Zika virus and the risk of imported infection in returned travelers: Implications for clinical care

Fetuses and infants with Amyoplasia congenita in congenital Zika syndrome: The evidence of a viral cause. A narrative review of 144 cases

OBJECTIVES

Amyoplasia congenita is the most frequent type of arthrogryposis causing fetal hypokinesia, leading to congenital contractures at birth. The pathogenesis is thought to be impaired blood circulation to the fetus early in pregnancy, with hypotension and hypoxia damaging the anterior horn cells. In animal studies however a prenatal infection with a poliomyelitis-like viral agent was demonstrated. Congenital Zika virus syndrome (CZVS) has recently been described in infants with severe microcephaly, and in 10-25% of cases arthrogryposis.

METHODS

A search in PubMed for CZVS yielded 124 studies. After a selection for arthrogryposis, 35 papers were included, describing 144 cases. The studies were divided into two categories. 1) Those (87 cases) focussing on imaging or histological data of congenital brain defects, contained insufficient information to link arthrogryposis specifically to lesions of the brain or spinal motor neuron. 2) In the other 57 cases detailed clinical data could be linked to neurophysiological, imaging or histological data.

RESULTS

In category 1 the most frequent brain abnormalities in imaging studies were ventriculomegaly, calcifications (subcortical, basal ganglia, cerebellum), hypoplasia of the brainstem and cerebellum, atrophy of the cerebral cortex, migration disorders and corpus callosum anomalies. In category 2, in 38 of 57 cases clinical data were indicative of Amyoplasia congenita. This diagnosis was confirmed by electromyographic findings (13 cases), by MRI (37 cases) or histology (12 cases) of the spinal cord. The latter showed small or absent lateral corticospinal tracts, and cell loss and degeneration of motor neuron cells. Zika virus-proteins and flavivirus-like particles were detected in cytoplasm of spinal neurons.

CONCLUSION

The phenotype of arthrogryposis in CZVS is consistent with Amyoplasia congenita. These findings warrant search for an intrauterine infection with any neurotropic viral agent with affinity to spinal motor neurons in neonates with Amyoplasia.

Zika Virus Non-Structural Protein 1 Antigen-Capture Immunoassay

Infection with Zika virus (ZIKV), a member of the Flavivirus genus of the Flaviviridae family, typically results in mild self-limited illness, but severe neurological disease occurs in a limited subset of patients. In contrast, serious outcomes commonly occur in pregnancy that affect the developing fetus, including microcephaly and other major birth defects. The genetic similarity of ZIKV to other widespread flaviviruses, such as dengue virus (DENV), presents a challenge to the development of specific ZIKV diagnostic assays. Nonstructural protein 1 (NS1) is established for use in immunodiagnostic assays for flaviviruses. To address the cross-reactivity of ZIKV NS1 with proteins from other flaviviruses we used site-directed mutagenesis to modify putative epitopes. Goat polyclonal antibodies to variant ZIKV NS1 were affinity-purified to remove antibodies binding to the closely related NS1 protein of DENV. An antigen-capture ELISA configured with the affinity-purified polyclonal antibody showed a linear dynamic range between approximately 500 and 30 ng/mL, with a limit of detection of between 1.95 and 7.8 ng/mL. NS1 proteins from DENV, yellow fever virus, St. Louis encephalitis virus and West Nile virus showed significantly reduced reactivity in the ZIKV antigen-capture ELISA. Refinement of approaches similar to those employed here could lead to development of ZIKV-specific immunoassays suitable for use in areas where infections with related flaviviruses are common.

Communicating the risk of contracting Zika virus to low income underserved pregnant Latinas: A clinic-based study

OBJECTIVE

Frequent travel between the Southern border states in the USA, Mexico, and Latin American countries increases the risk of the Zika virus (ZIKV) spread. Patient education on virus transmission is fundamental in decreasing the number of imported cases, particularly among pregnant women.

METHODS

The study used cross-sectional methodology to investigate information sources and knowledge concerning the ZIKV virus among 300 under-served pregnant Latinas recruited from prenatal care clinics in the North Texas region. Bivariate and multiple logistic regression models were used to investigate associations between the primary outcomes and patient characteristics.

RESULTS

Physicians, nurses, and families are the major sources for pregnancy information, while media/internet (65%) and physician/nurse (33%) are the main sources for ZIKV information. Less than one-half of the mothers reported that their physician/nurse did not discuss safe sexual practices or inquired about their sexual practices. A considerable proportion of women from the community clinic were neither warned nor queried about travel to ZIKV risk countries. There is an overall understanding of Zika virus transmission, symptoms, complications, and recommended guidelines. Younger age and single mother status are risk factors for lack of ZIKV knowledge. Foreign-born mothers are 2.5-3.0 times more likely to have knowledge on disease transmission, symptoms, and microcephaly condition. While, younger mothers (18-24) are less likely to have knowledge of ZIKV infection symptoms (fever, rash and pink eye) and transmission of infection via unprotected sexual (vaginal, anal, or oral) behavior, compared to older mothers.

CONCLUSIONS

Interventions are needed to heighten the knowledge of ZIKV, particularly among women of reproductive age and their male partners in the community health care setting. Our study underscores the need for health care providers to be trained in delivering messages to enhance risk perception during health emergencies to vulnerable and underserved families (lower economic background, language ability, and culture). During health emergencies, clinics must disseminate crucial information via multi modalities to ensure messages reach the targeted patients.

Knowledge of the Sexual Transmission of Zika Virus and Preventive Practices Against Zika Virus Among U.S. Travelers

Individuals are often at increased risk of acquiring infectious disease while traveling. We sought to understand knowledge, attitudes and practices (KAP) regarding Zika virus among travelers from the United States. A total of 1043 study participants were recruited from a probability-based internet panel. Participants self-reported their knowledge of Zika infection and modes of transmission, and identified actions they had taken to prevent Zika infection and transmission including actions to prevent unintentional pregnancy since becoming aware of the Zika virus. Logistic regression was used to model the odds of taking preventive actions against Zika infection with adjustment for potential confounding factors. Knowledge of the sexual transmissibility of Zika virus significantly increased the odds of taking a preventive action against Zika infection, especially condom use or sexual abstention. Participants reported preferences for receiving information about Zika from private doctors and from the Internet. Discrepancies between where travelers seek information about Zika and how they would like to receive information regarding Zika were also found. These findings suggest that improving targeted messaging through online media may increase awareness of the sexual transmissibility of Zika as well as improve health communications with U.S. travelers. Travelers who are unaware of potential disease risks are less likely to adopt personal protective measures to protect themselves and reduce disease spread. Thus, future work should focus on improving communication and providing education to adopt effective prevention strategies while traveling.

Zika knowledge and prevention practices among U.S. travelers: a large cross-sectional survey study

BACKGROUND

The aim of this study was to investigate what factors predict knowledge about Zika transmission, symptomology, and treatment among U.S. travelers and, additionally, to evaluate how Zika knowledge influences the adoption of personal protective behaviors.

METHODS

Data were collected as part of a cross-sectional survey study using a probability-based internet panel of U.S. travelers in June 2017. We ran logistic regression models of factors predicting Zika knowledge (high vs. low) and of knowledge predicting adoption of personal protective measures.

RESULTS

We found that traveling to a Zika endemic country and travelers' gender were both significantly predictive of higher Zika knowledge (odds ratio (OR): 1.48, 95% confidence interval (CI): 1.14-1.93 and OR: 1.44, 95% CI: 1.08-1.92), adjusting for age, race, education, income, and trip purpose. Additionally, among travelers to Zika endemic countries, individuals with higher Zika knowledge had significantly higher odds of engaging in preventive behaviors compared to those with lower knowledge. However, few travelers knew about the sexual transmission of Zika and adopted sexual prevention measures.

CONCLUSIONS

Our findings suggest that there are gaps in knowledge about the risks and transmission of Zika and travelers with low knowledge are less likely to engage in the appropriate prevention methods. Significantly, few U.S. travelers have knowledge of the sexual transmission of Zika and, accordingly, there is less overall engagement with prevention measures for this transmission mechanism than for vector-borne transmission.

Going Viral 2019: Zika, Chikungunya, and Dengue

Chikungunya and Zika virus infections are emerging diseases in the Americas, and dengue continues to be the most prevalent arthropod-borne virus in the world. These arbovirus diseases may spread by endemic transmission or as travel-related infections and have rapidly expanded their geographic distribution secondary to vector spread. All 3 share a similar clinical picture that includes a maculopapular rash. Zika is characterized by pruritic rash, low-grade fever, and arthralgia. Congenital nervous system malformations are a growing public-health concern. Chikungunya distinctive dermatologic manifestations include facial melanosis and bullous eruption. Dengue bleeding complications may be life-threatening and require inpatient management.

Insights into ZIKV-Mediated Innate Immune Responses in Human Dermal Fibroblasts and Epidermal Keratinocytes

Zika virus (ZIKV) has emerged as a global pathogen causing significant public health concern. ZIKV infections in humans principally occur via mosquito bites. Thus, host skin cells are permissive to ZIKV infection and are the first line of defense against the virus. Here, we examined the role and mechanisms of antiviral skin immunity against ZIKV infection. ZIKV infection (African lineage MR766) in human dermal fibroblasts, human epidermal keratinocytes, and HaCaT keratinocytes resulted in distinct expression changes in RIG-I-like receptors, such as RIG-I and MDA5. Inhibition of RIG-I using small interfering RNA resulted in increased viral gene expression and reduced induction of IFNs and IFN-stimulated genes. Furthermore, ZIKV NS1 directly interacted with RIG-I or MDA5 and down-regulated RIG-I-like receptor-mediated antiviral signaling pathways. Asian lineage ZIKV (PRVABC59) infection also showed a distinct pattern of antiviral immunity in human skin cells, compared with other ZIKV strains. Additionally, ZIKV infections in human neural progenitor cells induced the robust activation of RIG-I-like receptor-mediated signaling, followed by highly enhanced IFN-stimulated gene expression. Our findings provide important insights into ZIKV tropism and subsequent antiviral signaling pathways that regulate ZIKV replication in human dermal fibroblasts and human epidermal keratinocytes.

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.

Zika virus infection: epidemiology, clinical manifestations and diagnosis

PURPOSE OF REVIEW

Zika virus (ZIKV) is an arbovirus previously believed to cause only a mild and self-limiting illness. Recently, it has emerged as a new public health threat that caused a large outbreak in French Polynesia in 2013-2014 and since 2015 an explosive outbreak in Brazil, with an increase in severe congenital malformations (microcephaly) and neurological complications, mainly Guillain-Barré syndrome (GBS). Since then, it has spread through the Americas. On 1 February 2016, the WHO declared the ZIKV epidemic in Brazil a Public Health Emergency of International Concern. We reviewed the epidemiology of ZIKV infection, clinical presentations and diagnosis. We highlighted the clinical features and nonvector borne transmission of the virus.

RECENT FINDINGS

Association between ZIKV infection and severe foetal outcomes, including microcephaly and other birth defects; increased rate of GBS and other neurological complications due to the ongoing ZIKV outbreak; increased evidence to date of ZIKV being the only arbovirus linked to sexual transmission; the challenge of ZIKV diagnosis; and the need for a specific point-of care test in epidemic scenarios.

SUMMARY

The findings illustrate the emergence of a viral disease with the identification of new associated disorders, new modes of transmission, including maternal-foetal and sexual transmission.

Zika Virus: What Pediatric Emergency Medicine Physicians Need to Know

Zika virus is a mosquito-borne Flavivirus. It has emerged as an important infectious agent in the recent past, mainly because of its teratogenic effects on the fetus. This review highlights the epidemiology, diagnosis, and treatment of this emerging infection.

Paper microfluidics for nucleic acid amplification testing (NAAT) of infectious diseases

The diagnosis of infectious diseases is entering a new and interesting phase. Technologies based on paper microfluidics, coupled to developments in isothermal amplification of Nucleic Acids (NAs) raise opportunities for bringing the methods of molecular biology in the field, in a low setting environment. A lot of work has been performed in the domain over the last few years and the landscape of contributions is rich and diverse. Most often, the level of sample preparation differs, along with the sample nature, the amplification and detection methods, and the design of the device, among other features. In this review, we attempt to offer a structured description of the state of the art. The domain is not mature and there exist bottlenecks that hamper the realization of Nucleic Acid Amplification Tests (NAATs) complying with the constraints of the field in low and middle income countries. In this domain however, the pace of progress is impressively fast. This review is written for a broad Lab on a Chip audience.

Zika virus dynamics: When does sexual transmission matter?

The Zika virus (ZIKV) has captured worldwide attention with the ongoing epidemic in South America and its link to severe birth defects, most notably microcephaly. ZIKV is spread to humans through a combination of vector and sexual transmission, but the relative contribution of these transmission routes to the overall epidemic remains largely unknown. Furthermore, a disparity in the reported number of infections between males and females has been observed. We develop a mathematical model that describes the transmission dynamics of ZIKV to determine the processes driving the observed epidemic patterns. Our model reveals a 4.8% contribution of sexual transmission to the basic reproductive number, R₀. This contribution is too minor to independently sustain an outbreak but suggests that vector transmission is the main driver of the ongoing epidemic. We also find a minor, yet statistically significant, difference in the mean number of cases in males and females, both at the peak of the epidemic and at equilibrium. While this suggests an intrinsic disparity between males and females, the differences do not account for the vastly greater number of reported cases for females, indicative of a large reporting bias. In addition, we identify conditions under which sexual transmission may play a key role in sparking an epidemic, including temperate areas where ZIKV mosquito vectors are less prevalent.

The Emerging Zika Virus Threat: A Guide for Dermatologists

We provide a guide for dermatologists to follow if they encounter patients with a rash and clinical history suspicious of Zika virus infection, including diagnostic testing and management options. We also provide an illustrative case report of a patient from Brazil who was diagnosed with Zika virus infection after presenting with a generalized pruritic rash. One of the most prominent symptoms of Zika virus infection is a cutaneous eruption. As such, it is especially necessary for dermatologists to understand this virus so that they may appropriately recognize this entity as a diagnostic consideration in the clinic. The rash associated with Zika virus infection is most commonly an erythematous maculopapular eruption that presents after an initial 3-4 days of fever, headache, and arthralgia or myalgia. The rash typically lasts for an average of 6 days, and can spread to involve any part of the body, including the face, torso, extremities, palms, and soles.

Zika virus infection in pregnancy: a systematic review of disease course and complications

Objectives

To characterize maternal Zika virus (ZIKV) infection and complement the evidence base for the WHO interim guidance on pregnancy management in the context of ZIKV infection.

Methods

We searched the relevant database from inception until March 2016. Two review authors independently screened and assessed full texts of eligible reports and extracted data from relevant studies. The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS) and the National Institute of Health (NIH) tool for observational studies and case series/reports, respectively.

Results

Among 142 eligible full-text articles, 18 met the inclusion criteria (13 case series/reports and five cohort studies). Common symptoms among pregnant women with suspected/confirmed ZIKV infection were fever, rash, and arthralgia. One case of Guillain-Barré syndrome was reported among ZIKV-infected mothers, no other case of severe maternal morbidity or mortality reported. Complications reported in association with maternal ZIKV infection included a broad range of fetal and newborn neurological and ocular abnormalities; fetal growth restriction, stillbirth, and perinatal death. Microcephaly was the primary neurological complication reported in eight studies, with an incidence of about 1% among newborns of ZIKV infected women in one study.

Conclusion

Given the extensive and variable fetal and newborn presentations/complications associated with prenatal ZIKV infection, and the dearth of information provided, knowledge gaps are evident. Further research and comprehensive reporting may provide a better understanding of ZIKV infection in pregnancy and attendant maternal/fetal complications. This knowledge could inform the creation of effective and evidence-based strategies, guidelines and recommendations aimed at the management of maternal ZIKV infection. Adherence to current best practice guidelines for prenatal care among health providers is encouraged, in the context of maternal ZIKV infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s12978-017-0285-6) contains supplementary material, which is available to authorized users.

Zika Virus Infection: Current Concerns and Perspectives

The Zika virus outbreaks highlight the growing importance need for a reliable, specific and rapid diagnostic device to detect Zika virus, as it is often recognized as a mild disease without being identified. Many Zika virus infection cases have been misdiagnosed or underreported because of the non-specific clinical presentation. The aim of this review was to provide a critical and comprehensive overview of the published peer-reviewed evidence related to clinical presentations, various diagnostic methods and modes of transmission of Zika virus infection, as well as potential therapeutic targets to combat microcephaly. Zika virus is mainly transmitted through bites from Aedes aegypti mosquito. It can also be transmitted through blood, perinatally and sexually. Pregnant women are advised to postpone or avoid travelling to areas where active Zika virus transmission is reported, as this infection is directly linked to foetal microcephaly. Due to the high prevalence of Guillain-Barre syndrome and microcephaly in the endemic area, it is vital to confirm the diagnosis of Zika virus. Zika virus infection had been declared as a public health emergency and of international concern by the World Health Organisation. Governments and agencies should play an important role in terms of investing time and resources to fundamentally understand this infection so that a vaccine can be developed besides raising awareness.

Risk of Zika virus transmission in the Euro-Mediterranean area and the added value of building preparedness to arboviral threats from a One Health perspective

In the alarming context of risk of Zika virus (ZIKV) transmission in the Euro-Mediterranean area, there is a need to examine whether capacities to detect, diagnose and notify ZIKV infections in the region are in place and whether ongoing capacity-building initiatives are filling existing gaps.

The MediLabSecure network, created in 2014, comprises 55 laboratories of virology and medical entomology and 19 public health institutions in 19 countries in the Balkans, North-Africa, the Middle-East and the Black Sea regions. It aims to set up awareness, risk assessment, monitoring and control of emerging and re-emerging vector-borne viruses. We here examine the actions and strategies that MediLabSecure has been implementing and how they will contribute to the prevention and control of the ZIKV threat in the Euro-Mediterranean area.

Capacity-building for arbovirus diagnostics is a major objective of the project and follows a methodological rather than disease-driven approach. This enables the implementation of laboratory trainings on techniques that are common to several arboviruses, including ZIKV, and putting into action appropriate diagnostic tools in the target region.

Moreover, by its One Health approach and the interaction of its four sub-networks in human virology, animal virology, medical entomology and public health, MediLabSecure is fostering intersectoral collaboration, expertise and sharing of information. The resulting exchanges (methodological, communication and operational) across disciplines and across countries, dedicated research on intersectoral collaboration and increasing diagnostic capacities are providing new paths and tools to public health professionals to face emerging viral threats such as a ZIKV epidemic in the Euro-Mediterranean region.

Zika virus infection in 18 travellers returning from Surinam and the Dominican Republic, The Netherlands, November 2015-March 2016

PURPOSE

We report 18 cases of confirmed Zika virus (ZIKV) infection in travellers returning to the Netherlands from Surinam (South America, bordering northern Brazil) and the Dominican Republic.

METHODS

In a multi-centre study, we collected epidemiological, virological and clinical characteristics, as well as data on travel history, underlying illness and laboratory results of the 18 imported ZIKV infection cases using a standardised form.

RESULTS

Most cases had a self-limiting course of disease, two patients developed complications, one had Guillain-Barré and another had severe thrombocytopenia. Four patients had underlying illness. One of the reported cases was pregnant. Three of 13 patients tested had a weak-positive result for dengue IgM. The majority of patients were born in Suriname and/or visiting friends and relatives (VFR).

CONCLUSIONS

Providing pre-travel advice among travellers, especially VFR travellers, is needed to enhance the use of preventive measures against ZIKV infection. Further evidence on health risks associated with ZIKV infection is urgently needed.

Mapping Zika virus disease incidence in Valle del Cauca

OBJECTIVE

Geographical information systems (GIS) use for development of epidemiological maps in tropical diseases is increasingly frequently utilized. Here, we apply this technique to map the current Zika virus (ZIKV) outbreak in Colombia.

METHODS

Surveillance cases data of the ongoing epidemic of ZIKV in Valle del Cauca department and its capital, Cali (2015-2016), were used to estimate cumulated incidence rates (cases/100,000 population) to develop the first maps in the department and it municipalities. The GIS software used was Kosmo Desktop 3.0RC1^®. Three thematic incidence rate maps were developed.

RESULTS

Up to April 2, 2016, 9,825 cases of ZIKV were reported (15.15 % of the country cases). The burden of ZIKV infection has been concentrated in the North of the department. Valle del Cauca borders with other departments with incidence of ZIKV infection, such as Quindío (173 cases) and Risaralda (687 cases). Eleven municipalities of Valle del Cauca had cases in the range between 250 and 499 cases/100,000, all in the North and East of the department. Cali, the capital concentrates more than a third of the reported cases of ZIKV in Valle del Cauca.

CONCLUSIONS

Use of GIS-based epidemiological maps allows to guide decision-making for prevention and control of diseases that constitute significant public health problems in the region and the country, such as exemplified by the emergence of ZIKV infection, particularly in departments such as Valle del Cauca with a high disease incidence.

The Clinical Spectrum of Zika Virus in Returning Travelers

INTRODUCTION

The clinical spectrum of Zika virus had, to date, been described in small series from endemic/epidemic countries and is not well established.

METHODS

We describe the clinical manifestations of laboratory-proven Zika virus infection in Israeli travelers during December 2015-February 2016, and review all published cases of travel-related Zika virus.

RESULTS

During the study period, 8 returning Israeli travelers were diagnosed with Zika virus infection. In addition, 41 published cases were included, mostly from Latin America to Europe and North America. Overall, 65.3% were diagnosed by polymerase chain reaction. Rash was the most frequent symptom, present in 95.7% of cases, followed by fever and arthralgia. Conjunctivitis was present in 53.1%; however, only 40.3% presented with a triad of conjunctivitis, fever, and rash. Less frequent symptoms included dysgeusia and nightmares, which, together with arthralgia, persisted for several weeks in some travelers.

CONCLUSIONS

Zika virus clinical picture in travelers is diverse. Prolonged symptoms may occur.

Microcefalia e Zika Vírus: características e associações

Objetivo: Discutir a associação entre microcefalia e a infecção materna por Zika Vírus. A microcefalia é o tamanho da cabeça menor do que o esperado em comparação com bebês do mesmo sexo e idade. Entre as causas conhecidas, estão as infecções congênitas. O aumento de casos entre outubro e novembro de 2015 no nordeste brasileiro, que coincidiu com a presença da circulação de novo vírus no país, em maio do mesmo ano, criou a hipótese de associação entre a microcefalia e a infecção materna durante a gravidez. O Zika Vírus é um arbovírus similar ao da Febre Amarela e da Dengue, transmitido principalmente através da picada do Aedes aegypti. A provável transmissão por relação sexual e transfusão de sangue, além de outros vetores como o Aedes albopictus e possivelmente até o pernilongo (Culex sp) aumentam a necessidade de cuidados preventivos em relação à infecção. O exame para detecção viral idealmente é realizado até o quinto dia após o início dos sintomas. Sorologias ainda não são amplamente disponíveis no Brasil. Métodos: Revisão narrativa da literatura. Conclusão: A associação entre casos de microcefalia e o Zika Vírus é embasada nos relatos de relação têmporo-espacial, padrão de alterações neurológicas associado a malformações congênitas, presença do RNA viral no líquido amniótico e nos tecidos de fetos. As respostas definitivas de causalidade serão possíveis após pesquisas e disponibilidade de exames laboratoriais. As evidências até agora apoiam fortemente esta hipótese e todas as medidas preventivas devem ser estimuladas.

Concern over Zika virus outbreak: another alarming global threat

Zika virus, as highlighted by the World Health Organization in February 2016, has emerged as a public health emergency of international concern. Zika virus is enveloped and icosahedral, and has a nonsegmented, single-stranded, positive-sense RNA genome. It belongs to Flaviviridae family. Aedes aegypticus mosquito is the known vector. Transmission is anthroponotic (human to vector to human) during outbreaks, or occurs perinatally in utero, sexually, and via transfusion of infected blood. Zika virus is turning out to be a major public health concern. Not only has it shown dramatic teratogenic association and caused serious neurological concerns but it has also spread around the globe. Countries that have not yet been affected by Zika virus should adopt proper preventive methods to limit its spread in the population.

Estimated Zika virus importations to Europe by travellers from Brazil

BACKGROUND

Given the interconnectivity of Brazil with the rest of the world, Zika virus (ZIKV) infections have the potential to spread rapidly around the world via viremic travellers. The extent of spread depends on the travel volume and the endemicity in the exporting country. In the absence of reliable surveillance data, we did mathematical modelling to estimate the number of importations of ZIKV from Brazil into Europe.

DESIGN

We applied a previously developed mathematical model on importations of dengue to estimate the number of ZIKV importations into Europe, based on the travel volume, the probability of being infected at the time of travel, the population size of Brazil, and the estimated incidence of ZIKV infections.

RESULTS

Our model estimated between 508 and 1,778 imported infections into Europe in 2016, of which we would expect between 116 and 355 symptomatic Zika infections; with the highest number of importations being into France, Portugal and Italy.

CONCLUSIONS

Our model identified high-risk countries in Europe. Such data can assist policymakers and public health professionals in estimating the extent of importations in order to prepare for the scale up of laboratory diagnostic assays and estimate the occurrence of Guillain-Barré Syndrome, potential sexual transmission, and infants with congenital ZIKV syndrome.

Zika virus infections imported from Brazil to Portugal, 2015

Zika virus is an emerging arbovirus transmitted by Aedes sp. mosquitoes like the Dengue and Chikungunya viruses. Zika virus was until recently considered a mild pathogenic mosquito-borne flavivirus with very few reported benign human infections. In 2007, an epidemic in Micronesia initiated the turnover in the epidemiological history of Zika virus and more recently, the potential association with congenital microcephaly cases in Brazil 2015, still under investigation, led the World Health Organization (WHO) to declare a Public Health Emergency of International Concern on February 1, 2016.

Here, we present the clinical and laboratory aspects related to the first four imported human cases of Zika virus in Portugal from Brazil, and alert, regarding the high level of traveling between Portugal and Brazil, and the ongoing expansion of this virus in the Americas, for the threat for Zika virus introduction in Europe and the possible introduction to Madeira Island where Aedes aegypti is present.

Deciphering emerging Zika and dengue viral epidemics: Implications for global maternal-child health burden

Since its discovery in 1947 in Uganda and control and eradication efforts have aimed at its vectors (Aedes mosquitoes) in Latin America in the 1950s, an absolute neglect of Zika programs and interventions has been documented in Aedes endemic and epidemic-prone countries. The current unprecedented Zika viral epidemics and rapid spread in the Western hemisphere pose a substantial global threat, with associated anxiety and consequences. The lack of safe and effective drugs and vaccines against Zika or dengue epidemics further buttresses the realization from the West Africa Ebola outbreak that most emerging disease-prone countries are still poorly prepared for an emergency response. This paper examines knowledge gaps in both emerging and neglected arthropod-borne flavivirus infectious diseases associated with poverty and their implications for fostering local, national and regional emerging disease preparedness, effective and robust surveillance–response systems, sustained control and eventual elimination. Strengthening the regional and Global Health Flavivirus Surveillance-Response Network (GHFV-SRN) with other models of socio-economic, climatic, environmental and ecological mitigation and adaptation strategies will be necessary to improve evidence-based national and global maternal–child health agenda and action plans.