[Ocular manifestations of Zika virus: What we do and do not know]

Ocular Manifestations of Flavivirus Infections

Flaviviruses are a group of positive-sense, single-stranded RNA viruses predominantly transmitted by arthropods (mainly mosquitoes) that cause severe endemic infections and epidemics on a global scale. They represent a major cause of systemic morbidity and death and are expanding worldwide. Among this group, dengue fever, the West Nile virus, yellow fever, Japanese Encephalitis, and, recently, the Zika virus have been linked to a spectrum of ocular manifestations. These manifestations encompass subconjunctival hemorrhages and conjunctivitis, anterior and posterior uveitis (inclusive of vitritis, chorioretinitis, and retinal vasculitis), maculopathy, retinal hemorrhages, and optic neuritis. Clinical diagnosis of these infectious diseases is primarily based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. Diagnosis confirmation relies on laboratory testing, including RT-PCR and serological testing. Ocular involvement typically follows a self-limited course but can result in irreversible visual impairment. Effective treatments of flavivirus infections are currently unavailable. Prevention remains the mainstay for arthropod vector and zoonotic disease control. Effective vaccines are available only for the yellow fever virus, dengue virus, and Japanese Encephalitis virus. This review comprehensively summarizes the current knowledge regarding the ophthalmic manifestations of the foremost flavivirus-associated human diseases.

Fundus Changes in the Offspring of Mothers With Confirmed Zika Virus Infection During Pregnancy in French Guiana, Guadeloupe, and Martinique, French West Indies

Importance

Most ocular lesions have been described for children with congenital Zika syndrome. The frequency of finding ocular abnormalities is unknown among children exposed to Zika virus (ZIKV) during pregnancy. This study was conducted on newborns whose mothers were positive for ZIKV, confirmed with reverse-transcription polymerase chain reaction (RT-PCR) testing.

Objective

To report ocular fundus manifestations in newborns with congenital ZIKV exposure in French Guiana, Martinique, and Guadeloupe, French West Indies, to assess its prevalence. Risk factors, such as the presence of extraocular fetopathies and the gestational term at infection, were sought.

Design, Setting, and Participants

This was a cross-sectional multicentric study, conducted from August 1, 2016, to April 30, 2019, for which data were collected prospectively. The study inception was at the beginning of 2016 from the onset of the ZIKV epidemic in the French West Indies. Newborns whose mothers tested positive (by RT-PCR) for ZIKV during pregnancy were included.

Interventions

Fundus examination was performed using widefield retinal imaging after pupil dilation. Infection date, delivery mode, and newborn measurements were collected.

Main Outcomes and Measures

Anomalies of the vitreous, choroid, retina, and optic disc.

Results

A total of 330 children (mean [SD] age, 68 [IQR, 22-440] days; 170 girls [51.5%]) were included. Eleven children (3.3%) had perivascular retinal hemorrhages, and 3 (0.9%) had lesions compatible with congenital ZIKV infection: 1 child had torpedo maculopathy, 1 child had a chorioretinal scar with iris and lens coloboma, and 1 child had a chorioretinal scar. Retinal hemorrhages were found at childbirth during early screening. Lesions compatible with congenital ZIKV infection were not associated with the presence of extraocular fetopathy. Microcephaly was not associated with lesions compatible with congenital ZIKV infection (odds ratio [OR], 9.1; 95% CI, 0.8-105.3; P = .08), but severe microcephaly was associated with an OR of 81 (95% CI, 5.1-1297.8; P = .002).

Conclusions and Relevance

Results of this cross-sectional study suggest that the ocular anomalies found may be associated with ZIKV in 0.9% of the exposed population. Ocular lesions were rare, affected mostly the choroid and retina, and seemed to be associated with choroiditis-related scarring that developed during fetal growth.

[Ocular manifestations of viral diseases]

Les infections virales peuvent toucher l’ensemble des tuniques oculaires et mettre en jeu la fonction visuelle à plus ou moins courte terme. Les kératites et kérato-uvéites liées au virus HSV-1 sont les atteintes les plus fréquentes. Les récurrences entraînent une opacification cornéenne irréversible qui en fait la première cause de cécité d’origine infectieuse dans les pays occidentaux, et justifient un traitement antiviral préventif au long cours. Le zona ophtalmique (10 à 20 % des zonas), peut s’accompagner d’atteintes oculaires sévères (kératites, kérato-uvéites), dont 30 % deviennent chroniques/récurrentes, et de douleurs post-zostériennes, redoutables dans le territoire trigéminé. Les rétinites nécrosantes liées aux herpesvirus (HSV, VZV, CMV), sont rares mais constituent des urgences fonctionnelles absolues nécessitant un traitement antiviral par voie intraveineuse et intravitréenne. Les conjonctivites à adénovirus constituent la première cause de conjonctivite infectieuse. Le plus souvent bénignes, elles sont extrêmement contagieuses et peuvent se compliquer de lésions cornéennes invalidantes persistant plusieurs mois, voire années. Certaines arboviroses s’accompagnent de manifestations oculaires inflammatoires. Dans le cas du Zika, les infections congénitales peuvent se compliquer d’atrophie maculaire et/ou optique. Les conjonctivites sont très fréquentes à la phase aiguë de la maladie à virus Ebola, dont 15 % des survivants présentent des atteintes inflammatoires chroniques sévères liées à la persistance du virus dans les tissus uvéaux. Enfin, dans le cadre de la COVID-19, les conjonctivites ne sont pas très fréquentes mais peuvent être inaugurales, voire au premier plan et sont associées à une excrétion virale lacrymale qui doit faire prendre toutes les précautions.

Google Searches and Detection of Conjunctivitis Epidemics Worldwide

PURPOSE

Epidemic and seasonal infectious conjunctivitis outbreaks can impact education, workforce, and economy adversely. Yet conjunctivitis typically is not a reportable disease, potentially delaying mitigating intervention. Our study objective was to determine if conjunctivitis epidemics could be identified using Google Trends search data.

DESIGN

Search data for conjunctivitis-related and control search terms from 5 years and countries worldwide were obtained. Country and term were masked. Temporal scan statistics were applied to identify candidate epidemics. Candidates then were assessed for geotemporal concordance with an a priori defined collection of known reported conjunctivitis outbreaks, as a measure of sensitivity.

PARTICIPANTS

Populations by country that searched Google's search engine using our study terms.

MAIN OUTCOME MEASURES

Percent of known conjunctivitis outbreaks also found in the same country and period by our candidate epidemics, identified from conjunctivitis-related searches.

RESULTS

We identified 135 candidate conjunctivitis epidemic periods from 77 countries. Compared with our a priori defined collection of known reported outbreaks, candidate conjunctivitis epidemics identified 18 of 26 (69% sensitivity) of the reported country-wide or island nationwide outbreaks, or both; 9 of 20 (45% sensitivity) of the reported region or district-wide outbreaks, or both; but far fewer nosocomial and reported smaller outbreaks. Similar overall and individual sensitivity, as well as specificity, were found on a country-level basis. We also found that 83% of our candidate epidemics had start dates before (of those, 20% were more than 12 weeks before) their concurrent reported outbreak's report issuance date. Permutation tests provided evidence that on average, conjunctivitis candidate epidemics occurred geotemporally closer to outbreak reports than chance alone suggests (P < 0.001) unlike control term candidates (P = 0.40).

CONCLUSIONS

Conjunctivitis outbreaks can be detected using temporal scan analysis of Google search data alone, with more than 80% detected before an outbreak report's issuance date, some as early as the reported outbreak's start date. Future approaches using data from smaller regions, social media, and more search terms may improve sensitivity further and cross-validate detected candidates, allowing identification of candidate conjunctivitis epidemics from Internet search data potentially to complementarily benefit traditional reporting and detection systems to improve epidemic awareness.

[Ocular manifestations of emerging arboviruses: Dengue fever, Chikungunya, Zika virus, West Nile virus, and yellow fever (French translation of the article)]

Arboviruses are viral diseases transmitted by mosquitoes and tics bites. They are a major cause of morbidity and sometimes mortality. Their expansion is constant and due in part to climate change and globalization. Mostly found in tropical regions, arboviruses are sometimes the source of epidemics in Europe. Recently, the Chikungunya virus and the Zika virus were responsible for very large epidemics impacting populations that had never been in contact with those viruses. There are currently no effective antiviral treatments or vaccines. Ocular manifestations due to those infections are thus more frequent and increasingly better described. They are sometimes, as with Zika, complicated by a congenital ocular syndrome. The goal of this review is to describe the ophthalmological manifestations of Dengue fever, Chikungunya virus, Zika virus, West Nile virus, and yellow fever.

Clinical Age-Specific Seasonal Conjunctivitis Patterns and Their Online Detection in Twitter, Blog, Forum, and Comment Social Media Posts

Purpose

We sought to determine whether big data from social media might reveal seasonal trends of conjunctivitis, most forms of which are nonreportable.

Methods

Social media posts (from Twitter, and from online forums and blogs) were classified by age and by conjunctivitis type (allergic or infectious) using Boolean and machine learning methods. Based on spline smoothing, we estimated the circular mean occurrence time (a measure of central tendency for occurrence) and the circular variance (a measure of uniformity of occurrence throughout the year, providing an index of seasonality). Clinical records from a large tertiary care provider were analyzed in a similar way for comparison.

Results

Social media posts machine-coded as being related to infectious conjunctivitis showed similar times of occurrence and degree of seasonality to clinical infectious cases, and likewise for machine-coded allergic conjunctivitis posts compared to clinical allergic cases. Allergic conjunctivitis showed a distinctively different seasonal pattern than infectious conjunctivitis, with a mean occurrence time later in the spring. Infectious conjunctivitis for children showed markedly greater seasonality than for adults, though the occurrence times were similar; no such difference for allergic conjunctivitis was seen.

Conclusions

Social media posts broadly track the seasonal occurrence of allergic and infectious conjunctivitis, and may be a useful supplement for epidemiologic monitoring.

Ocular manifestations of emerging arboviruses: Dengue fever, Chikungunya, Zika virus, West Nile virus, and yellow fever

Arboviruses are viral diseases transmitted by mosquitoes and tick bites. They are a major cause of morbidity and sometimes mortality. Their expansion is constant and due in part to climate change and globalization. Mostly found in tropical regions, arboviruses are sometimes the source of epidemics in Europe. Recently, the Chikungunya virus and the Zika virus were responsible for very large epidemics impacting populations that had never been in contact with those viruses. There are currently no effective antiviral treatments or vaccines. Ocular manifestations due to those infections are thus more frequent and increasingly better described. They are sometimes, as with Zika, complicated by a congenital ocular syndrome. The goal of this review is to describe the ophthalmological manifestations of Dengue fever, Chikungunya virus, Zika virus, West Nile virus, and yellow fever.

Zika virus outbreak: a review of neurological complications, diagnosis, and treatment options

Zika virus (ZIKV) is an arbovirus transmitted mainly by mosquitos of Aedes species. The virus has emerged in recent years and spread throughout North and South Americas. The recent outbreak of ZIKV started in Brazil (2015) has resulted in infections surpassing a million mark. Contrary to the previous beliefs that Zika causes mildly symptomatic infections fever, headache, rash, arthralgia, and conjunctivitis, the recent outbreak associated ZIKV to serious neurological complications such as microcephaly, Guillain-Barré syndrome, and eye infections. The recent outbreak has resulted in an astonishing number of microcephaly cases in fetus and infants. Consequently, numerous studies were conducted using in vitro cell and in vivo animal models. These studies showed clear links between ZIKV infections and neurological abnormalities. Diagnosis methods based on nucleic acid and serological detection facilitated rapid and accurate identification of ZIKV infections. New transmission modalities such as sexual and transplacental transmission were uncovered. Given the seriousness of ZIKV infections, WHO declared the development of safe and effective vaccines and new antiviral drugs as an urgent global health priority. Rapid work in this direction has led to the identification of several vaccine and antiviral drug candidates. Here, we review the remarkable progress made in understanding the molecular links between ZIKV infections and neurological irregularities, new diagnosis methods, potential targets for antiviral drugs, and the current state of vaccine development.