Human enterovirus and parechovirus infections in newborns with sepsis-like illness and neurological disorders

Severe neonatal enterovirus infection in twins with different outcomes: A case report

Enteroviruses are among the most common causes of acute viral illness worldwide, and in neonates, the clinical course of these infections is heterogeneous. Severe complications, such as myocarditis, are associated with high mortality rates. In this case report, we present the clinical course of premature twins born at 35 weeks of gestational age, suffering from a severe neonatal enterovirus infection with cardiac involvement, which proved fatal in one of the twins. This course led to prompt identification in the other twin and facilitated timely transfer to a neonatal intensive care unit with neonatal hemodynamic expertise, and facilitated the timely transfer to a neonatal intensive care nit with hemodynamic expertise and immediate availability of AZCMO would it have been indicated. Early supportive therapy in the other twin contributed to a positive outcome. Therefore, we emphasize the importance of early recognition in averting adverse consequences. As a recommendation, we propose routine screening of enterovirus in viral panels for febrile newborns.

Isolation and characterization of phage display-derived scFv antibodies against human parechovirus 1 VP0 protein

Human parechoviruses (PeVs) are common viruses that are associated with a variety of diseases from mild gastrointestinal and respiratory symptoms to severe central nervous system infections. Until now there has not been antibodies for visualizing parechovirus infection. We used E. coli recombinant PeV-A1-VP0 protein as a target in phage display single chain variable fragment (scFv) antibody library panning. Three rounds of panning allowed identification and isolation of several candidate scFv clones, which tested positive in enzyme-linked immunosorbent assay (ELISA) against VP0. Three scFv clones (scFv-55, -59 and -71) with different CDR-3 sequences were further purified and tested in ELISA, Western blot and immunofluorescence microscopy (IFA) against a set of PeV-A1 isolates and a few isolates representing PeV types 2–6. In IFA, all three scFv binders recognized twenty PeV-A1 isolates. ScFv-55 and -71 also recognized clinical representatives of PeV types 1–6 both in IFA and in capture ELISA, while scFv-59 only recognized PeV-A1, -A2 and -A6. PeV-A1-VP0 (Harris strain) sequence was used to generate a peptide library, which allowed identification of a putative unique conformational antibody epitope with fully conserved flanking regions and a more variable core VVTYDSKL, shared between the scFv antibodies. Sequencing of the VP0 region of virus samples and sequence comparisons against parechoviral sequences in GenBank revealed 107 PeV-A1, -A3, -A8, -A17, -A (untyped) sequences with this exact epitope core sequence, which was most dominant among PeV-A1 isolates. These data suggest the first-time isolation of broad range phage display antibodies against human parechoviruses that may be used in diagnostic antibody development.

Neurodevelopmental Outcomes of Infants Younger Than 90 Days Old Following Enterovirus and Parechovirus Infections of the Central Nervous System

Enteroviruses (EVs) and human parechoviruses (HPeVs) are a major cause of central nervous system (CNS) infection in young infants. They have been implicated in neurodevelopmental delay, however limited data are available. The aim of this study is to describe the clinical outcome of young infants and to assess and compare the medium-term neurodevelopment following CNS infections caused by EV and HPeV. A multicentre observational ambispective study was conducted between May 2013 and March 2018. Children under 3 months of age with EV or HPeV CNS infection excluding encephalitis were included. Infants were contacted 1 year after the acute infection and their neurological development was evaluated using the Ages and Stages Questionnaire-3 (ASQ-3). If any area assessed was abnormal during the first round of tests, a second round was completed 6 to 12 months later. Forty-eight young infants with EV and HPeV CNS infection were identified: 33 (68.8%) were positive for EV and 15 (31.3%) for HPeV. At first assessment 14 out of 29 EV (48.3%) and 3 out of 15 HPeV (20%) positive cases presented some developmental concern in the ASQ-3 test. EV-positive infants showed mild and moderate alteration in all domains analyzed and HPeV-positive infants showed mild alterations only in gross and fine motor domains. Significant alterations in communication were observed in EV-positive but not in HPeV-positive infants (31 vs. 0%, p = 0.016). At second assessment 4 out of 13 EV-positive patients (30.8%) showed mild to moderate concerns in communication and gross motor function domains and 3 out of 13 (23.1%) showed significant concern in fine motor function. Although CNS infections without associated encephalitis are generally assumed to be benign our study shows that at a median age of 18 months almost half of the EV-infected infants (48.3%) and 20% of HPeV-positive infants presented some developmental concern in the ASQ-3 test. We recommend monitor the neurological development of infants during the first years of life after HPeV CNS infection and especially after EV CNS infection, even in mild cases, for an early intervention and stimulation of psychomotor development if necessary.

Multicystic Encephalomalacia: The Neuropathology of Systemic Neonatal Parechovirus Infection

The Neuropathology of Human Parechovirus (HPeV) is not widely described due to the relatively recent discovery of the virus combined with a limited number of autopsy case reports. We report the case of an infant boy born at 38 weeks who, six days after birth, presented with fever and severe neurological dysfunction. Human Parechovirus Type 3 (HPeV3) RNA was detected in his cerebrospinal fluid (CSF) and blood. He died five days after his initial presentation. Neuropathologic examination demonstrated multicystic encephalomalacia (ME). This case report confirms that white matter pathology is dominant in HPeV3 infection. A unique feature, of HPeV encephalomalacia is absence of CSF pleocytosis and minimal inflammation in the meninges. The findings permit comment on the pathogenesis of brain injury by this virus.

Emerging Non-Polio Enteroviruses recognized in the framework of the Acute Flaccid Paralyses (AFP) surveillance system in Northern Italy, 2016-2018

BACKGROUND

Acute Flaccid Paralyses Surveillance (AFPS) monitors the emergence of polioviruses and can track Non-Polio Enteroviruses (NPEVs). We report AFPS activity in the Lombardy region (Northern Italy) from 2016 to 2018.

METHODS

Fecal and respiratory samples were collected from children <15 years who met the WHO definition of an AFP case, analyzed by virus isolation in cell cultures (RD/L20B) and by a one-step real-time RT-PCR assay specific for the 5'-noncoding-region of NPEV. NPEV-positive specimens were further analyzed by sequencing a fragment of the VP1 gene.

RESULTS

36 AFP cases (89 stool and 32 respiratory samples) were reported with an incidence of 1.1/100'000, 0.9/100'000, 0.6/100'000 children <15 years in 2016, 2017, 2018, respectively. Poliovirus was not identified, whereas NPEVs were detected in 19.4% (7/36) of AFP cases. The presence of one Echovirus-25 (2016), two EV- and D68 (2016 and 2018), one EV-A71 (2016), and one Echovirus-30 (2016) sharing high nucleotide identity with NPEVs detected in Europe was identified.

CONCLUSION

The absence of polio was confirmed. The unpredicted detection of emerging EV-D68, EV-A71, and E-30 sharing high sequence nucleotide similarity with viruses involved in the latest outbreaks, provided valuable and up-to-date information, emphasizing the importance of monitoring NPEVs through AFPS.

The yield of CSF molecular testing in febrile neonates

We retrospectively examined the yield of a cerebrospinal fluid (CSF) multiplex real-time PCR assay of febrile young infants undergoing a full sepsis work-up. Eighty infants were included in the study: Forty-nine (61%) neonates and 31 (39%) 29-90 day-old patients were included in the study. A viral pathogen was detected in 59% (47/80) of the samples, human enterovirus in 53% (42/80) and Human parechovirus in 6% (5/80). The CSF of nearly half of the subjects with CNS infection was without pleocytosis; all CSF cultures were negative. Multiplex PCR CSF testing enhances the diagnosis of pathogen-specific viral CNS infection among febrile young infants.

Neurological and neurodevelopmental outcomes after human parechovirus CNS infection in neonates and young children: a systematic review and meta-analysis

BACKGROUND

Human parechoviruses are a major cause of CNS infection in neonates and young children. They have been implicated in neurological sequelae and neurodevelopmental delay. However, the magnitude of this effect has not been systematically reviewed or assessed with meta-analyses. We investigated short-term, medium-term, and long-term neurological sequelae and neurodevelopmental delay in neonates and young children after parechovirus-CNS-infection.

METHODS

In this systematic review and meta-analyses of studies, we searched PubMed, Embase, and PsycInfo, from the inception of the database until March 18, 2019, for reviews, systematic reviews, cohort studies, case series, and case control studies reporting on neurological or neurodevelopmental outcomes of children 3 months or younger with parechovirus infection of the CNS. Studies that were published after Dec 31, 2007, assessed children younger than 16 years, detailed parechoviruses infection of the CNS (confirmed by PCR), and followed up on neurological and neurodevelopmental outcomes were included. Studies published before Dec 31, 2007, were excluded. The predefined primary outcomes were the proportions of children with neurological sequelae, impairment in auditory or visual functions, or gross motor function delay. The proportion of children in whom neurological or neurodevelopmental outcomes were reported was pooled in meta-analyses. For each outcome variable we calculated the pooled proportion with 95% CI. The proportion of children in whom neurological or neurodevelopmental outcomes were reported was extracted by one author and checked by another. Two authors independently assessed the methodological quality of the studies.

FINDINGS

20 studies were eligible for quantitative synthesis. The meta-analyses showed an increasing proportion of children with neurological sequelae over time: 5% during short-term follow-up (pooled proportion 0·05 [95% CI 0·03-0·08], I²=0·00%; p=0·83) increasing to 27% during long-term follow-up (0·27 [0·17-0·40], I²=52·74%; p=0·026). The proportion of children with suspected neurodevelopmental delay was 9% or more during long-term follow-up. High heterogeneity and methodological issues in the included studies mean that the results should be interpreted with caution.

INTERPRETATION

This systematic review suggests the importance of long follow-up, preferably up to preschool or school age (5-6 years), of children with parechovirus infection of the CNS. Although not clinically severe, we found an increasing proportion of neonates and young children with CNS infection had associated neurological sequelae and neurodevelopmental delay over time. We recommend the use of standardised methods to assess neurological and neurodevelopmental functions of these children and to compare results with age-matched reference groups.

FUNDING

No funding was received for this study.

Novel scoring system for differentiating parechovirus-A3 and enterovirus infection in neonates and young infants

BACKGROUND

Parechovirus-A3 (PeV-A3) and the enteroviruses (EVs) are the most common viral pathogens responsible for sepsis and meningoencephalitis in neonates and young infants; however, differences in the clinical presentations of two infections are not well described.

OBJECTIVES

To describe the clinical presentations of PeV-A3- and EVs-related diseases and develop a novel scoring system to differentiate two diseases.

STUDY DESIGN

This prospective study used real-time PCR and genetic sequencing to evaluate viral etiologies of febrile neonates and infants <4 months with suspected sepsis or meningoencephalitis in Niigata area, Japan, in 2014-2016. The clinical manifestations of PeV-A3- and EVs-infected patients were compared, and a novel scoring system was developed after identifying the most distinguishable clinical findings, followed by the external cohort validation.

RESULTS

In 210 patients evaluated, we identified 56 PeV-A3-infected (27%) and 43 EVs-infected (20%) patients. The following clinical manifestations were significant in PeV-A3-infected patients, as compared with EVs-infected patients; a higher body temperature (38.9°C vs. 38.5°C, P < .01) and heart rate (181/min vs. 168/min, P = .01), cold extremities (72% vs. 34%, P < .01) and skin mottling (65% vs. 23%, P < .01), lower white blood cell count (5,200/μL vs. 8,900/μL, P < .01) and incidence of cerebrospinal fluid (CSF) pleocytosis (2% vs. 63%, P < .01). Using some of these significant findings, the scoring system successfully distinguished the diseases (accuracy: 86% and 83% for the derivative and external validation cohorts, respectively).

CONCLUSIONS

We found significant clinical manifestations in PeV-A3-infected patients compared to EVs-infected patients. The scoring system may be helpful to distinguish two infections, especially at onset of outbreak.

Human parechovirus type 5 neurological infection in a neonate with a favourable outcome: A case report

The majority of parechovirus A type 5 (PeV-A5) infections have been reported in patients with gastrointestinal syndromes. In contrast, a sepsis-like illness associated with PeV-A5 infection has been reported only anecdotally. Herein, we report the first case in Italy of a PeV-A5 neurological infection presenting in a neonate with a sepsis-like syndrome. The patient, a healthy male infant born at 41 weeks of gestation, was highly distressed and inconsolable, and had been crying persistently, with poor breastfeeding, since the previous day. From day 2 to day 4, the newborn was feverish with mild irritability; breastfeeding was preserved and regularly supported. His clinical condition progressively improved, with defervescence on day 4. He was discharged after 7 days, and neurological examination results indicated only mild impairment in visual fixation and vertical eye tracking and mild axial hypotonia. The Italian PeV-A5 strain was phylogenetically related to three strains detected in Denmark in 2012, as well as to one detected in Australia and one in Greece in 2015, with an average nucleotide identity of 97.9% (range 95.9-100.0%). Enterovirus/PeV infection in the newborn should be ruled out in cases of infants with unexplained fever and/or a sepsis-like syndrome and/or meningoencephalitis. An aetiological diagnosis is essential to avoid the unnecessary administration of antibiotics and to plan long-term follow-up until schooling.

Enteroviral infection in neonates

Enteroviruses generally cause mild and self-limited diseases, but they have been found to affect neonates much differently, and often more severely than older children. Clinical manifestations are difficult to differentiate from those of bacterial sepsis, such as fever, poor feeding, lethargy, respiratory distress and cardiovascular collapse. Severe life threatening complications, including hepatic necrosis with coagulopathy, meningoencephalitis and myocarditis, usually present during the first week of life. Factors affecting severity and outcome include virus serotype, mode of transmission, and presence or absence of passively acquired, serotype-specific maternal antibodies. Echoviruses and coxsackievirus B viruses are most common serotypes associated with the neonatal sepsis. An awareness of the clinical syndromes, recognition of the risk factors and monitoring parameters associated with severe cases and use of rapid reverse-transcriptase polymerase chain reaction test for viral load may help physicians in diagnosing severe cases in a timely manner. Prompt aggressive treatment including early intravenous immunoglobulin treatment may help in reducing morbidity and mortality. Enterovirus infections in neonates are common and should be routinely considered in the differential diagnosis of febrile neonates, particularly during enterovirus season. This article provides an overview of what is known about non-polio enteroviruses in neonates including epidemiology, transmission, clinical presentation, diagnosis, and treatment.

Picornavirus etiology of acute infections among hospitalized infants

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Enteroviruses (EV) and parechoviruses (PeV) cause a range of illness, including severe illness in young children.

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Of 319 patients aged <1 year, CSF specimens from 13 (4.1%) were positive for EV and from 11 (3.4%) for PeV.

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Sequencing revealed a variety of EV types and the predominance of PeV-A3 among the PeV-positive case-patients.

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Clinicians should consider EV and PeV infections in infants presenting with febrile illness.

Background

Enteroviruses (EV) and parechoviruses (PeV) are ubiquitous viruses that cause a range of illness, including acute illness in children aged <1 year.

Objectives

We describe EV and PeV infections among children from 2 US study sites aged <1 year and hospitalized with acute infections. For EV- and PeV-negative case-patients, we explored other viral etiologies.

Methods

Participants were aged <1 year, hospitalized during 2016, and had cerebrospinal fluid (CSF) collected for routine diagnostic testing. Demographic and clinical data were abstracted from medical charts, and residual specimens were sent to CDC for confirmatory testing and typing.

Results

Of 472 eligible case-patients, CSF specimen was available for 319 (67.6%). Among those, 13 (4.1%) were positive for EV and 11 (3.4%) for PeV. Most case-patients (86.8%, n = 277) were aged <2 months, as were all EV- or PeV-positive case-patients. None of the positive case-patients had underlying conditions, and the chief complaint for 91.7% (n = 22) was fever. Twelve positive case-patients were admitted to intensive care (ICU) and had brief hospital stays (median 2 days). Sequencing revealed a variety of EV types and the predominance of PeV-A3 among the PeV-positive case-patients.

Conclusions

A range of EV and PeV types were associated with acute febrile illnesses leading to hospitalization in children aged <2 months. Approximately half of EV and PeV case-patients were admitted to ICU, but length of hospital stay was brief and illnesses were generally self-limiting. Clinicians should consider EV and PeV infections in infants presenting with febrile illness.

Neurodevelopment medium-term outcome after parechovirus infection

AIM

Human parechoviruses (HPeV) are responsible for fever without a source (FWS), sepsis-like illness and encephalitis in neonates and children under 3 months of age. Short-term outcome is generally good, but there is great concern about medium and long- term outcome of infants after HPeV infection. The aim of this study is to assess the medium-term outcome in infants following HPeV infection without encephalitis.

METHODS

Patients who suffered HPeV infection involving cerebrospinal fluid were evaluated twice using Ages and Stages Questionnaire-3 (ASQ-3). The first evaluation was conducted at least one year after the infection and the second one year later.

RESULTS

Sixteen patients were evaluated in the first assessment, and three of them presented mild alterations in motor function domains. Moreover, hypotonia was observed in the neurologic exam in one case, and hemiparesis in another case. In the second assessment fifteen patients were included, and only the patient with hemiparesis continued presenting gross motor disfunction, with complete recovery of the remaining patients.

INTERPRETATION

We have observed a good medium-term prognosis in infants after HPeV infections, with improvement of mild motor alterations after at-home intervention. Infants who suffer HPeV infection without encephalitis seem to have a better prognosis than those with encephalitis.

Outcome of routine cerebrospinal fluid screening for enterovirus and human parechovirus infection among infants with sepsis-like illness or meningitis in Cornwall, UK

Enteroviruses (EV) and human parechoviruses (HPeV) are known and emerging cause of sepsis-like illnesses in infants; however, testing is not yet routine. We retrospectively evaluated the number of diagnosed EV/HPeV infections in children under the age of 5 years who presented with sepsis-like illness or meningitis in Cornwall, UK, before and after routine implementation of viral screening of cerebrospinal fluid samples. During the 4-year period prior to routine testing, we identified 20 cases of EV meningitis and no cases of HPeV. In the year after introduction of routine screening, 27 cases of EV and 14 cases of HPeV were identified in 1 year. The majority of EV/HPeV infections occurred among children under 3 months old between May and August. Clinical and laboratory characteristics of EV and HPeV infections were mostly indistinguishable. We found that CSF pleocytosis and biochemistry-based testing strategy could miss 48.1 and 78.5% of EV and HPeV cases, respectively. With routine viral screening, the mean length of hospital stay (3.8 vs 5.9 days, P < 0.001) and antibiotic days (2.8 vs 4.7 days, P < 0.001) were significantly reduced in EV/HPeV-positive cases compared to a similar cohort without any detectable microbial aetiology.

CONCLUSION

Routine EV and HPeV testing of CSF samples in children has the potential to reduce length of stay and antibiotic use. What is Known: • EV and HPeV are frequent cause of meningitis and sepsis-like illness among young children. • There is increasing evidence supporting routine EV and HPeV testing of paediatric CSF. What is New: • Outcome of routine EV and HPeV testing in Cornwall, UK. • The value of testing all paediatric CSF without any screening criteria. • A rapid diagnosis of EV/HPeV can significantly reduce length of hospital stay and unnecessary antibiotics.

Epidemiology and Immune Pathogenesis of Viral Sepsis

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis can be caused by a broad range of pathogens; however, bacterial infections represent the majority of sepsis cases. Up to 42% of sepsis presentations are culture negative, suggesting a non-bacterial cause. Despite this, diagnosis of viral sepsis remains very rare. Almost any virus can cause sepsis in vulnerable patients (e.g., neonates, infants, and other immunosuppressed groups). The prevalence of viral sepsis is not known, nor is there enough information to make an accurate estimate. The initial standard of care for all cases of sepsis, even those that are subsequently proven to be culture negative, is the immediate use of broad-spectrum antibiotics. In the absence of definite diagnostic criteria for viral sepsis, or at least to exclude bacterial sepsis, this inevitably leads to unnecessary antimicrobial use, with associated consequences for antimicrobial resistance, effects on the host microbiome and excess healthcare costs. It is important to understand non-bacterial causes of sepsis so that inappropriate treatment can be minimised, and appropriate treatments can be developed to improve outcomes. In this review, we summarise what is known about viral sepsis, its most common causes, and how the immune responses to severe viral infections can contribute to sepsis. We also discuss strategies to improve our understanding of viral sepsis, and ways we can integrate this new information into effective treatment.

High prevalence of developmental concern amongst infants at 12 months following hospitalised parechovirus infection

AIM

The human parechovirus (HPeV) is an increasingly recognised cause of sepsis and central nervous system infection in young infants for which there are limited long-term outcome data. We aimed to assess neurodevelopmental outcome and quality of life in infants following hospitalised HPeV infection.

METHODS

This cohort study was a 12-month follow-up of infants who were hospitalised with confirmed HPeV infection at the Sydney Children's Hospitals Network during an outbreak in Sydney in 2013. Telephone interviews were conducted with parents/guardians. We administered standardised questionnaires, including: Ages and Stages Questionnaire (ASQ), Liverpool Outcome Score-follow-up, Pediatric Quality of Life Inventory(PedsQL) Infant scales and Short-Form health survey (SF-12).

RESULTS

We followed up 46 of 79 infants (58%) aged between 12 and 16 months who had been hospitalised with HPeV infection; 19% showed significant concern in developmental attainment (ASQ3 score <2 standard deviation below population mean), and 50% showed some concern (<1 standard deviation below mean). ASQ3 developmental outcome was associated with the presence of neurodevelopmental sequelae (lower total Liverpool Outcome Score) and poorer health-related quality of life (HRQOL) in physical functioning (PedsQL physical component score), but not overall HRQOL (total PedsQL score) or parental HRQOL (SF-12 scores). No significant associations were identified between clinical or laboratory features during acute hospitalisation and adverse outcome on ASQ3.

CONCLUSIONS

A high proportion of infants show developmental concern at 12-month follow-up post-hospitalisation with HPeV infection. Clinical features during hospitalisation were not associated with adverse outcomes at 12 months. These results suggest that careful follow-up of young infants hospitalised with HPeV disease may be warranted.

Prevalence and characteristics of human parechovirus and enterovirus infection in febrile infants

BACKGROUND

Human parechovirus (HPeV) and human non-polio enterovirus (EV) are important causes of fever without source (FWS) in young infants. Their prevalence and clinical characteristics are largely unknown in Asian countries. This study was conducted to elucidate the epidemiology and clinical characteristics of HPeV and EV infection in febrile young infants in Japan.

METHODS

During February 2010-August 2015, we obtained 53 stool, 44 throat swab, and 20 cerebrospinal fluid samples from 56 infants (<3 months) with FWS at a single hospital. To each sample, we applied reverse transcription-polymerase chain reaction for HPeV and EV. We compared the clinical characteristics of HPeV and EV patients.

RESULTS

HPeV was detected in 11 and EV in 17 patients. HPeV was detected during July-September. HPeV patients, compared with EV patients, had lower age (32 vs 47 days; P = n.s.), higher prevalence of exclusive breast-feeding (81.8 vs 29.4%; P = 0.024), and lower prevalence of sick contacts (36.4 vs 88.2%; P = 0.010). More HPeV than EV patients met the systemic inflammatory response syndrome criteria (90.9 vs 52.9%; P = 0.049). In the HPeV group, leukopenia, thrombopenia, and elevated deviation enzyme were observed, although the prevalence of abnormal cerebrospinal fluid was significantly lower than in the EV group. HPeV patients had longer hospital stay (7 vs 5 days; P = 0.025).

CONCLUSION

HPeV and EV are important causal viruses of FWS. Characteristic clinical pictures exist in these virus infections, but further research is needed to accumulate more cases to produce a comprehensive picture of these virus infections.

Nosocomial Outbreak of Parechovirus 3 Infection among Newborns, Austria, 2014

In 2014, sepsis-like illness affected 9 full-term newborns in 1 hospital in Austria. Although results of initial microbiological testing were negative, electron microscopy identified picornavirus. Archived serum samples and feces obtained after discharge were positive by PCR for human parechovirus 3. This infection should be included in differential diagnoses of sepsis-like illness in newborns.

Human picornaviruses associated with neurological diseases and their neutralization by antibodies

Picornaviruses are the most commonly encountered infectious agents in mankind. They typically cause mild infections of the gastrointestinal or respiratory tract, but sometimes also invade the central nervous system. There, they can cause severe diseases with long-term sequelae and even be lethal. The most infamous picornavirus is poliovirus, for which significant epidemics of poliomyelitis were reported from the end of the nineteenth century. A successful vaccination campaign has brought poliovirus close to eradication, but neurological diseases caused by other picornaviruses have increasingly been reported since the late 1990s. In this review we focus on enterovirus 71, coxsackievirus A16, enterovirus 68 and human parechovirus 3, which have recently drawn attention because of their links to severe neurological diseases. We discuss the clinical relevance of these viruses and the primary role of humoral immunity in controlling them, and summarize current knowledge on the neutralization of such viruses by antibodies.

Cutaneous manifestations of systemic viral diseases in neonates: an update

PURPOSE OF REVIEW

Dermatologic findings may be the first signs of a neonatal viral infection. This review provides an update of the diagnostic features and therapies for selected viral illnesses [herpes simplex virus (HSV), varicella zoster virus, enterovirus, and Zika virus] that present with cutaneous manifestations in the neonate.

RECENT FINDINGS

HSV DNA polymerase chain reaction of plasma and cerebrospinal fluid, routinely used in the diagnosis of neonatal HSV, may have expanded utility in assessing prognosis and acyclovir therapeutic efficacy. Maternal antiviral suppressive therapy may alter the clinical appearance of congenital HSV, resulting in delayed diagnosis and treatment. VariZIG, a varicella zoster immune globulin, is a US Food and Drug Administration approved form of prophylaxis for varicella. The Centers for Disease Control and Prevention has expanded the period of VariZIG eligibility for preterm infants, a group particularly susceptible to severe varicella infection. For severe neonatal enterovirus sepsis, the results of a randomized, double-blind, placebo-controlled trial of pleconaril, a viral capsid inhibitor, suggest that this compound is an effective therapy. Human Parechovirus type 3, a strain within a newly formed viral genus, has a similar, and potentially underestimated, clinical presentation to enterovirus sepsis. However, a distinctive erythematous palmoplantar rash may be specific to human Parechovirus type 3 infection. Perinatal Zika virus infection in the neonate may present with a nonspecific macular and papular rash. As this rash is not specific, obtaining a maternal travel history and, if appropriate, requesting additional diagnostic testing are critical for early diagnosis.

SUMMARY

Neonatal rashes may be harmless and transient, whereas others may reflect the presence of a severe systemic illness. Recognizing key cutaneous features of viral-associated rashes may aid in the prompt and accurate diagnosis and treatment of neonatal viral illnesses.

Fifteen-minute consultation: enterovirus meningitis and encephalitis-when can we stop the antibiotics?

Enterovirus (EV) is the most common cause of aseptic meningitis and has a benign course, unlike EV encephalitis, which can result in long-term neurological sequelae. There are no active treatments or prophylactic agents, and management is purely supportive. Obtaining an EV-positive cerebrospinal fluid result usually allows antimicrobial treatment to be stopped. This review will answer some of the common questions surrounding EV meningitis/encephalitis.

Comparative analysis of viral shedding in pediatric and adult subjects with central nervous system-associated enterovirus infections from 2013 to 2015 in Switzerland

BACKGROUND

Several enterovirus (EV) genotypes can result in aseptic meningitis, but their routes of access to the central nervous system remain to be elucidated and may differ between the pediatric and adult populations.

OBJECTIVE

To assess the pattern of viral shedding in pediatric and adult subjects with acute EV meningitis and to generate EV surveillance data for Switzerland.

STUDY DESIGN

All pediatric and adult subjects admitted to the University Hospitals of Geneva with a diagnosis of EV meningitis between 2013 and 2015 were enrolled. A quantitative EV real-time reverse transcriptase (rRT)-PCR was performed on the cerebrospinal fluid (CSF), blood, stool, urine and respiratory specimens to assess viral shedding and provide a comparative analysis of pediatric and adult populations. EV genotyping was systematically performed.

RESULTS

EV positivity rates differed significantly between pediatric and adult subjects; 62.5% of pediatric cases (no adult case) were EV-positive in stool and blood for subjects for whom these samples were all collected. Similarly, the EV viral load in blood was significantly higher in pediatric subjects. Blood C-reactive protein levels were lower and the number of leucocytes/mm³ in the CSF were higher in non-viremic than in viremic pediatric subjects, respectively. A greater diversity of EV genotypes was observed in pediatric cases, with a predominance of echovirus 30 in children ≥3 years old and adults.

CONCLUSION

In contrast to adults, EV-disseminated infections are predominant in pediatric subjects and show different patterns of EV viral shedding. This observation may be useful for clinicians and contribute to modify current practices of patient care.

Surveillance of poliomyelitis in Northern Italy: Results of acute flaccid paralysis surveillance and environmental surveillance, 2012-2015

Although in the last years poliovirus (PV) transmission has been reported at the lowest levels ever recorded, the spread of virus from endemic countries endures; the high levels of immigration flows across the Mediterranean Sea jeopardize Italy for PV reintroduction. The World Health Organization (WHO) strategic plan for global poliomyelitis (polio) eradication indicates the nationwide surveillance of Acute Flaccid Paralysis (AFP) as the gold standard for detecting cases of polio. In addition, the Environmental Surveillance (ES), seeking the presence of PV and Non-Polio Enterovirus (NPEV) in sewage, is recognized as a powerful tool to confirm PV circulation in absence of AFP cases, especially in polio-free countries. Here we report the results of AFP surveillance (AFPS) and ES in Lombardy (Northern Italy) from 2012 to 2015. Forty-eight AFP cases were identified during the study period. No AFP case was caused by PV infection. NPEVs were identified in 6.3% (3/48) of AFP cases. The annual AFP incidence rate was 0.87/100'000 children <15 y in 2012, 1.42/100'000 in 2013, 1.02/100'000 in 2014, and 0.47/100'000 in 2015; according to WHO indicators, the sensitivity of AFPS was adequate in 2013 and 2014. Completeness of case investigation raised progressively during the study period to achieve the WHO standards in 2014 (92.3%) and 2015 (100%). Completeness of follow-up increased from 72.7% in 2012 to 100% in 2014. In the framework of the ES conducted in Milan, 268 wastewater samples were collected from 2012 to 2015 and no PVs were isolated. In contrast, NPEVs were detected in 65.3% (175/268) of samples. All NPEVs characterized belonged to enterovirus species B: echovirus type 11, 6 and 3 were the most frequently detected viruses, representing 29.1% (41/141), 20.6% (29/141) and 9.2% (13/141) of genotyped NPEVs, respectively. Keeping strong and encouraging both AFPS and ES is crucial to ensure that PV will not return unnoticed in Italy - as well as in other polio-free countries - and, as a final point, to achieve the global polio eradication goal.

A 4-year Study on Epidemiologic and Molecular Characteristics of Human Parechoviruses and Enteroviruses Circulating in Children Younger Than 5 Years in Northern Italy

BACKGROUND

Human parechovirus (HPeV) and enterovirus (EV) infections are widespread and can lead to a broad range of symptoms, from the common cold to severe disease (SD). Because of the lack of Italian data, this 4-year retrospective cross-sectional study aimed to investigate the frequency, seasonality and molecular characteristics of EV and HPeV circulating in children younger than 5 years.

METHODS

A total of 812 samples were collected from children ≤5 years (56.5% males; median age: 20.6 months; interquartile range: 30.1 months) from September 2010 to August 2014. Two real-time RT-PCR assays were used for EV/HPeV and EV-D68 detection. Phylogenetic analysis was performed on the EV-VP1 gene and the HPeV-VP3/VP1 junction.

RESULTS

16.1% and 5.2% of samples were EV- and HPeV-positive, respectively. One sample was EV-D68-positive. The majority (nearly 80%) of EV/HPeV-positive samples was detected in children ≤3 years, during the summer/autumn seasons. The risk of EV infection was higher in children presenting with SD, whereas the risk of infection from HPeV was higher in infants ≤1 year. Most (61.7%) of molecularly characterized EVs belonged to species B, followed by A (29.4%). The majority (66.7%) of characterized HPeVs were type 1, followed by types 3 (20%) and 6 (13.3%).

CONCLUSIONS

This study shows the significant impact of EV/HPeV circulation in children, particularly among those ≤3 years and during and early autumn, with different pattern of viral strains. The implementation of a national surveillance system could clarify the epidemiologic and clinical characteristics of these viruses in the general population.

Prospective assessment of clinical symptoms associated with enterovirus and parechovirus genotypes in a multicenter study in Dutch children

BACKGROUND

Human non-polio enterovirus (EV) and human parechovirus (HPeV) are important pathogens of viral infection and aseptic meningitis in children. The aim of this study is to prospectively compare the incidence, clinical signs, blood and cerebrospinal fluid in EV and HPeV infected children.

OBJECTIVES

To compare the clinical symptoms and laboratory data of children with different EV and HPeV genotypes.

STUDY DESIGN

This study is part of a multicenter prospective cohort study. Children were included in 3 different hospitals in The Netherlands from 2008 to 2011.

RESULTS

Of 285 included patients, 140 (49%) had EV and 44 (15%) HPeV infection. Of children with EV infection 9 (6%) had EV-A, 109 (78%) EV-B, 12 (9%) had a non-type able EV and in 10 (7%) no genotyping was performed. Of children with HPeV infection, 24 (55%) had HPeV-3, 6 (14%) HPeV-1, 2 (5%) HPeV-4 and 1 (2%) HPeV-6. Meningitis was more frequent in EV than in HPeV infected children (54% vs. 36%, p=0.046), and in EV-B than EV-A infected children (60 vs. 33%). In contrast gastroenteritis was more frequent in HPeV than EV infected children (30% vs. 15%, p=0.030), and significantly more in HPeV-1 than HPeV-3 infected children (p<0.001).

CONCLUSIONS

EV infection is more often associated with meningitis and HPeV infection more often with a gastro-enteritis. EV genotype B infection is more often associated with meningitis than EV genotype A infection. HPeV-1 infection was more often associated with gastroenteritis than HPeV-3 infection.

Parechovirus Encephalitis and Neurodevelopmental Outcomes

OBJECTIVE

We aimed to describe the clinical features and outcome of human parechovirus (HPeV) encephalitis cases identified by the Australian Childhood Encephalitis (ACE) study.

METHODS

Infants with suspected encephalitis were prospectively identified in 5 hospitals through the (ACE) study. Cases of confirmed HPeV infection had comprehensive demographic, clinical, laboratory, imaging, and outcome at discharge data reviewed by an expert panel and were categorized by using predetermined case definitions. Twelve months after discharge, neurodevelopment was assessed by using the Ages and Stages Questionnaire (ASQ).

RESULTS

We identified thirteen cases of suspected encephalitis with HPeV infection between May 2013 and December 2014. Nine infants had confirmed encephalitis; median age was 13 days, including a twin pair. All had HPeV detected in cerebrospinal fluid with absent pleocytosis. Most were girls (7), admitted to ICU (8), and had seizures (8). Many were born preterm (5). Seven patients had white matter diffusion restriction on MRI; 3 with normal cranial ultrasounds. At discharge, 3 of 9 were assessed to have sequelae; however, at 12 months' follow-up, by using the ASQ, 5 of 8 infants showed neurodevelopmental sequelae: 3 severe (2 cerebral palsy, 1 central visual impairment). A further 2 showed concern in gross motor development.

CONCLUSIONS

Children with HPeV encephalitis were predominantly young, female infants with seizures and diffusion restriction on MRI. Cranial ultrasound is inadequately sensitive. HPeV encephalitis is associated with neurodevelopmental sequelae despite reassuring short-term outcomes. Given the absent cerebrospinal fluid pleocytosis and need for specific testing, HPeV could be missed as a cause of neonatal encephalopathy and subsequent cerebral palsy.

MicroRNA and Pathogenesis of Enterovirus Infection

There are no currently available specific antiviral therapies for non-polio Enterovirus infections. Although several vaccines have entered clinical trials, the efficacy requires further evaluation, particularly for cross-strain protective activity. Curing patients with viral infections is a public health problem due to antigen alterations and drug resistance caused by the high genomic mutation rate. To conquer these limits in the development of anti-Enterovirus treatments, a comprehensive understanding of the interactions between Enterovirus and host cells is urgently needed. MicroRNA (miRNA) constitutes the biggest family of gene regulators in mammalian cells and regulates almost a half of all human genes. The roles of miRNAs in Enterovirus pathogenesis have recently begun to be noted. In this review, we shed light on recent advances in the understanding of Enterovirus infection-modulated miRNAs. The impacts of altered host miRNAs on cellular processes, including immune escape, apoptosis, signal transduction, shutdown of host protein synthesis and viral replication, are discussed. Finally, miRNA-based medication provides a promising strategy for the development of antiviral therapy.

Human parechovius and enterovirus in neonates: Distinct infections with overlapping features

INTRODUCTION

Human parechoviruses (HPeVs) have recently been added to the family Picornaviridae, where Enteroviruses (HEV) belong. The specific characteristics of HPeV infection in the neonate are not clear, and their involvement in neonatal infection is believed to be largely underestimated. HPeV type 3 has been recently linked to sepsis-like illness and neurological involvement in the newborn.

OBJECTIVE

To assess the involvement of HPeV in central nervous system (CNS) infections throughout the neonatal period in term newborns, describe their clinical, analytical and cerebrospinal fluid (CSF) characteristics, and compare them to HEV infections.

METHODS

Term newborns admitted for neurological symptoms or a suspected infection, aged 0-30 days were prospectively recruited (September 2012-August 2014). Bacterial cultures were performed in all patients. Viral tests were performed in CSF including: RT-PCR for cytomegalovirus, Herpes simplex type 1 and 2, Epstein-Barr virus, HEV and HPeV. HEV and HPeV positive samples were genotyped.

RESULTS

Fifty-seven newborns were diagnosed of sepsis-like illness and/or CNS alteration. HEV (8.7%) and HPeV-3 (3.5%) were the two most common viral agents involved during the study period. The most frequent symptom at admission was fever. Irritability was present in 1/2 of HPeV and 1/5 of HEV cases. There were no other neurological symptoms. Blood and CSF analysis were unremarkable in HPeV infections. All cases resolved favorably.

CONCLUSIONS

HPeV infection was clinically very similar to that of HEV, while it featured normal blood and CSF analysis.

PRACTICE IMPLICATIONS

HPeV should be considered by clinicians in the differential diagnosis of neonatal infection, particularly when blood and CSF analysis are unremarkable.

Enterovirus and Parechovirus viraemia in young children presenting to the emergency room: Unrecognised and frequent

BACKGROUND

Human Enterovirus (EV) and Parechovirus (HPeV) are well recognised as agents causing disease in neonates, but their importance is poorly described in the general paediatric population consulting with a suspicion of infection.

OBJECTIVE

We investigated the prevalence of EV- or HPeV-associated infections in children presenting to a paediatric emergency department with a suspicion of infection.

STUDY DESIGN

Plasma specimens collected in our paediatric emergency room for clinical reasons were screened by specific real-time RT-PCR for the presence of EV and HPeV.

RESULTS

Based on an analyses of 233 plasma specimens, up to 6.9% and 2.6% were positive for EV and HPeV, respectively. Amongst the population <3y.o, prevalence of EV and HPeV viraemia was 11% and 3.7%, respectively. Importantly, 56.3% of positive EV specimens were detected in infants >3 months of age.

CONCLUSION

The prevalence of EV and HPeV viraemia in children <3 years old is largely underestimated. Our results confirm that EV should be suspected and included in the work-up in children >3 months of age and not restricted to neonates.

Comparison of epidemiology and clinical characteristics of infections by human parechovirus vs. those by enterovirus during the first month of life

Human parechoviruses (HPeV) have been recently recognized as important viral agents in paediatric infections. The aims of this study were to investigate the HPeV infection prevalence in infants <1 month in Spain and, secondly, to analyse the clinical and epidemiological characteristics of the infected patients compared with those infected by enterovirus (EV). Infants <1 month with neurological or systemic symptoms were included in a multicentre prospective study. EV and HPeV detection by RT-PCR and genotyping were performed in cerebrospinal fluids (CSF), sera or throat swabs. Out of the total of 84 infants studied during 2013, 32 were EV positive (38 %) and 9 HPeV positive (11 %). HPeV-3 was identified in eight cases and HPeV-5 in one. Mean age of HPeV-positive patients was 18 days. Diagnoses were fever without source (FWS) (67 %), clinical sepsis (22 %) and encephalitis (11 %). Leukocytes in blood and CSF were normal. Pleocytosis (p = 0.03) and meningitis (p = 0.001) were significantly more frequent in patients with EV infections than with HPeV.

CONCLUSIONS

Although HPeV-3 infections were detected less frequently than EV, they still account for approximately 10 % of the cases analysed in infants younger than 1 month. HPeV-3 was mainly associated with FWS and without leukocytosis and pleocytosis in CSF. In these cases, HPeV screening is desirable to identify the aetiologic agent and prevent unnecessary treatment and prolonged hospitalization.