Determinants of Outcomes of Adenoviral Keratoconjunctivitis

Natural history of adenoviral conjunctivitis in a US-based population: Viral load, signs, and symptoms

PURPOSE

To report the clinical signs, symptoms, and viral clearance in individuals in the United States with adenoviral conjunctivitis (Ad-Cs).

METHODS

Individuals ≥ 18 years presenting within 4 days of symptoms of Ad-Cs who met eligibility criteria and tested positive with both point-of-care immunoassay antigen and quantitative polymerase chain reaction (qPCR) testing were enrolled. Patient-reported symptoms, clinician-graded signs, and qPCR viral titers were collected at baseline, days 1-2, 4 (days 3-5), 7 (days 6-10), 14 (days 11-17) and 21 (days 18-21).

RESULTS

There was no detectable viral titers by the day 14 visit in 6/8 patients. By day 21, there was no detectable viral titers in the 7 participants who completed the visit; however, signs and symptoms persisted including: blurry vision (5/7), discomfort (2/7) or redness (1/7). Masked clinicians also noted conjunctival redness (4/7), follicular conjunctivitis (4/7) and bulbar edema (3/7).

CONCLUSION

Many patient-reported symptoms and clinical signs persist after viral titers are no longer detectable by qPCR. Using clinical signs and symptoms to determine quarantine duration may result in patients being furloughed longer than the time that the patient is infectious.

Infectious eye disease in the 21st century-an overview

Infectious diseases affecting the eye often cause unilateral or asymmetric visual loss in children and people of working age. This group of conditions includes viral, bacterial, fungal and parasitic diseases, both common and rare presentations which, in aggregate, may account for a significant portion of the global visual burden. Diagnosis is frequently challenging even in specialist centres, and many disease presentations are highly regional. In an age of globalisation, an understanding of the various modes of transmission and the geographic distribution of infections can be instructive to clinicians. The impact of eye infections on global disability is currently not sufficiently captured in global prevalence studies on visual impairment and blindness, which focus on bilateral disease in the over-50s. Moreover, in many cases it is hard to differentiate between infectious and immune-mediated diseases. Since infectious eye diseases can be preventable and frequently affect younger people, we argue that in future prevalence studies they should be considered as a separate category, including estimates of disability-adjusted life years (DALY) as a measure of overall disease burden. Numbers of ocular infections are uniquely affected by outbreaks as well as endemic transmission, and their control frequently relies on collaborative partnerships that go well beyond the remit of ophthalmology, encompassing domains as various as vaccination, antibiotic development, individual healthcare, vector control, mass drug administration, food supplementation, environmental and food hygiene, epidemiological mapping, and many more. Moreover, the anticipated impacts of global warming, conflict, food poverty, urbanisation and environmental degradation are likely to magnify their importance. While remote telemedicine can be a useful aide in the diagnosis of these conditions in resource-poor areas, enhanced global reporting networks and artificial intelligence systems may ultimately be required for disease surveillance and monitoring.

Relation Between Corneal Dendritic Cell Density and Tear Film Stability in Patients with Epidemic Keratoconjunctivitis Associated Dry Eye

PURPOSE

To clarify the ocular surface features of patients with recent history of epidemic keratoconjunctivitis (EKC) and the relation between corneal dendritic cells (DCs) and ocular discomfort.

METHODS

Normal controls (NC) and dry eye (DE) patients without EKC were recruited. Patients with recent EKC history (onset >4 weeks, but <20 weeks) were recruited as EKC + DE group (with dry eye) or EKC-DE group (without dry eye). Ocular surface disease index (OSDI) questionnaire, tear film parameters including lipid layer thickness, first tear break-up time (fBUT), average tear break-up time (aBUT), tear meniscus height and Schirmer I test, meibomian gland parameters, and in vivo corneal confocal microscopy were evaluated.

RESULTS

50 subjects in the NC group, 83 patients in the DE group, 76 patients in the EKC + DE group, and 38 patients in the EKC-DE group were included. Compared with the NC, DE, and EKC-DE groups, the EKC + DE group represented higher OSDI, lid margin, and meibum score (p < 0.05). In the EKC + DE group, the tear volume (10.5 ± 3.7 mm) was significantly higher than in the DE group (8.1 ± 2.8 mm, p < 0.001). The DC density in the EKC + DE group (29.98 ± 15.38 cells/image) was significantly higher than in NC, DE, and EKC-DE groups (4.68 ± 4.05 cells/image) (p < 0.001). The DC density was positively correlated with OSDI, lid margin, and meibum score (all p < 0.01) while inversely correlated with fBUT, aBUT (all p < 0.001) in the EKC + DE group.

CONCLUSIONS

Corneal DC density significantly correlates to ocular discomfort and tear film instability in patients with recent EKC history who suffer from DE without aqueous tear deficiency.

Cyclopentenylcytosine (CPE-C): In Vitro and In Vivo Evaluation as an Antiviral against Adenoviral Ocular Infections

Adenoviruses are the major cause of ocular viral infections worldwide. Currently, there is no approved antiviral treatment for these eye infections. Cyclopentenylcytosine (CPE-C) is an antiviral that has demonstrated activity against more than 20 viruses. The goals of the current study were to determine the in vitro and in vivo antiviral activity of CPE-C as well as its ocular toxicity. Antiviral activity was evaluated in vitro using standard plaque reduction assays to determine the 50% effective concentrations (EC₅₀s) and in vivo in the Ad5/NZW rabbit ocular replication model. Ocular toxicity was determined in uninfected rabbit eyes following topical ocular application. The in vitro EC50s for CPE-C ranged from 0.03 to 0.059 μg/mL for nine adenovirus types that commonly infect the eye. Ocular toxicity testing determined CPE-C to be non-irritating or practically non-irritating by Draize scoring. In vivo, 3% CPE-C topically administered 4X or 2X daily for 7 days to adenovirus-infected eyes demonstrated effective antiviral activity compared with the negative control and comparable antiviral activity to the positive control, 0.5% cidofovir, topically administered twice daily for 7 days. We conclude CPE-C was relatively non-toxic to rabbit eyes and demonstrated potent anti-adenoviral activity in vitro and in vivo.

Apollo Rising: Acute Conjunctivitis Outbreak in India, 2022

Purpose

To identify pathogens associated with the 2022 conjunctivitis outbreak in Tamil Nadu, India.

Methods

This prospective study was conducted in November of 2022. Patients with presumed acute infectious conjunctivitis presenting to the Aravind Eye Clinic in Madurai, India were eligible. Anterior nares and conjunctival samples from participants were obtained and processed for metagenomic RNA deep sequencing (RNA-seq).

Results

Samples from 29 patients were sequenced. A pathogen was identified in 28/29 (97%) patients. Coxsackievirus A24v, a highly infectious RNA virus, was the predominant pathogen and detected in 23/29 patients. Human adenovirus D (HAdV-D), a DNA virus commonly associated with conjunctivitis outbreaks, was detected in the remaining patients (5/29). Hemorrhagic conjunctiva was documented in both HAdV-D and coxsackievirus A24v affected patients but was not the predominant clinical presentation. Phylogenetic analysis of coxsackievirus A24v revealed a recent divergence from the 2015 outbreak.

Conclusions

Coxsackievirus A24v and HAdV-D were co-circulating during the 2022 conjunctivitis outbreak in Tamil Nadu, India. Clinical findings were similar between patients with HAD-V and coxsackievirus A24v associated conjunctivitis. As high-throughput technologies become more readily accessible and cost-effective, unbiased pathogen surveillance may prove useful for outbreak surveillance and control.

Case Series: Unbiased Deep Sequencing Analysis of Acute Infectious Conjunctivitis in an Ambulatory Eye Center in Berkeley, California

SIGNIFICANCE

Acute infectious conjunctivitis poses significant challenges to eye care providers. It can be highly transmissible, and because etiology is often presumed, correct treatment and management can be difficult. This study uses unbiased deep sequencing to identify causative pathogens of infectious conjunctivitis, potentially allowing for improved approaches to diagnosis and management.

PURPOSES

This study aimed to identify associated pathogens of acute infectious conjunctivitis in a single ambulatory eye care center.

CASE REPORTS

This study included patients who presented to the University of California Berkeley eye center with signs and symptoms suggestive of infectious conjunctivitis. From December 2021 to July 2021, samples were collected from seven subjects (ages ranging from 18 to 38). Deep sequencing identified associated pathogens in five of seven samples, including human adenovirus D, Haemophilus influenzae , Chlamydia trachomatis , and human coronavirus 229E.

CONCLUSIONS

Unbiased deep sequencing identified some unexpected pathogens in subjects with acute infectious conjunctivitis. Human adenovirus D was recovered from only one patient in this series. Although all samples were obtained during the COVID-19 pandemic, only one case of human coronavirus 229E and no SARS-CoV-2 were identified.

The molecular epidemiology, genotyping, and clinical manifestation of prevalent adenovirus infection during the epidemic keratoconjunctivitis, South of Iran

PURPOSE

Adenoviral-mediated keratoconjunctivitis is among the emergency diseases of ophthalmology with long-term sequels. The role of adenovirus infection, ocular-related genotypes, and association with ocular symptoms need to be investigated for epidemiological as well as clinical purposes.

METHODS

The affected patients from two close keratoconjunctivitis epidemics were included in the study. The swab samples were taken from patients; the total DNA was extracted and then used as a template for in-house Real-time PCR. Besides, partial Hexon genes of 11 adenovirus positive samples were amplified and submitted to sanger sequencing. Moreover, they were finally evaluated by phylogenetic analysis.

RESULTS

Of 153 patients, 92 (60.1%) were males and 47 cases (30.7%) had a history of eye infection in the family or colleagues. Real-time PCR tests of 126 samples (82.4%) were positive for adenovirus, and all eleven cases that underwent sequencing analysis were determined to be group 8 (HAdV-D8). Adenovirus infection has a significant relationship with infection among family or colleagues (p = 0.048), membrane formation (p = 0.047), conjunctival bleeding (p = 0.046), tearing, and pain(p < 0.05).

CONCLUSIONS

The results indicated that Adenovirus is the major cause of keratoconjunctivitis, and HAdV-D8 was the most common genotype in the area. There were some clinical manifestations associated with Adenovirus infection of the conjunctiva.

Correlation of Adenoviral Titers with Severity of Adenoviral Conjunctivitis and Time to Viral Clearance for 21 Days

SIGNIFICANCE

This investigation reports the correlation of conjunctival viral titers in adenoviral conjunctivitis with patient-reported symptoms and clinician-graded signs for 21 days of follow-up.

PURPOSE

Adenoviral conjunctivitis is a highly contagious viral eye infection with significant morbidity and economic impact. This study investigates whether severity of signs and symptoms and time to viral clearance are correlated with conjunctival viral titers at baseline and during 21 days of follow-up.

METHODS

The Reducing Adenoviral Patient Infected Days study was a pilot study of the efficacy of a single in-office administration of ophthalmic 5% povidone-iodine. This article outlines longitudinal analyses after the primary outcome report. Of 212 participants screened, 28 participants with quantitative polymerase chain reaction-confirmed adenoviral conjunctivitis were randomized and had follow-up visits on days 1, 2, 4, 7, 14, and 21. At each visit, clinician-graded signs, participant-reported symptoms, and a conjunctival swab for quantitative polymerase chain reaction analysis were obtained. The correlation of viral titers with symptoms and signs was calculated: (1) cross-sectionally at each visit and (2) longitudinally for 21 days using a repeated-measures mixed-effects model.

RESULTS

Twenty-five of 28 participants had sufficient data for this report. Higher viral titers for 21 days were correlated with greater severity of symptoms (tearing, matting, and redness, r ≥ 0.70; P < .02) and greater severity of clinical signs (bulbar redness and serous discharge, r ≥ 0.60; P < .01). Eyes with highest baseline viral titers required longer time to viral clearance ( r = 0.59, P = .008). Signs and symptoms persisted in approximately half of the eyes even after viral clearance.

CONCLUSIONS

Higher conjunctival viral titers across 21 days were strongly correlated with more severe signs and symptoms and longer time to viral clearance. Our results also indicate that symptoms and signs can persist after viral clearance.

Establishing an accurate and sensitive in vitro drug screening system for human adenovirus infection with human corneal cells

Epidemic keratoconjunctivitis (EKC) is a hazardous and highly contagious disease, with the potential to cause epidemic outbreaks in hospitals and other community settings. There are currently no approved drugs for human adenovirus (HAdV), the causative agent of EKC. To establish a novel drug screening system for ocular HAdV infections, we employed CRL11516, a non-cancerous but immortalized human corneal epithelial cell line. Brincidoforvir and 3'-deoxy-3'-fluorothymidine inhibit replication of HAdV species C type 1 (C1), C2, E4, and C6 to the same extent. This alternative assay system may allow for the evaluation of anti-HAdV activity and cell cytotoxicity of compounds within 2 days and without the need of the rabbit eye infection model.

Molecular analysis of human adenoviral keratoconjunctivitis cases: Results of a 2-year survey

Objective: This study aimed to determine the adenovirus genotypes and their epidemiological features between January 2018 and November 2019, in Istanbul, Turkey. Material and Methods: Conjunctival swab samples were obtained from patients who were clinically diagnosed with keratoconjunctivitis. Samples were screened with an Adeno Detector kit (Rapid Pathogen Screening, RPS Inc., South Williamsport, PA). Nucleic acid extraction and amplification were performed with the ADENOVIRUS ELITe MGB® kit in the ELITe In Genius instrument (Elitech Group, Torino, Italy). For subtyping of the strains, sequencing primers targeted the ‘Hypervariable Region 7’ (HVR-7) of the hexon gene were used. DNA sequence analysis (n:72) was performed with ABI PRISM® 3100 Genetic Analyzer (Applied Biosystems, USA), and subtyping was done by BLAST analysis. Results: The median viral load in the samples (n: 77) was 7 log10 copies/mL (IQR: 4.5-7.4 log10 copies/mL). The clinical finding score was found to be significantly higher in the high viral load group (Adenovirus DNA≥6 Log 10 copies/mL) than in the low viral load group (Adenovirus DNA

Adenoviruses in medicine: innocuous pathogen, predator, or partner

The consequences of human adenovirus (HAdV) infections are generally mild. However, despite the perception that HAdVs are harmless, infections can cause severe disease in certain individuals, including newborns, the immunocompromised, and those with pre-existing conditions, including respiratory or cardiac disease. In addition, HAdV outbreaks remain relatively common events and the recent emergence of more pathogenic genomic variants of various genotypes has been well documented. Coupled with evidence of zoonotic transmission, interspecies recombination, and the lack of approved AdV antivirals or widely available vaccines, HAdVs remain a threat to public health. At the same time, the detailed understanding of AdV biology garnered over nearly 7 decades of study has made this group of viruses a molecular workhorse for vaccine and gene therapy applications.

Machine Learning Prediction of Adenovirus D8 Conjunctivitis Complications From Viral Whole-Genome Sequence

Objective

To obtain complete DNA sequences of adenoviral (AdV) D8 genome from patients with conjunctivitis and determine the relation of sequence variation to clinical outcomes.

Design

This study is a post hoc analysis of banked conjunctival swab samples from the BAYnovation Study, a previously conducted, randomized controlled clinical trial for AdV conjunctivitis.

Participants

Ninety-six patients with AdV D8-positive conjunctivitis who received placebo treatment in the BAYnovation Study were included in the study.

Methods

DNA from conjunctival swabs was purified and subjected to whole-genome viral DNA sequencing. Adenovirus D8 variants were identified and correlated with clinical outcomes, including 2 machine learning methods.

Main Outcome Measures

Viral DNA sequence and development of subepithelial infiltrates (SEIs) were the main outcome measures.

Results

From initial sequencing of 80 AdV D8-positive samples, full adenoviral genome reconstructions were obtained for 71. A total of 630 single-nucleotide variants were identified, including 156 missense mutations. Sequence clustering revealed 3 previously unappreciated viral clades within the AdV D8 type. The likelihood of SEI development differed significantly between clades, ranging from 83% for Clade 1 to 46% for Clade 3. Genome-wide analysis of viral single-nucleotide polymorphisms failed to identify single-gene determinants of outcome. Two machine learning models were independently trained to predict clinical outcome using polymorphic sequences. Both machine learning models correctly predicted development of SEI outcomes in a newly sequenced validation set of 16 cases (P = 1.5 × 10^-5). Prediction was dependent on ensemble groups of polymorphisms across multiple genes.

Conclusions

Adenovirus D8 has ≥ 3 prevalent molecular substrains, which differ in propensity to result in SEIs. Development of SEIs can be accurately predicted from knowledge of full viral sequence. These results suggest that development of SEIs in AdV D8 conjunctivitis is largely attributable to pathologic viral sequence variants within the D8 type and establishes machine learning paradigms as a powerful technique for understanding viral pathogenicity.

Diagnostic accuracy of clinical signs, symptoms and point-of-care testing for early adenoviral conjunctivitis

CLINICAL RELEVANCE

This study identifies key signs and symptoms of acute conjunctivitis, that when combined with a point-of-care test, can improve clinician accuracy of diagnosing adenoviral conjunctivitis.

BACKGROUND

Adenoviral conjunctivitis is a common ocular infection with the potential for high economic impact due to widespread outbreaks and subsequent furloughs from work and school. In this report, we describe clinical signs and participant-reported symptoms that most accurately identify polymerase chain reaction (PCR)-confirmed adenoviral conjunctivitis.

METHODS

Adults with 'red eye' symptoms of four days or less were enrolled. Participants rated 10 ocular symptoms from 0 (not bothersome) to 10 (very bothersome), and indicated the presence or absence of systemic flu-like symptoms. Clinicians determined the presence or absence of swollen lymph nodes and rated the severity of eight ocular signs using a 5-point scale. An immunoassay targeting adenovirus antigen was utilised for the point-of-care test, and conjunctival swab samples were obtained for subsequent adenovirus detection by PCR analyses. Univariate and multivariate logistic regression models were used to identify symptoms and signs associated with PCR-confirmed adenoviral conjunctivitis. The diagnostic accuracy of these clinical findings, and the potential benefit of incorporating point-of-care test results, was assessed by calculating areas under the receiver operating characteristic curves (AUC).

RESULTS

Clinician-rated bulbar conjunctival redness, participant-rated eyelid swelling and overall ocular discomfort had the best predictive value in the multivariate logistic regression model with an AUC of 0.83. The addition of the point-of-care test results to these three clinical sign/symptom scores improved diagnostic accuracy, increasing the AUC to 0.94.

CONCLUSIONS

Conjunctival redness severity and participant-reported eyelid swelling and overall discomfort, along with adenoviral point-of-care test results, were highly predictive in identifying individuals with PCR-confirmed adenoviral conjunctivitis. Improved diagnostic accuracy by clinicians at the initial presenting visit could prevent unnecessary work furloughs and facilitate earlier treatment decisions.

The relationship between clinical findings and viral load in Adenoviral Keratoconjunctivitis

The study aimed to evaluate the relationship between clinical findings and viral load in adenoviral keratoconjunctivitis (Ad-Kc). In this cross-sectional study, 30 eyes of 30 patients with Ad-Kc were enrolled. The real-time polymerase chain reaction was performed to detect and quantify adenovirus in all samples. The patient groups were divided into three subgroups according to baseline viral loads (<10⁷, 10⁷-10⁸, >10⁸ HAdV copies/ml). The follow-up duration, HAdV DNA copy number, treatment regimen, and detailed clinical findings including uncorrected visual acuity, eyelid edema, conjunctival hyperemia, chemosis, follicular reaction, corneal involvement, conjunctival pseudomembrane, and subepithelial infiltrates (SEIs) were recorded. The study showed that a high initial viral load was associated with the development of SEIs and pseudomembrane formation (p<0.05). Clinical findings and ocular complications of Ad-Kc were found similar in treatment groups at the final visit (p>0.05). Our results showed that a high initial viral load in Ad-Kc may be predictive of inflammatory sequelae. Determination of the initial viral load in Ad-Kc may be helpful to better understand the clinical course of the disease and prevent complications.

First Record of HAdV-D20 Among Keratoconjunctivitis Patients in Iraq

Background

Human Adenovirus species D (HAdV-D) was common human viral pathogen especially in eye infection, consists of several types of which HAdV-D8, -D19 and -D37 were common in eye infection. This study includes detection of HAdV-D types implicated in conjunctivitis based on L2 (Penton protein) gene similarity.

Methods

Conjunctival swabs were collected from Keratoconjunctivitis patients as eye infection related to adenovirus. Viral nucleic acids were extracted and specific primer pairs for HAdV-D L2 gene (encoding for penton base protein) was used to amplify the target gene and only positive samples were sent to sequencing.

Results

The results revealed that only 6 samples give positive results for L2 gene amplification and then sent for sequencing for L2 (penton protein) gene-based typing. The results show that 4 local isolates (S1, S2, S3, S6) were similar to HAdV-D8 and 2 local isolates (S4, S5) were similar to HAdV-D20. Also the results display that the HAdV-37, prominent HAdV-D type of human eye infection, may be variant of HAdV-D20 due to that six variation were seen in S4and S5 local isolates nucleotide sequence in relation to HAdV-D37: T>C at position 14364, A>C at position 14411, T>C at position 14427, C>A at position 14448, G>A at position 14540 and T>C at position 14617, leading to only 2 amino acid change in resulted penton protein: T (Threonine) instead of K (Lysine) at position 204 and N (Asparagine) instead of D (Aspartic acid) at position 247.

Conclusion

The current study concludes the possibility of implication of HAdV-D20 in eye infections especially conjunctivitis.

The in vitro Evaluation of the Activity of COVID-19 Antiviral Drugs Against Adenovirus

Purpose

Presently, there is no approved antiviral therapy for adenovirus (HAdV) ocular infections. During the COVID-19 pandemic, increased attention has been focused on antiviral treatments. Remdesivir, hydroxychloroquine, ivermectin, and umifenovir (Arbidol) have been touted as potential antiviral treatments for COVID-19. The goal of the current study was to determine whether these potential COVID-19 antivirals produce in vitro antiviral activity against a panel of ocular adenovirus types.

Methods

The 50% effective concentrations (EC₅₀) of remdesivir (REM), hydroxychloroquine (HCQ), ivermectin (IVM), umifenovir (UMF) and cidofovir (CDV) (positive antiviral control) were determined for the human HAdV types HAdV3, HAdV4, HAdV5, HAdV7a, HAdV8, HAdV19/64 and HAdV37 using standard plaque-reduction assays in A549 cells.

Results

The range of mean in vitro EC₅₀ concentrations for each antiviral across the range of HAdV types is as follows: The positive antiviral control, CDV, ranged from 0.47 to 9.62 µM; REM ranged from 0.21 to 11.27 µM; UMF ranged from 3.72 to 64.8 µM; IVR ranged from 2.60 to 201.3 µM; and HCQ was >10 µM for all Ad types because of toxicity to the A549 cells. REM produced lower EC₅₀ concentrations than CDV for 6 of 7 HAdV types. Potency increases with lower EC₅₀ concentrations.

Conclusion

REM demonstrated anti-adenovirus activity in a range similar to that demonstrated by cidofovir. UMF and IVR demonstrated larger ranges of antiviral activity than CDV and REM across the panel of HAdV types. The anti-adenovirus activity of HCQ could not be determined due to cytotoxicity. Further investigation of REM, UMF, and IVR as antivirals for adenovirus is indicated.

Molecular Diagnostics for Ocular Infectious Diseases: LXXVIII Edward Jackson Memorial Lecture

PURPOSE

To review the use of molecular diagnostic techniques in the management of ocular infectious disease.

DESIGN

Retrospective review.

METHODS

A combination of literature review and personal recollections are used.

RESULTS

Although the broad term molecular diagnostics may encompass techniques to identify pathogens via protein or metabolomic signatures, this review concentrates on detection of pathogen nucleic acid as an indicator of infection. The introduction of the polymerase chain reaction (PCR) in 1985 opened a new era in analysis of nucleic acids. This technique was soon applied to the detection of potential pathogen DNA and RNA, including viruses, bacteria, and parasites in infectious eye disease. Advances in PCR have allowed class-specific diagnostics (ie, pan-bacterial and pan-fungal), quantitation of pathogen DNA, and multiplexed testing. The Human Genome Project in the early 2000s greatly accelerated development of DNA sequencers, ushering in the era of "Next Generation Sequencing" and permitting pathogen-agnostic methods for the detection of potential infectious agents. Most recently, new technologies such as nanopore sequencing have reduced both cost and equipment requirements for whole-genome sequencing; when coupled with real-time sequence analysis methods, these methods offer the promise of true, real-time, point-of-service ocular infectious disease diagnostics.

CONCLUSIONS

Molecular methods for pathogen detection have greatly advanced the diagnosis of ocular infectious disease. Further methodologic advances will have a direct impact on the management of these conditions.

Human Adenovirus Subtype 21a Isolates From Children With Severe Lower Respiratory Illness in China

Human adenovirus type 21 (HAdV-21) is an important pathogen associated with acute respiratory infection (ARI), but it was rarely reported and characterized so far. In this study, 151 of 1,704 (8.9%) pediatric patients (≤14 years old) hospitalized with ARI in Guangzhou, China in 2019 were positive for HAdV which was the third most frequently detected pathogen. Two HAdV-21-positive patients presented with severe lower respiratory illness and had similar initial symptoms at onset of illness. Then two HAdV-21 strains were isolated and characterized. The two HAdV-21 strains were sequenced and classified as subtype 21a with genomes closely related to strain BB/201903 found in Bengbu, China in March 2019. Phylogenetic analysis for whole genome and major antigen proteins of global HAdV-21 strains showed that HAdV-21 could be classified into two branches, branch 1 including genotype 21p, branch 2 including all other strains dividing into genotype 21a and 21b. There was no significant difference in the plaque size, or the replication curves between the two HAdV-21a strains and the prototype strain HAdV-21p AV-1645. However, there were five highly variable regions (HVR1, HVR3, HVR4, HVR5, and HVR7) in the hexon protein that varied between two branches. Mice immunized with one branch strain showed 2-4-fold lower neutralizing antibody titers against another branch strain. In summary, this study firstly reported two HAdV-21a infections of children in China, characterized two isolates of HAdV-21a associated with severe lower respiratory illness; our results could be important for understanding the HAdV-21 epidemiology and pathogenic, and for developing HAdV-21 vaccine and drug.

Molecular and Clinical Characterization of Human Adenovirus E4-Associated Conjunctivitis

PURPOSE

To determine the characteristics of conjunctivitis associated with human adenovirus E4 (AdV E4).

METHODS

Samples and outcomes from 500 patients with conjunctivitis were obtained from the NVC-422 randomized controlled clinical trial comparing auriclosene to placebo. Molecular typing identified 36 cases associated with AdV E4. Signs and symptoms at presentation and at the day 18 endpoint were compared with the larger cohort of 262 subjects with conjunctivitis caused by due to AdV D8. Full viral genomes of 22 AdV E4 isolates were reconstructed.

RESULTS

AdV E4 was the most frequently identified adenoviral type in conjunctivitis cases from the United States. Signs and symptoms at presentation were comparable to those associated with AdV D8. Viral load at presentation was comparable between groups but resolution was more rapid in the AdV E4 group. Clinical signs were fully resolved by day 18 in 26 of 36 (72%) patients with AdV E4. Subepithelial infiltrates developed in 12 of 36 (33%) patients with AdV E4 compared with 98 of 215 (45%) patients with AdV D8 (P = .0001). One hundred twenty-four polymorphisms were observed among 22 whole viral genome sequences, which clustered into 3 clades. Patients in each clade developed subepithelial infiltrates. Neither single nucleotide polymorphism analysis nor machine learning approaches identified specific sequence features predictive of presenting signs or outcome.

CONCLUSIONS

AdV E4 conjunctivitis may be indistinguishable at presentation from AdV D8-associated disease. Resolution of viral load for AdV E4 appears more rapid than for AdV D8, and the risk for subepithelial infiltrates appears lower. Multiple substrains of AdV E4 are in circulation but all appeared equivalently pathogenic for conjunctivitis. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Human Adenovirus Species D Interactions with Corneal Stromal Cells

Notable among the many communicable agents known to infect the human cornea is the human adenovirus, with less than ten adenoviruses having corneal tropism out of more than 100 known types. The syndrome of epidemic keratoconjunctivitis (EKC), caused principally by human adenovirus, presents acutely with epithelial keratitis, and later with stromal keratitis that can be chronic and recurrent. In this review, we discuss the current state of knowledge regarding the molecular biology of adenovirus infection of corneal stromal cells, among which the fibroblast-like keratocyte is the most predominant, in order to elucidate basic pathophysiologic mechanisms of stromal keratitis in the human patient with EKC.

Association of Public Health Measures During the COVID-19 Pandemic With the Incidence of Infectious Conjunctivitis

Importance

Infectious conjunctivitis is highly transmissible and a public health concern. While mitigation strategies have been successful on a local level, population-wide decreases in spread are rare.

Objective

To evaluate whether internet search interest and emergency department visits for infectious conjunctivitis were associated with public health interventions adopted during the COVID-19 pandemic.

Design, Setting, and Participants

Internet search data from the US and emergency department data from a single academic center in the US were used in this study. Publicly available smartphone mobility data were temporally aligned to quantify social distancing. Internet search term trends for nonallergic conjunctivitis, corneal abrasions, and posterior vitreous detachments were obtained. Additionally, all patients who presented to a single emergency department from February 2015 to February 2021 were included in a review. Physician notes for emergency department visits at a single academic center with the same diagnoses were extracted. Causal inference was performed using a bayesian structural time-series model. Data were compared from before and after April 2020, when the US Centers for Disease Control and Prevention recommended members of the public wear masks, stay at least 6 feet from others who did not reside in the same home, avoid crowds, and quarantine if experiencing flulike symptoms or exposure to persons with COVID-19 symptoms.

Exposures

Symptoms of or interest in conjunctivitis in the context of the COVID-19 pandemic.

Main Outcome and Measures

The hypothesis was that there would be a decrease in internet search interest and emergency department visits for infectious conjunctivitis after the adaptation of public health measures targeted to curb COVID-19.

Results

A total of 1156 emergency department encounters with a diagnosis of conjunctivitis were noted from January 2015 to February 2021. Emergency department encounters for nonallergic conjunctivitis decreased by 37.3% (95% CI, -12.9% to -60.6%; P < .001). In contrast, encounters for corneal abrasion (1.1% [95% CI, -29.3% to 29.1%]; P = .47) and posterior vitreous detachments (7.9% [95% CI, -46.9% to 66.6%]; P = .39) remained stable after adjusting for total emergency department encounters. Search interest in conjunctivitis decreased by 34.2% (95% CI, -30.6% to -37.6%; P < .001) after widespread implementation of public health interventions to mitigate COVID-19.

Conclusions and Relevance

Public health interventions, such as social distancing, increased emphasis on hygiene, and travel restrictions during the COVID-19 pandemic, were associated with decreased search interest in nonallergic conjunctivitis and conjunctivitis-associated emergency department encounters. Mobility data may provide novel metrics of social distancing. These data provide evidence of a sustained population-wide decrease in infectious conjunctivitis.

Efficacy of a Single Administration of 5% Povidone-Iodine in the Treatment of Adenoviral Conjunctivitis

PURPOSE

To evaluate the safety and efficacy of a single, in-office administration of 5% povidone-iodine (PVP-I) compared to artificial tears (AT) for adenoviral conjunctivitis (Ad-Cs).

DESIGN

Double-masked pilot randomized trial.

METHODS

Patients presenting with presumed adenoviral conjunctivitis were screened at 9 U.S. clinics.

INCLUSION CRITERIA

≥18 years of age, symptoms ≤4 days, and a positive AdenoPlus test.

EXCLUSION CRITERIA

thyroid disease, iodine allergy, recent ocular surgery, and ocular findings inconsistent with early-stage Ad-Cs. Randomization was to a single administration of 5% PVP-I or AT in 1 eye and examinations on days 1-2, 4, 7, 14, and 21 with conjunctival swabs taken at each visit for quantitative polymerase chain reaction. Primary outcome was percent reduction from peak viral load. Secondary outcomes were improvement in clinical signs and symptoms.

RESULTS

Of 56 patients randomized, 28 had detectable viral titers at baseline. Day 4 posttreatment, viral titers in the 5% PVP-I and AT groups were 2.5% ± 2.7% and 14.4% ± 10.5% of peak, respectively (P = .020). Severity of participant-reported tearing, lid swelling, and redness as well as clinician-graded mucoid discharge, bulbar redness, and bulbar edema were lower in the 5% PVP-I group than AT group on day 4 (P < .05). After day 4, viral titers and severity of signs and symptoms decreased markedly in both groups and no differences between groups were detected.

CONCLUSIONS

Pilot data suggest a single, in-office administration of 5% PVP-I could reduce viral load and hasten improvement of clinical signs and symptoms in patients with Ad-Cs.

Predictive Accuracy and Densitometric Analysis of Point-of-Care Immunoassay for Adenoviral Conjunctivitis

Purpose

Accurate diagnosis of adenoviral conjunctivitis (Ad-Cs) is important for timely and appropriate patient management to reduce disease transmission. This study assessed the diagnostic accuracy of a commercially available point-of-care adenovirus immunoassay and determined whether its predictive accuracy is influenced by signal intensities of test result bands.

Methods

Point-of-care immunoassay (AdenoPlus) testing and quantitative polymerase chain reaction (qPCR) testing was performed on conjunctival swab samples obtained from eyes of 186 eligible adult participants with presumed infectious conjunctivitis and symptoms of ≤4 days. Masked observers assessed signal intensities of the immunoassay test and control bands using densitometry.

Results

Ad-Cs was confirmed by qPCR in 28 of the 56 eyes that tested positive on the AdenoPlus, a 50% positive predictive value (95% confidence interval [CI] = 36.9, 63.1). No adenovirus was detected by qPCR in 128 of 130 eyes that tested negative on AdenoPlus, a 98.5% negative predictive value (CI = 96.3, 100). Sensitivity and specificity were 93% (CI = 84.4, 100) and 82% (CI = 76.0, 88.1), respectively. Viral titers significantly correlated with ratio of test band signal intensities (R² = 0.32, P = 0.002). Higher positive predictive value was associated with higher densitometry ratios (receiver operating characteristic [ROC] area = 0.71; 95% CI = 0.59, 0.83).

Conclusions

Densitometric analyses suggest that the diagnostic accuracy of AdenoPlus is influenced by the signal intensity of the test result bands. Visual comparison of the test band intensities by clinicians could reduce the false positive rate of point-of-care immunoassays and aid in the diagnosis of viral infections.

Translational Relevance

Ratiometric densitometry of point-of-care immunoassays could aid clinicians’ decision making in diagnosing infectious diseases, including Ad-Cs.

Enteric adenovirus epidemiology from historical fecal samples in Brazil (1998-2005): Pre-rotavirus vaccine era

Human adenovirus (HAdV) is recognized as frequent cause of acute gastroenteritis and enteric viruses can be preserved in frozen stored feces for long periods of times. The purpose of the present study was to investigate enteric HAdV genotypic diversity in archival fecal specimens stored from 1998 to 2005 in order to understand the natural history of HAdV in diarrheal patients in Brazil before rotavirus vaccine introduction. A total of 3346 specimens were tested for HAdV using conventional PCR. Genotypes were identified by sequencing. HAdV was detected in 6.8% (228/3346). Positivity was higher in children ≤ 5 years and males (p < 0.05). HAdV was most frequently observed during winter and spring seasons (p < 0.05). HAdV-F41 was the most prevalent genotype (59.2%;135/228), followed by HAdV-F40 (16.2%;37/228), HAdV-C1 (5.2%;12/228), HAdV-C2 (5.2%;12/228), HAdV-C5 (3.1%;7/228), HAdV-A12 (1.3%;3/228), HAdV-E4 (0.9%;2/228), HAdV-B3 (0.9%;2/228) and HAdV-B21 (0.4%;1/228). In 7.6% (17/228) only species D could be defined. HAdV-E4 strains were phylogenetic analyzed and classified as lineage (a)-like PG II. HAdV prevalence remained stable in Brazilian population, regardless rotavirus vaccine introduction. The predominant HAdV genotypes detected did not change over time, highlighting a high diversity of circulating strains in the country throughout decades. Due to the historical lack of HAdV genotyping surveillance in Brazil, HAdV-E4 epidemiology is virtually unknown in the country. The present study contributed significantly to the understanding of the natural history of HAdV in diarrheal patients in Brazil. The acquired data are important for clinical diagnosis, particularly for studies investigating enteric viruses' prevalence and molecular epidemiology of archival clinical specimens.

Keep Eyes on COVID-19: Ophthalmic Symptoms and Potential Transmission of SARS-CoV-2 through the Oculus

In December 2019, a new coronavirus disease 2019 (COVID-19) emerged and rapidly spread globally, posing a worldwide health emergency. The pathogen causing this pandemic was identified as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It is well known that SARS-CoV-2 transmits via respiratory droplets and close contact with infected individuals or contaminated items. In addition to these two major transmission routes, other modes of transmission have not been confirmed. Considering that some COVID-19 patients have presented with ocular discomforts and positive SARS-CoV-2 RNA in ocular surfaces, as well as the discovery of the SARS-CoV-2 receptors, angiotensin-converting enzyme 2, and transmembrane protease, serine 2, in the oculus, the ocular surface is now thought to be a possible alternative route of SARS-CoV-2 transmission and a replication site. This review summarizes the evidence connecting COVID-19 with ocular tissues, ocular symptoms during SARS-CoV-2 infection, the potential role of the conjunctiva in SARS-CoV-2 transmission, and the physiopathological mechanisms. Appropriate precautions in ophthalmology departments, including innovative complete and effective patient management plans, protective personal equipment, hand hygiene, and strict personal distance intervals, are essential to effectively minimize the spread of SARS-CoV-2 and control the pandemic.

Efficacy of compartmentalization in controlling an adenovirus type 54 keratoconjunctivitis outbreak on Oki Island, Japan

PURPOSE

To analyze the epidemiologic characteristics of an outbreak of human adenovirus type 54 (HAdV-54) on Oki Island, Shimane Prefecture, Japan, in 2017 and to assess the effectiveness of a compartmentalization method in controlling the incidence and spread.

STUDY DESIGN

Retrospective cohort study.

METHODS

The infection was diagnosed in 136 individuals, and typing was confirmed by PCR and direct sequencing. The epidemiologic characteristics of the disease including the infection rate, incubation period, and basic reproductive number (R0), ie, number of cases directly infected by an infectious patient during the course of the disease, were investigated. The effectiveness of compartmentalization for infection control was determined by simulating the outbreak using the Susceptible-Exposed-Infectious-Recovered (SEIR) model.

RESULTS

The majority of the HAdV-54-infected individuals were the children of 3 nursery schools (A, B, and C) and their parents on Oki Island. The infection rates in the 3 schools were 13.2%, 16.9%, and 17.2%, respectively. The one class of school B without the index case was initially compartmentalized, and the infection rate in this compartment was 0%. The incubation period was calculated to be 9.3 ± 3.5 days, and the disease duration, 13.0 ± 5.4 days. The R0 was 1.43. Using these parameters, a SEIR model was constructed. The SEIR model well predicted the daily incidence of infection and indicated that the compartmentalization method provides effective reduction in the incidence of the infection, with much earlier control.

CONCLUSIONS

The compartmentalization method is effective to control HAdV-54 outbreaks.

Estimating the Incidence of Conjunctivitis by Comparing the Frequency of Google Search Terms With Clinical Data: Retrospective Study

Background

Infectious conjunctivitis is contagious and may lead to an outbreak. Prevention systems can help to avoid an outbreak.

Objective

We aimed to evaluate if Google search data on conjunctivitis and associated terms can be used to estimate the incidence and if the data can provide an estimation for outbreaks.

Methods

We obtained Google search data over 4 years for the German term for conjunctivitis (“Bindehautentzündung”) and 714 associated terms in 12 selected German cities and Germany as a whole using the Google AdWords Keyword Planner. The search volume from Freiburg was correlated with clinical data from the Freiburg emergency practice (Eye Center University of Freiburg).

Results

The search volume for the German term for conjunctivitis in Germany as a whole and in the 12 German cities showed a highly uniform seasonal pattern. Cross-correlation between the temporal search frequencies in Germany as a whole and the 12 selected cities was high without any lag. Cross-correlation of the search volume in Freiburg with the frequency of conjunctivitis (International Statistical Classification of Diseases and Related Health Problems [ICD] code group “H10.-”) from the centralized ophthalmologic emergency practice in Freiburg revealed a considerable temporal association, with the emergency practice lagging behind the frequency. Additionally, Pearson correlation between the count of patients per month and the count of searches per month in Freiburg was statistically significant (P=.04).

Conclusions

We observed a close correlation between the Google search volume for the signs and symptoms of conjunctivitis and the frequency of patients with a congruent diagnosis in the Freiburg region. Regional deviations from the nationwide average search volume may therefore indicate a regional outbreak of infectious conjunctivitis.

Adenovirus and the Cornea: More Than Meets the Eye

Human adenoviruses cause disease at multiple mucosal sites, including the respiratory, gastrointestinal, and genitourinary tracts, and are common agents of conjunctivitis. One site of infection that has received sparse attention is the cornea, a transparent tissue and the window of the eye. While most adenovirus infections are self-limited, corneal inflammation (keratitis) due to adenovirus can persist or recur for months to years after infection, leading to reduced vision, discomfort, and light sensitivity. Topical corticosteroids effectively suppress late adenovirus keratitis but are associated with vision-threatening side effects. In this short review, we summarize current knowledge on infection of the cornea by adenoviruses, including corneal epithelial cell receptors and determinants of corneal tropism. We briefly discuss mechanisms of stromal keratitis due to adenovirus infection, and review an emerging therapy to mitigate adenovirus corneal infections based on evolving knowledge of corneal epithelial receptor usage.

Unilateral upper eyelid eversion and kink associated with epidemic keratoconjunctivitis

Purpose

Upper lid eversion in adults from non-cicatricial causes is rare. We report a case of upper eyelid eversion secondary to epidemic keratoconjunctivitis (EKC).

Observations

A 37 year-old female presented with unilateral upper lid eversion. Known for left upper lid ptosis repair in childhood, the patient presented with seven-day history of severe bilateral conjunctivitis and eversion of her left upper lid three days prior. On exam, she had follicular conjunctivitis, punctate epithelial keratopathy with subepithelial infiltrates and membranes bilaterally, with an everted upper lid tarsus, and swollen and ulcerated palpebral conjunctiva. She received topical and oral prednisone to quickly reduce the inflammation, as well as moxifloxacin drops and lubrication. When the swelling subsided, the tarsus adopted a kinked and everted configuration, and was managed successfully with reversion, pressure patching, shielding and close follow-up.

Conclusions and Importamce

This is the first reported case of upper lid eversion secondary to EKC, likely due to sudden marked inflammation and edema of the posterior lamella caused by the adenoviral infection. This case was successfully managed with conservative therapy.

Current Trends in Tonometry and Tonometer Tip Disinfection

PRECIS

A survey among members of the American Glaucoma Society (AGS) and the American Optometry Association (AOA) on tonometer preference and tonometer disinfection indicates a shift to disposable tonometer tips compared with 1987.

PURPOSE

This survey's purpose was to determine how eye care providers responded to the 2008 Centers of Disease Control (CDC) tonometer disinfection guidelines, which recommend 10% hypochlorite (dilute bleach) for reusable tonometers. Tonometers measure the eye pressure when they touch the cornea, an essential part of the eye examination.

METHODS

AGS and AOA members were surveyed on tonometer preference, tonometer use, disinfection process, disinfectants, disinfection timing, and tonometer damage.

RESULTS

Survey responses from 79 AOA members and 197 AGS members are included. The Goldmann tonometer is considered most accurate (70, 89% AOA and 161, 82% AGS). It is preferred by 54 (70%) AOA and 193 (98%) AGS members. Many providers (165) use reusable Goldmann tonometer tips (77, 79% AOA, 88, 45% AGS), and most clean with 70% isopropyl alcohol wipes 59 (77%) AOA and 54 (61%) AGS. In summary, 126 of 276 participants (8, 10% AOA and 118, 60% AGS) follow CDC guidelines by using disposable tips (2 AOA and 109 AGS) or disinfecting reusable tips with 10% hypochlorite (6 AOA and 9 AGS).

CONCLUSIONS

The majority of AGS providers follow current CDC tonometer disinfection guidelines by shifting to disposable Goldmann tonometer tips. Only a minority of providers who use reusable tonometer tips disinfect with dilute bleach. Continued education on proper tonometer disinfection is critical to prevent eye-care related infection due to improper disinfection.

Pentacam corneal densitometry-guided treatment of adenoviral corneal subepithelial infiltrates: a comparative study between transepithelial phototherapeutic keratectomy and topical tacrolimus

PURPOSE

To compare the changes in the measurement of corneal densitometry and total corneal higher-order aberrations (HOAs) between topical tacrolimus and transepithelial phototherapeutic keratectomy (Te-PTK) in the treatment of adenoviral corneal subepithelial infiltrates (SEIs).

SUBJECT AND METHODS

This is an interventional prospective randomized study, including 63 eyes of 35 patients with symptomatic adenoviral corneal SEIs for at least 6 months. All patients underwent previous topical steroid therapy associated with unsatisfactory response and/or complications. Patients were assigned into three groups: (1) Te-PTK group: Te-PTK with MMC 0.02% was performed by a Technolas; Teneo excimer laser; (2) tacrolimus group: tacrolimus 0.03% ointment was applied once daily for 2-6 months; the endpoint of treatment was based on the improvement in the corneal densitometry, BCVA, and OSDI; and (3) control group: no intervention was done. BCVA, corneal densitometry, and total corneal higher-order aberrations (HOAs) evaluation using Pentacam HR were done at the baseline, 1 week, and then 1, 3, 6, and 12 months of the study.

RESULTS

The study population was similar between all groups. The mean follow-up was 12.75 ± 0.9 months. Bilateral corneal SEI was recorded at 80%. At 12-month follow-ups, the mean BCVA improved in both the Te-PTK and tacrolimus groups without significant changes in the control group. The mean corneal densitometry of the anterior, central, and total cornea decreased significantly in the Te-PTK and tacrolimus groups. HO-RMS and total RMS decreased significantly in the Te-PTK and tacrolimus groups. BCVA, corneal densitometry (anterior, central, and total cornea), and corneal aberrations (total coma, total trefoil, HO-RMS, and total RMS) values were significantly better for the Te-PTK and tacrolimus groups than the control group. There were no statistically significant differences between Te-PTK and tacrolimus groups in terms of BCVA, corneal densitometry, corneal HOA, and the persistence of corneal SEIs. The persistence of corneal SEIs was significantly lower in Te-PTK and tacrolimus groups than the control group.

CONCLUSION

Te-PTK and topical tacrolimus are effective methods for the treatment of adenoviral corneal SEIs improving visual acuity, corneal densitometry, and corneal HOA. The densitometry program of the Pentacam may give an objective guide for the treatment of adenoviral corneal SEIs.

TRIAL REGISTRATION

ClinicalTrials.gov ID is NCT04267991.

Characteristic of slow growth in cell culture of adenovirus type 54 causing nationwide outbreak epidemic keratoconjunctivitis in Japan

PURPOSE

To characterize the virological features of adenovirus type 54 (Ad54) causing nationwide outbreak of severe epidemic keratoconjunctivitis (EKC) in Japan, we comparatively analysed the viral propagation phenotype of Ad54 and other Ads: type 37 (Ad37), 64 (Ad64), and 5 (Ad5), in A549 cells quantitatively.

STUDY DESIGN

Laboratory investigation.

METHODS

We compared the growth rate of Ads using copy numbers and cytopathic effect observation during propagation in A549 cell lines. Expressions of mRNA of E1 gene were also calculated and compared. Phylogenetic analysis of the region, including putative promoter of E1 gene and E1 open reading frame (ORF), were performed.

RESULTS

Increases in viral loads, growth rate, and viral propagation were slower for Ad54 than for other Ads. The expression level of the E1 gene per infected cell was lower for Ad54 than for other Ad types on post-infection day 1. Phylogenetic analysis of the E1 gene putative promoter and ORF revealed Ad54 was the closest to Ad type 8.

CONCLUSION

The propagation of Ad54 in A549 is slow compared with Ad37, Ad64 and Ad5. This slow propagation could have been caused by slow genomic replication resulting from delayed viral entry or E1 transcription initiation. The EKC caused by Ad54 needs more attention because the slow propagation of Ad54 may contribute to prolonged disease duration.

Mystery eye: Human adenovirus and the enigma of epidemic keratoconjunctivitis

Known to occur in widespread outbreaks, epidemic keratoconjunctivitis (EKC) is a severe ocular surface infection with a strong historical association with human adenovirus (HAdV). While the conjunctival manifestations can vary from mild follicular conjunctivitis to hyper-acute, exudative conjunctivitis with formation of conjunctival membranes, EKC is distinct as the only form of adenovirus conjunctivitis in which the cornea is also involved, likely due to the specific corneal epithelial tropism of its causative viral agents. The initial development of a punctate or geographic epithelial keratitis may herald the later formation of stromal keratitis, and manifest as subepithelial infiltrates which often persist or recur for months to years after the acute infection has resolved. The chronic keratitis in EKC is associated with foreign body sensation, photophobia, glare, and reduced vision. However, over a century since the first clinical descriptions of EKC, and over 60 years since the first causative agent, human adenovirus type 8, was identified, our understanding of this disorder remains limited. This is underscored by a current lack of effective diagnostic tools and treatments. In part, stasis in our knowledge base has been encouraged by the continued acceptance, and indeed propagation of, inaccurate paradigms pertaining to disease etiology and pathogenesis, particularly with regard to mechanisms of innate and adaptive immunity within the cornea. Owing to its often persistent and medically refractory visual sequelae, reconsideration of key aspects of EKC disease biology is warranted to identify new treatment targets to curb its worldwide socioeconomic burden.

Genomic foundations of evolution and ocular pathogenesis in human adenovirus species D

Human adenovirus commonly causes infections of respiratory, gastrointestinal, genitourinary, and ocular surface mucosae. Although most adenovirus eye infections are mild and self-limited, specific viruses within human adenovirus species D are associated with epidemic keratoconjunctivitis (EKC), a severe and highly contagious ocular surface infection, which can lead to chronic and/or recurrent, visually disabling keratitis. In this review, we discuss the links between adenovirus ontogeny, genomics, immune responses, and corneal pathogenesis, for those viruses that cause EKC.

Disparate Entry of Adenoviruses Dictates Differential Innate Immune Responses on the Ocular Surface

Human adenovirus infection of the ocular surface is associated with severe keratoconjunctivitis and the formation of subepithelial corneal infiltrates, which may persist and impair vision for months to years following infection. Long term pathology persists well beyond the resolution of viral replication, indicating that the prolonged immune response is not virus-mediated. However, it is not clear how these responses are sustained or even initiated following infection. This review discusses recent work from our laboratory and others which demonstrates different entry pathways specific to both adenovirus and cell type. These findings suggest that adenoviruses may stimulate specific pattern recognition receptors in an entry/trafficking-dependent manner, leading to distinct immune responses dependent on the virus/cell type combination. Additional work is needed to understand the specific connections between adenoviral entry and the stimulation of innate immune responses by the various cell types present on the ocular surface.

Unbiased Pathogen Detection and Host Gene Profiling for Conjunctivitis

PURPOSE

The etiology of conjunctivitis is often misdiagnosed. An ideal diagnostic test would identify all possible infectious causes. In this study, we apply unbiased metagenomic RNA deep sequencing (MDS) to identify pathogens causing conjunctivitis.

DESIGN

Molecular study of prospectively collected conjunctival swabs from patients with presumed infectious conjunctivitis.

PARTICIPANTS

Patients with presumed acute infectious conjunctivitis.

METHODS

Conjunctival swabs were collected from patients presenting with acute conjunctivitis. Swabs were processed for MDS. Pathogens were identified using a rapid computational pipeline to analyze the nonhost sequences obtained from MDS. Differential gene expression analysis was performed to evaluate for host transcriptome signatures for infectious types. Clinical samples were deidentified, and laboratory personnel handling the samples and interpreting the data were masked.

MAIN OUTCOME MEASURES

Pathogens and differential transcripts identified by MDS.

RESULTS

Metagenomic RNA deep sequencing detected pathogens in 86% (12/14) of the patients tested. Swabs from 10 of 14 patients were positive for human adenovirus (HAdV) while swabs from 2 of 14 patients were positive for Vittaforma corneae (a parasitic fungal species of the microsporidia group). Samples positive for HAdV by RNA-seq were independently verified in a CLIA-certified laboratory. Pathogen-directed polymerase chain reaction confirmed the presence of V. corneae genome in the samples positive by RNA-seq. Local host transcriptome analysis identified 12 differentially expressed genes that provided distinct expression signatures for patients infected with HAdV compared with V. corneae.

CONCLUSIONS

Metagenomic RNA deep sequencing can reliably detect and quantify common and rare pathogens causing conjunctivitis, and identify strains. The unbiased nature of metagenomic RNA deep sequencing allowed an expanded scope of pathogen detection, including fungal species not commonly associated with acute conjunctivitis. In addition, the identification of infection type-specific local host transcriptome signatures may allow for pathogen detection even when the pathogen load is too low for direct identification.

Benzalkonium Chloride Demonstrates Concentration-Dependent Antiviral Activity Against Adenovirus In Vitro

Purpose: Adenoviral conjunctivitis is the most common cause of conjunctivitis worldwide with no approved antiviral treatment. Benzalkonium chloride (BAK) is a common preservative in ophthalmic medications and is the active ingredient in some skin disinfectants and hand sanitizers. BAK is known to be effective in killing bacteria and enveloped viruses; however, its activity against ocular types of nonenveloped adenoviruses (Ads) is unknown. The goal was to determine whether BAK is an effective antiviral agent against common human ocular types of adenovirus in vitro. Methods: The direct inactivating activity of BAK was determined by incubating several human adenovirus types with BAK concentrations of 0.001%, 0.003%, 0.005%, 0.01%, 0.1%, and 0% for 1 h at 33°C. Resulting adenovirus titers were determined after treatment. Decreases in titers of ≥3 Log₁₀ were considered virucidal, while decreases in titers of <1 Log₁₀ were considered ineffective. Results: BAK 0.1% was virucidal for Ad3, Ad5, Ad7a, Ad19/64, and Ad37, while it reduced titers >1 Log₁₀, but <3 Log₁₀ for Ad4 and Ad8. Decreases in titers >1 Log₁₀ were demonstrated for BAK 0.003%, 0.005%, and 0.01% for Ad5 only. Decreases in titers for the other adenovirus types for those concentrations were ≤0.53 Log₁₀. 0.001% BAK produced minimal decreases in titers for all types. Conclusions: BAK, at 0.01% or less was not consistently effective as an antiviral against adenovirus, but higher concentrations, such as 0.1%, should be further investigated as a possible topical treatment for adenoviral ocular infections, providing ocular toxicity is not an issue.

Evaluation of a silver-amplified immunochromatography kit for adenoviral conjunctivitis

OBJECTIVE

To compare and evaluate the sensitivity of a newly developed silver-amplified immunochromatography (SAI) kit with various immunochromatography (IC) kits for adenoviruses based on the detection limit (copies/test).

METHODS

An SAI kit and four ophthalmic IC kits were evaluated. The detection limits of the five kits were determined using the limiting dilution method for 15 conjunctivitis-associated adenoviruses (adenoviruses 1, 2, 3, 4, 5, 7, 8, 11, 37, 53, 54, 56, 64, 81, and 85). The detection limits were presented as numerical values as determined by real-time polymerase chain reaction (PCR).

RESULTS

The detection limit of the SAI kit for the adenovirus types ranged from 1.0 × 10³ -5.0 × 10 ⁴  copies/test (geometric mean, 4.7 × 10 ³ ). SAI had a 10-250-fold lower detection limit than the four IC kits for all adenoviruses studied. There were also differences in detection limits among the adenovirus types for each kit.

DISCUSSION

The detection limit of the SAI kit was drastically reduced because the silver-amplification reaction increased the color development sensitivity. The results revealed the high sensitivity of SAI for detecting adenoviruses and suggested its usefulness for conjunctivitis examination.