Enterovirus infections in hospitals of Ile de France region over 2013

Active inoculation with an inactivated Coxsackievirus A2 vaccine induces neutralizing antibodies and protects mice against lethal infection

Coxsackievirus A2 (CVA2) is one of the causative agents of hand-foot-and-mouth disease (HFMD), which poses a great challenge for global public health. However, presently, there are no available commercial vaccines or antivirals to prevent CVA2 infection. Here, we present an inactivated Vero cell-based whole CVA2 vaccine candidate and evaluate its safety and efficacy in this study. Neonatal BALB/c mice were vaccinated at 5 and 7 days old, respectively, and then challenged with either homologous or heterologous strain of CVA2 at a lethal dose at 10 days old. The inactivated whole CVA2 vaccine candidate showed a high protective efficacy. Additionally, our inactivated vaccine stimulated the production of CVA2-specific IgG1 and IgG2a antibodies in vivo and high titers of neutralization antibodies (NtAbs) in the serum of immunized mice. Maternal immunization with the inactivated CVA2 vaccine provided full protection to pups against lethal infection. Compared with mice inoculated with only alum, the viral loads were decreased, and pathological changes were relieved in tissue samples of immunized mice. Moreover, the transcription levels of some genes related to cytokines (IFN-γ and TNF-α, MCP-1, IL-6, CXCL-10 etc.) were significantly reduced. The number of immune cells and levels of cytokines in peripheral blood of mice inoculated with only alum were higher than that of immunized mice. It is noteworthy that this vaccine showed a good cross-immunity efficacy against Enterovirus A71 (EVA71) challenge. In conclusion, our findings suggest that this experimental inactivated CVA2 vaccine is a promising component of polyvalent vaccines related to HFMD in the near future.

Current status of hand-foot-and-mouth disease

Hand-foot-and-mouth disease (HFMD) is a viral illness commonly seen in young children under 5 years of age, characterized by typical manifestations such as oral herpes and rashes on the hands and feet. These symptoms typically resolve spontaneously within a few days without complications. Over the past two decades, our understanding of HFMD has greatly improved and it has received significant attention. A variety of research studies, including epidemiological, animal, and in vitro studies, suggest that the disease may be associated with potentially fatal neurological complications. These findings reveal clinical, epidemiological, pathological, and etiological characteristics that are quite different from initial understandings of the illness. It is important to note that HFMD has been linked to severe cardiopulmonary complications, as well as severe neurological sequelae that can be observed during follow-up. At present, there is no specific pharmaceutical intervention for HFMD. An inactivated Enterovirus A71 (EV-A71) vaccine that has been approved by the China Food and Drug Administration (CFDA) has been shown to provide a high level of protection against EV-A71-related HFMD. However, the simultaneous circulation of multiple pathogens and the evolution of the molecular epidemiology of infectious agents make interventions based solely on a single agent comparatively inadequate. Enteroviruses are highly contagious and have a predilection for the nervous system, particularly in child populations, which contributes to the ongoing outbreak. Given the substantial impact of HFMD around the world, this Review synthesizes the current knowledge of the virology, epidemiology, pathogenesis, therapy, sequelae, and vaccine development of HFMD to improve clinical practices and public health efforts.

Efficacy of Coxsackievirus A2 vaccine candidates correlating to humoral immunity in mice challenged with a mouse-adapted strain

BACKGROUND

In recent years, Coxsackievirus A2 (CV-A2) has become one of the main serotypes of enterovirus species A associated with hand, foot and mouth disease (HFMD) in China. It has also caused HFMD epidemics in many countries all over the world. Currently, there are no effective, preventive vaccines against it.

METHODS

A CV-A2 strain was isolated in RD cells and then adapted to grow in Vero cells. This is in compliance with guidelines for cell substrates allowed for human vaccines by the Chinese regulatory authority. Groups of newborn Kunming mice were inoculated on day 3 and day 9 using two formulations of candidate vaccines, empty particles and full particles. They were then challenged on day 14 at a lethal dose with a mouse-adapted strain.

RESULTS

The mice in the control group all died within 14 days post-challenge whereas most of the mice in the candidate vaccine groups survived. It was found that the titers of neutralizing antibodies was dose-dependent in sera of immunized mice. The results also showed that the vaccine candidates stimulated a strong humoral immune response and protected the mice from disease and death. The virus loads in tissues or organs were significantly reduced and pathological changes were either weak or not observed in the immunized groups compared with those in Al(OH)₃ control group. Preliminary mapping of the nucleotide and amino acid residues potentially related to cell tropism of the vaccine strain and virulence of the challenge strain was performed.

CONCLUSION

The results showed that the RD cell-isolated and Vero cell-adapted CV-A2 strain is a promising vaccine candidate. This active immunization-challenge mouse model mimics the vaccination and then exposure to wildtype viruses, compared with passive immunization-challenge model, and is invaluable for efficacy evaluation in studies on multivalent vaccines containing CV-A2 against HFMD.

Epidemiology and clinical manifestations of different enterovirus and rhinovirus types show EV‐D68 may still impact on severity of respiratory infections

Respiratory infections are often caused by enteroviruses (EVs). The aim of this study was to identify whether certain types of EV were more likely to cause severe illness in 2016, when an increasing spread of upper respiratory infections was observed in Gothenburg, Sweden. The EV strain in 137 of 1341 nasopharyngeal samples reactive for EV by polymerase chain reaction could be typed by sequencing the viral 5′‐untranslated region and VP1 regions. Phylogenetic trees were constructed. Patient records were reviewed. Hospital care was needed for 46 of 74 patients with available medical records. The majority of the patients (83) were infected with the rhinovirus (RV). The remaining 54 were infected with EV A, B, C, and D strains of 13 different types, with EV‐D68 and CV‐A10 being the most common (17 vs. 14). Significantly more patients with EV‐D68 presented with dyspnea, both when compared with other EV types (p = 0.003) and compared to all other EV and RV infections (p = 0.04). Phylogenetic analysis of the sequences revealed the spread of both Asian and European CV‐A10 strains and 12 different RV C types. This study showed an abundance of different EV types spreading during a year with increased upper respiratory increased infections. EV‐D68 infections were associated with more severe disease manifestation. Other EV and RV types were more evenly distributed between hospitalized and nonhospitalized patients. The EV type CV‐A10 was also found in infected patients, which warrants further studies and surveillance, as this pathogen could cause more severe disease and outbreaks of hand, foot, and mouth disease.

Analysis of miRNAs Involved in Mouse Heart Injury Upon Coxsackievirus A2 Infection

Coxsackievirus A2 (CVA2) has recently been constantly detected, and is associated with viral myocarditis in children. Our previous study demonstrated that CVA2 led to heart damage in a neonatal murine model. However, the molecular mechanism of heart injury caused by CVA2 remains largely unknown. Emerging evidence suggests the significant functions of miRNAs in Coxsackievirus infection. To investigate potential miRNAs involved in heart injury caused by CVA2, our study, for the first time, conducted a RNA-seq in vivo employing infected mice hearts. In total, 87, 101 and 76 differentially expressed miRNAs were identified at 3 days post infection (dpi), 7 dpi and 7 dpi vs 3 dpi. Importantly, above 3 comparison strategies shared 34 differentially expressed miRNAs. These results were confirmed by quantitative PCR (qPCR). Next, we did GO, KEGG, and miRNA-mRNA integrated analysis of differential miRNAs. The dual-luciferase reporter assay confirmed the miRNA-mRNA pairs. To further confirm the above enriched pathways and processes, we did Western blotting and immunofluorescence staining. Our results suggest that inflammatory responses, T cell activation, apoptosis, autophagy, antiviral immunity, NK cell infiltration, and the disruption of tight junctions are involved in the pathogenesis of heart injury caused by CVA2. The dysregulated miRNAs and pathways recognized in the current study can improve the understanding of the intricate interactions between CVA2 and the heart injury, opening a novel avenue for the future study of CVA2 pathogenesis.

Cases of Acute Flaccid Paralysis Associated with Coxsackievirus A2: Findings of a 20-Year Surveillance in the Russian Federation

Surveillance for acute flaccid paralysis syndrome (AFP) in children under 15 is the backbone of the Global Polio Eradication Initiative. Laboratory examination of stool samples from AFP cases allows the detection of, along with polioviruses, a variety of non-polio enteroviruses (NPEV). The etiological significance of these viruses in the occurrence of AFP cases has been definitively established only for enteroviruses A71 and D68. Enterovirus Coxsackie A2 (CVA2) is most often associated with vesicular pharyngitis and hand, foot and mouth disease. Among 7280 AFP cases registered in Russia over 20 years (2001–2020), CVA2 was isolated only from five cases. However, these included three children aged 3 to 4 years, without overt immune deficiency, immunized with 4–5 doses of poliovirus vaccine in accordance with the National Vaccination Schedule. The disease resulted in persistent residual paralysis. Clinical and laboratory data corresponded to poliomyelitis developing during poliovirus infection. These findings are compatible with CVA2 being the cause of AFP. Molecular analysis of CVA2 from these patients and a number of AFP cases in other countries did not reveal association with a specific phylogenetic group, suggesting that virus genetics is unlikely to explain the pathogenic profile. The overall results highlight the value of AFP surveillance not just for polio control but for studies of uncommon AFP agents.

The Disruption of the Endothelial Barrier Contributes to Acute Lung Injury Induced by Coxsackievirus A2 Infection in Mice

Sporadic occurrences and outbreaks of hand, foot, and mouth disease (HFMD) caused by Coxsackievirus A2 (CVA2) have frequently reported worldwide recently, which pose a great challenge to public health. Epidemiological studies have suggested that the main cause of death in critical patients is pulmonary edema. However, the pathogenesis of this underlying comorbidity remains unclear. In this study, we utilized the 5-day-old BALB/c mouse model of lethal CVA2 infection to evaluate lung damage. We found that the permeability of lung microvascular was significantly increased after CVA2 infection. We also observed the direct infection and apoptosis of lung endothelial cells as well as the destruction of tight junctions between endothelial cells. CVA2 infection led to the degradation of tight junction proteins (e.g., ZO-1, claudin-5, and occludin). The gene transcription levels of von Willebrand factor (vWF), endothelin (ET), thrombomodulin (THBD), granular membrane protein 140 (GMP140), and intercellular cell adhesion molecule-1 (ICAM-1) related to endothelial dysfunction were all significantly increased. Additionally, CVA2 infection induced the increased expression of inflammatory cytokines (IL-6, IL-1β, and MCP-1) and the activation of p38 mitogen-activated protein kinase (MAPK). In conclusion, the disruption of the endothelial barrier contributes to acute lung injury induced by CVA2 infection; targeting p38-MAPK signaling may provide a therapeutic approach for pulmonary edema in critical infections of HFMD.

Coxsackievirus A2 Leads to Heart Injury in a Neonatal Mouse Model

Coxsackievirus A2 (CVA2) has emerged as an active pathogen that has been implicated in hand, foot, and mouth disease (HFMD) and herpangina outbreaks worldwide. It has been reported that severe cases with CVA2 infection develop into heart injury, which may be one of the causes of death. However, the mechanisms of CVA2-induced heart injury have not been well understood. In this study, we used a neonatal mouse model of CVA2 to investigate the possible mechanisms of heart injury. We detected CVA2 replication and apoptosis in heart tissues from infected mice. The activity of total aspartate transaminase (AST) and lactate dehydrogenase (LDH) was notably increased in heart tissues from infected mice. CVA2 infection also led to the disruption of cell-matrix interactions in heart tissues, including the increases of matrix metalloproteinase (MMP)3, MMP8, MMP9, connective tissue growth factor (CTGF) and tissue inhibitors of metalloproteinases (TIMP)4. Infiltrating leukocytes (CD45⁺ and CD11b⁺ cells) were observed in heart tissues of infected mice. Correspondingly, the expression levels of inflammatory cytokines in tissue lysates of hearts, including tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1β), IL6 and monocyte chemoattractant protein-1 (MCP-1) were significantly elevated in CVA2 infected mice. Inflammatory signal pathways in heart tissues, including phosphatidylinositol 3-kinase (PI3K)-AKT, mitogen-activated protein kinases (MAPK) and nuclear factor kappa B (NF-κB), were also activated after infection. In summary, CVA2 infection leads to heart injury in a neonatal mouse model, which might be related to viral replication, increased expression levels of MMP-related enzymes and excessive inflammatory responses.

Neonatal Murine Model of Coxsackievirus A2 Infection for the Evaluation of Antiviral Therapeutics and Vaccination

Coxsackievirus (CV) A2 has emerged as an important etiological agent in the pathogen spectrum of hand, foot, and mouth disease (HFMD). The symptoms of CVA2 infections are generally mild, but worsen rapidly in some people, posing a serious threat to children’s health. However, compared with enterovirus 71 detected frequently in fatal cases, limited attention has been paid to CVA2 infections because of its benign clinical course. In the present study, we identified three CVA2 strains from HFMD infections and used the cell-adapted CVA2 strain HN202009 to inoculate 5-day-old BALB/c mice intramuscularly. These mice developed remarkably neurological symptoms such as ataxia, hind-limb paralysis, and death. Histopathological determination showed neuronophagia, pulmonary hemorrhage, myofiberlysis and viral myocarditis. Viral replication was detected in multiple organs and tissues, and CVA2 exhibited strong tropism to muscle tissue. The severity of illness was associated with abnormally high levels of inflammatory cytokines, including interleukin (IL)-6, IL-10, tumor necrosis factor α, and monocyte chemotactic protein 1, although the blockade of these proinflammatory cytokines had no obvious protection. We also tested whether an experimental formaldehyde-inactivated CVA2 vaccine could induce protective immune response in adult mice. The CVA2 antisera from the vaccinated mice were effective against CVA2 infection. Moreover, the inactivated CVA2 vaccine could successfully generate immune protection in neonatal mice. Our results indicated that the neonatal mouse model could be a useful tool to study CVA2 infection and to develop CVA2 vaccines.

Pediatric Enteroviral Central Nervous System Infections in Bialystok, Poland: Epidemiology, Viral Types, and Drivers of Seasonal Variation

Enteroviruses are common causes of infections of the central nervous system (CNS) that in temperate climates tend to peak in the summer. The aim of the study was to describe epidemiology, drivers of seasonality, and types of enteroviruses causing infections of the CNS in children in Northeastern Poland. We prospectively collected data on children hospitalized with infection of the CNS attributed to enteroviruses in Bialystok, Poland, from January 2015 to December 2019. In total, 224 children were included. Nineteen different enterovirus types were identified in isolates collected from 188 children. Coxsackie B5 (32%), echovirus 30 (20%), and echovirus 6 (14%) were the three most common types. Enteroviruses were more prevalent during the summer–fall season. Infections caused by echovirus 30 peaked early in June and coxsackievirus B5 in July, whereas echovirus 6 peaked late in October. Phylogenetic analyses of these three enterovirus types showed multiple lineages co-circulating in this region. Mean air temperatures and precipitation rates were independently associated with monthly number of cases. Considering lack of effective treatment or vaccine, easy transmission of enteroviruses between susceptible individuals, their high mutation rate and prolonged time of viral shedding, continued monitoring and surveillance are imperative to recognize enteroviral infections of the CNS and the changes in circulation of enteroviruses in Poland.

Non-polio enterovirus infections in children with central nervous system disorders in Shanghai, 2016-2018: Serotypes and clinical characteristics

BACKGROUND

Non-polio enrerovirus causes a wide spectrum of neurologic syndromes. The epidemiological and clinical profiles of non-polio enrerovirus-associated central nervous system infections vary by regions and over year.

OBJECTIVES

This study aimed to understand the prevalence, serotypes and clinical characteristics of enterovirus-associated aseptic meningitis, encephalitis and meningo-encephalitis in children in Shanghai during 2016-2018.

METHODS

We collected the clinical data and the cerebrospinal fluid specimens from the pediatric patients with aseptic meningitis, encephalitis and meningo-encephalitis during 2016-2018. The nested RT-PCR and sequencing were performed to identify enterovirus and serotypes.

RESULTS

A total of 424 patients were included in this study and their non-duplicated cerebrospinal fluid specimens were collected during the acute stage of illness. Based on PCR assay, enterovirus was detected in 272 (64.15 %) patients, of whom, the ratio of male to female subjects was 1.99, and the mean age was 5.71 ± 3.55 years (range: 0.03-16 years). There were 17 serotypes identified. Echovirus 30 (24.63 %), Coxsackievirus A10 (20.96 %), Coxsackievirus A6 (18.01 %) accounted for 63.6 %, followed by Coxsackievirus B5 (7.72 %), Echovirus 6 (5.88 %), and other serotypes (22.8 %). Of the 10 (3.68 %) critically severe patients, all had refractory seizure, 8 required mechanical ventilation, 7 survivors had recurrent attacks of epilepsy and 3 abandoned treatment; Coxsackievirus A10, Echovirus 9, Coxsackievirus A2, Coxsackievirus A6 and Echovirus 6 were identified.

CONCLUSIONS

Non-polio enterovirus is the major pathogen causing aseptic meningitis, encephalitis and meningo-encephalitis in Chinese children and can cause life-threatening encephalitis and severe sequelae.

Epidemiologic and Molecular Study of EVs in Hospitalized Children With Severe Acute Respiratory Infection

BACKGROUND

To evaluate the enterovirus (EV)-positivity rate in respiratory samples collected from children ≤15 years hospitalized with severe acute respiratory infections (SARIs) and to describe the epidemiologic and molecular characteristics of EVs.

METHODS

Respiratory samples were collected from 2468 children hospitalized with SARI at a university and research hospital in Milan (September 1, 2014 to August 31, 2017). EV and EV-D68 RNA were detected using a commercial multiplex and a specific real-time RT-PCR assay, respectively. The EV-D68-negative samples were then characterized by partial sequencing of the VP1 gene.

RESULTS

EV-RNA was detected in 9% (222/2468) of SARI cases, 77% were children ≤3 years, almost 13% of whom required intensive care. EVs circulated all-year-round in 2 distinct epidemic waves (May-August and November-December). An EV-D68 outbreak, responsible for 14.8% of EV-positive-SARIs, occurred in 2016 and 5 newly emerging EV types were identified. Twenty-two EV types were detected and remarkable heterogeneity was observed in species distribution and between different pediatric age groups.

CONCLUSIONS

This study showed that EV-positivity rate for our SARI series was 9%. The molecular detection and characterization of EVs allowed for the rapid detection of an EV-D68 outbreak and revealed the presence of emerging EV types that may pose a public health threat. The lack of routine screening and EV characterization in respiratory tract infections hampers the assessment of their epidemiologic and molecular features.

Poliovirus and non-polio-enterovirus environmental surveillance in Parma within the "Global Polio Eradication Program" (GPEI)

Poliovirus and non-polio-enterovirus environmental surveillance in Parma within the “Global Polio Eradication Program” (GPEI)

Background: Environmental surveillance of poliovirus plays an essential role in GPEI both for the detection of WTP and VDPV circulation in endemic areas and for monitoring their absence in polio-free countries. Methods: Since 2005 to 2018, in Parma, 642 wastewater samples were collected from the two wastewater treatment plants and analyzed according to the WHO Guidelines. All isolates supposed being poliovirus were sent to ISS reference laboratory for molecular characterization while NPEV only refer to samples up to 2016. Results: Positivity was obtained in 68% of samples without significant difference between the two treatment plants. Six polioviruses (1.4%) were detected, all characterized as Sabin-like: 4 of them (66.7%) were type 3 and 2 (33.3%) type 1. Coxsackieviruses B mainly recurred among NPEV (85%) while residual 15% was Echoviruses. B4 was the most frequent Coxsackie serotype isolated (31%) while, among Echovirus, Echo 7 and Echo 11 prevail (both 23%). Conclusion: As OPV isn’t used in Italy since 2002, recovery of Sabin-like polioviruses indicates the possibility of poliovirus reintroduction, considering also the important exposure to migratory flows. Finally, monitoring the environmental circulation of NPEV, could compensate for the lack of a surveillance system of the infections they cause. (www.actabiomedica.it)

Poliovirus and Other Enteroviruses from Environmental Surveillance in Italy, 2009-2015

Within the initiatives for poliomyelitis eradication by WHO, Italy activated an environmental surveillance (ES) in 2005. ES complements clinical Acute Flaccid Paralysis (AFP) surveillance for possible polio cases, detects poliovirus circulation in environmental sewage, and is used to monitor transmission in communities. In addition to polioviruses, the analyses comprised: (i) the monitoring of the presence of non-polio enteroviruses in sewage samples and (ii) the temporal and geographical distribution of the detected viruses. From 2009 to 2015, 2880 sewage samples were collected from eight cities participating in the surveillance. Overall, 1479 samples resulted positive for enteroviruses. No wild-type polioviruses were found, although four Sabin-like polioviruses were detected. The low degree of mutation found in the genomes of these four isolates suggests that these viruses have had a limited circulation in the population. All non-polio enteroviruses belonged to species B and the most frequent serotype was CV-B5, followed by CV-B4, E-11, E-6, E-7, CV-B3, and CV-B2. Variations in the frequency of different serotypes were also observed in different seasons and/or Italian areas. Environmental surveillance in Italy, as part of the 'WHO global polio eradication program', is a powerful tool to augment the polio surveillance and to investigate the silent circulation or the re-emergence of enteroviruses in the population.

Strain-dependent effects of clinical echovirus 30 outbreak isolates at the blood-CSF barrier

BACKGROUND

Echovirus (E) 30 (E-30) meningitis is characterized by neuroinflammation involving immune cell pleocytosis at the protective barriers of the central nervous system (CNS). In this context, infection of the blood-cerebrospinal fluid barrier (BCSFB), which has been demonstrated to be involved in enteroviral CNS pathogenesis, may affect the tight junction (TJ) and adherens junction (AJ) function and morphology.

METHODS

We used an in vitro human choroid plexus epithelial (HIBCPP) cell model to investigate the effect of three clinical outbreak strains (13-311, 13-759, and 14-397) isolated in Germany in 2013, and compared them to E-30 Bastianni. Conducting transepithelial electrical resistance (TEER), paracellular dextran flux measurement, quantitative real-time polymerase chain reaction (qPCR), western blot, and immunofluorescence analysis, we investigated TJ and AJ function and morphology as well as strain-specific E-30 infection patterns. Additionally, transmission electron and focused ion beam microscopy electron microscopy (FIB-SEM) was used to evaluate the mode of leukocyte transmigration. Genome sequencing and phylogenetic analyses were performed to discriminate potential genetic differences among the outbreak strains.

RESULTS

We observed a significant strain-dependent decrease in TEER with strains E-30 Bastianni and 13-311, whereas paracellular dextran flux was only affected by E-30 Bastianni. Despite strong similarities among the outbreak strains in replication characteristics and particle distribution, strain 13-311 was the only outbreak isolate revealing comparable disruptive effects on TJ (Zonula Occludens (ZO) 1 and occludin) and AJ (E-cadherin) morphology to E-30 Bastianni. Notwithstanding significant junctional alterations upon E-30 infection, we observed both para- and transcellular leukocyte migration across HIBCPP cells. Complete genome sequencing revealed differences between the strains analyzed, but no explicit correlation with the observed strain-dependent effects on HIBCPP cells was possible.

CONCLUSION

The findings revealed distinct E-30 strain-specific effects on barrier integrity and junctional morphology. Despite E-30-induced barrier alterations leukocyte trafficking did not exclusively occur via the paracellular route.

High prevalence of coxsackievirus A2 in children with herpangina in Thailand in 2015

Coxsackievirus (CV) is a member of the genus Enterovirus and the family Picornaviridae. CV infection can cause herpangina, a disease characterized by multiple ulcers on the tonsils and soft palate affecting mostly young children. CV strains are categorized by serotypes. Unfortunately, serotypes responsible for infections in patients are often undetermined. This knowledge gap partly contributes to the ineffective prevention and control of CV-associated herpangina in Southeast Asia. To characterize the viral etiology of children presented with herpangina, 295 throat swabs were tested for human enterovirus infection. Using RT-PCR specific for the viral 5'UTR/VP2 and the VP1 regions, two most frequent CV types found in these samples were CV-A2 (33.33%, 40/120) and CV-A4 (15.8%, 19/120). Phylogenetic analysis of the VP1 gene demonstrated that the CV-A2 strains in this study not only were closely related to those previously identified in Asia and Europe, but the majority clustered into a distinct group. Thus, infection predominantly by CV-A2 and CV-A4 caused herpangina in 2015 in Thailand.

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.

Molecular epidemiology of enterovirus and parechovirus infections according to patient age over a 4-year period in Spain

The epidemiology and clinical association of enterovirus (EV) and parechovirus (HPeV) infections, as well as the type-distribution-according-to-age, were determined during a 4-year study period in Spain. During 2010-2013, a total of 21,832 clinical samples were screened for EV and the detection frequency was 6.5% (1,430). Of the total EV-negative samples, only 1,873 samples from 2011 to 2013 were available for HPeV testing. HPeV was detected in 42 (2%) of them. Positive samples were genotyped using PCR and sequencing. EV infections occurred in all age groups of patients: neonates (17%), children 28 days to 2 years (29%), children 2-14 years (40%), and adults (14%). Thirty-four different EV types were identified. HPeV infections were detected exclusively in infants <8 m (70% neonates, P < 0.05). All but one HPeV were HPeV-3. Differences in type frequency detection were found according to age and clinical manifestation. Coxsackievirus (CV)-B4 (61%), CV-B5 (83%), and HPeV-3 (64%) were more frequent in neonates than in older patients (P < 0.05). Echovirus (E)-3 (60%), E-18 (47%), E-25 (62%), CV-A6 (61%), CV-A16 (72%), and EV-71 (75%) were mainly detected in children 28 days to 2 years (P < 0.05), whereas, E-6 (79%), E-20 (88%), and E-30 (85%) were predominant in children >2 years and adults (P < 0.05). Clinically, meningitis was associated with EV (P < 0.01) whereas, encephalitis was more frequent in HPeV-infected patients. CV-B types were associated with myocarditis (90%; P < 0.05) and EV species A with hand-foot-mouth-disease/atypical exanthema (88%; P < 0.05). J. Med. Virol. 89:435-442, 2017. © 2016 Wiley Periodicals, Inc.