained minimally with fluorescein. In vivo confocal microscopy revealed bright double-walled structures and smaller bright round structures in the superficial epithelial debris and epithelium. Molecular diagnosis with MDS of E. hellem was confirmed by polymerase chain reaction. Clinical resolution and normalization of in vivo confocal microscopy was observed after a 6-week course of topical azithromycin. The patient elected a 3-week course of topical voriconazole 1% for definitive antimicrosporidial treatment, with no evidence of persistent infection 1 month later. CONCLUSIONS: Microsporidial (E. hellem) keratoconjunctivitis can occur through avian transmission in immunocompetent hosts. Topical azithromycin may be effective against this pathogen. MDS has utility in the diagnosis of atypical keratoconjunctivitis.