Clinical and virological analysis of epidemic keratoconjunctivitis caused by adenovirus type 54 in a regional ophthalmic clinic in Kyushu, Japan

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.

Evaluation of anti-adenoviral effects of the polyvinyl alcohol iodine ophthalmic solution

PURPOSE

To investigate the virucidal effects of a polyvinyl alcohol iodine, Saniode, against 16 types of human mastadenovirus (HAdV) causing ophthalmic, respiratory, gastrointestinal, urinary, and systemic infections.

STUDY DESIGN

Laboratory investigation METHODS: Fifty microliters of Saniode were exposed to 10 μL each containing HAdV virus stock solution of 1 × 106 copies/μL of HAdV-1, -2, -3, -4, 5, -6, -7, -8, -11, -37, -53, -54, -56, -64, -81, and -85 for 10 s, 30 s, 1 min, and 3 min. After neutralization with 0.5% sodium thiosulfate, the mixture was diluted by ten-fold serial dilution and inoculated into 24 wells containing confluent A549 cell monolayers. Virucidal effects were calculated relative to the positive control on days 7-10 and observed until 30 days post-infection.

RESULTS

Saniode satisfied the EN-14476 criterion for virucidal effects (>99.99%) for all HAdV types at all exposure times, including at 10 s on days 7 to 10 post-infection. All types of HAdVs that reacted for > 1 min achieved 99.99% reduction, including after 30 days.

CONCLUSION

Saniode displayed virucidal effects against all tested HAdV types. Currently, with no specific medication available for HAdVs in ocular infection, this could be an option to prevent the spread of keratoconjunctivitis.

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.

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.

An outbreak of adenovirus D8 keratoconjunctivitis in Leicester, United Kingdom, from March to August 2019

We report a large epidemic (n = 126) of keratoconjunctivitis predominantly with two lineages of adenovirus (AdV) type D8 in patients seen in eye casualty between march and August 2019. Other AdV species identified by viral sequencing included B, C, and E. Despite various features of more severe eye disease being present, these were not significantly different between the different AdV species, with similar rates of pseudomembrane formation and keratitis observed in patients with AdV species B as for those with AdV species D.

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.

Comparative study of topical regimen for adenoviral kearoconjunctivitis by 0.1% fluorometholone with and without polyvinyl alcohol iodine

PURPOSE

The aim of this study was to compare the efficacy of the topical regimens of iodine/steroids vs. antibiotics/steroids in acute to subacute adenoviral keratoconjunctivitis.

STUDY DESIGN

A prospective open-label study.

PATIENTS AND METHODS

Nineteen patients diagnosed with unilateral or bilateral adenoviral conjunctivitis at less than 1 week from onset were enrolled in this study. Patients were divided randomly into two groups; group 1 was treated with 1.5% levofloxacin with 0.1% fluorometholone administered four times a day and group 2 was treated with a sixfold dilution of polyvinyl alcohol iodine (PAI) solution with 0.1% fluorometholone four times a day. Conjunctival samples from all affected eyes were obtained for real-time PCR. The total scores of acute signs (i.e., eyelid edema, conjunctival injecton, conjunctival discharge, follicules, pseudomembranes, subconjunctival hemorrhage) and symptoms, HAdV DNA copy number, and the presence of multiple subepithelial corneal infiltrates (MSI) were evaluated every 5 visits up to Day 30 after diagnosis.

RESULTS

Comparing the total scores of acute signs and symptoms and viral load, we observed no significant differences between the two groups. At day 15 after diagnosis the proportion of patients with MSI in group 2 (35.7%) was significantly lower than in group 1 (0%).

CONCLUSIONS

The impact of topical iodine/steroid therapy on acute signs and symptoms associated with adenoviral conjunctivitis is limited and not substantially different in the responses to antibiotics/steroids. However, this regimen results in a significant decrease in the incidence of MSI during the subacute phase of infection.

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.

A 8-year retrospective clinical analysis of 272 patients of epidemic Keratoconjunctivitis in Beijing, China

Background

Epidemic keratoconjunctivitis (EKC) is one of the most common eye infections worldwide. The analysis of clinical manifestations in different age groups help better know the disease. This study aims to provide more detailed analysis of 272 cases of EKC in 8 years, describe the differences of the clinical features among different age groups, and establish new clinical grading criteria.

Methods

272 individuals were reviewed (2011–2019) in Beijing China. All the patients were classified into 3 grades according to the new grading criteria. The typical clinical signs of EKC and the photographs of the multiple subepithelial corneal infiltrates (MSI) were collected and analyzed. The number of 3 grades among and within different age groups were compared. The incidence of the typical signs among and within different age groups were compared. The proportion of each region of the cornea involved by MSI were compared.

Results

No significant differences were detected among the 4 groups in terms of the number of mild, moderate and severe cases, no matter in all-patients analysis (P = 0.271) nor in acute-phase-patients analysis (P = 0.203). The proportion of the severe cases was the highest among all patients (P = 0.000). Among the incidence of the typical signs, corneal involvement was the most common accounting for 69.8% (P<0.05). The probability of central region involvement was significantly higher than that of pericentral region involvement (P = 0.015) and peripheral region involvement (P = 0.000).

Conclusions

Appropriate attention should be paid on EKC, because of the considerable proportion of severe cases, the high incidence of corneal lesion, and the high incidence of central region involvement of MSI.

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.

An outbreak of epidemic keratoconjunctivitis caused by human adenovirus type 8 in primary school, southwest China

Background

Two outbreaks of epidemic keratoconjunctivitis (EKC) occurred successively with an interval of 5 days in two primary boarding schools in Weixi Lisu Autonomous County, Diqing, and Tibetan Autonomous Prefecture, Yunnan. The aims of this study were to determine the intensity and characteristics of the outbreaks, as well as the clinical manifestations in the patients, the risk factors for infection and the pathogen responsible for the two outbreaks.

Methods

An outbreak investigation was conducted in two primary schools, and a case-control study including patients from the Weixi County Ethnic Primary School was performed. Relevant specimens were collected according to the case definition, and next-generation sequencing was employed to identify the pathogen. An epidemiological investigation method was used to analyse the related epidemiological characteristics, such as risk factors. The phylogenetic tree was constructed by MEGA 7.0.

Results

A total of 331 acute conjunctivitis cases, including probable cases of EKC, were reported in the two schools, and the attack rates were 30.59% (171/559, 95%CI: 26.76–34.42) and 20.41% (160/784, 95%CI: 17.58–23.24), respectively. Cases occurred in all grades and classes in both schools, and only one staff member in each school presented illness. The epidemics lasted for 54 days and 45 days, respectively. The patients had typical manifestations of EKC, such as acute onset, follicular hyperplasia, pseudomembrane formation, preauricular lymphadenopathy, corneal involvement and blurred vision, and a relatively long disease course (average 9.40 days, longest 23 days and shortest 7 days). The risk factor for infection was close contact with a patient or personal items contaminated by a patient. The pathogen responsible for the outbreaks was HAdV-8. The virus was highly similar to the 2016 HAdV-8 strain from Tibet, China.

Conclusions

This study strongly suggests that HAdV-8 could lead to serious consequences. This is the second report of a HAdV-8-associated EKC outbreak in mainland China. Tibetan HAdV-8 might be circulating in southwest China; therefore, it is necessary to monitor the pathogens causing acute conjunctivitis in this area.

Frequency of adenovirus serotype 8 in patients with Keratoconjunctivitis, in Ahvaz, Iran

BACKGROUND AND OBJECTIVES

Adenoviral keratoconjunctivitis is an extremely frequent ophthalmological disease caused by various serological subtypes of human adenovirus (HAdV) worldwide. Adenoviruses serotypes 8, 11, 19, 37 frequently cause epidemic keratoconjunctivitis (EKC). This study was conducted to evaluate the frequency of adenovirus serotypes in patients with EKC in Ahvaz, Iran.

MATERIALS AND METHODS

Eighty-eight ocular swabs were collected from patients with EKC. The specimens were analyzed for detection of adenovirus by standard PCR. The PCR products were further sequenced and analyzed to determine the serotypes.

RESULTS

The study population consisted of 49/88 (55.7%) males and 39/88 (44.3%) females. Among them 25 (51.02%) males and 22 (56.41%) females were positive for HAdV serotype 8 (p= 0.488). Overall forty-seven (53.4%) samples were positive for AdV serotype 8 while forty-one patients (46.59%) were negative for the adenovirus serotypes.

CONCLUSION

The results of this study revealed predominanance of HAdV 8 with high prevalence of 53.4% among patients with Keratoconjunctivitis. Forty-one patients (46.59%) were negative for adenovirus. Still, the role for other related viruses such as enteroviruses need to be investigated in patients with EKC.

Evaluation of adenovirus amplified detection of immunochromatographic test using tears including conjunctival exudate in patients with adenoviral keratoconjunctivitis

BACKGROUND

We evaluated a novel silver amplification immunochromatography test for rapid detection of adenovirus (AdV) antigen equipped with an automated reader system using tears including conjunctival exudate in patients with adenoviral keratoconjunctivitis.

METHODS

Two kinds of immunochromatographic (IC) kits, a conventional IC kit for conjunctival scrapings (control kit) and an IC kit using tears including conjunctival exudate collected by pressing a filter paper strip on the conjunctiva (test kit), were tested on 90 patients who attended Migita Eye Clinic with suspected adenoviral conjunctivitis. The results of the test kits were automatically obtained by a specific reader, which was based on silver amplification immunochromatography system, in 15 min. The detection of AdV was confirmed by real-time polymerase chain reaction (PCR) method, and typing was performed by direct sequencing. Comparative dilution assay was carried out with the two kits, using AdV type 3 and type 54 strains.

RESULTS

The sensitivity of the control kit and test kit was 89.8% and 98.3%, respectively. The specificity of both kits was 100%. A significant difference in the sensitivities of the two IC kits against PCR positivity was observed (P < 0.01). A significant correlation was found between AdV DNA copy numbers on a logarithmic scale obtained with the two tests (P < 0.01). The sensitivity of the test kit was 32-64-fold higher than that of the control kit without silver amplification for both AdV types.

CONCLUSIONS

These results suggest that this novel amplified AdV detection kit using tears including conjunctival exudate is useful, because it decreases patients' discomfort from specimen collection and its sensitivity is significantly higher than that of the conventional IC kit.

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.

Human adenoviral type 54 keratoconjunctivitis accompanied by stellate keratitis and keratic precipitates: two cases

BACKGROUND

Of the 10 patients with adenoviral type 54 keratoconjunctivitis examined at Nojima Hospital, 2 developed stellate keratitis and mutton-fat keratic precipitates (KPs) following acute symptoms.

CASE PRESENTATION

We encountered 10 cases of epidemic keratoconjunctivitis from August to October 2017. All patients were adults with a mean age of 60.9 ± 10.0 years. The species D human adenovirus (HAdV)-54 was detected in the conjunctival scrapings of these patients. Fluorometholone instillation was administered during the first week for acute symptomatic relief. Case 1: A 64-year-old female was prescribed with fluorometholone instillation, which was discontinued after 1 week when her symptoms alleviated. One week after discontinuation of the instillation, she presented with blurred vision in her left eye with KPs and multiple stellate keratitis. The anterior chamber had no apparent cells. Her symptoms disappeared after 1 week of betamethasone instillation. Case 2: A 66-year-old female was prescribed with 0.1% fluorometholone instillation, which was discontinued within10 days. Three months after the appearance of initial symptoms, multiple subepithelial corneal infiltrates (MSI) appeared in her eyes. Stellate keratitis and dark-brown pigmentation were observed in the centres of MSI, with several cells in the anterior chamber. Betamethasone was prescribed, and MSI and stellate keratitis improved within 1 week. However, KPs were observed in the left eye. The instillation was continued for 3 more weeks until symptoms improved.

CONCLUSIONS

MSI is an immune reaction that occurs after the disappearance of acute symptoms. Here, corneal findings and KPs were observed after improvement in eye redness and discontinuation of steroids. These symptoms were presumed to be secondary inflammation due to immune response to the adenoviral antigen. The clinical features of HAdV-54 keratoconjunctivitis on the ocular surface are initially moderate, but become active in the subacute to chronic phases. This may develop atypical findings, including stellate keratitis with KPs. Although early steroid administration can relieve acute symptoms, it may facilitate chronic corneal immunological reaction.