Ebola Virus Persistence in Ocular Tissues and Fluids (EVICT) Study: Reverse Transcription-Polymerase Chain Reaction and Cataract Surgery Outcomes of Ebola Survivors in Sierra Leone

Clinical characteristics and aetiology of uveitis in a viral haemorrhagic fever zone

BACKGROUND/OBJECTIVES

Studies on uveitis in Sierra Leone were conducted prior to the Ebola Virus Disease epidemic of 2013-16, which was associated with uveitis in 20% of survivors. They did not include imaging or investigation of tuberculosis and used laboratory services outside the country. We performed a cross-sectional study on patients presenting with uveitis to establish their clinical characteristics and identify the impact of in-country laboratory diagnoses.

METHODS

We invited uveitis cases presenting to Eye Clinics in Sierra Leone from March to September 2022 to participate in the study. They underwent a diagnostic work-up, including fundus and ocular coherence tomography imaging. Active uveitis cases underwent further investigations including serology and immunological tests for syphilis, tuberculosis, herpetic viruses and HIV and chest radiographs.

RESULTS

We recruited 128 patients. The median age was 34 (IQR 19) years and there was an equal gender split. Panuveitis was the predominant anatomical uveitis type (n = 51, 40%), followed by posterior uveitis (n = 36, 28%). Bilateral disease affected 40 patients (31%). Active uveitis was identified in 75 (59%) cases. ICD 11 definition of blindness with VA < 3/60 occurred in 55 (33%) uveitis eyes. Aetiology of uveitis from clinical and laboratory assessment demonstrated that most cases were of undifferentiated aetiology (n = 66, 52%), followed by toxoplasmosis (n = 46, 36%). Trauma contributed to eight (6%) cases, syphilis to 5 (4%) cases and Ebola to 2 (2%).

CONCLUSIONS

Uveitis was associated with high levels of visual impairment. Posterior and panuveitis contributed to the highest proportion of uveitis cases. Laboratory studies helped differentiate syphilis as a significant aetiology of uveitis.

Ebola virus disease sequelae and viral persistence in animal models: Implications for the future

Ebola virus disease (EVD), caused by infection with Ebola virus, results in severe, acute illness with a high mortality rate. As the incidence of outbreaks of EVD increases and with the development and approval of medical countermeasures (MCMs) against the acute disease, late phases of EVD, including sequelae, recrudescence, and viral persistence, are occuring more frequently and are now a focus of ongoing research. Existing animal disease models recapitulate acute EVD but are not suitable to investigate the mechanisms of these late disease phenomena. Although there are challenges in establishing such a late disease model, the filovirus research community has begun to call for the development of an EBOV persistence model to address late disease concerns. Ultimately, this will aid the development of MCMs against late disease and benefit survivors of future EVD and filovirus outbreaks.

Visual acuity and vision-related quality of life outcomes following cataract surgery in Ebola virus disease survivors

Objectives

The objectives of this study were to assess relationships between vision-related quality of life (QoL) and visual acuity (VA) in Ebola virus disease (EVD) survivors after cataract surgery in the Ebola Viral Persistence in Ocular Tissues and Fluids (EVICT) Study.

Materials and Methods

EVD survivors with undetectable Ebola virus (EBOV) ribonucleic acid in their aqueous humour were eligible to receive manual small-incision cataract surgery (MSICS). Among those that received surgery, assessments of VA and vision-related QoL were assessed pre-and post-cataract surgery. VA was converted from units on a tumbling 'E' chart to the logarithm of the minimal angle of resolution VA (logMAR VA). Vision-related QoL was assessed using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). Linear regression was used to evaluate the associations between VA and vision-related QoL. P = 0.05 was considered statistically significant for all analyses.

Results

Thirty-four EVD survivors underwent cataract surgery in the EVICT study. Before MSICS, the mean logMAR VA was 2.24 (standard deviation [SD]: 0.98), and the mean NEI-VFQ-25 composite score was 54 (SD: 15); however, there was no significant association between the pre-surgery measurements (average difference in VA/10 unit increase in NEI-VFQ-25: -0.04, 95% confidence interval (CI): -0.33-0.26, P = 0.80). There was a significant improvement in logMAR VA after MSICS (mean: 1.6, P < 0.001), but there was no significant change in the NEI-VFQ-25 composite (-0.87, 95% (CI): -10.32-8.59, P = 0.85). None of the subscales showed significant improvements (P > 0.12 for all); however, the magnitude of the mean change for distance activities (6.65), near activities (6.76), general vision (-7.69), social functioning (-9.13) and colour vision (13.33) met the criteria for a clinically meaningful difference (4-6). In the subset with paired measurements (n = 16), there were no significant association changes in logMAR VA and NEI VFQ-25 composite scores (P > 0.12 for all).

Conclusion

Following cataract surgery, VA in EVD survivors improved, but these improvements were not reflected in NEI VFQ-25 composite scores or specific subscales; however, the small sample size limits generalizability absent more research. Differences in sociocultural context and activities that affect the QoL in resource-limited areas may contribute to the limitations seen with NEI VFQ-25. In addition, better eye dominance could contribute to any lack of association as NEI VFQ-25 evaluates vision as a whole. Further, assessment of factors contributing to improved QoL may help to define the impact of vision health in varied environments.

Ebola virus disrupts the inner blood-retinal barrier by induction of vascular endothelial growth factor in pericytes

Ebola virus (EBOV) causes severe hemorrhagic fever in humans with high mortality. In Ebola virus disease (EVD) survivors, EBOV persistence in the eyes may break through the inner blood-retinal barrier (iBRB), leading to ocular complications and EVD recurrence. However, the mechanism by which EBOV affects the iBRB remains unclear. Here, we used the in vitro iBRB model to simulate EBOV in retinal tissue and found that Ebola virus-like particles (EBO-VLPs) could disrupt the iBRB. Cytokine screening revealed that EBO-VLPs stimulate pericytes to secrete vascular endothelial growth factor (VEGF) to cause iBRB breakdown. VEGF downregulates claudin-1 to disrupt the iBRB. Ebola glycoprotein is crucial for VEGF stimulation and iBRB breakdown. Furthermore, EBO-VLPs caused iBRB breakdown by stimulating VEGF in rats. This study provides a mechanistic insight into that EBOV disrupts the iBRB, which will assist in developing new strategies to treat EBOV persistence in EVD survivors.

Viral Infection and Antiviral Treatments in Ocular Pathologies

Ocular viral infections are common and widespread globally. These infectious diseases are a major cause of acute red eyes and vision loss. The eye and its nearby tissues can be infected by several viral agents, causing infections with a short course and limited ocular implications or a long clinical progression and serious consequences for the function and structure of the ocular region. Several surveillance studies underline the increased emergence of drug resistance among pathogenic viral strains, limiting treatment options for these infections. Currently, in the event of resistant infections, topical or systemic corticosteroids are useful in the management of associated immune reactions in the eye, which contribute to ocular dysfunction. Many cases of viral eye infections are misdiagnosed as being of bacterial origin. In these cases, therapy begins late and is not targeted at the actual cause of the infection, often leading to severe ocular compromises, such as corneal infiltrates, conjunctival scarring, and reduced visual acuity. The present study aims at a better understanding of the viral pathogens that cause eye infections, along with the treatment options available.

Persistent intraocular Ebola virus RNA is associated with severe uveitis in a convalescent rhesus monkey

Despite increasing evidence that uveitis is common and consequential in survivors of Ebola virus disease (EVD), the host-pathogen determinants of the clinical phenotype are undefined, including the pathogenetic role of persistent viral antigen, ocular tissue-specific immune responses, and histopathologic characterization. Absent sampling of human intraocular fluids and tissues, these questions might be investigated in animal models of disease; however, challenges intrinsic to the nonhuman primate model and the animal biosafety level 4 setting have historically limited inquiry. In a rhesus monkey survivor of experimental Ebola virus (EBOV) infection, we observed and documented the clinical, virologic, immunologic, and histopathologic features of severe uveitis. Here we show the clinical natural history, resultant ocular pathology, intraocular antigen-specific antibody detection, and persistent intraocular EBOV RNA detected long after clinical resolution. The association of persistent EBOV RNA as a potential driver of severe immunopathology has pathophysiologic implications for understanding, preventing, and mitigating vision-threatening uveitis in EVD survivors.

Deep characterization of uveitis in a rhesus monkey confirms Ebola virus RNA persistence is associated with severe immunopathology in the eye, with broader implications for the prevention and treatment of sight-threatening uveitis in human survivors of Ebola virus.

Ocular manifestations of recent viral pandemics: A literature review

Viral pandemics often take the world by storm, urging the medical community to prioritize the most evident systemic manifestations, often causing ocular manifestations to go unnoticed. This literature review highlights the ocular complications of the Monkeypox, SARS-CoV-2, MERS, Ebola, H1N1, and Zika viruses as the most recent viral pandemics. Research into the effects of these pandemics began immediately. Moreover, it also discusses the ocular complications of the vaccines and treatments that were used in the scope of the viral pandemics. Additionally, this review discusses the role of the eye as an important route of viral transmission, and thereafter, the International recommendations to reduce the incidence of viral transmission were mentioned. Lastly, this paper wants to lay out a platform for researchers who want to learn more about how viruses show up in the eye.

Ophthalmic sequelae and psychosocial impact in pediatric ebola survivors

Background

Ebola virus disease (EVD) outbreaks in West Africa (2013-2016) and the Democratic Republic of Congo (2018-2020) have resulted in thousands of EVD survivors who remain at-risk for survivor sequelae. While EVD survivorship has been broadly reported in adult populations, pediatric EVD survivors are under-represented. In this cross-sectional study, we investigated the prevalence of eye disease, health-related quality-of-life, vision-related quality-of-life, and the burden of mental illness among pediatric EVD survivors in Sierra Leone.

Methods

Twenty-three pediatric EVD survivors and 58 EVD close contacts were enrolled. Participants underwent a comprehensive ophthalmic examination and completed the following surveys: Pediatric Quality of Life Inventory Version 4.0, Effect of Youngsters Eyesight on Quality-of-Life, and the Revised Child Anxiety and Depression Scale.

Findings

A higher prevalence of uveitis was observed in EVD survivor eyes (10·8%) cohort compared to close contacts eyes (1·7%, p=0·03). Overall, 47·8% of EVD survivor eyes and 31·9% of close contact eyes presented with an eye disease at the time of our study (p=0·25). Individuals diagnosed with an ocular complication had poorer vision-related quality-of-life (p=0·02).

Interpretation

Both health related quality-of-life and vision-related quality-of-life were poor among EVD survivors and close contacts. The high prevalence of eye disease associated with reduced vision health, suggests that cross-disciplinary approaches are needed to address the unmet needs of EVD survivors.

Funding

National Institutes of Health R01 EY029594, K23 EY030158; National Eye Institute; Research to Prevent Blindness (Emory Eye Center); Marcus Foundation Combating Childhood Illness; Emory Global Health Institute; Stanley M. Truhlsen Family Foundation.

Presence of SARS-CoV-2 Viral RNA in Aqueous Humor of Asymptomatic Individuals

PURPOSE

The purpose of this study was to determine whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is detectable in the aqueous of asymptomatic individuals presenting for ophthalmic surgery.

DESIGN

Prospective cross-sectional study.

METHODS

Setting and participants: all patients undergoing anterior segment surgery at an ambulatory surgical center (ASC) belonging to a tertiary academic center in South Florida during a 102-day period between June and September 2020 received nasal swab testing for SARS-CoV-2 and underwent a relevant review of symptoms prior to surgery, with negative results required for both in order to proceed with surgery. Main outcomes and measurements: a small sample of aqueous humor (approximately 0.2 cc) was acquired at the beginning of anterior segment surgery from all participants. Aqueous humor was analyzed for SARS-CoV-2 viral ribonucleic acid (RNA) using real-time reverse transcriptase polymerase chain reaction. Demographic information was acquired from participants for secondary analyses.

RESULTS

A total of 70 samples were acquired. Of those, 39 samples were excluded due to insufficient material or inconclusive results. Of 31 samples that were successfully analyzed, 6 (19.4%) demonstrated detectable SARS-CoV-2 RNA. None of the 6 individuals (0%) with detectable viral RNA in aqueous humor reported symptoms during the year, compared to 2 of 25 individuals (8%) with negative samples (P = 1). Positive samples were distributed throughout the study period, including both the first and the last days of enrollment.

CONCLUSIONS

The presence of SARS-CoV-2 viral RNA in aqueous despite negative nasal swab testing confirmed its presence beyond the blood-ocular barrier in asymptomatic individuals and raises the possibility that the virus may persist in immunoprivileged spaces despite an absence of symptoms.

Implementation of the Ebola Virus Persistence in Ocular Tissues and Fluids (EVICT) study: Lessons learned for vision health systems strengthening in Sierra Leone

Background

Following the West African Ebola virus disease (EVD) outbreak of 2013–2016 and more recent EVD outbreaks in the Democratic Republic of Congo, thousands of EVD survivors are at-risk for sequelae including uveitis, which can lead to unremitting inflammation and vision loss from cataract. Because of the known risk of Ebola virus persistence in ocular fluid and the need to provide vision-restorative, safe cataract surgery, the Ebola Virus Persistence in Ocular Tissues and Fluids (EVICT) Study was implemented in Sierra Leone. During implementation of this multi-national study, challenges included regulatory approvals, mobilization, community engagement, infection prevention and control, and collaboration between multiple disciplines. In this report, we address the multifacted approach to address these challenges and the impact of implementation science research to address an urgent clinical subspecialty need in an outbreak setting.

Methodology/Principal findings

Given the patient care need to develop a protocol to evaluate ocular fluid for Ebola virus RNA persistence prior to cataract surgery, as well as protocols to provide reassurance to ophthalmologists caring for EVD survivors with cataracts, the EVICT study was designed and implemented through the work of the Ministry of Health, Sierra Leone National Eye Programme, and international partnerships. The EVICT study showed that all 50 patients who underwent ocular fluid sampling at 19 and 34 months, respectively, tested negative for Ebola virus RNA. Thirty-four patients underwent successful cataract surgery with visual acuity improvement. Here we describe the methodology for study implementation, challenges encountered, and key issues that impacted EVD vision care in the immediate aftermath of the EVD outbreak. Key aspects of the EVICT study included defining the pertinent questions and clinical need, partnership alignment with key stakeholders, community engagement with EVD survivor associations, in-country and international regulatory approvals, study site design for infection prevention and control, and thorough plans for EVD survivor follow-up care and monitoring. Challenges encountered included patient mobilization owing to transportation routes and distance of patients in rural districts. Strong in-country partnerships and multiple international organizations overcame these challenges so that lessons learned could be applied for future EVD outbreaks in West and Central Africa including EVD outbreaks that are ongoing in Guinea and Democratic Republic of Congo.

Conclusions/Significance

The EVICT Study showed that cataract surgery with a protocol-driven approach was safe and vision-restorative for EVD survivors, which provided guidance for EVD ophthalmic surgical care. Ophthalmologic care remains a key aspect of the public health response for EVD outbreaks but requires a meticulous, yet partnered approach with international and local in-country partners. Future efforts may build on this framework for clinical care and to improve our understanding of ophthalmic sequelae, develop treatment paradigms for EVD survivors, and strengthen vision health systems in resource-limited settings.

Ocular manifestations of emerging viral diseases

Emerging infectious diseases (EIDs) are an increasing threat to public health on a global scale. In recent times, the most prominent outbreaks have constituted RNA viruses, spreading via droplets (COVID-19 and Influenza A H1N1), directly between humans (Ebola and Marburg), via arthropod vectors (Dengue, Zika, West Nile, Chikungunya, Crimean Congo) and zoonotically (Lassa fever, Nipah, Rift Valley fever, Hantaviruses). However, specific approved antiviral therapies and vaccine availability are scarce, and public health measures remain critical. Patients can present with a spectrum of ocular manifestations. Emerging infectious diseases should therefore be considered in the differential diagnosis of ocular inflammatory conditions in patients inhabiting or returning from endemic territories, and more general vigilance is advisable in the context of a global pandemic. Eye specialists are in a position to facilitate swift diagnosis, improve clinical outcomes, and contribute to wider public health efforts during outbreaks. This article reviews those emerging viral diseases associated with reports of ocular manifestations and summarizes details pertinent to practicing eye specialists.

Ebola virus antibody decay-stimulation in a high proportion of survivors

Neutralizing antibody function provides a foundation for the efficacy of vaccines and therapies^1–3. Here, using a robust in vitro Ebola virus (EBOV) pseudo-particle infection assay and a well-defined set of solid-phase assays, we describe a wide spectrum of antibody responses in a cohort of healthy survivors of the Sierra Leone EBOV outbreak of 2013–2016. Pseudo-particle virus-neutralizing antibodies correlated with total anti-EBOV reactivity and neutralizing antibodies against live EBOV. Variant EBOV glycoproteins (1995 and 2014 strains) were similarly neutralized. During longitudinal follow-up, antibody responses fluctuated in a ‘decay–stimulation–decay’ pattern that suggests de novo restimulation by EBOV antigens after recovery. A pharmacodynamic model of antibody reactivity identified a decay half-life of 77–100 days and a doubling time of 46–86 days in a high proportion of survivors. The highest antibody reactivity was observed around 200 days after an individual had recovered. The model suggests that EBOV antibody reactivity declines over 0.5–2 years after recovery. In a high proportion of healthy survivors, antibody responses undergo rapid restimulation. Vigilant follow-up of survivors and possible elective de novo antigenic stimulation by vaccine immunization should be considered in order to prevent EBOV viral recrudescence in recovering individuals and thereby to mitigate the potential risk of reseeding an outbreak.

In many survivors of Ebola virus infection, antibody responses show long-term patterns of decline followed by restimulation, possibly owing to recrudescence of persisting virus.

Efficacy and Safety Outcomes of Cataract Surgery in Survivors of Ebola Virus Disease: 12-Month Results From the PREVAIL VII Study

Purpose

In survivors of Ebola virus disease (EVD), intraocular viral persistence raises questions about the timing and safety of cataract surgery. To the best of our knowledge, this is the first controlled study evaluating Ebola virus persistence and cataract surgery safety and outcomes in EVD survivors.

Methods

Seropositive EVD survivors and seronegative controls with vision worse than 20/40 from cataract and without active intraocular inflammation were enrolled. Aqueous humor from survivors was tested with reverse transcription-polymerase chain reaction for Ebola viral RNA. Participants underwent manual small-incision cataract surgery and 1 year of follow-up examinations.

Results

Twenty-two eyes of 22 survivors and 12 eyes of eight controls underwent cataract surgery. All of the aqueous samples tested negative for Ebola viral RNA. Median visual acuity improved from 20/200 at baseline to 20/25 at 1 year in survivors and from count fingers to 20/50 in controls (overall, P < 0.001; between groups, P = 0.07). After a 1-month course of topical corticosteroids, 55% of survivors and 67% of controls demonstrated at least 1+ anterior chamber cell. Twelve months after surgery, optical coherence tomography revealed a median increase in macular central subfield thickness of 42 µm compared with baseline (overall, P = 0.029; between groups, P = 0.995).

Conclusions

EVD survivors and controls demonstrated significant visual improvement from cataract surgery. The persistence of intraocular inflammation highlights the importance of follow-up. The absence of detectable intraocular Ebola viral RNA provides guidance regarding the safety of eye surgery in Ebola survivors.

Translational Relevance

These findings demonstrate the safety and efficacy of cataract surgery in Ebola survivors and will inform ocular surgery guidelines in this population.

Efficacy of intracameral antibiotics following manual small incision cataract surgery in reducing the rates of endophthalmitis: A meta-analysis

BACKGROUND

Manual small incision cataract surgery (MSICS) is a widely used technique for cataract surgery in the developing world. Higher rates of postoperative endophthalmitis have been reported with this technique compared with phaco-emulsification. The purpose of this study was to evaluate the efficacy of prophylactic intracameral (IC) antibiotics in reducing the rates of postoperative endophthalmitis following MSICS.

METHODS

Systematic review and meta-analysis of patients undergoing MSICS. A literature search in PubMed and EMBASE databases was performed to identify studies published from October 1992 to April 2020 evaluating MSICS with a minimum of 500 eyes reported. Two authors independently assessed eligibility, extracted data and assessed the risk of bias. Heterogeneity was assessed using the I² test.

RESULTS

Twelve studies enrolling 1 494 307 eyes were included. IC antibiotics were used in 725 324 (48.5%) eyes. The risk ratio of developing endophthalmitis was 2.94 (95% CI, 1.07-8.12; P = .037) in eyes that did not receive IC antibiotics.

CONCLUSIONS

Routine use of IC antibiotics may help to reduce the rates of endophthalmitis following MSICS and significantly improve the safety of this effective form of cataract surgery.

Characterization of Ebola Virus-Associated Eye Disease

IMPORTANCE

Survivors of Ebola virus disease (EVD) may experience ocular sequelae. Comparison with antibody-negative individuals from the local population is required to characterize the disease.

OBJECTIVE

To assess features of ophthalmic disease specific to EVD.

DESIGN, SETTING, AND PARTICIPANTS

This baseline cross-sectional analysis of survivors of EVD and their close contacts was conducted within PREVAIL III, a 5-year, longitudinal cohort study. Participants who enrolled at John F. Kennedy Medical Center in Liberia, West Africa from June 2015 to March 2016 were included in this analysis. Close contacts were defined as household members or sex partners of survivors of EVD. Data were analyzed from July 2016 to July 2020.

EXPOSURES

All participants, both survivors and close contacts, underwent testing of IgG antibody levels against Ebola virus surface glycoprotein.

MAIN OUTCOMES AND MEASURES

Ocular symptoms, anterior and posterior ophthalmologic examination findings, and optical coherence tomography images were compared between antibody-positive survivors and antibody-negative close contacts.

RESULTS

A total of 564 antibody-positive survivors (320 [56.7%] female; mean [SD] age, 30.3 [14.0] years) and 635 antibody-negative close contacts (347 [54.6%] female; mean [SD] age, 25.8 [15.5] years) were enrolled in this study. Survivors were more likely to demonstrate color vision deficit (28.9% vs 19.0%, odds ratio [OR], 1.6; 95% CI, 1.2-2.1) and lower intraocular pressure (12.4 vs 13.5 mm Hg; mean difference, -1.2 mm Hg; 95% CI, -1.6 to -0.8 mm Hg) compared with close contacts. Dilated fundus examination revealed a higher percentage of vitreous cells (7.8% vs 0.5%; OR, 16.6; 95% CI, 5.0-55.2) and macular scars (4.6% vs 1.6%; OR, 2.8; 95% CI, 1.4-5.5) in survivors than in close contacts. Uveitis was present in 26.4% of survivors and 12.1% of close contacts (OR, 2.4; 95% CI, 1.8-3.2). Among all participants with uveitis, survivors were more likely than close contacts to have intermediate uveitis (34.2% vs 6.5% of all cases; OR, 7.8; 95% CI, 3.1-19.7) and had thicker mean central subfield thickness on optical coherence tomography (222 vs 212 μm; mean difference, 14.4 μm; 95% CI, 1.9-26.9 μm).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, survivors of EVD had a distinct spectrum of ocular and neuro-ophthalmologic findings compared with close contacts that potentially require medical and surgical treatment.

Ophthalmic manifestations and vision impairment in Lassa fever survivors

The purpose of this study was to describe the ocular findings, structural ocular complications, and vision impairment in a cohort of Lassa fever survivors in Kenema, Sierra Leone. A retrospective, uncontrolled, cross-sectional study of 31 Lassa fever survivors (62 eyes) who underwent an ophthalmic evaluation in January 2018 at the Kenema Government Hospital in Kenema, Sierra Leone was performed. Data collection included demographic information, ocular/systemic symptoms, visual acuity (VA), and ophthalmic examination findings. Main outcome measures included anterior and posterior segment ophthalmic manifestations and level of VA impairment in Lassa fever survivors. Anterior segment findings included cataract (18%) and pterygium (2%), while posterior segment manifestations consisted of glaucoma (6%), preretinal hemorrhage (2%), and lattice degeneration (2%). Findings suggestive of prior sequelae of uveitis included chorioretinal scarring (5%), retinal fibrosis (3%), and vitreous opacity (2%). Visual acuity was normal/mildly impaired in 53 eyes (85%), moderately impaired in 6 eyes (10%), and 3 eyes (5%) were considered blind by the World Health Organization (WHO) criteria. Median VA was worse in Lassa fever survivors with ophthalmic disease findings (p<0.0001) for both anterior segment (p<0.0001) and posterior segment disease (p<0.013). Untreated cataract was a significant cause of visual acuity impairment (p<0.0001). Lassa fever survivors in this cohort were found to have cataract and posterior segment findings that potentially represent sequelae of uveitis associated with visual impairment. Future studies are warranted to improve our understanding of the spectrum of ocular disease in this emerging infectious disease of public health consequence.

Ebola, COVID-19, and emerging infectious disease: lessons learned and future preparedness

PURPOSE OF REVIEW

To highlight the lessons learned from the Ebola outbreak that may inform our approach to the COVID-19 pandemic, particularly related to the widespread disruption of healthcare, ophthalmic disease manifestations, and vision health systems strengthening for future outbreaks.

RECENT FINDINGS

Coronavirus disease 2019 (COVID-19), first detected in China in December 2019, has become a worldwide health emergency, with significant disruption of all aspects of society, including travel, business, and medical care. Although this pandemic has had unprecedented effects on healthcare delivery in the United States, experiences from recent Ebola virus disease (EVD) outbreaks in Africa provide insight and inform our approach to COVID-19 and outbreak preparedness. Like COVID-19, the rapid emergence of Ebola required new clinical and surgical approaches to understand its associated spectrum of ophthalmic complications and the potential for Ebola viral persistence within the eye and in tear film. Recent reports of ophthalmic findings associated with COVID-19 include conjunctivitis, retinopathy, and molecular evidence of virus within the tear film in a minority of cases. Yet, more rigorous approaches to understand ophthalmic disease and transmission risk associated with COVID-19 are needed. Gaps also remain in our understanding of eye disease associated with other high priority emerging infectious diseases including Nipah, Lassa fever, Marburg virus, and others.

SUMMARY

Thoroughly understanding the ophthalmic findings and transmission risk associated with COVID-19 is paramount during this pandemic, providing additional measures of safety while resuming ophthalmic care for all patients. Vision health systems preparedness measures developed during recent EVD outbreaks and the current pandemic provide models for ophthalmic clinical practice, research, and education, as we continue to address COVID-19 and future emerging infectious disease threats.

Pathogenesis of SARS-CoV-2 in Transgenic Mice Expressing Human Angiotensin-Converting Enzyme 2

COVID-19 has spread worldwide since 2019 and is now a severe threat to public health. We previously identified the causative agent as a novel SARS-related coronavirus (SARS-CoV-2) that uses human angiotensin-converting enzyme 2 (hACE2) as the entry receptor. Here, we successfully developed a SARS-CoV-2 hACE2 transgenic mouse (HFH4-hACE2 in C3B6 mice) infection model. The infected mice generated typical interstitial pneumonia and pathology that were similar to those of COVID-19 patients. Viral quantification revealed the lungs as the major site of infection, although viral RNA could also be found in the eye, heart, and brain in some mice. Virus identical to SARS-CoV-2 in full-genome sequences was isolated from the infected lung and brain tissues. Last, we showed that pre-exposure to SARS-CoV-2 could protect mice from severe pneumonia. Our results show that the hACE2 mouse would be a valuable tool for testing potential vaccines and therapeutics.

Absence of Severe Acute Respiratory Syndrome-Coronavirus-2 RNA in ocular tissues

Purpose

To evaluate the status of ocular donor tissues of a COVID-19 postmortem donor.

Methods

SARS-CoV-2 was detected via a pharyngeal swab and broncho-alveolar lavage in the COVID-19 suspect. Postmortem tissue procurement and preparation were performed with personal protective equipment (PPE) and the necessary protective measures. qRT-PCR-testing was performed for the following ocular tissues and fluids: conjunctival fluid swabs, bulbar conjunctiva, corneal epithelium, corneal stroma, corneal endothelium, anterior chamber fluid, lens, iris, vitreous, retina, uvea, sclera, and optic nerve. Informed consent and Institutional Review Board approval was obtained prior to this study (196/2020BO2; Date of approval: 03/26/2020; Ethics Committee of the University of Tuebingen).

Results

In all ocular tissue and fluid samples no SARS-CoV-2 RNA was detected via qRT-PCR of the confirmed COVID-19 postmortem donor.

Conclusions and Importance

Late-stage COVID-19 patients might not harbor an ocular reservoir of SARS-CoV-2. The risk of transmitting SARS-CoV-2 via ocular tissues and fluids might be low. This may bear future implications for patient management in ophthalmological practice, surgery and transplantation.

Approach to Cataract Surgery in an Ebola Virus Disease Survivor with Prior Ocular Viral Persistence

A 46-year-old patient with previously documented Ebola virus persistence in his ocular fluid, associated with severe panuveitis, developed a visually significant cataract. A multidisciplinary approach was taken to prevent and control infection. Ebola virus persistence was assessed before and during the operation to provide safe, vision-restorative phacoemulsification surgery.

Clinical characteristics of emergency surgery patients infected with coronavirus disease 2019 (COVID-19) pneumonia in Wuhan, China

Background

We aimed to investigate clinical symptoms and epidemiologic features of emergency surgery patients infected with the 2019 novel coronavirus disease (COVID-19). More than 5 million people worldwide have been diagnosed with COVID-19 since December 2019 to the time of this publication. Thousands of emergency operations have been carried out since December 2019. To date, however, no literature has focused on the clinical symptoms of emergency surgery patients with COVID-19 pneumonia.

Methods

We conducted a retrospective cohort study of 164 emergency surgery patients with or without COVID-19 pneumonia in Zhongnan Hospital of Wuhan University in Wuhan, China, from January 1, 2020, to January 20, 2020. For this report, the final date of follow-up was February 5, 2020. The associated clinical, laboratory, epidemiologic, demographic, radiologic, and outcome data were collected and analyzed.

Results

Of the 164 emergency surgery patients, the median age was 41 years (interquartile range, 29–89), and 136 (82.9%) were women. The associated main clinical symptom included fever (93 [56.7%])，dry cough (56 [34.2%]), fatigue (86 [52.4%]), nausea (78 [47.6%]), and dizziness (77 [47%]). Of 54 emergency surgery patients infected with COVID-19, the median age was 46 years (interquartile range: 25–89), and 45 (83.3%) were women. The pathologic clinical symptoms investigated included fever (54 [100%]), fatigue (48 [88.9%]), nausea (52 [96.3%]), dizziness (46 [85.2%]), and dry cough (44 [81.5%]). The lymphopenia (0.37 × 10⁹/L [interquartile range: 0.23-0.65]) and increased C-reactive protein (24.7 × 10⁹/L [interquartile range: 13.57-38]) were observed. The preoperative fever and postoperative fever in emergency surgery patients with or without COVID-19 pneumonia were analyzed in this study. Of 54 emergency surgery patients with COVID-19, 15 (27.8%) showed preoperative fever, 54 (100%) had postoperative fever. Of 110 emergency surgery patients without COVID-19, 5 (4.5%) had preoperative fever, 31 (28.2%) patients had postoperative fever. In emergency surgery patients with COVID-19, the fever lasted more than 7 days, markedly exceeded the length of time non–COVID-19 patients experienced fever (approximately 3 days). Furthermore, 43 health care workers were exposed to emergency surgery patients with COVID-19 pneumonia and were infected with COVID-19 pneumonia.

Conclusion

In our study, the clinical symptoms of emergency surgery patients infected with COVID-19 displayed marked differences from those reporting common COVID-19 pneumonia. In addition, the health care workers were suspected to have been exposed to a great risk when caring for emergency surgery patients with COVID-19 pneumonia. Management guidelines of emergency surgery patients are described in in this report.

Pathogenesis of Uveitis in Ebola Virus Disease Survivors: Evolving Understanding from Outbreaks to Animal Models

Ebola virus disease (EVD) and emerging infectious disease threats continue to threaten life, prosperity and global health security. To properly counteract EVD, an improved understanding of the long-term impact of recent EVD outbreaks in West Africa and the Democratic Republic of Congo are needed. In the wake of recent outbreaks, numerous health sequelae were identified in EVD survivors. These findings include joint pains, headaches, myalgias, and uveitis, a vision-threatening inflammatory condition of the eye. Retrospective and more recent prospective studies of EVD survivors from West Africa have demonstrated that uveitis may occur in 13–34% of patients with an increase in prevalence from baseline to 12-month follow-up. The clinical spectrum of disease ranges from mild, anterior uveitis to severe, sight-threatening panuveitis. Untreated inflammation may ultimately lead to secondary complications of cataract and posterior synechiae, with resultant vision impairment. The identification of Ebola virus persistence in immune privileged organs, such as the eye, with subsequent tissue inflammation and edema may lead to vision loss. Non-human primate models of EVD have demonstrated tissue localization to the eye including macrophage reservoirs within the vitreous matter. Moreover, in vitro models of Ebola virus have shown permissiveness in retinal pigment epithelial cells, potentially contributing to viral persistence. Broad perspectives from epidemiologic studies of the outbreak, animal modeling, and immunologic studies of EVD survivors have demonstrated the spectrum of the eye disease, tissue specificity of Ebola virus infection, and antigen-specific immunologic response. Further studies in these areas will elucidate the mechanisms of this highly prevalent disease with the potential for improved therapeutics for Ebola virus in immune-privileged sites.

Evolving Longitudinal Retinal Observations in a Cohort of Survivors of Ebola Virus Disease

Importance

The 2-year ophthalmic sequelae of Ebola virus disease (EVD) in survivors of the 2013 to 2016 epidemic is unknown and may have public health implications for future outbreaks.

Objective

To assess the potential for uveitis recurrence, the behavior of dark without pressure, and visual outcomes in a cohort of Sierra Leonean survivors of EVD 2 years following the 2013 to 2016 Ebola epidemic.

Design, Setting, and Participants

Prospective, 1-year observational cohort study performed between 2016 and 2017 at 34 Military Hospital, Freetown, Sierra Leone. Participants included survivors of EVD who reported ocular symptoms since Ebola treatment unit discharge and were participants of a previous case-control study. Participants were invited for ophthalmic reexamination and finger-prick blood sampling for immunoglobulin G (IgG) to Toxoplasma gondii and HIV.

Exposures

Ebola virus disease.

Main Outcomes and Measures

Primary outcome measure: comparative ultra-widefield retinal imaging. Secondary outcome measures: visual acuity and detection of IgG to T gondii and HIV.

Results

Of 57 survivors of EVD who underwent repeated ophthalmic evaluation, 37 were women (64.9%). Mean (SD) age was 31.9 (11.1) years. Median interval between first and last examination was 370 days (interquartile range [IQR], 365-397.5 days), and median time from discharge to last examination was 779 days (IQR, 732-821 days). Fifteen eyes of 10 survivors (17.5%) had retinal lesions secondary to EVD. No new EVD-associated retinal lesions were observed. Two survivors (3.5%) developed new posterior uveitis resembling toxoplasmosis chorioretinitis and 41 (73%) were seropositive for T gondii IgG. Areas of dark without pressure were observed either confined to the perimeter of Ebola retinal lesions (n = 7) and non-Ebola lesions (n = 2), involving extensive retinal areas adjacent to Ebola retinal lesions (n = 4) and non-Ebola lesions (n = 2) or in isolation (n = 6). Both expansion and regression of areas of dark without pressure were observed over the study period. Best eye-presenting visual acuity had mild or no visual impairment in 55 survivors (96.4%) 2 years following discharge.

Conclusions and Relevance

Vision was maintained in survivors of EVD 2 years following discharge. Evolving regions of dark without pressure may be associated with EVD retinal lesions and might suggest the presence of an ongoing intraretinal stimulus, which may be associated with infective etiology. Treatment strategies should account for the possibility of toxoplasmosis chorioretinitis recurrence within survivors of EVD.

Ebola Virus Disease: Epidemiology, Clinical Features, Management, and Prevention

Ebola virus disease (EVD) is a deadly zoonotic disease caused by the Ebola virus. There is no specific treatment approved for EVD. Supportive care and management of complications are mainstays of treatment. Effective outbreak control requires a multidisciplinary team effort applying case management, infection prevention and control practices, surveillance and contact tracing, a good laboratory service, safe and dignified burials, and social and community mobilization. This article highlights the epidemiology, clinical features, diagnosis, management, and prevention of EVD. The emerging diagnostic technologies, rapid viral characterization, geospatial mapping of EVD transmission, and new treatments and vaccines are discussed.

Lassa Virus Targeting of Anterior Uvea and Endothelium of Cornea and Conjunctiva in Eye of Guinea Pig Model

Lassa virus (LASV), a hemorrhagic fever virus endemic to West Africa, causes conjunctivitis in patients with acute disease. To examine ocular manifestations of LASV, we histologically examined eyes from infected guinea pigs. In fatal disease, LASV immunostaining was most prominent in the anterior uvea, especially in the filtration angle, ciliary body, and iris and in and around vessels in the bulbar conjunctiva and peripheral cornea, where it co-localized with an endothelial marker (platelet endothelial cell adhesion molecule). Antigen was primarily associated with infiltration of T-lymphocytes around vessels in the anterior uvea and with new vessel formation at the peripheral cornea. In animals that exhibited clinical signs but survived infection, eyes had little to no inflammation and no LASV immunostaining 6 weeks after infection. Overall, in this model, LASV antigen was restricted to the anterior uvea and was associated with mild chronic inflammation in animals with severe disease but was not detected in survivors.

Emergent threats: lessons learnt from Ebola

Recent disease outbreaks have demonstrated the severe health, economic and political crises that epidemics can trigger. The rate of emergence of infectious diseases is accelerating and, with deepening globalisation, pathogens are increasingly mobile. Yet the 2014-2015 West African Ebola epidemic exposed major gaps in the world's capacity to prevent and respond to epidemics. In the midst of the world's second largest ever recorded Ebola outbreak in the Democratic Republic of the Congo, we reflect on six of the many lessons learnt from the epidemic in West Africa, focusing on progress made and the challenges ahead in preparing for future threats. While Ebola and other emerging epidemics will remain a challenge in the years to come, by working in partnership with affected communities and across sectors, and by investing in robust health systems, it is within our power to be better prepared when they strike.

TiO2 Nanoparticle-Enhanced Linker Recombinant Strand Displacement Amplification (LRSDA) for Universal Label-Free Visual Bioassays

The influence of nanomaterials on dynamic isothermal amplification and their morphology regulated by bionic biological reactions in vitro remain unknown. From a theoretical perspective, TiO₂ nanoparticles enhance the amplification efficiency and reaction specificity of recombinase polymerase amplification (RPA). These nanoparticles aggregated into larger nanoclusters by adsorbing RPA components, termed nanoscale RPA factories, which increased their local concentrations to enhance RPA. Following the nick/extension cycles mediated by a bifunctional linker located at the 5' end of the forward primers, the TiO₂ nanoparticle-enhanced LRSDA process produces single-stranded products, constituting the G-quadruplex DNAzymes and catalyzing the chromogenic substrate to facilitate colorimetric analysis for on-site bioassays. Salmonella spp. and genetically modified maize MON810 could be detected with a detection limit of 4 cfu/mL and 0.1% transgenic components, respectively. Briefly, TiO₂-assisted isothermal molecular amplification addressed the demands of practical on-site applications.

Expression of microRNA in human retinal pigment epithelial cells following infection with Zaire ebolavirus

OBJECTIVE

Survivors of Ebola virus disease (EVD) are at risk of developing blinding intraocular inflammation-or uveitis-which is associated with retinal pigment epithelial (RPE) scarring and persistence of live Zaire ebolavirus (EBOV) within the eye. As part of a large research project aimed at defining the human RPE cell response to being infected with EBOV, this work focused on the microRNAs (miRNAs) associated with the infection.

RESULTS

Using RNA-sequencing, we detected 13 highly induced and 2 highly repressed human miRNAs in human ARPE-19 RPE cells infected with EBOV, including hsa-miR-1307-5p, hsa-miR-29b-3p and hsa-miR-33a-5p (up-regulated), and hsa-miR-3074-3p and hsa-miR-27b-5p (down-regulated). EBOV-miR-1-5p was also found in infected RPE cells. Through computational identification of putative miRNA targets, we predicted a broad range of regulatory activities, including effects on innate and adaptive immune responses, cellular metabolism, cell cycle progression, apoptosis and autophagy. The most highly-connected molecule in the miR-target network was leucine-rich repeat kinase 2, which is involved in neuroinflammation and lysosomal processing. Our findings should stimulate new studies on the impact of miRNA changes in EBOV-infected RPE cells to further understanding of intraocular viral persistence and the pathogenesis of uveitis in EVD survivors.

Association of Ebola Virus Infection With Hearing Loss in Regions Where Ebola Virus Infection Is Endemic: A Systematic Review

Importance

Many survivors of Ebola virus infection describe new-onset hearing loss after infection. The prevalence, severity, and pathophysiologic features of hearing loss in this population have not been well characterized.

Objective

To perform a systematic review of the current literature to characterize hearing loss in survivors of Ebola virus infection.

Evidence Review

This study adhered to the relevant sections of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Searches through PubMed, Embase, and Google Scholar were performed to include publications written in English from January 1, 1965, to October 1, 2018. Relevant vocabulary terms and key terms related to Ebola and hearing loss were used. Two investigators independently screened the eligible studies, extracted data, and assessed quality and risk of bias.

Findings

Of 127 publications reviewed, 15 met the criteria for inclusion; 3 were retrospective case-control studies (level of evidence, 3), and 12 were cross-sectional studies or case reports (level of evidence, 4). Studies included 1775 survivors of Ebola virus infection (993 female [55.9%]) and 363 uninfected controls (186 female [51.2%]) from the Democratic Republic of the Congo, Uganda, Guinea, Liberia, and Sierra Leone. The duration of follow-up ranged from 0 to 29 months (median, 5 months). Hearing loss was reported in 147 survivors of Ebola virus infection (8.3%). Among studies that compared survivors with controls, the reported odds ratios for hearing loss in survivors was 7.50 (95% CI, 3.91-14.39; range, 1.4-12.1). Including all studies, the odds ratio of hearing loss in survivors vs controls in countries where Ebola virus infection is endemic was 1.84 (95% CI, 1.10-3.08).

Conclusions and Relevance

Survivors of Ebola virus infection had higher rates of hearing loss than uninfected controls in regions where the infection is endemic. Further research with consistent objective methods and pure-tone audiometry may be needed to better characterize the hearing loss, understand its pathophysiologic features, and develop treatments.

Early Human B Cell Response to Ebola Virus in Four U.S. Survivors of Infection

The human B cell response to natural filovirus infections early after recovery is poorly understood. Previous serologic studies suggest that some Ebola virus survivors exhibit delayed antibody responses with low magnitude and quality. Here, we sought to study the population of individual memory B cells induced early in convalescence. We isolated monoclonal antibodies (MAbs) from memory B cells from four survivors treated for Ebola virus disease (EVD) 1 or 3 months after discharge from the hospital. At the early time points postrecovery, the frequency of Ebola-specific B cells was low and dominated by clones that were cross-reactive with both Ebola glycoprotein (GP) and with the secreted GP (sGP) form. Of 25 MAbs isolated from four donors, only one exhibited neutralization activity. This neutralizing MAb, designated MAb EBOV237, recognizes an epitope in the glycan cap of the surface glycoprotein. In vivo murine lethal challenge studies showed that EBOV237 conferred protection when given prophylactically at a level similar to that of the ZMapp component MAb 13C6. The results suggest that the human B cell response to EVD 1 to 3 months postdischarge is characterized by a paucity of broad or potent neutralizing clones. However, the neutralizing epitope in the glycan cap recognized by EBOV237 may play a role in the early human antibody response to EVD and should be considered in rational design strategies for new Ebola virus vaccine candidates.IMPORTANCE The pathogenesis of Ebola virus disease (EVD) in humans is complex, and the mechanisms contributing to immunity are poorly understood. In particular, it appears that the quality and magnitude of the human B cell response early after recovery from EVD may be reduced compared to most viral infections. Here, we isolated human monoclonal antibodies from B cells of four survivors of EVD at 1 or 3 months after hospital discharge. Ebola-specific memory B cells early in convalescence were low in frequency, and the antibodies they encoded demonstrated poor neutralizing potencies. One neutralizing antibody that protected mice from lethal infection, EBOV237, was identified in the panel of 25 human antibodies isolated. Recognition of the glycan cap epitope recognized by EBOV237 suggests that this antigenic site should be considered in vaccine design and treatment strategies for EVD.

Development of a screening eye clinic for Ebola virus disease survivors: Lessons learned and rapid implementation at ELWA Hospital in Monrovia, Liberia 2015

BACKGROUND

In the wake of the West African Ebola virus disease (EVD) outbreak of 2014-2016, thousands of EVD survivors began to manifest a constellation of systemic and ophthalmic sequelae. Besides systemic arthralgias, myalgias, and abdominal pain, patients were developing uveitis, a spectrum of inflammatory eye disease leading to eye pain, redness, and vision loss. To investigate this emerging eye disease, resources and equipment were needed to promptly evaluate this sight-threatening condition, particularly given our identification of Ebola virus in the ocular fluid of an EVD survivor during disease convalescence.

METHODOLOGY/PRINCIPAL FINDINGS

A collaborative effort involving ophthalmologists, infectious disease specialists, eye care nurses, and physician leadership at Eternal Love Winning Africa (ELWA) Hospital in Liberia led to the development of a unique screening eye clinic for EVD survivors to screen, treat, and refer patients for more definitive care. Medications, resources, and equipment were procured from a variety of sources including discount websites, donations, purchasing with humanitarian discounts, and limited retail to develop a screening eye clinic and rapidly perform detailed ophthalmologic exams. Findings were documented in 96 EVD survivors to inform public health officials and eye care providers of the emerging disease process. Personal protective equipment was tailored to the environment and implications of EBOV persistence within intraocular fluid.

CONCLUSIONS/SIGNIFICANCE

A screening eye clinic was feasible and effective for the rapid screening, care, and referral of EVD survivors with uveitis and retinal disease. Patients were screened promptly for an initial assessment of the disease process, which has informed other efforts within West Africa related to immediate patient care needs and our collective understanding of EVD sequelae. Further attention is needed to understand the pathogensis and treatment of ophthalmic sequelae given recent EVD outbreaks in West Africa and ongoing outbreak within Democratic Republic of Congo.

Development of a screening eye clinic for Ebola virus disease survivors: Lessons learned and rapid implementation at ELWA Hospital in Monrovia, Liberia 2015

BACKGROUND

In the wake of the West African Ebola virus disease (EVD) outbreak of 2014-2016, thousands of EVD survivors began to manifest a constellation of systemic and ophthalmic sequelae. Besides systemic arthralgias, myalgias, and abdominal pain, patients were developing uveitis, a spectrum of inflammatory eye disease leading to eye pain, redness, and vision loss. To investigate this emerging eye disease, resources and equipment were needed to promptly evaluate this sight-threatening condition, particularly given our identification of Ebola virus in the ocular fluid of an EVD survivor during disease convalescence.

METHODOLOGY/PRINCIPAL FINDINGS

A collaborative effort involving ophthalmologists, infectious disease specialists, eye care nurses, and physician leadership at Eternal Love Winning Africa (ELWA) Hospital in Liberia led to the development of a unique screening eye clinic for EVD survivors to screen, treat, and refer patients for more definitive care. Medications, resources, and equipment were procured from a variety of sources including discount websites, donations, purchasing with humanitarian discounts, and limited retail to develop a screening eye clinic and rapidly perform detailed ophthalmologic exams. Findings were documented in 96 EVD survivors to inform public health officials and eye care providers of the emerging disease process. Personal protective equipment was tailored to the environment and implications of EBOV persistence within intraocular fluid.

CONCLUSIONS/SIGNIFICANCE

A screening eye clinic was feasible and effective for the rapid screening, care, and referral of EVD survivors with uveitis and retinal disease. Patients were screened promptly for an initial assessment of the disease process, which has informed other efforts within West Africa related to immediate patient care needs and our collective understanding of EVD sequelae. Further attention is needed to understand the pathogensis and treatment of ophthalmic sequelae given recent EVD outbreaks in West Africa and ongoing outbreak within Democratic Republic of Congo.

Cataract management in Ebola virus disease survivors: clinical and scientific implications

"The EVICT study was the first study to demonstrate a step-wise approach on how to safely screen EVD survivors for cataract surgery, providing evidence that vision restoration though surgical management was safe and feasible in this cohort of EVD survivors".

Emerging infectious uveitis: Chikungunya, dengue, Zika and Ebola: A review

Recently recognized forms of uveitis include intraocular inflammations that occur during or following one of several emerging infectious diseases: chikungunya fever, dengue, Zika virus disease and Ebola virus disease. Anterior, intermediate, posterior and pan-uveitis have been described in individuals infected with chikungunya virus. Persons who contract dengue or Zika viruses also may develop different types of uveitis in the course of the infection: maculopathy is a common manifestation of dengue eye disease, and Zika eye disease may cause hypertensive anterior uveitis or mimic a white dot syndrome. Up to one-third of Ebola survivors develop aggressive uveitis, which is frequently associated with vision loss and complicated by cataract. There are no specific anti-viral drugs for these forms of uveitis, and thus treatment is largely supportive. In this article, we summarize the systemic infectious diseases and virology, and describe the clinical presentations, outcomes and management of emerging viral forms of uveitis.

Ocular complications in Ebola virus disease survivors: the importance of continuing care in West Africa

Introduction

The largest Ebola virus (EBOV) outbreak occurred from 2013 - 2016 in West Africa and consequently resulted in the largest cohort of Ebola virus disease (EVD) survivors to date. Ocular disease is among the most common sequelae reported in EVD survivors. This review discusses the prevalence, manifestations, pathogenesis, diagnosis and management of EVD-related ocular disease.

Areas covered

An extensive review of the literature was performed to detail the prevalence and manifestations of EVD-related ocular disease. We also review current eye screening and treatment strategies and our current understanding and approach to invasive ophthalmic procedures including surgery.

Expert opinion

The ocular sequelae of EVD can lead to vision impairment or blindness, if untreated. Keys to the prevention of such an outcome include timely evaluation and access to appropriate ophthalmic care. The persistence of EBOV in the eye and other immune-privileged sites is the subject of ongoing investigation, but should not be a barrier to care if appropriate screening and biosafety measures are taken. Improved understanding of the pathogenesis of this condition and ongoing clinical care are needed for EVD survivors at-risk for ocular complications.

Persistence and Sexual Transmission of Filoviruses

There is an increasing frequency of reports regarding the persistence of the Ebola virus (EBOV) in Ebola virus disease (EVD) survivors. During the 2014⁻2016 West African EVD epidemic, sporadic transmission events resulted in the initiation of new chains of human-to-human transmission. Multiple reports strongly suggest that these re-emergences were linked to persistent EBOV infections and included sexual transmission from EVD survivors. Asymptomatic infection and long-term viral persistence in EVD survivors could result in incidental introductions of the Ebola virus in new geographic regions and raise important national and local public health concerns. Alarmingly, although the persistence of filoviruses and their potential for sexual transmission have been documented since the emergence of such viruses in 1967, there is limited knowledge regarding the events that result in filovirus transmission to, and persistence within, the male reproductive tract. Asymptomatic infection and long-term viral persistence in male EVD survivors could lead to incidental transfer of EBOV to new geographic regions, thereby generating widespread outbreaks that constitute a significant threat to national and global public health. Here, we review filovirus testicular persistence and discuss the current state of knowledge regarding the rates of persistence in male survivors, and mechanisms underlying reproductive tract localization and sexual transmission.

Clinical Manifestations and Pathogenesis of Uveitis in Ebola Virus Disease Survivors

In the wake of the international Ebola virus disease (EVD) outbreak from 2014 to 2016, thousands of EVD survivors are at-risk of ophthalmic manifestations, as well as systemic sequelae including arthralgias, abdominal pain, psychosocial stressors, and risk of viral persistence in immune-privileged organs. Ophthalmic manifestations in EVD survivors include a spectrum of disease ranging from anterior uveitis to panuveitis, which confers a high risk of vision impairment and blindness, particularly given the access and resource limitations for ophthalmic subspecialty care in West Africa. Clinical studies in EVD survivors, animal models of EVD and translational investigation, have provided early insight into eye disease pathogenesis. Specifically, ocular inflammation recently observed in EVD survivors is thought to involve direct viral infection, inflammation, and tissue edema. Future research is needed to understand the timing of uveitis onset and management strategies, including the role of antiviral and anti-inflammatory therapies.