Characteristics of Children Aged <18 Years with Zika Virus Disease Acquired Postnatally - U.S. States, January 2015-July 2016

Trends in emerging vector-borne viral infections and their outcome in children over two decades

This review utilizes quatitative methods and bibliometric data to analyse the trends of emerging and re-emerging vector-borne diseases, with a focus on their impact on pediatric population. To conduct this analysis, a systematic search of PubMed articles from the past two decades was performed, specifically looking at 26 different vector-borne viruses listed in WHO and CDC list of vector-borne viruses. The review found that diseases like Dengue, Zika, West Nile, and Chikungunya were frequently discussed in the literature. On the other hand, diseases such as Tick-borne encephalitis, Rift Valley fever, Venezuelan equine encephalitis, Sindbis fever, Venezuelan equine encephalitis, Ross River virus, and Eastern equine encephalitis showed an upward trend in publications, indicating potential resurgence. In addition to discussing trends and patterns, the review delves into the clinical manifestations and long-term effects of the top 10 viruses in children. It highlights various factors including deforestation, urbanization, global travel, and immunosuppression that contribute to disease emergence and resurgence. To effectively combat these vector-borne diseases, continuous surveillance is crucial. The review also emphasizes the importance of increased vaccination efforts and targeted research to address the health challenges they pose. IMPACT: This review employs quantitative analysis of publications to elucidate trends in emerging pediatric vector-borne viral diseases over two decades. Dengue, the most prevalent of these diseases, has spread to new regions. New strains of Japanese Encephalitis have caused outbreaks. Resurgence of Tick-borne Encephalitis, West Nile, and Yellow Fever due to vaccine hesitancy has also transpired. Continuous global surveillance, increased vaccination, and research into novel therapeutics are imperative to combat the substantial morbidity and mortality burden these diseases pose for children worldwide.

Emerging and re-emerging pediatric viral diseases: a continuing global challenge

The twenty-first century has been marked by a surge in viral epidemics and pandemics, highlighting the global health challenge posed by emerging and re-emerging pediatric viral diseases. This review article explores the complex dynamics contributing to this challenge, including climate change, globalization, socio-economic interconnectedness, geopolitical tensions, vaccine hesitancy, misinformation, and disparities in access to healthcare resources. Understanding the interactions between the environment, socioeconomics, and health is crucial for effectively addressing current and future outbreaks. This scoping review focuses on emerging and re-emerging viral infectious diseases, with an emphasis on pediatric vulnerability. It highlights the urgent need for prevention, preparedness, and response efforts, particularly in resource-limited communities disproportionately affected by climate change and spillover events. Adopting a One Health/Planetary Health approach, which integrates human, animal, and ecosystem health, can enhance equity and resilience in global communities. IMPACT: We provide a scoping review of emerging and re-emerging viral threats to global pediatric populations This review provides an update on current pediatric viral threats in the context of the COVID-19 pandemic This review aims to sensitize clinicians, epidemiologists, public health practitioners, and policy stakeholders/decision-makers to the role these viral diseases have in persistent pediatric morbidity and mortality.

A Bayesian belief network-based analytics methodology for early-stage risk detection of novel diseases

During a pandemic, medical specialists have substantial challenges in discovering and validating new disease risk factors and designing effective treatment strategies. Traditionally, this approach entails several clinical studies and trials that might last several years, during which strict preventive measures are enforced to manage the outbreak and limit the death toll. Advanced data analytics technologies, on the other hand, could be utilized to monitor and expedite the procedure. This research integrates evolutionary search algorithms, Bayesian belief networks, and innovative interpretation techniques to provide a comprehensive exploratory-descriptive-explanatory machine learning methodology to assist clinical decision-makers in responding promptly to pandemic scenarios. The proposed approach is illustrated through a case study in which the survival of COVID-19 patients is determined using inpatient and emergency department (ED) encounters from a real-world electronic health record database. Following an exploratory phase in which genetic algorithms are used to identify a set of the most critical chronic risk factors and their validation using descriptive tools based on the concept of Bayesian Belief Nets, the framework develops and trains a probabilistic graphical model to explain and predict patient survival (with an AUC of 0.92). Finally, a publicly available online, probabilistic decision support inference simulator was constructed to facilitate what-if analysis and aid general users and healthcare professionals in interpreting model findings. The results widely corroborate intensive and expensive clinical trial research assessments.

Clinical and Preclinical Evidence for Adverse Neurodevelopment after Postnatal Zika Virus Infection

Although the Zika virus (ZIKV) typically causes mild or no symptoms in adults, during the 2015−2016 outbreak, ZIKV infection in pregnancy resulted in a spectrum of diseases in infants, including birth defects and neurodevelopmental disorders identified in childhood. While intense clinical and basic science research has focused on the neurodevelopmental outcomes of prenatal ZIKV infection, less is known about the consequences of infection during early life. Considering the neurotropism of ZIKV and the rapidly-developing postnatal brain, it is important to understand how infection during infancy may disrupt neurodevelopment. This paper reviews the current knowledge regarding early postnatal ZIKV infection. Emerging clinical evidence supports the hypothesis that ZIKV infection during infancy can result in negative neurologic consequences. However, clinical data regarding postnatal ZIKV infection in children are limited; as such, animal models play an important role in understanding the potential complications of ZIKV infection related to the vulnerable developing brain. Preclinical data provide insight into the potential behavioral, cognitive, and motor domains that clinical studies should examine in pediatric populations exposed to ZIKV during infancy.

Postnatally Acquired Zika Virus Disease Among Children, United States, 2016-2017

BACKGROUND

The clinical findings among children with postnatally acquired Zika virus disease are not well characterized. We describe and compare clinical signs and symptoms for children aged <18 years.

METHODS

Zika virus disease cases were included if they met the national surveillance case definition, had illness onset in 2016 or 2017, resided in a participating state, and were reported to the Centers for Disease Control and Prevention. Pediatric cases were aged <18 years; congenital and perinatal infections were excluded. Pediatric cases were matched to adult cases (18‒49 years). Clinical information was compared between younger and older pediatric cases and between children and adults.

RESULTS

A total of 141 pediatric Zika virus disease cases were identified; none experienced neurologic disease. Overall, 28 (20%) were treated in an emergency department, 1 (<1%) was hospitalized; none died. Of the 4 primary clinical signs and symptoms associated with Zika virus disease, 133 (94%) children had rash, 104 (74%) fever, 67 (48%) arthralgia, and 51 (36%) conjunctivitis. Fever, arthralgia, and myalgia were more common in older children (12‒17 years) than younger children (1‒11 years). Arthralgia, arthritis, edema, and myalgia were more common in adults compared to children.

CONCLUSIONS

This report supports previous findings that Zika virus disease is generally mild in children. The most common symptoms are similar to other childhood infections, and clinical findings and outcomes are similar to those in adults. Healthcare providers should consider a diagnosis of Zika virus infection in children with fever, rash, arthralgia, or conjunctivitis, who reside in or have traveled to an area where Zika virus transmission is occurring.

Zika Virus Infection in Tourists Travelling to Thailand: Case Series Report

Thailand is a popular tourist destination where Zika virus (ZIKV) transmission is currently active. To our knowledge, there are no reports of ZIKV infection imported from Thailand and affecting children. Here, we describe the clinical and microbiological findings in three cases of vector-borne ZIKV infection: An 11-year-old boy, a 2-year-old girl, and her pregnant mother, this last case leading to the prenatal exposure of her second baby to ZIKV in the second trimester of pregnancy. All patients were diagnosed after traveling to Thailand between September 2019 and January 2020. No complications were detected in any patient at follow-up, and the prenatally exposed fetus showed no abnormalities during intensive antenatal health care monitoring. On postnatal study, there were no clinical signs or microbiological findings of mother-to-child ZIKV transmission. ZIKV IgG was initially positive, but seroreversion occurred at 4 months of life. This report describes the clinical and serological evolution of vector-borne ZIKV infection occurring in dengue-naïve tourists returning from Thailand. The World Health Organization currently recommends that pre-travel advice to prevent arbovirus infection should be maintained in travelers to Southeast Asia.

Postnatal symptomatic Zika virus infections in children and adolescents: A systematic review

BACKGROUND

Recent Zika virus (ZIKV) outbreaks in the Pacific and the Americas have highlighted clinically significant congenital neurological abnormalities resulting from ZIKV infection in pregnancy. However, little is known about ZIKV infections in children and adolescents, a group that is potentially vulnerable to ZIKV neurovirulence.

METHODS

We conducted a systematic review on the clinical presentation and complications of children and adolescents aged 0 to 18 years with a robust diagnosis of ZIKV infection. We searched PubMed, Web of Science, LILACs, and EMBASE until 13 February 2020 and screened reference lists of eligible articles. We assessed the studies' risk of bias using pre-specified criteria.

FINDINGS

Our review collated the evidence from 2543 pediatric ZIKV cases representing 17 countries and territories, identified in 1 cohort study, 9 case series and 22 case reports. The most commonly observed signs and symptoms of ZIKV infection in children and adolescents were mild and included fever, rash, conjunctivitis and arthralgia. The frequency of neurological complications was reported only in the largest case series (identified in 1.0% of cases) and in an additional 14 children identified from hospital-based surveillance studies and case reports. ZIKV-related mortality was primarily accompanied by co-morbidity and was reported in one case series (<0.5% of cases) and three case reports. One death was attributed to complications of Guillain-Barré Syndrome secondary to ZIKV infection.

CONCLUSIONS AND RELEVANCE

Based on the current evidence, the clinical presentation of ZIKV infection in children and adolescents appears to be primarily mild and similar to the presentation in adults, with rare instances of severe complications and/or mortality. However, reliable estimation of the risks of ZIKV complications in these age groups is limited by the scarcity and quality of published data. Additional prospective studies are needed to improve understanding of the relative frequency of the signs, symptoms, and complications associated with pediatric ZIKV infections and to investigate any potential effects of early life ZIKV exposure on neurodevelopment.

Long-term alterations in brain and behavior after postnatal Zika virus infection in infant macaques

Zika virus (ZIKV) infection has a profound impact on the fetal nervous system. The postnatal period is also a time of rapid brain growth, and it is important to understand the potential neurobehavioral consequences of ZIKV infection during infancy. Here we show that postnatal ZIKV infection in a rhesus macaque model resulted in long-term behavioral, motor, and cognitive changes, including increased emotional reactivity, decreased social contact, loss of balance, and deficits in visual recognition memory at one year of age. Structural and functional MRI showed that ZIKV-infected infant rhesus macaques had persistent enlargement of lateral ventricles, smaller volumes and altered functional connectivity between brain areas important for socioemotional behavior, cognitive, and motor function (e.g. amygdala, hippocampus, cerebellum). Neuropathological changes corresponded with neuroimaging results and were consistent with the behavioral and memory deficits. Overall, this study demonstrates that postnatal ZIKV infection in this model may have long-lasting neurodevelopmental consequences.

Arboviral diseases in pediatrics

OBJECTIVES

To present the currently available evidence on transmission, clinical, diagnostic methods, treatment, and prevention methods of major arboviruses that occur in childhood.

SOURCE OF DATA

Non-systematic review carried out in MEDLINE (PubMed), LILACS (VHL), Scopus, Web of Science, Cochrane, CAPES Portal, and Google Scholar databases for the past five years using the search terms arboviruses, dengue, chikungunya, Zika, Mayaro, and West Nile fever, as well as child, newborn, and adolescent.

SYNTHESIS OF DATA

The main characteristic of arboviruses is the fact that part of their replication cycle occurs inside insect vectors, thus being classically transmitted to humans through the bite of mosquitoes (hematophagous arthropods), although non-vector transmission of these viruses is also possible in specific situations. These diseases remain a major public health challenge, due to the lack of specific antiviral treatment, the co-circulation of different arboviruses in endemic/epidemic regions, the lack of effective and safe immunizations for the vast majority of these viruses, and the great difficulty in vector control, especially in large urban centers.

CONCLUSIONS

Children are especially vulnerable to this group of diseases due to characteristics that facilitate the development of the most severe forms. More detailed knowledge of this group of diseases allows the pediatrician to diagnose them earlier, implement the correct treatment, monitor warning signs for the most severe forms, and establish effective preventive measures.

Age-dependent manifestations and case definitions of paediatric Zika: a prospective cohort study

BACKGROUND

Paedeatric Zika remains an understudied topic. WHO and the Pan American Health Organization (PAHO) Zika case definitions have not been assessed in children. We aimed to characterise clinical profiles and evaluate the diagnostic performance of the WHO and PAHO case definitions in a large cohort of paediatric Zika cases.

METHODS

From January, 2016 to February, 2017, encompassing the major 2016 Zika epidemic, participants in the Pediatric Dengue Cohort Study (PDCS) in Managua, Nicaragua, were encouraged to visit the study health centre at first indication of any illness. PDCS participants were aged 2-14 years, healthy at enrolment, and recruited before the initiation of the present study. Molecular and serological assays were used to test participants exhibiting any of four broad clinical profiles suspected of resulting from a symptomatic Zika virus infection. These clinical profiles were: fever and at least two of headache, retro-orbital pain, myalgia, arthralgia, rash, haemorrhagic manifestations, and leukopenia; fever and at least two of nausea or vomiting, rash, aches and pains, positive tourniquet test, leukopenia, and any dengue warning sign; undifferentiated fever without evident cause, with or without any other clinical finding; and afebrile rash with or without any other clinical finding. We characterised acute clinical findings (signs, symptoms, and complete blood counts) in both Zika cases and non-Zika cases.

FINDINGS

We prospectively followed a cohort of about 3700 children, of which 1110 were deemed eligible for inclusion. Four participants with laboratory-confirmed Zika (three co-infections with dengue virus, one missing complete blood count data) and two participants who were non-Zika cases (missing complete blood count data) were excluded from analysis. We analysed 556 laboratory-confirmed Zika and 548 non-Zika cases. The WHO case definition captured 176 confirmed Zika cases, and the PAHO definition 109 confirmed Zika cases, who presented with the most clinical findings and a dengue-like clinical profile. The remaining two thirds of Zika cases, principally characterised by undifferentiated fever or afebrile rash, were missed. Among Zika cases, rash (n=440)-particularly generalised erythematous rash (n=334)-fever (n=333), leukopenia (n=217), and headache (n=203) were most common and peaked within 3 days of illness onset. The most common Zika presentation over the first week of illness was rash only (n=80). The sensitivity of Zika case definitions increased across paediatric age (from 11·3% to 56·1% for the WHO case definition and from 6·0% to 36·6% for the PAHO case definition), as the prevalence of most clinical findings (particularly arthralgia) increased with age, irrespective of previous dengue virus infection. Consequently, Zika manifested differently across paediatric age; older Zika cases presented with a dengue-like clinical profile while younger Zika cases presented with undifferentiated fever or afebrile rash.

INTERPRETATION

We provide the most thorough description of paediatric Zika to date. Most paediatric Zika cases go undetected under the WHO and PAHO case definitions, suggesting that current standards for Zika case ascertainment require revision. Zika manifests with mild but differing clinical profiles across paediatric age, presenting major challenges to diagnosis, surveillance, and efforts to control future Zika epidemics.

FUNDING

US National Institutes of Health.

Maternal-Fetal Interplay in Zika Virus Infection and Adverse Perinatal Outcomes

During pregnancy, the organization of complex tolerance mechanisms occurs to assure non-rejection of the semiallogeneic fetus. Pregnancy is a period of vulnerability to some viral infections, mainly during the first and second trimesters, that may cause congenital damage to the fetus. Recently, Zika virus (ZIKV) infection has gained great notoriety due to the occurrence of congenital ZIKV syndrome, characterized by fetal microcephaly, which results from the ability of ZIKV to infect placental cells and neural precursors in the fetus. Importantly, in addition to the congenital effects, studies have shown that perinatal ZIKV infection causes a number of disorders, including maculopapular rash, conjunctivitis, and arthralgia. In this paper, we contextualize the immunological aspects involved in the maternal-fetal interface and vulnerability to ZIKV infection, especially the alterations resulting in perinatal outcomes. This highlights the need to develop protective maternal vaccine strategies or interventions that are capable of preventing fetal or even neonatal infection.

Viral Febrile Illnesses and Emerging Pathogens

Emerging or emerged diseases and viral pathogens are responsible historically and currently for large epidemics, global pandemics, and significant morbidity and mortality. Our civilization will continue to face the emergence of new pathogens and viruses: viruses will continue to evolve and adapt to new environments at a high rate; our population continues to grow through birth rate, land development, and migration; climate change will continue to increase the vector burden and spread and change the migratory pattern of animals; and our societal mobility will continue to increase through rapid transportation. The clinical evaluation of the febrile patient with a potential emerging viral pathogen involves documenting the likelihood for an infection by a detailed travel history, calculation of an incubation time by exposure, and an understanding of the disease progression though the clinical illness, which drives the differential diagnosis and the type of diagnostics ordered. Ultimately, the proper identification and diagnosis of a patient with a viral febrile illness due to an emerging pathogen will elicit the appropriate precautions to protect health care providers and communities, deliver appropriate therapeutic interventions, and initiate a targeted public health response.

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The majority of emerging diseases are caused by viruses, with many that are transmitted by insect vectors or are zoonotic.

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RNA viruses in particular have high mutation rates and can evolve rapidly in new and changing environments. This, in combination with societal factors, climate change, and rapid travel, has increased the number of epidemics from emerging pathogens in the last several decades.

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Understanding the travel history, incubation time of potential viruses, and the clinical presentation by illness day is essential in making the right diagnosis and identifying the infecting virus.

Zika Virus Infection in Hypothalamus Causes Hormone Deficiencies and Leads to Irreversible Growth Delay and Memory Impairment in Mice

Zika virus (ZIKV) can cause microcephaly in the fetus. However, its effects on body growth and the development of children with postnatal ZIKV infection are largely unknown. To examine this, we intraperitoneally challenged mouse pups with ZIKV. Infection causes an irreversible growth delay and deficits in spatial learning and memory, with growth-relevant hormones significantly reduced during infection. These effects are associated with ZIKV RNA expression in the hypothalamus, blood, and brain but not in the pituitary and thyroid. Infection is also associated with hypothalamic inflammation, and ZIKV antigen is detectable in neuroendocrine cells producing thyrotropin-releasing hormone. Moreover, early administration of growth hormone could significantly improve growth delay. Our results demonstrate that ZIKV can infect the hypothalamus, causing multi-hormone deficiencies and delayed growth and development in a mouse model. Therefore, prospective multidisciplinary follow-up of ZIKV-infected children may be necessary to understand potential effects of this virus on childhood development.

Clinical, laboratory and immune aspects of Zika virus-associated encephalitis in children

OBJECTIVE

To evaluate the clinical, laboratory, and immune characteristics of Zika virus (ZIKV)-associated encephalitis in pediatric patients after the epidemic in Huila, southern Colombia.

METHODS

A pediatric neuro-surveillance hospital study was conducted in a referral health center in southern Colombia, from October 2016 to October 2017. Cases of encephalitis were confirmed by nucleic acid amplification tests and serological methods in cerebrospinal fluid (CSF), plasma, and/or urine. Levels of six cytokines were evaluated by flow cytometry. Patients underwent daily clinical and laboratory follow-up.

RESULTS

Twenty children with probable encephalitis were included for further studies and 16 of them were confirmed. Four cases of bacterial meningoencephalitis (Streptococcus pneumoniae, group B Streptococcus, Staphylococcus epidermidis, and Escherichia coli) and 12 cases of viral encephalitis were identified, six of them associated with ZIKV infection. Other viral encephalitis cases were caused by herpes viruses (n=3), enterovirus (n=2), and dengue virus type 2 (DENV-2; n=1) infections. ZIKV-associated encephalitis symptoms subsided faster than those of patients with encephalitis caused by other agents. CSF analysis revealed lymphocytic pleocytosis. Compared to healthy controls, children with ZIKV-associated encephalitis presented modest plasma interleukin (IL)-10 but not IL-2, IL-4, IL-6, interferon gamma (IFN-γ), or tumor necrosis factor alpha (TNF-α). Cytokine expression was differentially regulated, as dramatically elevated IL-6, IL-10, and IFN-γ levels were observed in CSF but not in paired plasma samples in one of the patients with ZIKV detectable in CSF.

CONCLUSIONS

This study provides evidence that ZIKV is responsible for pediatric encephalitis in endemic areas, and the local presence of the virus may induce cephalic but not systemic expression of cytokines.

Postnatal Zika virus infection is associated with persistent abnormalities in brain structure, function, and behavior in infant macaques

The Zika virus (ZIKV) epidemic is associated with fetal brain lesions and other serious birth defects classified as congenital ZIKV syndrome. Postnatal ZIKV infection in infants and children has been reported; however, data on brain anatomy, function, and behavioral outcomes following infection are absent. We show that postnatal ZIKV infection of infant rhesus macaques (RMs) results in persistent structural and functional alterations of the central nervous system compared to age-matched controls. We demonstrate ZIKV lymphoid tropism and neurotropism in infant RMs and histopathologic abnormalities in the peripheral and central nervous systems including inflammatory infiltrates, astrogliosis, and Wallerian degeneration. Structural and resting-state functional magnetic resonance imaging (MRI/rs-fMRI) show persistent enlargement of lateral ventricles, maturational changes in specific brain regions, and altered functional connectivity (FC) between brain areas involved in emotional behavior and arousal functions, including weakened amygdala-hippocampal connectivity in two of two ZIKV-infected infant RMs several months after clearance of ZIKV RNA from peripheral blood. ZIKV infection also results in distinct alterations in the species-typical emotional reactivity to acute stress, which were predicted by the weak amygdala-hippocampal FC. We demonstrate that postnatal ZIKV infection of infants in this model affects neurodevelopment, suggesting that long-term clinical monitoring of pediatric cases is warranted.

Findings and lessons from establishing Zika virus surveillance in southern Viet Nam, 2016

Objective

To document the evolution and optimization of the Zika virus (ZIKV) disease surveillance system in southern Viet Nam in 2016 and to describe the characteristics of the identified ZIKV-positive cases.

Methods

We established a sentinel surveillance system to monitor ZIKV transmission in eight sites in eight provinces and expanded the system to 71 sites in 20 provinces in southern Viet Nam in 2016. Blood and urine samples from patients who met the case definition at the sentinel sites were tested for ZIKV using real-time reverse transcription polymerase chain reaction at the Pasteur Institute in Ho Chi Minh City (PI-HCMC). We conducted descriptive analysis and mapped the ZIKV-positive cases.

Results

In 2016, 2190 specimens from 20 provinces in southern Viet Nam were tested for ZIKV at PI-HCMC; 626 (28.6%), 484 (22.1%), 35 (1.6%) and 1045 (47.7%) tests were conducted in the first, second, third and fourth quarters of the year, respectively. Of these tested specimens, 214 (9.8%) were ZIKV positive with 212 (99.1%) identified in the fourth quarter. In the fourth quarter, the highest positivity rate was those in age groups 30–39 years (30.0%) and 40–59 years (31.6%). Of the 214 ZIKV-positive patients, 210 (98.1%) presented with rash, 194 (90.7%) with fever, 149 (69.6%) with muscle pain, 123 (57.5%) with joint pain and 66 (30.8%) with conjunctivitis.

Discussion

The surveillance system for ZIKV disease underwent several phases of optimization in 2016, guided by the most up-to-date local data. Here we demonstrate an adaptable surveillance system that detected ZIKV-positive cases in southern Viet Nam.

Emerging arboviruses and implications for pediatric transplantation: A review

Recent years have brought a rise in newly emergent viral infections, primarily in the form of previously known arthropod-transmitted viruses that have increased significantly in both incidence and geographical range. Of particular note are DENV, CHIKV, and ZIKV, which are transmitted mostly by Aedes species of mosquitoes that exhibit a wide and increasing global distribution. Being important pathogens for the general population, these viruses have the potential to be devastating in the international transplant community, with graft rejection and death as possible outcomes of infection. In this review, we discuss the current state of knowledge for these viruses as well as repercussions of infection in the solid organ and HSCT population, with a focus, when possible, on pediatric patients.

Zika Virus Infection in Children

Zika virus is a mosquito-borne Flavivirus responsible for symptomatic and asymptomatic infections in humans. Zika was first identified in Africa as a cause of sporadic febrile illness. Beginning in 2015, Zika virus infection was identified in Brazil and linked with several symptomatic infections. Notably, congenital infections were observed with marked neurologic abnormalities. Diagnosis relies on detection of Zika virus by real-time polymerase chain reaction or by the presence of anti-Zika antibodies. Treatment of this viral illness remains supportive; however, proactive screening and interventions are indicated in the treatment of infants with symptomatic congenital infection.

The Diversification of Zika Virus: Are There Two Distinct Lineages?

Zika virus (ZIKV) has caused explosive epidemics in the Pacific and the Americas, posing a serious threat to public health. Conventional opinion advocates that ZIKV evolved into two distinct lineages, namely, African and Asian. Descendants of this latter lineage dispersed globally causing major epidemics. However, based on shared amino acid replacements and phylogenetic analyses, it was recently contentiously proposed that the Asian lineage was a direct descendant of the African lineage. To address this contentious issue, we reconstructed a phylogenetic tree of ZIKV using the method based on shared amino acid replacements and found that ZIKV evolved into two distinct lineages. This supports the conventional phylogenetic divergence pattern of ZIKV. Evidence of recombination and sequencing errors was identified among the large collection of ZIKV. As such problematic sequences could confound the phylogenetic analyses, they were removed. Bayesian phylogenetic analyses using the improved sequence data enabled estimates for the divergence time in the past of the African and Asian lineages of ∼180 years ago. Moreover, we found that the Asian lineage viruses did not evolve at an elevated rate. Our findings provide additional support for the conventional opinion that the Asian lineage of ZIKV diverged from the African lineage.

Symptomatic Zika Virus Infection in Infants, Children, and Adolescents Living in Puerto Rico

IMPORTANCE

Little information is available regarding Zika virus (ZIKV) infection in children.

OBJECTIVE

To describe patients younger than 18 years who were infected with ZIKV and were enrolled in the Sentinel Enhanced Dengue and Acute Febrile Illness Surveillance System (SEDSS).

DESIGN, SETTING, AND PARTICIPANTS

Children infected with ZIKV with 7 or fewer days of fever or emancipated minors aged 14 to 17 years with a generalized maculopapular rash, arthritis or arthralgia, or nonpurulent conjunctivitis were eligible for enrollment on or before December 31, 2016, in Puerto Rico. Patients were evaluated using ZIKV polymerase chain reaction testing at 7 or fewer days after the onset of symptoms. Available ZIKV polymerase chain reaction-positive specimens were evaluated to determine viral loads.

EXPOSURES

Confirmed polymerase chain reaction-positive ZIKV infection.

MAIN OUTCOMES AND MEASURES

Clinical characteristics and viral loads of symptomatic children with confirmed ZIKV infection.

RESULTS

Of 7191 children enrolled in SEDSS on or before December 31, 2016, only those with confirmed ZIKV infection (351 participants) were included in this study. Participants who had confirmed ZIKV infection included 25 infants (7.1%), 69 children (19.7%) aged 1 to 4 years, 95 (27.1%) aged 5 to 9 years, and 162 (46.1%) aged 10 to 17 years. Among these, 260 patients (74.1%) presented for evaluation of ZIKV infection at fewer than 3 days after the onset of symptoms, 340 (96.9%) were discharged to home after evaluation, and 349 (99.4%) had fever, 280 (79.8%) had a rash, 243 (69.2%) had facial or neck erythema, 234 (66.7%) had fatigue, 223 (63.5%) had headache, 212 (60.4%) had chills, 206 (58.7%) had pruritus, and 204 (58.1%) had conjunctival hyperemia. Of 480 specimens collected (317 serum and 163 urine specimens) from 349 children, the median number of days after the onset of symptoms was lower for children who had serum specimens (1 day [interquartile range (IQR), 1-2 days]) than for children who had urine specimens (2 [1-3] days) (P < .001). Of 131 children who had both serum and urine specimens collected on the same day, the median viral load was higher in serum than in urine (median [IQR], 23 098 [8784-88 242] copies/mL for serum vs 9966 [2815-52 774] copies/mL for urine; P = .02). When a single serum sample from each of 317 patients was analyzed, there were no statistically significant differences in median viral loads according to age, sex, or disposition. However, the median serum viral load varied significantly according to the number of days after the onset of symptoms (0 days, 106 778 [IQR, 9772-1 571 718] copies/mL; 1 day, 46 299 [10 663-255 030] copies/mL; 2 days, 20 678 [8763-42 458] copies/mL; and ≥3 days, 15 901 [5135-49 248] copies/mL; P = .001).

CONCLUSIONS AND RELEVANCE

This study represents the largest study to date of ZIKV infection in the pediatric population. Most children infected with ZIKV had fever, rash, and conjunctival hyperemia. The children usually presented for evaluation at fewer than 3 days after the onset of symptoms. Viral loads for ZIKV were higher in serum vs urine specimens. Median viral loads in serum specimens differed significantly according to the number of days after the onset of symptoms.

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.

Zika and Public Health: Understanding the Epidemiology and Information Environment

Because Zika is a newly emerging infectious disease with little previous information known about it, there are many epidemiologic and clinical questions. The complexity of providing care to those who are at risk for infection or are already infected with Zika in this evidence-scarce environment cannot be understated. In this article, we provide an overview of the Zika virus (ZIKV) in the context of public health and pediatric health care. A broad public health focus is used to provide relevant information for addressing important questions about the epidemic and to facilitate communication with patients, parents, and caregivers within the current information environment. We explore issues regarding the epidemiology of the virus (including why ZIKV outbreaks are occurring), what has changed since the sporadic case reports before the outbreaks, why the true incidence is difficult to estimate, why attack rates vary by population and geography, and why the association between Zika and congenital Zika syndrome and Guillain-Barré syndrome have only come to light recently. Additionally, challenges related to the current information environment, traditional and informal information sources about the ZIKV, and examples of Zika public health communication campaigns are discussed. Importantly, we review the existing findings regarding the US population's Zika-related knowledge, attitudes, beliefs, and behavior by highlighting variations and gaps. We conclude by identifying related research questions that remain critical.

Neuroimaging Findings in Normocephalic Newborns With Intrauterine Zika Virus Exposure

BACKGROUND

Congenital Zika infection can result in a spectrum of neurological abnormalities in the newborn. Newborns exposed to Zika virus in utero often have neuroimaging as part of their clinical evaluation.

METHODS

Through the Congenital Zika Program at Children's National Health System in Washington DC, we performed fetal or neonatal neuroimaging, including magnetic resonance imaging and ultrasound, on over 70 fetuses or neonates with intrauterine Zika exposure. Novel findings on neonatal brain magnetic resonance imaging were observed in two instances.

RESULTS

Gadolinium-contrast magnetic resonance imaging showed enhancement of multiple cranial nerves at three days of age on one infant. Another infant underwent magnetic resonance imaging at 16 days of age and was shown to have a chronic ischemic cerebral infarction. This infant had previously normal fetal magnetic resonance imaging.

CONCLUSION

Cranial nerve enhancement and cerebral infarction may be among the expanding list of neurological findings in congenital Zika infection. Postnatal brain magnetic resonance imaging should be considered for newborns exposed to Zika virus in utero.

Zika virus infection in children: epidemiology and clinical manifestations

PURPOSE

The purpose of this review is to comprehensively review Congenital Zika Syndrome in regard to their epidemiology and clinical manifestations.

METHODS

This subject review of congenital Zika syndrome was composed after conducting a thorough review of the available literature on this topic using PubMed and other primary sources.

RESULTS

The first epidemic of Zika virus infection in Brazil was followed by an unexpected sharp increase in the incidence of infants born with microcephaly and the description of a new disease, the congenital Zika syndrome. This review focuses on the epidemiological and clinical aspects of Zika infection in children. We conducted a brief historical account of the virus description in 1947, the rare cases of Zika infection occurring up to 2007, and the first epidemics in the Pacific between 2007 and 2014. We also discussed the isolation of the virus in Brazil in 2015 and its spread in the Americas, the microcephaly outbreak in Brazil and its association with Zika virus, and the current epidemiological panorama. We address the known clinical spectrum of Zika virus infection in the pediatric population, including manifestations of acute infection and congenital Zika syndrome, with emphasis on cranial, ophthalmic, and orthopedic abnormalities.

CONCLUSION

While much has been learned about congenital Zika syndrome, the full spectrum of this infection is not yet known. This review is based on current, limited data about Zika vírus infection. As more information becomes available, we will have a more accurate picture of this new disease.

Epidemiology of Pediatric Zika Virus Infections

BACKGROUND AND OBJECTIVE

In July 2016, local transmission of Zika virus (ZIKV) was announced in Miami-Dade County, Florida. In this report, we describe the epidemiology of pediatric ZIKV infections in locally acquired and travel-associated cases.

METHODS

All children aged 1 to 17 years tested for ZIKV between October 1, 2015, and March 29, 2017, were included. SAS 9.4 was used to analyze age, sex, race and/or ethnicity, origin of exposure, onset date, affiliation with a household cluster, clinical symptoms, hospitalizations, viremia, viruria, and antibody detection in specimens.

RESULTS

Among 478 confirmed ZIKV cases in Miami-Dade County, 33 (6.9%) occurred in children (1-17 years). Twenty-seven (82.3%) cases were travel-associated. The median age of a pediatric Zika case patient was 11 years. Seventeen (51.5%) case patients were boys, and 23 (69.9%) were Hispanic. Among 31 symptomatic cases, all reported having rash, 25 (80.6%) reported fever, 9 (29.0%) reported conjunctivitis, and 7 (22.6%) reported arthralgia. Sixteen (48.5%) cases reported 2 of 4 and 8 (24.2%) reported 3 of 4 main symptoms.

CONCLUSIONS

This report found that the majority of children identified during the 2016 ZIKV outbreak only presented with 2 of the 4 main symptoms. In addition, pediatric ZIKV cases were frequently associated with symptomatic household members.

Zika Virus Disease in Children in Colombia, August 2015 to May 2016

BACKGROUND

Children are considered a potentially vulnerable population for Zika virus infection. However, data on paediatric Zika virus infection are sparse.

METHODS

We analysed data from Colombia's national surveillance system during the 2015-2016 Zika virus outbreak on patients meeting the clinical case definition of Zika virus disease (ZVD) among children aged 1 month to 18 years to estimate incidence by demographic characteristics and characterize the occurrence of selected complications.

RESULTS

Between August 14, 2015, and May 28, 2016, there were 18 576 reported cases of postnatal ZVD among children aged 1 month to 18 years. Laboratory testing was prioritized for high-risk patients (infants, pregnant women, adults aged ≥65 years, and persons with serious co-morbidities); among 1655 that were tested by real-time reverse transcriptase polymerase chain reaction, 1207 (72.9%) were positive. The cumulative incidence of reported ZVD was 114.4 per 100 000. The incidence differed by sex, depending on age group; the largest difference was observed for 15-18 year olds, with females having a higher incidence than males (cumulative incidence ratio 2.5, 95% confidence interval 2.3, 2.7). At the time of report to the surveillance system, 631 patients (3.4%) were hospitalised and 96 (0.5%) had a report of an accompanying neurological diagnosis, including Guillain-Barré syndrome in 40 patients.

CONCLUSIONS

Only a small proportion of reported paediatric ZVD cases in Colombia were hospitalized or had reported neurological conditions following ZVD. However, the potential for some serious outcomes demonstrates the importance of preventing Zika virus infection in children.

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.

Clinical Impact of Non-Congenital Zika Virus Infection in Infants and Children

PURPOSE OF REVIEW

While the Zika virus (ZIKV) has been noted for its distinct neurotropism and identified as a significant cause for a congenital infection syndrome, there has been increased recognition of the importance to better understand the clinical impact of non-congenital ZIKV infection in infants and children. This article reviews reports of perinatal and breast milk transmission of ZIKV and summarizes current clinical outcome data of pediatric non-congenital ZIKV infection.

RECENT FINDINGS

Perinatal transmission and presence of infective ZIKV particles in breast milk have been reported. Most symptomatic non-congenital ZIKV infection in infants and children is mild and self-limited, but long-term follow-up studies are lacking. The mechanism and impact of perinatal and breast milk transmission is unclear. The current WHO infant feeding guidelines in areas of ZIKV transmission support breastfeeding. Unless any scientific data raise concern regarding transmission via breastfeeding, the current guidelines should continue to be followed. Prospective population-based cohort studies to investigate maternal, perinatal, infant, and child outcomes are needed.

Zika Virus Infection

In less than 2 years since entry into the Americas, we have witnessed the emergent spread of Zika virus into large subsets of immunologically naïve human populations and then encountered the devastating effects of microcephaly and brain anomalies that can arise from in utero infection with the virus. Diagnostic evaluation and management of affected infants continues to evolve as our understanding of Zika virus rapidly advances. The development of a safe and effective vaccine holds the potential to attenuate the spread of infection and limit the impact of congenital infection.

Emerging Zoonotic and Vector-Borne Viral Diseases

Many vector-borne and zoonotic diseases are considered to be emerging; since they are either newly reported to cause human disease, or are causing disease in geographical locations or species not previously documented. In the past 15 years, significant outbreaks of Severe Acute Respiratory Syndrome (or SARS) and Middle Eastern Respiratory Syndrome (or MERS), Nipah and Hendra, Ebola virus disease and Zika fever and others have been reported. In this chapter the clinical characteristics, epidemiological aspects, treatment and prevention and information related to the laboratory investigation of important zoonotic and vector-borne diseases that have emerged in the past 10 years, and how this affects children, will be discussed. Furthermore rabies, considered a neglected viral disease with the majority of victims in Africa being children, will also be addressed.