Mystery eye: Human adenovirus and the enigma of epidemic keratoconjunctivitis

Vitamin D and tear fluid cytokines in predicting outcomes in viral conjunctivitis - A new outlook

PURPOSE

To determine the association between systemic vitamin D (VD) and immunoglobulin E (IgE) levels with severity and ocular surface inflammatory profile in patients with epidemic keratoconjunctivitis (EKC).

METHODS

210 eyes of 105 patients who were clinically diagnosed with EKC were included in the study. The levels of serum VD and serum IgE were measured. Schirmer's strip-based tear fluid (TF) was used to determine levels of IL-1β, IL-6, IL-10, IL-17A, TNFα, MMP9, sICAM1, and VEGF-A in a subset of patients.

RESULTS

Levels of VD were significantly ( P < 0.05) lower and levels of IgE were significantly higher in patients with severe forms of conjunctivitis compared to those with nonsevere forms. Majority of the patients with severe forms of the disease exhibited VD deficiency and/or abnormally high IgE. A negative correlation (r = -0.682; P < 0.0001) was observed between VD and IgE levels. TF levels of IL-1β, IL-6, TNFα, and sICAM1 were significantly higher in eyes with severe forms of conjunctivitis compared to those with nonsevere forms and controls. These factors showed a positive correlation ( P < 0.05) with IgE levels and a negative correlation ( P < 0.05) with VD levels.

CONCLUSION

Patients with severe forms of EKC exhibited VD deficiency and higher levels of IgE. Increased TF inflammatory factors demonstrated a disease causal relationship with VD and IgE. Hence, restoring the altered levels of VD and IgE to normal range would be pivotal in the prevention and management of severe conjunctivitis.

The Immune System-A Double-Edged Sword for Adenovirus-Based Therapies

Pathogenic adenovirus (Ad) infections are widespread but typically mild and transient, except in the immunocompromised. As vectors for gene therapy, vaccine, and oncology applications, Ad-based platforms offer advantages, including ease of genetic manipulation, scale of production, and well-established safety profiles, making them attractive tools for therapeutic development. However, the immune system often poses a significant challenge that must be overcome for adenovirus-based therapies to be truly efficacious. Both pre-existing anti-Ad immunity in the population as well as the rapid development of an immune response against engineered adenoviral vectors can have detrimental effects on the downstream impact of an adenovirus-based therapeutic. This review focuses on the different challenges posed, including pre-existing natural immunity and anti-vector immunity induced by a therapeutic, in the context of innate and adaptive immune responses. We summarise different approaches developed with the aim of tackling these problems, as well as their outcomes and potential future applications.

An outbreak of acute hemorrhagic conjunctivitis due to Coxsackievirus A24 in a residential school, Naharlagun, Arunachal Pradesh: July 2023

PURPOSE

An acute conjunctivitis outbreak was investigated at a residential school in Naharlagun, Arunachal Pradesh, Northeast India, in July 2023. We aimed to identify the etiological agent and assess any complications in follow-up cases.

METHODS

We used a structured questionnaire to record clinical findings and followed up with cases one-month post-conjunctivitis. Sixty-one cases were examined and eight conjunctival and oropharyngeal swab samples were collected after obtaining informed consent from guardians/school authorities. We screened for 33 viral and bacterial pathogens using an IVD-approved Real-time PCR assay. Further, the samples were subjected to nucleic acid sequencing.

RESULTS

Among 465 screened students and staff, 80 individuals (approximately 17.2%) showed acute hemorrhagic conjunctivitis symptoms among which 61 cases were available for clinical examination. We identified the Enterovirus responsible by targeted sequencing using next-generation sequencing. The etiological agent was found to be Coxsackievirus A24, a member of Enterovirus C, in seven out of eight samples subjected to sequencing. Common symptoms included conjunctival hyperemia and foreign body sensation (100%), bilateral eye involvement (73.8%), eye pain (70%), watery discharge (49.2%), and eyelid swelling (38%). Only 6.5% had purulent discharge. Most cases resolved within 5-6 days, with only 9.8% reporting abdominal symptoms post-conjunctivitis. No serious complications occurred within one month. Throat swabs aided in diagnosing enterovirus infections alongside eye swabs.

CONCLUSIONS

The outbreak of acute conjunctivitis was caused by Coxsackievirus A24, a member of Enterovirus C. Cases resolved spontaneously within 6-7 days, with no severe complications. Collecting oropharyngeal swabs alongside conjunctival swabs could improve enteroviral conjunctivitis diagnosis.

Epidemiology of Keratoconjunctivitis Across India from 2017 to 2019: A Multicentric Hospital-Based Study

PURPOSE

Conjunctivitis is one of the most common ocular conditions in clinical practice. Human adenoviruses have been the common causative agents known to cause epidemic kerato-conjunctivitis (EKC) in India from 1996 to 2019 with a positivity range of 13.8%-65.2%. The current study was initiated to throw light on the distribution of keratoconjunctivitis causing agents across India covering a span of 3 years.

METHODS

A total of 709 swabs were collected from patients in viral transport medium (VTM), and real-time PCR was done to identify agents including Adenovirus (HAdV), Enterovirus, HSV, and Chlamydia.

RESULTS

47.8% of the samples were positive for HAdV followed by HSV (3.4%), Enterovirus (2.7%), and Chlamydia (0.6%). Overall, 386 people (54.4%) tested positive for one of these infections, with Chandigarh (88.4%) and Port Blair (71.7%) showing higher positivity rate. Pre-auricular lymphadenopathy and follicles were significantly associated with increased risk of conjunctivitis.

CONCLUSION

Epidemiology of keratoconjunctivitis in the current study revealed HAdV to be predominant causative agent. Knowledge gained in such epidemiological studies guide us in outbreak expectations, limit antibiotic over-prescription, and enhance disease prevention.

Phylogenetic and Recombination Analysis of Clinical Vitreous Humor-Derived Adenovirus Isolates Reveals Discordance Between Serotype and Phylogeny

Purpose

To sequence, identify, and perform phylogenetic and recombination analysis on three clinical adenovirus samples taken from the vitreous humor at the Bascom Palmer Eye Institute.

Methods

The PacBio Sequel II was used to sequence the genomes of the three clinical adenovirus isolates. To identify the isolates, a full genome-based multiple sequence alignment (MSA) of 722 mastadenoviruses was generated using multiple alignment using fast Fourier transform (MAFFT). MAFFT was also used to generate genome-based human adenovirus B (HAdV-B) MSAs, as well as HAdV-B fiber, hexon, and penton protein-based MSAs. To examine recombination within HAdV-B, RF-Net 2 and Bootscan software programs were used.

Results

In the course of classifying three new atypical ocular adenovirus samples, taken from the vitreous humor, we found that all three isolates were HAdV-B species. The three Bascom Palmer HAdV-B genomes were then combined with over 300 HAdV-B genome sequences, including nine ocular HAdV-B genome sequences. Attempts to categorize the penton, hexon, and fiber serotypes using phylogeny of the three Bascom Palmer samples were inconclusive due to incongruence between serotype and phylogeny in the dataset. Recombination analysis using a subset of HAdV-B strains to generate a hybridization network detected recombination between nonhuman primate and human-derived strains, recombination between one HAdV-B strain and the HAdV-E outgroup, and limited recombination between the B1 and B2 clades.

Conclusions

The discordance between serotype and phylogeny detected in this study suggests that the current classification system does not accurately describe the natural history and phylogenetic relationships among adenoviruses.

Steroids in the Management of Infectious Keratitis

PURPOSE

To summarize the evidence base on the use of topical corticosteroids for infectious keratitis.

METHODS

Narrative review.

RESULTS

Infectious keratitis is a painful condition that often results in visually significant corneal stromal scarring, even when antimicrobial therapy is successful. Corticosteroids may reduce inflammation and subsequent scar formation and while relieving the acute ocular pain associated with a corneal ulcer. However, corticosteroids also reduce the host immune response, which could hinder the ability to clear infection. The safety and effectiveness of corticosteroids depends to a large part on the efficacy of the antimicrobials being used to treat the underlying infection. Randomized trials have found that corticosteroids are safe and effective for herpetic keratitis when used with appropriate antiviral therapy, and are safe for bacterial keratitis when used with broad spectrum topical antibiotics. The effectiveness of corticosteroids for bacterial keratitis has not been shown conclusively, although more advanced bacterial corneal ulcers may do better with corticosteroids. No randomized trials have assessed the safety and effectiveness of steroids for fungal or acanthamoeba keratitis. Animal studies suggest corticosteroids may be harmful in fungal keratitis, and observational human studies have found that steroids are harmful for fungal and acanthamoeba keratitis when started prior to anti-amoebics.

CONCLUSIONS

Topical corticosteroids, when used as an adjunct to antimicrobial therapy, may be beneficial if the antimicrobial being used can effectively clear or suppress the infection, such as in bacterial and herpetic keratitis. Randomized trials would be helpful to further delineate the role of corticosteroids for infectious keratitis.

Broad sialic acid usage amongst species D human adenovirus

Human adenoviruses (HAdV) are widespread pathogens causing usually mild infections. The Species D (HAdV-D) cause gastrointestinal tract infections and epidemic keratoconjunctivitis (EKC). Despite being significant pathogens, knowledge around HAdV-D mechanism of cell infection is lacking. Sialic acid (SA) usage has been proposed as a cell infection mechanism for EKC causing HAdV-D. Here we highlight an important role for SA engagement by many HAdV-D. We provide apo state crystal structures of 7 previously undetermined HAdV-D fiber-knob proteins, and structures of HAdV-D25, D29, D30 and D53 fiber-knob proteins in complex with SA. Biologically, we demonstrate that removal of cell surface SA reduced infectivity of HAdV-C5 vectors pseudotyped with HAdV-D fiber-knob proteins, whilst engagement of the classical HAdV receptor CAR was variable. Our data indicates variable usage of SA and CAR across HAdV-D. Better defining these interactions will enable improved development of antivirals and engineering of the viruses into refined therapeutic vectors.

Identification of BST2 as a conjunctival epithelial stem/progenitor cell marker

The conjunctival epithelium consists of conjunctival epithelial cells and goblet cells derived from conjunctival epithelial stem/progenitor cells. However, the source of these cells is not well known because no specific markers for conjunctival epithelial stem/progenitor cells have been discovered. Therefore, to identify conjunctival epithelial stem/progenitor cell markers, we performed single-cell RNA sequencing of a conjunctival epithelial cell population derived from human-induced pluripotent stem cells (hiPSCs). The following conjunctival epithelial markers were identified: BST2, SLC2A3, AGR2, TMEM54, OLR1, and TRIM29. Notably, BST2 was strongly positive in the basal conjunctival epithelium, which is thought to be rich in stem/progenitor cells. Moreover, BST2 was able to sort conjunctival epithelial stem/progenitor cells from hiPSC-derived ocular surface epithelial cell populations. BST2-positive cells were highly proliferative and capable of successfully generating conjunctival epithelial sheets containing goblet cells. In conclusion, BST2 has been identified as a specific marker of conjunctival epithelial stem/progenitor cells.

Viral Conjunctivitis

Viruses account for 80% of all cases of acute conjunctivitis and adenovirus; enterovirus and herpes virus are the common causative agents. In general, viral conjunctivitis spreads easily. Therefore, to control the spread, it is crucial to quickly diagnose illnesses, strictly implement hand washing laws, and sanitize surfaces. Swelling of the lid margin and ciliary injection are subjective symptoms, and eye discharge is frequently serofibrinous. Preauricular lymph node swelling can occasionally occur. Approximately 80% of cases of viral conjunctivitis are caused by adenoviruses. Adenoviral conjunctivitis may become a big global concern and may cause a pandemic. Diagnosis of herpes simplex viral conjunctivitis is crucial for using corticosteroid eye solution as a treatment for adenovirus conjunctivitis. Although specific treatments are not always accessible, early diagnosis of viral conjunctivitis may help to alleviate short-term symptoms and avoid long-term consequences.

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.

COVID-19 and the eye: Systemic and laboratory risk factors for retinopathy and detection of tear film SARS-CoV-2 RNA with a triplex RT-PCR assay

Purpose

To assess hospitalized COVID-19 inpatients for the prevalence of retinopathy and tear film SARS-CoV-2 RNA, and associated risk factors for their detection.

Methods

Hospitalized COVID-19 patients underwent dilated ophthalmic examination and fundus photography. Conjunctival swabs were assessed for SARS-CoV-2 RT-PCR via a triple target assay. We assessed the relationships of retinopathy with clinical outcomes, systemic risk factors and laboratory data.

Results

The median age was 59.5 years and 29 (48%) were female. Retinopathy associated with COVID-19 was observed in 12 of 60 patients (20%). The median age of patients with COVID-19 retinopathy was 51.5 compared to 62.5 years in individuals without retinopathy (p = 0.01). Median BMI was 34.3 in patients with retinopathy versus 30.9 in those without retinopathy (p = 0.04). Fifteen of 60 patients (25%) tested SARS-CoV-2 RNA-positive in their tear film without a relationship with timing of illness and hospitalization. The N2 gene was particularly sensitive with 18 of 19 eyes (94.7%) showing N2-positivity, including 2 patients with alpha variant-positivity (B.1.1.7).

Conclusion

Retinopathy was observed in 20% of patients hospitalized for COVID-19. Patients with retinopathy were more likely to be younger and have higher BMI than hospitalized patients without retinopathy. Tear film SARS-CoV-2 RNA was detected in 25% of patients. The relationship of obesity and age with retinopathy requires further investigation.

Topical Pharmacologic Interventions Versus Active Control, Placebo, or No Treatment for Epidemic Keratoconjunctivitis: Findings From a Cochrane Systematic Review

PURPOSE

To summarize key findings from a Cochrane systematic review of the effectiveness and safety of topical pharmacologic interventions compared with active control or placebo for epidemic keratoconjunctivitis (EKC).

DESIGN

Systematic review.

METHODS

We included randomized controlled trials that compared antiseptic agents, virustatic agents, or immune-modulating topical therapies with placebo or an active control. We adhered to Cochrane methods for trial selection, data extraction, risk of bias evaluation, and data synthesis.

RESULTS

Ten randomized controlled trials with 892 participants with acute or chronic EKC were included. Eight trials compared interventions with artificial tears or saline (n = 4) or with steroids (n = 4); two 3-arm trials contributed data to both comparisons. Estimates suggested that compared with tears, after povidone-iodine (PVP-I) alone (2 studies, 409 participants) more participants with acute EKC had resolution of symptoms (risk ratio [RR] 1.15 [95% confidence interval {CI} 1.07-1.24]) and signs (RR 3.19 [95% CI 2.29-4.45]) within 10 days. In 2 trials comparing treatments with steroid alone or steroid with levofloxacin, fewer eyes treated with PVP-I or polyvinyl alcohol iodine (PVA-I) plus steroid developed subepithelial infiltrates within 21 days (RR 0.08 [95% CI 0.01-0.55]; 69 eyes). No treatment was shown to improve resolution of infiltrates.

CONCLUSIONS

Low- to very low-level certainty of evidence suggested that PVP-I or PVA-I with steroid may confer some benefit in acute EKC, but imprecision from small sample sizes, the potential risk of bias from inadequate reporting or trial design, and variability in participant selection, outcome measurement, and reporting limit the amount and quality of evidence.

Eye Infection with SARS-CoV-2 as a Route to Systemic Immunization?

Infectious diseases of the conjunctiva and cornea usually leave behind both broad local and systemic immunity. Case reports of SARS-CoV-2-positive conjunctivitis with subsequent systemic immunity suggest a new route of immunization preventing the primary infection of the airways. Material and Methods: A total of 24 Syrian field hamsters were treated. In systematic animal experiments, we infected the eyes of n = 8 animals (group 1) and the airways of another n = 8 animals (group 2) with SARS-CoV-2 (Wuhan type); n = 8 hamsters served as controls (group 3). The weight development of the animals was recorded. After two weeks of observation of disease symptoms, all animals were re-exposed to SARS-CoV-2 in the respiratory tract (challenge) to determine whether immunity to the virus had been achieved. Results: The epi-ocularly infected animals (group 1) showed no clinically visible disease during the ocular infection phase. At most, there was a slightly reduced weight gain compared to the control group (group 3), while the respiratory infected animals (group 2) all lost weight, became lethargic, and slowly recovered after two weeks. After the challenge, none of the animals in groups 1 and 2 became ill again. The animals in the negative control (group 3) all became ill. Cytotoxic antibodies were detectable in the blood of the infected groups before and after challenge, with higher titers in the epi-ocularly infected animals. Conclusion: By epi-ocular infection with SARS-CoV-2, the development of systemic immunity with formation of cytotoxic antibodies without severe general disease could be observed in the experimental animals, which did not induce any more disease upon a second infection in the respiratory tract. Therefore, it can be concluded that a purely epi-ocular infection with SARS-CoV2 only induces a weak disease pattern followed by systemic immunity.

Rapid detection of viruses: Based on silver nanoparticles modified with bromine ions and acetonitrile

Nearly 200 million people have been diagnosed with COVID-19 since the outbreak in 2019, and this disease has claimed more than 5 million lives worldwide. Currently, researchers are focusing on vaccine development and the search for an effective strategy to control the infection source. This work designed a detection platform based on Surface-Enhanced Raman Spectroscopy (SERS) by introducing acetonitrile and calcium ions into the silver nanoparticle reinforced substrate system to realize the rapid detection of novel coronavirus. Acetonitrile may amplify the calcium-induced hot spots of silver nanoparticles and significantly enhanced the stability of silver nanoparticles. It also elicited highly sensitive SERS signals of the virus. This approach allowed us to capture the characteristic SERS signals of SARS-CoV-2, Human Adenovirus 3, and H1N1 influenza virus molecules at a concentration of 100 copies/test (PFU/test) with upstanding reproduction and signal-to-noise ratio. Machine learning recognition technology was employed to qualitatively distinguish the three virus molecules with 1000 groups of spectra of each virus. Acetonitrile is a potent internal marker in regulating the signal intensity of virus molecules in saliva and serum. Thus, we used the SERS peak intensity to quantify the virus content in saliva and serum. The results demonstrated a satisfactory linear relationship between peak intensity and protein concentration. Collectively, this rapid detection method has a broad application prospect in clinical diagnosis of viruses, management of emergent viral infectious diseases, and exploration of the interaction between viruses and host cells.

Prevalence of adenoviruses as ocular disease causatives in Saudi Arabia

Although Human Adenoviruses outbreaks are rare, there still could be a potential chance for those viruses to mutate and spread quickly in human populations with severe public health and socioeconomic consequences. Outbreaks often spread fairly quickly with considerable morbidity/mortality. Saudi Arabia's geopolitical and religious significance bring with it, millions of pilgrims, and tourists yearly. This presents a significant potential for HAdVs epidemics. This review shows that even with the mushrooming serotypes and genotypes, the scholarly knowledge on the nature, structure, transmission, and management of HAdVs is already well-established. Significant research is ongoing on pharmacological interventions, which, presently remain speculative and lacking in effectiveness. This review similarly uncovers a shortage of literature, both recent and dated, on epidemic keratoconjunctivitis in either Saudi Arabia or the Middle East.

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.

Photophobia in headache disorders: characteristics and potential mechanisms

Photophobia is present in multiple types of headache disorders. The coexistence of photophobia and headache suggested the potential reciprocal interactions between visual and pain pathways. In this review, we summarized the photophobic characteristics in different types of headache disorders in the context of the three diagnostic categories of headache disorders: (1) primary headaches: migraine, tension-type headache, and trigeminal autonomic cephalalgias; (2) secondary headaches: headaches attributed to traumatic brain injury, meningitis, non-traumatic subarachnoid hemorrhage and disorder of the eyes; (3) painful cranial neuropathies: trigeminal neuralgia and painful optic neuritis. We then discussed potential mechanisms for the coexistence of photophobia and headache. In conclusion, the characteristics of photophobia are different among these headache disorders. The coexistence of photophobia and headache is associated with the interactions between visual and pain pathway at retina, midbrain, thalamus, hypothalamus and visual cortex. The communication between these pathways may depend on calcitonin gene-related peptide and pituitary cyclase-activating polypeptide transmission. Moreover, cortical spreading depression, an upstream trigger of headache, also plays an important role in photophobia by increased nociceptive input to the thalamus.

Topical pharmacologic interventions versus placebo for epidemic keratoconjunctivitis

BACKGROUND

Viruses cause about 80% of all cases of acute conjunctivitis. Human adenoviruses are believed to account for 65% to 90% of cases of viral conjunctivitis, or 20% to 75% of all causes of infectious keratoconjunctivitis worldwide. Epidemic keratoconjunctivitis (EKC) is a highly contagious subset of adenoviral conjunctivitis that has been associated with large outbreaks at military installations and at medical facilities. It is accompanied by severe conjunctival inflammation, watery discharge, and light sensitivity, and can lead to chronic complications such as corneal and conjunctival scarring with discomfort and poor quality of vision. Due to a lack of consensus on the efficacy of any pharmacotherapy to alter the clinical course of EKC, no standard of care exists, therefore many clinicians offer only supportive care.

OBJECTIVES

To assess the efficacy and safety of topical pharmacological therapies versus placebo, an active control, or no treatment for adults with EKC.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, which contains the Cochrane Eyes and Vision Trials Register; 2021, Issue 4); Ovid MEDLINE; Ovid Embase; Latin American and Caribbean Health Sciences database (LILACS); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), with no restrictions on language or year of publication. The date of the last search was 27 April 2021.

SELECTION CRITERIA

We included randomized controlled trials in which antiseptic agents, virustatic agents, or topical immune-modulating therapy was compared with placebo, an active control, or no treatment.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology.

MAIN RESULTS

We identified 10 studies conducted in Asia, Europe, the Middle East, and North Africa with a total of 892 participants who were treated for 7 days to 6 months and followed for 7 days up to 1.5 years. Study characteristics and risk of bias In most studies participants were predominantly men (range: 44% to 90%), with an age range from 9 to 82 years. Three studies reported information on trial registration, but we found no published study protocol. The majority of trials had small sample sizes, ranging from 18 to 90 participants enrolled per study; the only exception was a trial that enrolled 350 participants. We judged most studies to be at high or unclear risk of bias across risk of bias domains. Findings We included 10 studies of 892 EKC participants and estimated combined intervention effects in analyses stratified by steroid-containing control treatment or artificial tears. Six trials contributed to the comparisons of topical interventions (povidone-iodine [PVP-I], trifluridine, ganciclovir, dexamethasone plus neomycin) with artificial tears (or saline). Very low certainty evidence from two trials comparing trifluridine or ganciclovir with artificial tears showed inconsistent effects on shortening the mean duration of cardinal symptoms or signs of EKC. Low certainty evidence based on two studies (409 participants) indicated that participants treated with PVP-I alone more often experienced resolution of symptoms (risk ratio (RR) 1.15, 95% confidence interval (CI) 1.07 to 1.24) and signs (RR 3.19, 95% CI 2.29 to 4.45) during the first week of treatment compared with those treated with artificial tears. Very low certainty evidence from two studies (77 participants) suggested that PVP-I or ganciclovir prevented the development of subepithelial infiltrates (SEI) when compared with artificial tears within 30 days of treatment (RR 0.24, 95% CI 0.10 to 0.56). Four studies compared topical interventions (tacrolimus, cyclosporin A [CsA], trifluridine, PVP-I + dexamethasone) with topical steroids, and one trial compared fluorometholone (FML) plus polyvinyl alcohol iodine (PVA-I) with FML plus levofloxacin. Evidence from one trial showed that more eyes receiving PVP-I 1.0% plus dexamethasone 0.1% had symptoms resolved by day seven compared with those receiving dexamethasone alone (RR 9.00, 95% CI 1.23 to 66.05; 52 eyes). In two trials, fewer eyes treated with PVP-I or PVA-I plus steroid developed SEI within 15 days of treatment compared with steroid alone or steroid plus levofloxacin (RR 0.08, 95% CI 0.01 to 0.55; 69 eyes). One study found that CsA was no more effective than steroid for resolving SEI within four weeks of treatment (RR 0.84, 95% CI 0.67 to 1.06; N = 88). The evidence from trials comparing topical interventions with steroids was overall of very low level certainty. Adverse effects Antiviral or antimicrobial agents plus steroid did not differ from artificial tears in terms of ocular discomfort upon instillation (RR 9.23, 95% CI 0.61 to 140.67; N = 19). CsA and tacrolimus eye drops were associated with more cases of severe ocular discomfort, and sometimes intolerance, when compared with steroids (RR 4.64, 95% CI 1.15 to 18.71; 2 studies; N = 141). Compared with steroids, tacrolimus did not increase the risk of elevated intraocular pressure (RR 0.07, 95% CI 0 to 1.13; 1 study; N = 80), while trifluridine conferred no additional risk compared to tear substitute (RR 5.50, 95% CI 0.31 to 96.49; 1 study; N = 97). Overall, bacterial superinfection was rare (one in 23 CsA users) and not associated with use of the intervention steroid (RR 3.63, 95% CI 0.15 to 84.98; N = 51). The evidence for all estimates was of low or very low certainty.

AUTHORS' CONCLUSIONS

The evidence for the seven specified outcomes was of low or very low certainty due to imprecision and high risk of bias. The evidence that antiviral agents shorten the duration of symptoms or signs when compared with artificial tears was inconclusive. Low certainty evidence suggests that PVP-I alone resolves signs and symptoms by seven days relative to artificial tears. PVP-I or PVA-I, alone or with steroid, is associated with lower risks of SEI development than artificial tears or steroid (very low certainty evidence). The currently available evidence is insufficient to determine whether any of the evaluated interventions confers an advantage over steroids or artificial tears with respect to virus eradication or its spread to initially uninvolved fellow eyes. Future updates of this review should provide evidence of high-level certainty from trials with larger sample sizes, enrollment of participants with similar durations of signs and symptoms, and validated methods to assess short- and long-term outcomes.

[Diagnosis and treatment of adenoviral keratoconjunctivitis]

PURPOSE

To improve the treatment of adenoviral lesions of the eye based on express diagnostics by the fluorescent antibody technique (FAT) and the use of modern drugs.

MATERIAL AND METHODS

The study included 184 patients (333 eyes) with various manifestations of adenoviral lesions of the ocular surface, who were divided into two groups: group 1 (149 patients, 196 eyes) - acute form, and group 2 (76 patients, 137 eyes) - long lasting form. Effectiveness of the proposed treatment was evaluated against separate group 3 (controls) consisting of 28 people (46 eyes) with completed acute adenovirus infection, who had previously received antibiotic and corticosteroid therapy in other clinics. Conjunctival scrapings of study patients were examined with FAT in our proposed modification. Study patients received local therapy with modern drugs (Okomistin, Aktipol).

RESULTS

FAT detected the adenovirus antigen in 169 cases in group 1 (86%) and in 99 cases in group 2 (72%). Treatment duration amounted to 12±6 days in group 1, 18±8 days in group 2, and 29±7 days in controls. In both study groups, the duration of treatment was significantly reduced in comparison with the controls (p<0.01). Stable clinical effect and complete restoration of visual acuity have been achieved in most cases. There were no allergic and side effects from the therapy.

CONCLUSION

Fluorescent antibody technique is a fast and effective way to diagnose adenovirus infection in ophthalmology. In terms of therapy, the use of an antiseptic, an antiviral drug and diluted corticosteroids is the most rational approach.

Human adenovirus (HAdV) infection in children with acute respiratory tract infections in Guangzhou, China, 2010-2021: a molecular epidemiology study

BACKGROUND

Human adenovirus (HAdV) infection can cause a variety of diseases. It is a major pathogen of pediatric acute respiratory tract infections (ARIs) and can be life-threatening in younger children. We described the epidemiology and subtypes shifting of HAdV among children with ARI in Guangzhou, China.

METHODS

We conducted a retrospective study of 161,079 children diagnosed with acute respiratory illness at the Guangzhou Women and Children's Medical Center between 2010 and 2021. HAdV specimens were detected by real-time PCR and the hexon gene was used for phylogenetic analysis.

RESULTS

Before the COVID-19 outbreak in Guangzhou, the annual frequency of adenovirus infection detected during this period ranged from 3.92% to 13.58%, with an epidemic peak every four to five years. HAdV demonstrated a clear seasonal distribution, with the lowest positivity in March and peaking during summer (July or August) every year. A significant increase in HAdV cases was recorded for 2018 and 2019, which coincided with a shift in the dominant HAdV subtype from HAdV-3 to HAdV-7. The latter was associated with a more severe disease compared to HAdV-3. The average mortality proportion for children infected with HAdV from 2016 to 2019 was 0.38% but increased to 20% in severe cases. After COVID-19 emerged, HAdV cases dropped to 2.68%, suggesting that non-pharmaceutical interventions probably reduced the transmission of HAdV in the community.

CONCLUSION

Our study provides the foundation for the understanding of the epidemiology of HAdV and its associated risks in children in Southern China.

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.

Microsporidia-induced stromal keratitis: a new cause of presumed immune stromal (interstitial) keratitis

BACKGROUND AND OBJECTIVE

To describe the clinical features, diagnosis and management of immune stromal keratitis/interstitial keratitis (IK) associated with microsporidial epithelial keratitis.

METHODS

Between October 2020 and January 2021, medical records of IK patients microbiologically proven as microsporidia from samples collected from corneal epithelium on smear examination, and/ or molecular analysis were reviewed. Demography, clinical profile and treatment were analysed. Real-time PCR (RT-PCR) for adenovirus (ADV), Epstein-Barr virus (EBV), herpes simplex virus (HSV) and varicella-zoster virus (VZV) was done.

RESULTS

Twenty of 152 (13%) microbiologically proven cases of microsporidial keratitis were diagnosed as IK during the study period, the mean age and duration of symptoms were 35.7±11.4 years and 46.3±27.7 days, respectively. Half had predisposing risk factors, like trauma; and 30% had prior recurrences. One-fourth of patients were using antivirals on presentation. Characteristic presentations included disciform keratitis(n=12), incomplete/complete ring(n=5), and combination(n=3), along with variable subepithelial infiltrates (n=14). All cases had stromal oedema, with an intact epithelium and fine pigment dusting on endothelium. Corneal epithelial scrapings had scanty microsporidia spores in smears of 17/20 (85%), and pan-microsporidial DNA was identified in 14/20 (70%), with Vittaforma corneae by sequencing in 11/20 (55%). Other viruses detected were ADV (14,70%), VZV (2,10%), EBV (1,5%) and HSV (1,5%). Rapid resolution of inflammation and oedema within 2 weeks of starting steroids was seen in all cases.

CONCLUSION

Microsporidia epithelial keratitis induced stromal inflammatory keratitis; is distinguished from microsporidial keratoconjunctivitis and stromal keratitis, by characteristic clinical features, and response to topical steroids.

Adenovirus: Epidemiology, Global Spread of Novel Types, and Approach to Treatment

Adenoviruses (AdVs) are DNA viruses that typically cause mild infections involving the upper or lower respiratory tract, gastrointestinal tract, or conjunctiva. Rare manifestations of AdV infections include hemorrhagic cystitis, hepatitis, hemorrhagic colitis, pancreatitis, nephritis, or meningoencephalitis. AdV infections are more common in young children, due to lack of humoral immunity. Epidemics of AdV infection may occur in healthy children or adults in closed or crowded settings (particularly military recruits). The vast majority of cases are self-limited. However, the clinical spectrum is broad and fatalities may occur. Dissemination is more likely in patients with impaired immunity (e.g., organ transplant recipients, human immunodeficiency virus infection). Fatality rates for untreated severe AdV pneumonia or disseminated disease may exceed 50%. More than 100 genotypes and 52 serotypes of AdV have been identified and classified into seven species designated HAdV-A through -G. Different types display different tissue tropisms that correlate with clinical manifestations of infection. The predominant types circulating at a given time differ among countries or regions, and change over time. Transmission of novel strains between countries or across continents and replacement of dominant viruses by new strains may occur. Treatment of AdV infections is controversial, as prospective, randomized therapeutic trials have not been done. Cidofovir has been the drug of choice for severe AdV infections, but not all patients require treatment. Live oral vaccines are highly efficacious in reducing the risk of respiratory AdV infection and are in routine use in the military in the United States but currently are not available to civilians.

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.

Foundational concepts in the biology of bacterial keratitis

Bacterial infections of the cornea, or bacterial keratitis (BK), are notorious for causing rapidly fulminant disease and permanent vision loss, even among treated patients. In the last sixty years, dramatic upward trajectories in the frequency of BK have been observed internationally, driven in large part by the commercialization of hydrogel contact lenses in the late 1960s. Despite this worsening burden of disease, current evidence-based therapies for BK - including broad-spectrum topical antibiotics and, if indicated, topical corticosteroids - fail to salvage vision in a substantial proportion of affected patients. Amid growing concerns of rapidly diminishing antibiotic utility, there has been renewed interest in urgently needed novel treatments that may improve clinical outcomes on an individual and public health level. Bridging the translational gap in the care of BK requires the identification of new therapeutic targets and rational treatment design, but neither of these aims can be achieved without understanding the complex biological processes that determine how bacterial corneal infections arise, progress, and resolve. In this chapter, we synthesize the current wealth of human and animal experimental data that now inform our understanding of basic BK pathophysiology, in context with modern concepts in ocular immunology and microbiology. By identifying the key molecular determinants of clinical disease, we explore how novel treatments can be developed and translated into routine patient care.

Oncolytic Adenovirus: Prospects for Cancer Immunotherapy

Immunotherapy has moved to the forefront of modern oncologic treatment in the past few decades. Various forms of immunotherapy currently are emerging, including oncolytic viruses. In this therapy, viruses are engineered to selectively propagate in tumor cells and reduce toxicity for non-neoplastic tissues. Adenovirus is one of the most frequently employed oncolytic viruses because of its capacity in tumor cell lysis and immune response stimulation. Upregulation of immunostimulatory signals induced by oncolytic adenoviruses (OAds) might significantly remove local immune suppression and amplify antitumor immune responses. Existing genetic engineering technology allows us to design OAds with increasingly better tumor tropism, selectivity, and antitumor efficacy. Several promising strategies to modify the genome of OAds have been applied: capsid modifications, small deletions in the pivotal viral genes, insertion of tumor-specific promoters, and addition of immunostimulatory transgenes. OAds armed with tumor-associated antigen (TAA) transgenes as cancer vaccines provide additional therapeutic strategies to trigger tumor-specific immunity. Furthermore, the combination of OAds and immune checkpoint inhibitors (ICIs) increases clinical benefit as evidence shown in completed and ongoing clinical trials, especially in the combination of OAds with antiprogrammed death 1/programed death ligand 1 (PD-1/PD-L1) therapy. Despite remarkable antitumor potency, oncolytic adenovirus immunotherapy is confronted with tough challenges such as antiviral immune response and obstruction of tumor microenvironment (TME). In this review, we focus on genomic modification strategies of oncolytic adenoviruses and applications of OAds in cancer immunotherapy.

Ocular redness - I: Etiology, pathogenesis, and assessment of conjunctival hyperemia

The translucent appearance of the conjunctiva allows for immediate visualization of changes in the circulation of the conjunctival microvasculature consisting of extensive branching of superficial and deep arterial systems and corresponding drainage pathways, and the translucent appearance of the conjunctiva allows for immediate visualization of changes in the circulation. Conjunctival hyperemia is caused by a pathological vasodilatory response of the microvasculature in response to inflammation due to a myriad of infectious and non-infectious etiologies. It is one of the most common contributors of ocular complaints that prompts visits to medical centers. Our understanding of these neurogenic and immune-mediated pathways has progressed over time and has played a critical role in developing targeted novel therapies. Due to a multitude of underlying etiologies, patients must be accurately diagnosed for efficacious management of conjunctival hyperemia. The diagnostic techniques used for the grading of conjunctival hyperemia have also evolved from descriptive and subjective grading scales to more reliable computer-based objective grading scales.

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.

The paradoxical problem with COVID-19 ocular infection: Moderate clinical manifestation and potential infection risk

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which induced mainly the respiratory damage also caused ocular surface symptoms. However, the detailed description of ocular manifestations, severity fluctuations in confirmed COVID-19 adult patients still lacked. We analyzed onset clinical symptoms and duration, ocular symptoms, needs for medication, outcomes in 28 conjunctivitis patients who were extracted from 3198 COVID-19 patients hospitalized in Huoshenshan Hospital and Taikangtongji Hospital, Wuhan, China. The expression levels of ACE2, TMPRSS2, ANPEP, DPP4, NRP1 on fetal and adult ocular surface and mouse lacrimal glands were assessed by single cell seq analysis. Our results indicated that conjunctivitis was a rare and self-limited complication in adults with COVID-19 while the existence of coronavirus receptors on human ocular surface and mouse lacrimal glands indicated the risk of SARS-CoV-2 infection. Our research firstly examined SARS-CoV-2 receptors, including the new discovered one, NRP1, on the fetal ocular surface and in the mouse lacrimal glands.