[Fatal case of enterovirus A71 hand, foot, and mouth disease infection]. / Décès d'un nourrisson dans un contexte de syndrome pieds-mains-bouche associé à l'entérovirus A71.

Hand, foot, and mouth disease associated with enterovirus (EV) infections is a common pediatric pathology that is usually considered as benign. However, neurological complications of varying severity, sometimes fatal, are possible, particularly when EV-A71 is involved. Several Asian countries are regularly affected by large-scale epidemics of EV infections with substantial morbidity and mortality, where early screening and appropriate therapeutic management are a public health challenge. In 2016, Europe experienced an epidemic of unusual magnitude, associated with increasing cases of severe neurological complications in Spain and France, mainly affecting children. Virological diagnosis is based on EV genome detection in peripheral clinical specimens (vesicles or oral ulcerations, throat, nasopharyngeal aspirate, stool) in addition to cerebrospinal fluid and blood. EV-A71 is rarely detected in cerebrospinal fluid, which renders the diagnosis of EV-A71-associated encephalitis challenging. We report the case of a 27-month-old child with hand, foot, and mouth disease turning into rapidly progressive and fatal cardiopulmonary failure associated with EV-A71 infection, in France in 2016. EV infections associated with hand, foot, and mouth disease warrant specific epidemiological surveillance outside the Asian region.

Outbreak of hand, foot and mouth disease/herpangina associated with coxsackievirus A6 and A10 infections in 2010, France: a large citywide, prospective observational study.

Hand, foot and mouth disease (HFMD) and herpangina (HA) are frequently caused by several distinct serotypes belonging to the human enterovirus A species (HEVA). Enterovirus 71 is considered as a significant public health threat because of rare but fatal neurological complications. A sentinel surveillance system involving paediatricians from Clermont-Ferrand (France) was set up to determine the clinical and epidemiological characteristics of HFMD/HA associated with enterovirus infections. A standardized report form was used to collect demographic and clinical data. Throat or buccal specimens were obtained prospectively and tested for the presence of enteroviruses. The frequency of HEVA serotypes was determined by genotyping. Phylogenetic relationships were analysed to identify potential new virus variants. From 1 April to 31 December 2010, a total of 222 children were enrolled. The predominant clinical presentation was HA (63.8%) and this was frequently associated with clinical signs of HFMD (48%). An enterovirus infection was diagnosed in 143 (64.4%) patients and serotype identification was achieved in 141/143 (98.6%). The predominant serotypes were coxsackievirus A10 (39.9%) and A6 (28%), followed by coxsackievirus A16 (17.5%) and enterovirus 71 (6.3%). Fever was observed in 115 (80.4%) children. No patient had neurological complications. Coxsackievirus A10 and A6 strains involved in the outbreak were consistently genetically related with those detected earlier in Finland and constituted distinct European lineages. Although several enterovirus serotypes have been involved in HFMD/HA cases, the outbreak described in this population survey was caused by coxsackievirus A6 and coxsackievirus A10, the third dual outbreak in Europe in the last 3 years.

Repeated genomic transfers from echovirus 30 to echovirus 6 lineages indicate co-divergence between co-circulating populations of the two human enterovirus serotypes.

Human echovirus types 6 (E-6) and 30 (E-30) cause seasonal epidemics of aseptic meningitis. These two enteroviruses are frequently observed in co-circulation, an epidemiological pattern that is prerequisite for the occurrence of dual infections, which can lead to recombination between co-infecting virus strains. Viral sequences were determined at loci 1D (VP1 capsid protein) and 3CD (non structural proteins) in 49 E-6 strains recovered in a single geographical region in France from 1999 to 2007, during the epidemiological survey of enterovirus infections. They were compared with previously recorded sequences of E-30 strains to investigate their evolutionary histories and possible recombination patterns. Phylogenetic analyses identified two distinct E-6 populations and different subpopulations. Assuming a relaxed molecular clock model and a Bayesian skyline demographic model in coalescent analyses with the BEAST program, the substitution rate in E-6 was estimated at 8.597×10(-3) and 6.252×10(-3) substitution/site/year for loci 1D and 3CD respectively. Consistent estimates of divergence times (t(MRCA)) were obtained for loci 1D and 3CD indicating that two distinct E-6 populations originated in 1997 and 1999. Incongruent phylogenetic patterns inferred for the two loci were indicative of recombination events between the two populations. Phylogenies including the E-30 3CD sequences showed close genetic relationships between E-6 and discrete E-30 subpopulations. Recombination breakpoints were located with statistical significance in E-6 and E-30 genomes. Estimates of t(MRCA) of phylogenetic recombinant clades indicated directional genetic transfers from E-30 to E-6 populations and their co-divergence over the time period studied.

Phylogenetic evidence for a recent spread of two populations of human enterovirus 71 in European countries.

Human enterovirus 71 (EV-71) is a cause of seasonal epidemics of hand, foot and mouth disease, and of less common but severe neurological manifestations. Uncertainty persists regarding the circulation of virus populations in several geographical areas and the timescale of their dissemination. We determined EV-71 sequences at loci 1D (VP1 capsid protein) and 3CD (non-structural proteins) in 86 strains recovered in Austria, France and Germany and performed an evolutionary genetic study of extant virus populations. Phylogenetic analyses positioned 78 of the 86 sequences within two clades among subgenogroups C1 and C2. A minor sequence cluster was assigned to subgenogroup C4. Analyses incorporating the available sequences estimated the substitution rate in genogroup C at 3.66 x 10(-3) and 4.46 x 10(-3) substitutions per site year(-1) for loci 1D and 3CD, respectively, assuming a relaxed molecular-clock model for sequence evolution. Most of the 'European' strains belonged to clades C1b and C2b, which originated in 1994 [95 % confidence interval (CI), 1992.7-1995.8] and 2002 (95 % CI, 2001.6-2003.8), respectively. Estimates of divergence times for locus 3CD were consistent with those measured for locus 1D. Intertwining between clades representing EV-71 subgenogroups and clades corresponding to other enterovirus types (notably early coxsackievirus A prototype strains) in the 3CD phylogeny is highly indicative of ancestral recombination events. Incongruent phylogenetic patterns estimated for loci 1D and 3CD show that a single tree cannot model the epidemic history of circulating EV-71 populations. The evolutionary timescale of genogroup C estimated for both loci was measured only in decades, indicating recent dissemination.

Impact of rapid enterovirus molecular diagnosis on the management of infants, children, and adults with aseptic meningitis.

Enteroviruses (EV) are the main etiological agents of aseptic meningitis. Diagnosis is made by detecting the genome using RT-PCR. The aim of the study was to evaluate the impact of a positive diagnosis on the management of infants, children, and adults. During 2005, 442 patients were admitted to hospital with suspected meningitis. Clinical and laboratory data and initial treatment were recorded for all patients with enteroviral meningitis. The turnaround time of tests and the length of hospital stay were analyzed. The results showed that EV-PCR detected EV in 69 patients (16%), 23% (16/69) were adults. About 18% of CSF samples had no pleocytosis. After positive PCR results, 63% of children were discharged immediately (mean 2 hr 30 min) and 95% within 24 hr. Infants and adults were discharged later (after 1.8 and 2 days, respectively). The use of antibiotics was significantly lower in children than in infants and adults. The PCR results allowed discontinuation of antibiotics in 50-60% of all patients treated. Patients received acyclovir in 16% of cases (7% children vs. 50% adults) and 23% (11% vs. 69%) underwent a CT scan. Clinical data were compared between patients whose positive EV-PCR results were available within 24 hr (n = 32) and those whose results were available > 24 hr after collection of CSF (n = 14). Duration of antibiotic treatment (difference: 2.3 days; P = 0.05) was reduced between the two groups. No statistical difference in the length of stay was observed. The EV-PCR assay should be performed daily in hospital laboratory practice and considered as part of the initial management of meningitis.

Phylogeography of circulating populations of human echovirus 30 over 50 years: nucleotide polymorphism and signature of purifying selection in the VP1 capsid protein gene.

A comprehensive set of 443 1D gene sequences (encoding the VP1 capsid protein) was analyzed to investigate the phylogenetic relationships and evolutionary patterns among strains of human echovirus 30 (E30; genus Enterovirus, family Picornaviridae) characterized over 50 years. Maximum-likelihood (ML) phylogenetic trees of complete and nonredundant 1D gene sequences (total length=876 nucleotides) showed evidence of distinct lineages related to the isolation period of virus strains. Virus transportation was confirmed as a major epidemiological factor in the appearance of epidemics since recurrence of aseptic meningitis outbreaks in a given geographic area was associated with distinct E30 variants detected earlier in distant regions. Detection of the codon changes associated with E30 evolution was investigated with methods implemented in the Datamonkey web server. Evolution of the 1D gene was dominated by continual negative (purifying) selection against nonsynonymous substitutions at most codon sites, as determined by dN/dS ratio. Amino acid polymorphism was maintained at a limited number of sites (10/292) in the VP1 protein (within loops connecting beta strands and C-terminus). Amino acid changes are allowed at these sites because they are likely exposed on the virion particle and nonsynonymous substitutions are observed in the corresponding codons because negative selection is relaxed.

[Genotyping and molecular epidemiology of non polyomyelitic enteroviruses]. / Génotypage et épidémiologie moléculaire des entérovirus non poliomyélitiques.

Nonpolio enteroviruses can be reliably identified with molecular and computer tools for taxonomic, diagnostic and epidemiologic purposes. Seroneutralization tests can efficiently be replaced by genotyping assays using the VP1 capsid protein encoding gene to identify enterovirus strains isolated in cell cultures. Genotyping showed the close genetic relatedness between human enterovirus serotypes and animal enteroviruses and also rhinoviruses currently classified in a separate genus within the Picornaviridae family. Enterovirus genotyping can be done prospectively within 2 to 5 days in a greater number of meningitis patients, using cerebrospinal fluid specimens and hence can help in providing a prompt response to health alert. In the molecular epidemiology of human enteroviruses, recent advances were made by investigating genetic diversity within individual serotypes (genotypes, lineages) and the patterns of circulation and transmission of virus variants involved in epidemics (echovirus 30, enterovirus 71). The observation of epidemiologic features such as the frequent viral immigration of strains from different geographical origins speaks in favour of developing molecular identification of enteroviruses. Recombinant enterovirus strains can also be identified by genotyping. Homologous recombination is a major contributor to the genetic diversity in enteroviruses. Molecular signatures of recombination events are observed in circulating strains, suggesting the occurrence of frequent co-infections during their circulation within the general population. The role of genetic recombination in the emergence of virus variants and its involvement in the epidemiology of human enteroviruses should be investigated.

[From prospective molecular diagnosis of enterovirus meningitis...to the prevention of antibiotic resistance]. / Du diagnostic moléculaire initial prospectif des méningites à entérovirus...à la lutte contre l'antibiorésistance.

Meningitis initially presents with intense manifestations that are not generally specific to a given etiology. The first major question for the physician is to decide whether to initiate a probabilistic treatment. Enteroviruses are a major cause of aseptic meningitis, which is benign in immunocompetent patients. Molecular diagnosis is now becoming the gold standard and its prospective use at the time of patient admission, on the sole basis of clinical suspicion of meningitis, has yielded more reliable data. Cytological and biochemical data from CSF analyses are of low predictive value to influence the initial decision to treat with antibiotics. In addition, cases of meningitis during winter are not uncommon. Adults are concerned in about 25% of cases. Thus, if molecular diagnostic tools are not rapidly available, patient management may be inconsistent, leading to unnecessary scans, laboratory investigations and treatment (including overconsumption of antibiotics). Current progress in the automation and practicability of viral genomic detection yields the result within a few hours after admission. Rapid molecular viral diagnosis of a benign disease that does not require treatment but which is initially worrying is of unquestionable advantage. It is of benefit to both the patient and the community because of its input on health economics, the needless consumption of drugs and, as a result, resistance to antibiotics. The diagnosis of meningitis can no longer remain a retrospective diagnosis after elimination of all the possible causes, since not prescribing unnecessary laboratory tests and not treating are true therapeutic decisions.

[Rapid diagnosis of rotavirus infections: comparative prospective study of two techniques for antigen detection in stool]. / Diagnostic rapide des infections à rotavirus: étude prospective comparative de deux techniques de détection d'antigènes dans les selles.

The ability of two commercially available diagnosis rapid assays in detecting rotavirus antigen was compared in a prospective study conducted from September 2002 to May 2003. Five hundred and twelve faecal specimens were studied by IDEIA Rotavirus enzyme immunoassay test (EIA) and Diarlex MB immunochromatographic test (ICG). Specimens giving discrepant results were examined by electron microscopy (EM) and clinical data reconsidered. Out of 512 stool specimens, 155 (30.3%) were positive and 332 (64.8%) negative with the two assays. Discrepant results were obtained for 25 (4.88%) specimens (24 children, 1 adult), with EIA giving more positive results. The retrospective examination by EM, possible for fifteen stools on the 25 that gave discrepant results, confirmed the presence of rotavirus in 7/14 stools which were positive only by EIA and in the stool specimen that was found positive only by ICG. The 25 clinical observations re-examination showed the presence of GEA signs in all cases. The statistical analysis shows an excellent concordance between the EIA and the ICG tests (kappa = 0.89, IC(95%) = [0.85-0.93]) in spite of the underestimation of ICG test in comparison with EIA test (P < 0.0001).

[Enteroviral meningitis in adults, underestimated illness: description of 30 observations from 1999 to 2000, and evolution of clinical practices during 2001]. / Les méningites à entérovirus chez les adultes. Pathologie sous-estimée ? A propos de 30 observations de 1999 à 2000 et évolution des pratiques médicales en 2001.

Enteroviral meningitis is well documented in children but underestimated in adults. The analysis of 30 cases of adult meningitis prospectively diagnosed by enterovirus genome detection (RT-PCR) in cerebrospinal fluid (CSF) between 1999 and 2000 in routine practice showed diagnosis to be problematic. Characteristic symptoms were inconstant (the association of fever/headache/stiff neck absent in 41%) and sometimes misleading (the presence of peribuccal lesions). CSF data showed a predominance of lymphocytes in only 44% of patients. The most reliable criterion was normal constant CSF glucose levels. Thirty three per cent of patients were admitted during cold months. Management of patients varied markedly between departments, and included computed tomography (33%), and the prescription of aciclovir (20%) or antibiotics (53%). A report of positive enterovirus RT-PCR had only low impact on management because it took 6 days to obtain the results (versus 3 days in children during the same period). These findings were communicated to all hospital physicians concerned and as a result, the number of RT-PCR in adults increased significantly during 2001. Again, enteroviral meningitis was diagnosed in adults despite a much lower incidence of the illness in 2001 compared to 2000. Thus this pathology should not be underestimated in adults. Considerable medical expenditure might be avoided (cumulative numbers of 172 days in hospital and 82 days of antibiotics in this study), if rapid and accurate diagnostic techniques were available.

Circulation of enteroviruses and persistence of meningitis cases in the winter of 1999-2000.

The seasonal incidence of enterovirus meningitis was analyzed in a prospective study of patients admitted for suspected meningitis from October 1, 1998 to April 30, 2000. In-house reverse transcription-polymerase chain reaction (RT-PCR) in cerebrospinal fluid (CSF) was used irrespective of cytological results. Fifty-two (45.2%) of the 115 patients had positive RT-PCR in CSF, including 44/86 children (51.2%) and 8/29 adults (27.6%). Six of the 52 (11.5%) had no pleocytosis. The numbers of CSF specimens with a predominance of lymphocytes or a predominance of neutrophils were closely similar. In 33 of the positive patients, an enterovirus, mainly echoviruses type 6 (48%) and 30 (24%), was recovered in one or more specimens. Sixteen cases of enteroviral meningitis were observed between November 1999 and March 2000 as against 2 cases between November 1998 and March 1999, showing that the disease persisted through the winter months of 1999-2000. During the same period, 96 enterovirus isolates were recovered from clinical specimens from other patients. The number of isolates was higher in the winter of 1999-2000 (P < 0.01) than in the winter of 1998-1999, indicating that the risk of enterovirus infection increased significantly in winter 1999-2000. Sixteen patients had aseptic meningitis, made a rapid recovery and had an enterovirus in throat swabs and stools (9/16) or in one of the two (7/16). RT-PCR was not requested. Nine patients were admitted during the cold months. The clinical management of both adult and child patients could be improved by year-round use of enterovirus generic RT-PCR.

Prospective analysis of 61 cases of enteroviral meningitis: interest of systematic genome detection in cerebrospinal fluid irrespective of cytologic examination results.

BACKGROUND: Enteroviruses are the most commonly identified cause of viral meningitis. Detection of the enterovirus genome in cerebrospinal fluid (CSF) using reverse-transcription polymerase chain reaction (PCR) has proved to be useful in diagnosis and is more rapid and sensitive than viral cultures. In routine practice, cytologic examination results of CSF are obtained swiftly and PCR indication is performed as a second step. OBJECTIVES: The aim of this study was to determine, by analysis of complete data from CSF results for 61 cases of proven enteroviral meningitis, whether cytologic CSF findings can be used to establish viral etiology and to indicate if PCR assay should be performed. STUDY DESIGN: From a prospective study of children admitted during 1997 for suspected enterovirus meningitis in which PCR and viral cultures of CSF were systematically performed, we selected 61 patients with proven enterovirus meningitis. We compared global white cell count (WCC), relative percentage of lymphocytes/neutrophils, PCR and culture for enterovirus, patient age, and clinical data. RESULTS: 92% of patients (56/61) had positive PCR in CSF and in 48% (29/61) enterovirus was isolated in CSF. Nine patients (14.75%) had WCC<10/mm(3); eight of them had positive PCR and two had positive culture. There were comparable numbers of CSF with a predominance of lymphocytes (n=25) and CSF with a predominance of neutrophils (n=22), and of positive PCR and positive cultures of CSF in the two groups. Results were not influenced by the age of the patients. CONCLUSION: Irrespective of other CSF parameters, it seems difficult to dispense with PCR assay for enterovirus genome detection. It should be introduced as a true rapid routine test. Early reporting of a positive PCR result could result in a considerable saving in health resources.

An outbreak due to echovirus type 30 in a neonatal unit in France in 1997: usefulness of PCR diagnosis.

Between February and August 1997, 53 patients with enterovirus meningitis were hospitalized in Clermont-Ferrand, France. All but one were children. Echovirus type 30 was involved in 70% of cases with identified serotype. The outbreak ceased on August 8. Two months later, a neonate was admitted to the neonatal unit with an echovirus type 30 meningitis thought to be acquired at delivery. Twenty days later a nosocomial outbreak of echovirus type 30 involving five neonates occurred. Two of them presented with meningitis and two with febrile seizure; One was asymptomatic. The retrospective examination of the maternal sera in a neutralization test, using the index case strain as a source of antigen, showed that none of the neonates was passively immunized before hospitalization. The use of genome detection in cerebrospinal fluid allowed rapid diagnosis and infection was contained by re-inforcing hygiene measures. Prospective examination of stools in the neonatal and paediatric units showed no further occurrences of the disease. No sporadic case was observed in the general population. Hence, nosocomial infections can occur a long time after an outbreak in the general population; rapid diagnosis with molecular tools is useful both for a definite diagnosis in patients already hospitalized, and to act as a rapid alert, even in intervals between seasonal outbreaks.

Comparative sensitivities of Sabin and Mahoney poliovirus type 1 prototype strains and two recent isolates to low concentrations of glutaraldehyde.

Significant intratypic differences in the glutaraldehyde (GTA) sensitivity of echovirus isolates have been shown. While exploring ways to optimize the study of GTA sensitivity of enteroviruses, we also observed intratypic differences in poliovirus type 1 isolates collected in France. A suspension procedure was used for assessing the virucidal effect of GTA at low concentrations (< or = 0.10%) against purified viruses. Two recent isolates of poliovirus type 1 tested were first fully characterized by the PCR restriction fragment length polymorphism (RFLP) test. The RFLP pattern of clinical isolate 5617 was similar to that of poliovirus type 1 LS-c, 2ab (Sabin strain), confirming the vaccine origin of strain 5617. The RFLP pattern of strain 5915 recovered from sewage was different from that of the Mahoney strain, suggesting a genetic variation in this wild isolate. We then analyzed under the same controlled conditions the GTA sensitivities of both isolates and their respective prototype strains. The wild Mahoney and 5915 strains exhibited significantly lower sensitivities to GTA than did the vaccine Sabin and 5617 strains. The inactivation rates of clinical isolates 5617 and 5915 were very similar to those of their corresponding reference Sabin and Mahoney strains. Both the conformational structure of the capsid of each strain and the amino acid constitution of structural polypeptides could be involved in the variations observed. The relevance of our comparative sensitivity studies to standardization of virucidal tests is discussed.