Severe and fatal neonatal infections linked to a new variant of echovirus 11, France, July 2022 to April 2023.

We report nine severe neonatal infections caused by a new variant of echovirus 11. All were male, eight were twins. At illness onset, they were 3-5 days-old and had severe sepsis and liver failure. This new variant, detected in France since April 2022, is still circulating and has caused more fatal neonatal enterovirus infections in 2022 and 2023 (8/496; 1.6%, seven associated with echovirus 11) compared with 2016 to 2021 (7/1,774; 0.4%). National and international alerts are warranted.

Repeated viral meningitis in a newborn.

Human enteroviruses (EV) are the most common cause of viral meningitis in children. Human parechoviruses (HPeV) are increasingly being recognized as a cause of central nervous system (CNS) infections and sepsis-like disease in children. Both viruses belong to Picornaviridae family. The clinical picture in EV and HPeV infections is usually nonspecific. Therefore, molecular detection of both viruses is needed for etiological diagnosis. In this case report, we describe and discuss clinical and laboratory findings of two consecutive episodes of viral meningitis caused by EV and HPeV, respectively, occurring in the first month of a newborn's life.

Emergence of enterovirus D68 clade D1, France, August to November 2018.

We report a seasonal increase of enterovirus D68 (EV-D68) cases in France, with 54 cases detected between 19 August and 14 November 2018. Molecular typing revealed that 20 of 32 of the isolates belonged to clade D1, only sporadically detected before in France. Median age of D1-cases was 42 years, 10 developed severe respiratory signs and one had neurological complications. The 2018-D1 viruses showed a genetic divergence of 3.34 % with D1 viruses identified previously.

Molecular diversity and biennial circulation of enterovirus D68: a systematic screening study in Lyon, France, 2010 to 2016.

BackgroundUnderstanding enterovirus D68 (EV-D68) circulation patterns as well as risk factors for severe respiratory and neurological illness is important for developing preventive strategies. Methods: Between 2010 and 2016, 11,132 respiratory specimens from hospitalised patients in Lyon, France, were screened for EV-D68 by PCR. Phylogenetic relationships of the viral-protein-1 sequences were reconstructed using maximum-likelihood and Bayesian-Markov-Chain-Monte-Carlo approaches. Results: Overall, 171 infections with a biennial pattern were detected, including seven, one, 55, none, 42, one and 65 cases annually during 2010-16. Children (< 16 years-old; n = 150) were mostly affected and 71% (n = 121) of the total patients were under 5 years-old. In 146 patients with medical reviews, 73% (n = 107) presented with acute respiratory distress. Among paediatric patients with medical reviews (n = 133), 55% (n=73) had an asthma/wheezing history, while among adults (n = 13), 11 had underlying diseases. In total, 45 patients had severe infections and 28 patients needed intensive care unit stays. No acute flaccid myelitis (AFM) was detected. We found genotypes A, B1, B2 B3 and D circulating, and no associations between these and clinical presentations. During the study, new genotypes continuously emerged, being replaced over time. We estimated that ancestors of currently circulating genotypes emerged in the late-1990s to 2010. Rises of the EV-D68 effective population size in Lyon coincided with infection upsurges. Phylogenetic analyses showed ongoing diversification of EV-D68 worldwide, coinciding with more infections in recent years and increases of reported AFM paediatric cases. Conclusions: Reinforcement of diagnostic capacities and clinical-based surveillance of EV-D68 infections is needed in Europe to assess the EV-D68 burden.

A new real-time RT-PCR targeting VP4-VP2 to detect and quantify enterovirus D68 in respiratory samples.

Causing an international outbreak of respiratory disease, Enterovirus D68 quickly entered the closed circle of emerging viral pathogens of public health significance. As rapid and accurate detection of EV-D68 is essential for an efficient clinical management, we designed and validated a new highly efficient one-step quantitative rRT-PCR specific to EV-D68 VP4-VP2 region. With 100% specificity and 95.6% sensitivity to all EV-D68 strains, this new assay can be reliably used to detect and quantify EV-D68 in respiratory samples and represents an interesting additional tool for diagnosis as it targets an original region of the genome.

A major outbreak of conjunctivitis caused by coxsackievirus A24, Réunion, January to April 2015.

From January to April 2015, Réunion experienced a major outbreak of acute haemorrhagic conjunctivitis (AHC) caused by coxsackievirus A24, which heavily impacted the healthcare system. According to the general practitioners' (GP) sentinel network, the number of medical consultations due to conjunctivitis during this period was estimated at ca 100,000. This report describes the characteristics of the outbreak, which were obtained through several different yet complementary surveillance systems on the island. These included the network of hospital emergency departments (OSCOUR network), the GPs' sentinel network, an Internet-based population cohort ('Koman i lé') participating in a survey on distinct symptoms including 'red eyes' and the monitoring of eye drop sales. Overall the results of the different surveillance approaches were in good agreement regarding the outbreak dynamic. A peak of patients with conjunctivitis was detected in the first 15 days of March (week 10 and 11), coinciding with increased eye drop sales on the island. Strains recovered from outbreak cases belonged to genotype IV and were most closely related to strains identified in AHC outbreaks in China, Egypt and Japan since 2010. Continued surveillance of AHC in Réunion remains important not only locally, but also because frequent exchanges between the island and mainland France may lead to introduction of this virus in Europe.

Severe paediatric conditions linked with EV-A71 and EV-D68, France, May to October 2016.

We report 59 cases of severe paediatric conditions linked with enterovirus (EV)-A71 and EV-D68 in France between May and October 2016. Fifty-two children had severe neurological symptoms. EV sequence-based typing for 42 cases revealed EV-A71 in 21 (18 subgenotype C1, detected for the first time in France) and EV-D68 in eight. Clinicians should be encouraged to obtain stool and respiratory specimens from patients presenting with severe neurological disorders for EV detection and characterisation.

Epidemiological and clinical characteristics of patients infected with enterovirus D68, France, July to December 2014.

In 2014, the United States (US) experienced a nationwide outbreak of enterovirus D68 (EV-D68) infection with 1,152 cases reported mainly in hospitalised children with severe asthma or bronchiolitis. Following the US alert, 11 laboratories of the French enterovirus (EV) surveillance network participated in an EV-D68 survey. A total of 6,229 respiratory samples, collected from 1 July to 31 December 2014, were screened for EV-D68 resulting in 212 EV-D68-positive samples. These 212 samples corresponded to 200 EV-D68 cases. The overall EV-D68 positivity rates among respiratory samples were of 5% (184/3,645) and 1.1% (28/2,584) in hospitalised children and adults respectively. The maximum weekly EV-D68 positivity rates were of 16.1% for children (n = 24/149; week 43) and 2.6% for adults (n = 3/115; week 42). Of 173 children with EV-D68 infection alone, the main symptoms were asthma (n = 83; 48.0%) and bronchiolitis (n = 37; 21.4%). One child developed acute flaccid paralysis (AFP) following EV-D68-associated pneumonia. Although there was no significant increase in severe respiratory tract infections reported to the French public health authorities, 10.7% (19/177) of the EV-D68 infected children and 14.3% (3/21) of the EV-D68 infected adults were hospitalised in intensive care units. Phylogenetic analysis of the viral protein 1 (VP1) sequences of 179 EV-D68 cases, revealed that 117 sequences (65.4%), including that of the case of AFP, belonged to the B2 variant of clade B viruses. Continuous surveillance of EV-D68 infections is warranted and could benefit from existing influenza-like illness and EV surveillance networks.

Disseminated rhinovirus C8 infection with infectious virus in blood and fatal outcome in a child with repeated episodes of bronchiolitis.

We report a fatal case of acute lower respiratory tract disease with human rhinovirus C (HRV-C) as the unique cause in a 19-month-old girl with a history of repeated episodes of bronchiolitis. HRV-C type 8 nucleic acids were observed in respiratory, stool, and cerebrospinal fluid samples, and infectious virions were isolated from patient serum after inoculation onto reconstituted airway epithelia.

Relevance of human parechovirus detection in cerebrospinal fluid samples from young infants with sepsis-like illness.

BACKGROUND: The human parechoviruses (HPeVs) were recently recognized as important viral pathogens involved in various illnesses in young children. However, routine detection is not performed in most clinical laboratories. Therefore, in this study, we aim to assess the relevance of HPeV detection in cerebrospinal fluid (CSF) of infants, according to clinical presentation. METHODS: A total of 120 CSF specimens collected during 2012 from infants aged less than 1 year and previously reported negative for Herpes simplex virus (HSV) and enterovirus were selected. HPeV detection was performed with a commercially available real-time RT-PCR and HPeV strains from positive samples were subsequently genotyped by sequencing. RESULTS: HPeV RNA was detected in nine (7.5%) CSF samples. The median age of infected children was 41 days (range: 19-122 days). HPeV genotyping could be performed on five samples and three HPeV-3, one HPeV-1, and one HPeV-4 were identified. Hyperthermia associated with mottled skin was the predominant clinical presentation. Most clinical presentations of HPeV-infected infants were mild with a final diagnosis of sepsis-like illness. The median hospital stay was 3.5 days and five children received antibiotics. CONCLUSION: Routine detection of HPeV in CSF may allow differential diagnosis of enterovirus infection and improve etiologic identification of sepsis-like illness in children.

Transmission patterns of human enterovirus 71 to, from and among European countries, 2003 to 2013.

Enterovirus 71 (EV-71) is involved in epidemics of hand, foot, and mouth disease (HFMD) and has been reported to occur with severe neurological complications in eastern and south-east Asia. In other geographical areas, the transmission of this virus is poorly understood. We used large sequence datasets (of the gene encoding the viral protein 1, VP1) and a Bayesian phylogenetic approach to compare the molecular epidemiology and geographical spread patterns of EV-71 subgenogroups B4, B5, C1, C2, and C4 in Europe relative to other parts of the world. For the study, European countries considered were European Union (EU) Member States and Iceland, Norway and Switzerland. Viruses of the B4, B5, and C4 subgenogroups circulate mainly in eastern and south-east Asia. In Europe sporadic introductions of these subgenogroups are observed, however C1 and C2 viruses predominate. The phylogenies showed evidence of multiple events of spread involving C1 and C2 viruses within Europe since the mid-1990s. Two waves of sporadic C2 infections also occurred in 2010 and 2013. The 2007 Dutch outbreak caused by C2 and the occurrence of B5 and C4 infections in the EU between 2004 and 2013 arose while the circulation of C1 viruses was low. A transmission chain involving a C4 virus was traced from Japan to the EU and then further to Canada between 2001 and 2006. Recent events whereby spread of viruses have occurred from, to, and within Europe appear to be involved in the long term survival of EV-71, highlighting the need for enhanced surveillance of this virus.

New introductions of enterovirus 71 subgenogroup C4 strains, France, 2012.

In France during 2012, human enterovirus 71 (EV-A71) subgenogroup C4 strains were detected in 4 children hospitalized for neonatal fever or meningitis. Phylogenetic analysis showed novel and independent EV-A71 introductions, presumably from China, and suggested circulation of C4 strains throughout France. This observation emphasizes the need for monitoring EV-A71 infections in Europe.

Phylogenetic patterns of human coxsackievirus B5 arise from population dynamics between two genogroups and reveal evolutionary factors of molecular adaptation and transmission.

The aim of this study was to gain insights into the tempo and mode of the evolutionary processes that sustain genetic diversity in coxsackievirus B5 (CVB5) and into the interplay with virus transmission. We estimated phylodynamic patterns with a large sample of virus strains collected in Europe by Bayesian statistical methods, reconstructed the ancestral states of genealogical nodes, and tested for selection. The genealogies estimated with the structural one-dimensional gene encoding the VP1 protein and nonstructural 3CD locus allowed the precise description of lineages over time and cocirculating virus populations within the two CVB5 clades, genogroups A and B. Strong negative selection shaped the evolution of both loci, but compelling phylogenetic data suggested that immune selection pressure resulted in the emergence of the two genogroups with opposed evolutionary pathways. The genogroups also differed in the temporal occurrence of the amino acid changes. The virus strains of genogroup A were characterized by sequential acquisition of nonsynonymous changes in residues exposed at the virus 5-fold axis. The genogroup B viruses were marked by selection of three changes in a different domain (VP1 C terminus) during its early emergence. These external changes resulted in a selective sweep, which was followed by an evolutionary stasis that is still ongoing after 50 years. The inferred population history of CVB5 showed an alternation of the prevailing genogroup during meningitis epidemics across Europe and is interpreted to be a consequence of partial cross-immunity.

Sudden Infant Death Associated with Rhinovirus Infection.

A less than one-month-old infant with symptoms of rhinitis died unexpectedly in his sleep. He was not born prematurely and had no known underlying disease. Cerebrospinal fluid, nasopharyngeal and lung samples, and rectal swab were found to be positive for subgroup A rhinovirus, while the blood was negative. This case highlights the important finding that the rhinovirus, a common pathogen associated with upper respiratory tract infections, can sometimes, as the only pathogen, lead to complications such as a cerebrospinal infection and be involved in the sudden infant death syndrome (SIDS). Vigilance is necessary in case of viral infections in the infant's environment, and measures of hygiene and protection must be encouraged in order to reduce the risk of the SIDS.

Severe enterovirus infections in patients with immune-mediated inflammatory diseases receiving anti-CD20 monoclonal antibodies.

OBJECTIVE: Patients with X linked agammaglobulinemia are susceptible to enterovirus (EV) infections. Similarly, severe EV infections have been described in patients with impaired B-cell response following treatment with anti-CD20 monoclonal antibodies (mAbs), mostly in those treated for haematological malignancies. We aimed to describe severe EV infections in patients receiving anti-CD20 mAbs for immune-mediated inflammatory diseases (IMIDs). METHODS: Patients were included following a screening of data collected through the routine surveillance of EV infections coordinated by the National Reference Center and a review of the literature. Additionally, neutralising antibodies were assessed in a patient with chronic EV-A71 meningoencephalitis. RESULTS: Nine original and 17 previously published cases were retrieved. Meningoencephalitis (n=21/26, 81%) associated with EV-positive cerebrospinal fluid (n=20/22, 91%) was the most common manifestation. The mortality rate was high (27%). EV was the only causal agents in all reported cases. Patients received multiple anti-CD20 mAbs infusions (median 8 (5-10)), resulting in complete B-cell depletion and moderate hypogammaglobulinemia (median 4.9 g/L (4.3-6.7)), and had limited concomitant immunosuppressive treatments. Finally, in a patient with EV-A71 meningoencephalitis, a lack of B-cell response to EV was shown. CONCLUSION: EV infection should be evoked in patients with IMIDs presenting with atypical organ involvement, especially meningoencephalitis. Anti-CD20 mAbs may lead to impaired B-cell response against EV, although an underlying primary immunodeficiency should systematically be discussed.

Ex vivo and in vivo inhibition of human rhinovirus replication by a new pseudosubstrate of viral 2A protease.

Human rhinoviruses (HRVs) remain a significant public health problem as they are the major cause of both upper and lower respiratory tract infections. Unfortunately, to date no vaccine or antiviral against these pathogens is available. Here, using a high-throughput yeast two-hybrid screening, we identified a 6-amino-acid hit peptide, LVLQTM, which acted as a pseudosubstrate of the viral 2A cysteine protease (2A(pro)) and inhibited its activity. This peptide was chemically modified with a reactive electrophilic fluoromethylketone group to form a covalent linkage with the nucleophilic active-site thiol of the enzyme. Ex vivo and in vivo experiments showed that thus converted, LVLQTM was a strong inhibitor of HRV replication in both A549 cells and mice. To our knowledge, this is the first report validating a compound against HRV infection in a mouse model.

Norovirus and sapovirus infections after allogeneic hematopoietic stem cell transplantation: is it worth it to look for them?

Norovirus (NoV) and Sapovirus (SaV) are potential causative agents of diarrhea after allogeneic HSCT but little is known in this population. We performed a retrospective analysis by RT-PCR of calicivirus (NoV and SaV), Human adenovirus (HAdV), rotavirus (RV), Aichi virus (AiV), enterovirus (EV), human parechovirus (HPeV) and Human bocavirus (HBoV) in the diarrheal stools of patients after allogeneic HSCT. 49/162 patients had positive viral assays: HAdV (17%), EV (7%), NoV (4.3%), RV and HBoV (3.1% each), SaV (1.9%), AiV (1.2%), HPeV (0.6%). Seven patients were positive for NoV and 3 for SaV. Among viruses-positive samples, the frequency of caliciviruses cases was 7% in the 6 months post-HSCT compared to 40% after (p < 0.0001). The median duration of symptom was 0.7 months but 2 cases, occurring more than one year after HSCT, were chronic, undiagnosed and strongly contributed to morbidity. Systematic testing of caliciviruses appears especially useful in late chronic diarrhea.

Blocking human enterovirus 71 replication by targeting viral 2A protease.

OBJECTIVES: Human enterovirus 71 (EV-71), a member of the Enterovirus genus, constitutes a major public health issue in the Asia-Pacific region, where it is associated with several severe neurological complications. There is currently no effective vaccine or antiviral against EV-71. The aim of this study was to determine whether the six amino acid peptide LVLQTM, which was previously shown to inhibit human rhinovirus (HRV) 2A protease (2A(pro)) activity in vitro and HRV replication in vivo in mice, could be of more general use against enteroviruses and more particularly against EV-71. METHODS: To investigate whether the LVLQTM peptide was a pseudosubstrate of EV-71 2A(pro), a recombinant luciferase containing the LVLQTM sequence was designed so that recognition of this sequence by 2A(pro) led to luciferase activation. Direct interaction between EV-71 2A(pro) and the LVLQTM peptide was further confirmed by isothermal titration calorimetry. We then tested the effects of the peptide on EV-71 2A(pro) cleavage activity and EV-71 replication in HeLa cells. RESULTS: We showed that the LVLQTM peptide behaved as an effective substrate analogue of EV-71 2A(pro), which binds into the active site of the protease with a dissociation rate constant of 9.6 µM. Moreover, LVLQTM significantly inhibited eIF4G cleavage activity of 2A(pro) as well as EV-71 replication in HeLa cells. CONCLUSIONS: This study demonstrates that the LVLQTM peptide that has previously been shown to inhibit HRV replication is also an effective inhibitor of EV-71 2A(pro) and therefore of EV-71 replication, opening new doors in the development of new antivirals against EV-71.

A mouse model for Chikungunya: young age and inefficient type-I interferon signaling are risk factors for severe disease.

Chikungunya virus (CHIKV) is a re-emerging arbovirus responsible for a massive outbreak currently afflicting the Indian Ocean region and India. Infection from CHIKV typically induces a mild disease in humans, characterized by fever, myalgia, arthralgia, and rash. Cases of severe CHIKV infection involving the central nervous system (CNS) have recently been described in neonates as well as in adults with underlying conditions. The pathophysiology of CHIKV infection and the basis for disease severity are unknown. To address these critical issues, we have developed an animal model of CHIKV infection. We show here that whereas wild type (WT) adult mice are resistant to CHIKV infection, WT mouse neonates are susceptible and neonatal disease severity is age-dependent. Adult mice with a partially (IFN-alpha/betaR(+/-)) or totally (IFN-alpha/betaR(-/-)) abrogated type-I IFN pathway develop a mild or severe infection, respectively. In mice with a mild infection, after a burst of viral replication in the liver, CHIKV primarily targets muscle, joint, and skin fibroblasts, a cell and tissue tropism similar to that observed in biopsy samples of CHIKV-infected humans. In case of severe infections, CHIKV also disseminates to other tissues including the CNS, where it specifically targets the choroid plexuses and the leptomeninges. Together, these data indicate that CHIKV-associated symptoms match viral tissue and cell tropisms, and demonstrate that the fibroblast is a predominant target cell of CHIKV. These data also identify the neonatal phase and inefficient type-I IFN signaling as risk factors for severe CHIKV-associated disease. The development of a permissive small animal model will expedite the testing of future vaccines and therapeutic candidates.