Geneviève Billaud

The impact of dual viral infection in infants admitted to a pediatric intensive care unit associated with severe bronchiolitis.

Introduction: Bronchiolitis is a major cause of morbidity and mortality in early childhood worldwide. The presence of more than one pathogen may influence the natural history of acute bronchiolitis in infants. Objective: To investigate the relevance of dual viral infection in infants with severe bronchiolitis hospitalized in a short-term unit compared with those in a pediatric intensive care unit (PICU). Study Design: One hundred eighty infants <1 year old hospitalized with bronchiolitis in a short-term unit (n = 92) or admitted to the PICU (n = 88) during 2 consecutive winter seasons 2003/2004 and 2004/2005 were evaluated. Molecular biology and standard methods were used to diagnose human respiratory viruses in nasal/throat swabs and nasal aspirates. Clinical data related to host factors and viral prevalence were compared among infants requiring or not PICU support. Results: A viral agent was identified in 96.1% of infants with bronchiolitis. Respiratory syncytial virus (70.6% and 73.6%, respectively in the short-term unit and PICU) and rhinovirus (18.5% and 25.3%, respectively in the short-term unit and PICU) were the main detected respiratory viruses in infants hospitalized in both units. No significant difference in viral prevalence was observed between the populations studied. From multivariate analysis, infants with coinfections were 2.7 times (95% CI: 1.2–6.2) more at risk for PICU admission than those with a single infection. Respiratory syncytial virus and rhinovirus were the viruses most frequently identified in mixed infections in infants hospitalized with bronchiolitis. Conclusions: Dual viral infection is a relevant risk factor for the admission of infants with severe bronchiolitis to the PICU.

Human parechovirus infections, Lyon, France, 2008-10: evidence for severe cases.

BACKGROUND Although data documenting the frequency and severity of human parechovirus type 3 (HPeV-3) infection in infants have been published in Canada, the USA, the UK and the Netherlands, no data from France are available. OBJECTIVES To determine the detection frequency of HPeV in cerebrospinal fluid (CSF) samples collected from children aged <5 years hospitalized between 2008 and 2010 in the University Hospital of Lyon and to describe the clinical, virological and biological characteristics associated with HPeV infection. STUDY DESIGN A total of 1128 CSF samples were retrospectively tested using the Parechovirus-Rgene™ real-time RT-PCR assay. Positive samples were typed by sequencing using the CDC method. Retrospective analysis of the medical charts was performed. RESULTS Over a 3-year period, 33/1128 (2.9%) CSF samples were found to be HPeV-positive. In 2010, 9.3% of the children aged <3 months (32% in June) were detected HPeV-positive. The median age at diagnosis was 26 days (8-131 days). Most patients (86%) presented with fever or a sepsis-like syndrome. Three patients (2 with septic shock syndrome, 1 with severe respiratory distress) required hospitalization in an intensive care unit. An HPeV-3 acute infection was identified in an 11-day-old girl who died from sudden infant death syndrome. Of 29 patients genotyped, 28 were infected with HPeV-3 and one with HPeV-4. CONCLUSIONS HPeV is a significant cause of sepsis and severe sepsis in children <3 months. Routine screening for HPeV in CSF and blood should thus be performed more extensively and could improve clinical management.

Resistance of herpes simplex viruses to acyclovir: an update from a ten-year survey in France.

The widespread use of acyclovir (ACV) and the increasing number of immunocompromised patients have raised concern about an increase in ACV-resistant herpes simplex virus (HSV). ACV resistance has traditionally been a major concern for immunocompromised patients with a frequency reported between 2.5% and 10%. The aim of this study was to reassess the status of HSV resistance to ACV in immunocompetent and immunocompromised patients over a ten year period, between 2002 and 2011. This was done by retrospectively following 1425 patients. In immunocompetent patients, prevalence of resistance did not exceed 0.5% during the study period; whereas in immunocompromised patients, a significant increase was observed, rising from 3.8% between 2002 and 2006 (7/182 patients) to 15.7% between 2007 and 2011 (28/178) (p=0.0001). This sharp rise in resistance may largely be represented by allogeneic hematopoietic stem cell transplant patients, in which the prevalence of ACV resistance rose similarly from 14.3% (4/28) between 2002 and 2006 to 46.5% (26/56) between 2007 and 2011 (p=0.005). No increase in ACV resistance was detected in association with other types of immune deficiencies. Genotypic characterization of HSV UL23 thymidine kinase and UL30 DNA polymerase genes revealed 11 and 7 previously unreported substitutions, respectively. These substitutions may be related to potential polymorphisms, drug resistance, or other mutations of unclear significance.

Epidemiology of human enterovirus 71 infections in France, 2000-2009

BACKGROUND Human enterovirus 71 (EV-71) emerged as a significant pathogen able to cause large outbreaks involving severe neurological cases and children fatalities in Asia. OBJECTIVES To describe epidemiology of EV-71 infections in France. STUDY DESIGN Fifty-nine patients admitted in 12 different hospitals from 1994 to 2009 were included. The entire VP1 coding gene of 58 EV-71 strains was sequenced and phylogenetic analyses were performed to assign strains to genogroups/subgenogroups and to compare French isolates to European and worldwide isolates. RESULTS The median age of the patients was 1.04 years (9 days to 7 years). Among 46 documented EV-71 infections, 39 were self-limited. Seven children developed severe sepsis-like, respiratory or neurological complications. Among them, 2 children died from acute respiratory distress syndrome. All the EV-71 strains belonged to genogroup C: 31 isolates belonged to subgenogroup C1, 26 to subgenogroup C2 and 1 to subgenogroup C4. All the strains were genetically related to other European strains isolated at the same period of time. Although C1 isolates were predominant between 1994 and 2005, C2 strains have been predominant since 2007. No association was found between any genotype and the age or the clinical symptoms. CONCLUSIONS The C4 subgenogroup, which was associated with large outbreaks in China, did not spread in France. It is important to monitor more carefully the EV-71 strains circulating in France to detect the introduction of new genetic variants that could be associated with major outbreaks.

Epidemiology and burden of rotavirus diarrhea in day care centers in Lyon, France

This study gives, for the first time, an estimate of the incidence and the cost of rotavirus infection in day care centers in Lyon, France.

Pediatric neurological complications associated with the A(H1N1)pdm09 influenza infection

BACKGROUND Influenza-related neurological complications (INC) have been reported during seasonal flu in children. OBJECTIVES To investigate the types, outcomes and incidence of INC occurring during the 2009 A(H1N1) pandemic, a retrospective analyze was conducted in the single French pediatric hospital of Lyon from October 2009 to February 2010. STUDY DESIGN All children presenting with fever, influenza-like illness, respiratory distress or neurological symptoms were tested for influenza A(H1N1)pdm09 infection from respiratory specimens using real time RT-PCR. RESULTS INC occurred in 14 A(H1N1)pdm09 positive children (7.7% of A(H1N1)pdm09 positive children admitted to hospital) with a median age of 5.1 years. Admission to the intensive care unit (ICU) was required for nine children (64.3%). Half of the children with INC had comorbidity and three had coinfection, both characteristics mainly found in children requiring the ICU. All children received oral oseltamivir treatment. Febrile seizures were observed in eight children, half of them having a chronic comorbidity (2 epilepsy, 1 nonketotic hyperglycinemia, 1 anoxic encephalopathy). Other INC, less commonly reported, included 2 cases of encephalitis, 1 encephalopathy, 1 basilar artery thrombosis, 1 myasthenic crisis and 1 coma. Eleven of the 14 children (78.6%) recovered, one had a minor disability, one child developed a locked-in syndrome and one died from complications of an acute necrotizing encephalopathy. DISCUSSION INC can be observed even in children with no underlying disorder. It may lead to dramatic issue in a significant number of cases.

Drug Targets in Herpes Simplex and Epstein Barr Virus Infections

Herpes simplex virus (HSV) and Epstein Barr Virus (EBV) are Herpesviridae. Although infections are often subclinical, HSV can cause mild to severe diseases, especially in immunocompromised patients. EBV infections are also often asymptomatic but this virus may be associated to carcinoma in immunocompetent patients and to severe diseases in immunocompromised patients. These viruses establish latency, in neuronal cells for HSV and in B-cells for EBV, and may reactivate, with or without symptoms. There are few drugs licensed for the treatment of HSV infections. Most of them target the viral DNA polymerase, in which acyclovir remains the reference treatment some thirty years after its discovery. The emergence of resistant viral strains, mainly in immunocompromised patients, highlights the crucial need for the development of new anti-herpes drugs that can inhibit infection by both wild-type viruses and acyclovir-resistant strains. No antiviral drug has been yet licensed for EBV. Therapies mainly rely on control of immunosuppression and/or immunotherapies. Antiviral drug such as acyclovir and ganciclovir have been used with limited impact except when used with drugs that induce EBV lytic cycle. Over the last few years, significant efforts have been made to set up a range of strategies for the identification of potential new antiviral drugs. For HSV, and more strikingly for EBV, there is a crucial need for antiviral drug active on latent virus. One alternative is to develop drugs with different mechanisms of action. The present article reviews potential targets, viral and cellular, for which specific inhibitors have been identified.

Successful H1N1 influenza vaccination of children receiving chemotherapy for solid tumors.

Background: The hemato-oncology community has been seriously concerned about the H1N1 pandemic of 2009. Here, we report on the evaluation of the immunogenicity and tolerability of H1N1v monovalent vaccines in young patients with cancer during this pandemic. Procedure: Between December 7, 2009 and February 26, 2010, 20 children receiving chemotherapy for solid tumors at the Institute of Hematology and Pediatric Oncology of Lyon, were immunized by 2 doses of either AS03-adjuvanted or nonadjuvanted vaccine. The level of specific antibodies was assessed at D21 and D42. Results: Seroconversion was observed in 13 of the 20 cases (65%), and 18 of 20 cases (90%) had protective titers after the 2 doses. Exploratory univariate analysis failed to show a significant influence of prevaccination lymphocyte counts on seroresponse rates. Conclusions: These data suggest that H1N1v monovalent vaccines were well tolerated by young cancer patients while on chemotherapy and achieved protective immune response in most cases.

The clinical interest of HSV1 semi-quantification in bronchoalveolar lavage

BACKGROUND Detecting high herpes simplex (HSV) viral load in lower respiratory tract samples is reported to be significantly associated with the severity of the illness in critical patients, particularly in patients on mechanical ventilation. It may therefore be of interest to quantify HSV in bronchoalveolar lavage (BAL). Quantitative PCR for HSV is not commonly available in clinical routine. Real-time PCR tests are, however, used commonly and provide semi-quantitative information based on the cycle threshold (Ct). OBJECTIVES Our objectives were to determine the clinically significant threshold and to study the impact of viral load normalisation in relation to cell quantity in samples using real-time PCR. STUDY DESIGN During the period 2011-2012, 59 HSV1 positive BAL were included. HSV viral load was determined by a quantitative real-time PCR (R-gene, Argène BioMérieux, France) and compared to a semi-quantitative real-time PCR (SmartCycler®HerpesSimplex, Cepheid, USA). Viral load normalisation was determined using a real-time PCR targeting a cellular gene (Cc r-gene kit, Argène BioMérieux, France). The significant threshold was determined versus clinical features by statistical analysis (Epiinfo Software v3.5.1 CDC). RESULTS A viral load of 10(4) copies/ml of BAL was significantly associated with admission to the intensive care unit (p<0.001), mechanical ventilation (p<0.01) and death (p<0.01), with no influence of viral load normalisation in relation to cell quantity in the sample. This viral load was equivalent to a Ct value of 31 in the semi-quantitative technique. CONCLUSIONS As semi-quantitative techniques are currently used in many labs, determining this Ct value could be useful for interpreting the clinical advantages of detecting HSV in BAL.

Myocarditis and cardiac channelopathies: A deadly association?

Bicuspid valve type 1 28 (70%) 41±12 40±11 .8 19±10 22±14 .5 6.5±1.3 5.8±2.1 .2 Bicuspid valve type 2 12 (30%) 40±11 44±13 .3 21±13 21±10 .9 5.9±2 7±.8 .2 Aortic root dilatation 6 (15%) 41±12 39±4 .6 21±12 16±12 .3 6.3±2 5.2±.6 .2 Ascending aortic dilatation 16 (40%) 41±12 40±11 .6 21±14 20±10 .9 5.6±1.6 6.8±2.1 .1 Aortic valve regurgitation 17 (43%) 41±13 41±10 .9 20±11 22±13 .6 6.2±2.2 5.9±1.5 .6 Aortic valve stenosis 9 (23%) 41±12 40±10 .9 18±10 29±15 .002 6.4±1.7 5.1±2.2 .1