Guillain-Barré Syndrome Associated with Zika Virus Infection in a Traveler Returning from Guyana

Development and pre-clinical evaluation of a Zika virus diagnostic for low resource settings

Introduction

Zika virus (ZIKV) is a re-emerging flavivirus that poses a significant public health threat. ZIKV exhibits a wide array of non-vector borne human transmission routes, such as sexual transmission, transplacental transmission and blood transfusion. Detection and surveillance of ZIKV is considered paramount in prevention of major outbreaks. With the majority of cases reported in low-resource locations, simple, low-cost detection methods are considered highly desirable.

Materials and Methods

Here we have developed a sensitive and specific ZIKV diagnostic using reverse transcription recombinase-aided amplification (RT-RAA) coupled with lateral flow detection (LFD) targeting a highly conserved region of the ZIKV NS1 gene.

Results

We show our rapid, isothermal-ZIKV-diagnostic (Iso-ZIKV-Dx) can detect 500 copies of synthetic ZIKV RNA/μL in under 30 min at a constant 39°C. Using simulated urine samples, we observed that Iso-ZIKV-Dx also detects as low as 34.28 RNA copies/reaction of ZIKV (MR766 strain). Specificity testing confirmed that our test does not detect any co-circulating flaviviruses (dengue, West Nile, Japanese encephalitis, Murray Valley encephalitis and yellow fever viruses) or chikungunya virus. Sample processing results show complete inactivation of ZIKV (MR766 strain) in 5 min at room temperature using our novel viral RNA sample preparation reagent. Furthermore, lateral flow strips testing demonstrates positive diagnoses in as little as 5 min in running buffer.

Discussion

Contrary to conventional RT-qPCR, our Iso-ZIKV-Dx does not require expensive machinery, specialised laboratory settings or extensively trained personnel. Pre-clinical evaluation demonstrates that our test exhibits robust, in-field capabilities without compromising sensitivity or specificity. When compared to the gold-standard RT-qPCR, our Iso-ZIKV-Dx test offers an array of applications that extend beyond diagnostics alone, including potential for surveillance and monitoring of ZIKV vector competency.

Clinical Neurophysiology of Zika Virus-Related Disorders of the Peripheral Nervous System in Adults

SUMMARY

During the 2013 to 2016 outbreak in the Pacific and Americas, Zika virus infection resulted not only in febrile and cutaneous manifestations but also in (severe) neurologic complications. These included both central and peripheral nervous system disorders. The most frequent was Guillain-Barré syndrome that typically developed 1 to 2 weeks after the acute infection. Later, other peripheral nervous system syndromes were recognized in association with the viral infection, broadening the spectrum of Zika virus-related peripheral nervous system syndromes. In the current article, the authors review all available clinical neurophysiology data on Guillain-Barré syndrome and other peripheral nervous system syndromes in an attempt to characterize the major patterns of involvement related to Zika virus. The authors also highlight the clinical usefulness of nerve conduction studies and needle EMG in the investigation of suspected Zika virus-related Guillain-Barré syndrome.

Molecular techniques for the genomic viral RNA detection of West Nile, Dengue, Zika and Chikungunya arboviruses: a narrative review

Introduction: Molecular technology has played an important role in arboviruses diagnostics. PCR-based methods stand out in terms of sensitivity, specificity, cost, robustness, and accessibility, and especially the isothermal amplification (IA) method is ideal for field-adaptable diagnostics in resource-limited settings (RLS).Areas covered: In this review, we provide an overview of the various molecular methods for West Nile, Zika, Dengue and Chikungunya. We summarize literature works reporting the assessment and use of in house and commercial assays. We describe limitations and challenges in the usage of methods and opportunities for novel approaches such as NNext-GenerationSequencing (NGS).Expert opinion: The rapidity and accuracy of differential diagnosis is essential for a successful clinical management, particularly in co-circulation area of arboviruses. Several commercial diagnostic molecular assays are available, but many are not affordable by RLS and not usable as Point-of-care/Point-of-need (POC/PON) such as RReal-TimeRT-PCR, Array-based methods and NGS. In contrast, the IA-based system fits better for POC/PON but it is still not ideal for the multiplexing detection system. Improvement in the characterization and validation of current molecular assays is needed to optimize their translation to the point of care.

Militão de Albuquerque MDF. Guillain-Barré syndrome related to Zika virus infection: A systematic review and meta-analysis of the clinical and electrophysiological phenotype

Background

The Zika virus (ZIKV) has been associated with Guillain-Barré syndrome (GBS) in epidemiological studies. Whether ZIKV-associated GBS is related to a specific clinical or electrophysiological phenotype has not been established. To this end, we performed a systematic review and meta-analysis of all published studies on ZIKV-related GBS.

Methods

We searched Pubmed, EMBASE and LILACS, and included all papers, reports or bulletins with full text in English, Spanish or Portuguese, reporting original data of patients with GBS and a suspected, probable or confirmed recent ZIKV infection. Data were extracted according to a predefined protocol, and pooled proportions were calculated.

Results

Thirty-five studies were included (13 single case reports and 22 case series, case-control or cohort studies), reporting on a total of 601 GBS patients with a suspected, probable or confirmed ZIKV infection. Data from 21 studies and 587 cases were available to be summarized. ZIKV infection was confirmed in 21%, probable in 22% and suspected in 57% of cases. ZIKV PCR was positive in 30% (95%CI 15–47) of tested patients. The most common clinical features were: limb weakness 97% (95%CI 93–99), diminished/absent reflexes 96% (95%CI 88–100), sensory symptoms 82% (95%CI 76–88), and facial palsy 51% (95%CI 44–58). Median time between infectious and neurological symptoms was 5–12 days. Most cases had a demyelinating electrophysiological subtype and half of cases were admitted to the Intensive Care Unit (ICU). Heterogeneity between studies was moderate to substantial for most variables.

Conclusions

The clinical phenotype of GBS associated with ZIKV infection reported in literature is generally a sensorimotor demyelinating GBS with frequent facial palsy and a severe disease course often necessitating ICU admittance. Time between infectious and neurological symptoms and negative PCR in most cases suggests a post-infectious disease mechanism. Heterogeneity between studies was considerable and results may be subject to reporting bias. This study was registered on the international Prospective Register of Systematic Reviews (CRD42018081959).

Guillain-Barré syndrome (GBS) is a rare but severe neurological disease, characterized by an acute onset flaccid paralysis. GBS is thought to be caused by an exaggerated immune response to common infections that damages the peripheral nerves. The Zika virus (ZIKV) is the most recent pathogen to be connected to GBS, when large outbreaks of ZIKV infection in French Polynesia and Latin America were followed by an increased incidence of GBS patients. To better understand the clinical features and outcome of ZIKV-related GBS, we have performed a systematic review and meta-analysis of all published studies on GBS related to ZIKV. We identified 35 studies, reporting on a total of 601 patients with GBS and a suspected, probable or confirmed Zika virus infection, and were able to summarize data of 587 patients from 21 studies in a pooled analysis. Our study shows that published cases with ZIKV-related GBS generally have both sensory and motor symptoms, facial palsy, demyelination on electrophysiological examination, and a severe disease course that often necessitates ICU admittance. The relatively long time between infectious and neurologic symptoms and the lack of detection of viral particles in bodily fluids in most patients suggest a post-infectious rather than an infectious pathogenesis. However, these results should be interpreted taking into account the heterogeneity between studies, which was considerable for many variables, and a possible reporting bias of more severe cases. Outbreaks of ZIKV and GBS may appear in the future and our study can help clinicians in diagnosing and managing GBS patients in ZIKV endemic areas, and increases our understanding of the neuropathology of ZIKV.

Dengue Virus Infection of Blood-Brain Barrier Cells: Consequences of Severe Disease

More than 500 million people worldwide are infected each year by any of the four-dengue virus (DENV) serotypes. The clinical spectrum caused during these infections is wide and some patients may develop neurological alterations during or after the infection, which could be explained by the cryptic neurotropic and neurovirulent features of flaviviruses like DENV. Using in vivo and in vitro models, researchers have demonstrated that DENV can affect the cells from the blood-brain barrier (BBB) in several ways, which could result in brain tissue damage, neuronal loss, glial activation, tissue inflammation and hemorrhages. The latter suggests that BBB may be compromised during infection; however, it is not clear whether the damage is due to the infection per se or to the local and/or systemic inflammatory response established or activated by the BBB cells. Similarly, the kinetics and cascade of events that trigger tissue damage, and the cells that initiate it, are unknown. This review presents evidence of the BBB cell infection with DENV and the response established toward it by these cells; it also describes the consequences of this response on the nervous tissue, compares these evidence with the one reported with neurotropic viruses of the Flaviviridae family, and shows the complexity and unpredictability of dengue and the neurological alterations induced by it. Clinical evidence and in vitro and in vivo models suggest that this virus uses the bloodstream to enter nerve tissue where it infects the different cells of the neurovascular unit. Each of the cell populations respond individually and collectively and control infection and inflammation, in other cases this response exacerbates the damage leaving irreversible sequelae or causing death. This information will allow us to understand more about the complex disease known as dengue, and its impact on a specialized and delicate tissue like is the nervous tissue.

Mucocutaneous Features of Zika-a Review

PURPOSE OF REVIEW

We review the range of dermatological signs seen in Zika infection and the possible relationship between the rash and viremia. We also hoped to explore the utility of mucocutaneous manifestations in narrowing the differential diagnosis from other similar flaviviruses.

RECENT FINDINGS

Clinical manifestations of Zika infection share many similarities with other mosquito-borne viruses such as dengue. These include non-specific symptoms such as a fever, rash, arthralgia, myalgia, and conjunctivitis. The morphology of the rash in Zika infection is not very specific and commonly described as maculopapular and centrifugal that usually extends to become diffuse. We reviewed 123 publications, encompassing a total of 368 Zika cases. One hundred seven cases with rash had sufficient data for detailed analysis. 8.4% of cases with rash had hemorrhagic manifestations such as palatal petechiae and bleeding ulcers. Only 20 reported cases were tested for viremia during presence of rash, and 70.6% of these cases were positive. While mucocutaneous complications are common in Zika infection, more research is necessary to determine the impact of rash on diagnosis, prognosis, and transmissibility in Zika infection.

Zika Virus-Associated Aseptic Meningitis and Guillain-Barre Syndrome in a Traveler Returning from Latin America: a Case Report and Mini-Review

ZIKV-associated Guillain-Barré syndrome presents with an accelerated clinical course compared to classic post-infectious Guillain-Barré syndrome. Clinicians should anticipate and screen patients with ZIKV infection for neurologic complications bearing in mind that these may manifest during the acute viremic phase or during early convalescence.

Zika in travellers 1947-2017: a systematic review

INTRODUCTION

Travellers contributed substantially to the rapid spread of Zika virus (ZIKV). They act as sentinel and may unmask ongoing ZIKV transmission in countries where outbreaks have not yet been reported. Our objectives were to (i) describe the burden of ZIKV infections in international travellers over time; (ii) estimate the proportion of birth defects as a result of maternal ZIKV infection in travellers; (iii) track the extent of sexual transmission; (iv) summarize ZIKV infections in returning travellers as reported by the GeoSentinel network; and (v) identify countries without reports on local ZIKV transmission where travellers served as sentinel.

METHODS

We performed a systematic review from 1947 to April 2017 on travel-associated ZIKV infections. We also compared published reports on autochthonous ZIKV transmission in Asia with published reports on exportations from travellers in Asia.

RESULTS

Of 314 papers that fit the inclusion criteria, 61 were eligible for final analysis. There was an exponential increase in the number of reported ZIKV infected travellers from the years 2013 to 2016, which declined in 2017. Amongst pregnant women with ZIKV infection, (5%) resulted in a fetus or infant with ZIKV-associated birth defects. An estimated 1% of the total number of ZIKV cases reported in the USA and Europe were acquired through sexual transmission. Through the GeoSentinel network, five countries (Indonesia, Philippines, Thailand, Vietnam, Cameroon) were identified as sentinel markers where ZIKV was exported despite the absence of reported local transmission.

CONCLUSIONS

Mobility patterns and travel volumes can help to identify the most likely origin of importation, and also in predicting further propagation. Studies on pregnant returning travellers have contributed to a better understanding of the risk estimates of congenital Zika syndrome/microcephaly as a result of maternal ZIKV infection, and the relative contribution of sexual transmisison.

Neurological complications of Zika virus infection

INTRODUCTION

Zika virus (ZIKV) disease is a vector-borne infectious disease transmitted by Aedes mosquitoes. Recently, ZIKV has caused outbreaks in most American countries. Areas covered: Publications about neurological complications of ZIKV infection retrieved from pubmed searchers were reviewed, and reference lists and relevant articles from review articles were also examined. Vertical/intrauterine transmission leads to congenital infection and causes microcephaly and congenital ZIKV syndrome. ZIKV preferentially infects human neural progenitor cells and triggers cell apoptosis. ZIKV RNA has been identified in foetal brain tissue and brains of microcephalic infants who died; amniotic fluid and placentas of pregnant mothers; and umbilical cord, cerebro-spinal fluid and meninges of newborns. The increase in the number of Guillain-Barre syndrome (GBS) cases during the ZIKV outbreak in the Americas provides epidemiological evidence for the link between ZIKV infection and GBS. Less frequently reported ZIKV neurological complications include encephalitis/meningoencephalitis, acute disseminated encephalomyelitis, myelitis, cerebrovascular complications (ischemic infarction; vasculopathy), seizures and encephalopathy, sensory polyneuropathy and sensory neuronopathy. Analysis of GBS incidence could serve as an epidemiological 'marker' or sentinel for ZIKV disease and other neurological complications associated to ZIKV. Expert commentary: An expanding spectrum of neurological complications associated with ZIKV infection is being recognised.

Guillain-Barré syndrome and Zika virus outbreaks

PURPOSE OF REVIEW

Arboviruses have been associated with central and peripheral nervous system injuries, in special the flaviviruses. Guillain-Barré syndrome (GBS), transverse myelitis, meningoencephalitis, ophthalmological manifestations, and other neurological complications have been recently associated to Zika virus (ZIKV) infection. In this review, we aim to analyze the epidemiological aspects, possible pathophysiology, and what we have learned about the clinical and laboratory findings, as well as treatment of patients with ZIKV-associated neurological complications.

RECENT FINDINGS

In the last decades, case series have suggested a possible link between flaviviruses and development of GBS. Recently, large outbreaks of ZIKV infection in Asia and the Americas have led to an increased incidence of GBS in these territories. Rapidly, several case reports and case series have reported an increase of all clinical forms and electrophysiological patterns of GBS, also including cases with associated central nervous system involvement. Finally, cases suggestive of acute transient polyneuritis, as well as acute and progressive postinfectious neuropathies associated to ZIKV infection have been reported, questioning the usually implicated mechanisms of neuronal injury.

SUMMARY

The recent ZIKV outbreaks have triggered the occurrence of a myriad of neurological manifestations likely associated to this arbovirosis, in special GBS and its variants.

Zika virus infection as a cause of congenital brain abnormalities and Guillain-Barré syndrome: From systematic review to living systematic review

Background. The Zika virus (ZIKV) outbreak in the Americas has caused international concern due to neurological sequelae linked to the infection, such as microcephaly and Guillain-Barré syndrome (GBS). The World Health Organization stated that there is “sufficient evidence to conclude that Zika virus is a cause of congenital abnormalities and is a trigger of GBS”. This conclusion was based on a systematic review of the evidence published until 30.05.2016. Since then, the body of evidence has grown substantially, leading to this update of that systematic review with new evidence published from 30.05.2016 – 18.01.2017, update 1.

Methods. We review evidence on the causal link between ZIKV infection and adverse congenital outcomes and the causal link between ZIKV infection and GBS or immune-mediated thrombocytopaenia purpura. We also describe the transition of the review into a living systematic review, a review that is continually updated.

Results. Between 30.05.2016 and 18.01.2017, we identified 2413 publications, of which 101 publications were included. The evidence added in this update confirms the conclusion of a causal association between ZIKV and adverse congenital outcomes. New findings expand the evidence base in the dimensions of biological plausibility, strength of association, animal experiments and specificity. For GBS, the body of evidence has grown during the search period for update 1, but only for dimensions that were already populated in the previous version. There is still a limited understanding of the biological pathways that potentially cause the occurrence of autoimmune disease following ZIKV infection.

Conclusions. This systematic review confirms previous conclusions that ZIKV is a cause of congenital abnormalities, including microcephaly, and is a trigger of GBS. The transition to living systematic review techniques and methodology provides a proof of concept for the use of these methods to synthesise evidence about an emerging pathogen such as ZIKV.

Zika clinical updates: implications for pediatrics

PURPOSE OF REVIEW

Zika virus (ZIKV), a mosquito-borne flavivirus, has gained recognition over the past few years as an important new cause of congenital infection. As a result, it is critical that pediatricians understand its epidemiology, clinical presentation, clinical sequelae, and management.

RECENT FINDINGS

The recent ZIKV epidemiology, clinical presentation of acute infection in children and complications, perinatal infection, and congenital infection will be summarized in this ZIKV review. This will be followed by a brief summary on ZIKV diagnosis, management, treatment, and prevention.

SUMMARY

The field of clinical research in ZIKV has rapidly evolved over recent months. It is critical that pediatricians continue to stay up-to-date with the continuously evolving understanding of the clinical aspects of ZIKV to ensure optimal identification and management of affected infants and children. Given the recent changes in Centers for Disease Control and Prevention guidelines to limit screening of asymptomatic pregnant women in the United States with possible ZIKV exposure, comprehensive ZIKV clinical knowledge becomes even more crucial.

Epidemiology of Zika Virus Infection

Long known to be endemic in Africa and Southeast Asia and a rare cause of acute febrile illness, Zika virus (ZIKAV) arose from obscurity when an Asian genotype ZIKAV caused an outbreak of mild febrile illness in 2007 in Yap State, Federated States of Micronesia. Subsequent viral spread in the Pacific led to a large outbreak in French Polynesia commencing in 2013. After its recognition in the Americas through March 2017, the Pan American Health Organization has received reports of >750000 suspected and laboratory-confirmed cases of autochthonous ZIKAV transmission. Outbreaks in most countries in the Americas peaked in early to mid-2016. Increased surveillance in several Southeast Asian counties has led to increased case recognition, including an outbreak in Singapore, and the first reports of birth defects linked to ZIKAV in the region. As of April 2017, the World Health Organization reported 84 countries or territories with current or previous ZIKAV transmission.

Characterization of cis-Acting RNA Elements of Zika Virus by Using a Self-Splicing Ribozyme-Dependent Infectious Clone

Zika virus (ZIKV) has caused significant outbreaks and epidemics in the Americas recently, raising global concern due to its ability to cause microcephaly and other neurological complications. A stable and efficient infectious clone of ZIKV is urgently needed. However, the instability and toxicity of flavivirus cDNA clones in Escherichia coli hosts has hindered the development of ZIKV infectious clones. Here, using a novel self-splicing ribozyme-based strategy, we generated a stable infectious cDNA clone of a contemporary ZIKV strain imported from Venezuela to China in 2016. The constructed clone contained a modified version of the group II self-splicing intron P.li.LSUI2 near the junction between the E and NS1 genes, which were removed from the RNA transcripts by an easy-to-establish in vitro splicing reaction. Transfection of the spliced RNAs into BHK-21 cells led to the production of infectious progeny virus that resembled the parental virus. Finally, potential cis-acting RNA elements in ZIKV genomic RNA were identified based on this novel reverse genetics system, and the critical role of 5'-SLA promoter and 5'-3' cyclization sequences were characterized by a combination of different assays. Our results provide another stable and reliable reverse genetics system for ZIKV that will help study ZIKV infection and pathogenesis, and the novel self-splicing intron-based strategy could be further expanded for the construction of infectious clones from other emerging and reemerging flaviviruses.IMPORTANCE The ongoing Zika virus (ZIKV) outbreaks have drawn global concern due to the unexpected causal link to fetus microcephaly and other severe neurological complications. The infectious cDNA clones of ZIKV are critical for the research community to study the virus, understand the disease, and inform vaccine design and antiviral screening. A panel of existing technologies have been utilized to develop ZIKV infectious clones. Here, we successfully generated a stable infectious clone of a 2016 ZIKV strain using a novel self-splicing ribozyme-based technology that abolished the potential toxicity of ZIKV cDNA clones to the E. coli host. Moreover, two crucial cis-acting replication elements (5'-SLA and 5'-CS) of ZIKV were first identified using this novel reverse genetics system. This novel self-splicing ribozyme-based reverse genetics platform will be widely utilized in future ZIKV studies and provide insight for the development of infectious clones of other emerging viruses.