Yellow fever vaccine-associated neurologic and viscerotropic disease: a 10-year case series of the French National Reference Center for Arboviruses with clinical and immunological insights

BACKGROUND

Immunization against the Yellow fever virus (YFV) with the 17D live-attenuated vaccine is the most effective way to prevent the disease. However, unexpected severe adverse events can occur. They consist in a neurological impairment - neurological disease (YEL-AND), a YF-like illness - viscerotropic disease (YEL-AVD) or anaphylaxis. In this article, we describe the epidemiology, clinical and biological features of YEL-AND and YEL-AVD cases reported to the French National Reference Center for Arboviruses (NRCA) in the past 10 years.

METHODS

We conducted a national, retrospective study using the database of the NRCA from June 2012 to June 2022. All patients whose biological samples were sent to the NRCA for detection of YFV by serology and/or RT-qPCR for a suspected vaccine-associated adverse event were included. We collected data by reading medical records and conducted complementary neuro-immunological analysis, followed by a search for autoimmunity against type-1-interferon when samples were available at the NRCA.

RESULTS

There were 10 cases of YEL-AND and 2 cases of YEL-AVD reported to the NRCA in the past 10 years, which represented an overall incidence of 0.6 for 100 000 doses. A total of 6/12 cases were previously healthy patients (50%, mean age 31 years), and 4/12 cases had cardiovascular co-morbidities (42%, mean age 56 years). The majority of YEL-AND had a favourable outcome at 6 months of follow up. One YEL-AVD patient passed. In secondary analyses, we evidenced a significant blood cerebrospinal fluid (CSF) barrier dysfunction, without intrathecal synthesis of immunoglobulin and without argument for a neuron damage. We further detected a significant rate of anti-type-1alpha interferon antibodies in 3/10 tested patients (2 YEL-AND and 1 YEL-AVD).

CONCLUSION

YEL-AND and YEL-AVD are rare events that can underlie defect in the innate immunity of apparently healthy or mild co-morbid subjects. Outcome was generally favourable in the YEL-AND cases of our series, but still life-threatening or even fatal in the YEL-AVD cases.

Unique Changes in the Incidence of Acute Chest Syndrome in Children With Sickle Cell Disease Unravel the Role of Respiratory Pathogens: A Time Series Analysis

BACKGROUND

Acute chest syndrome (ACS) is a life-threatening complication of sickle cell disease (SCD). Although respiratory pathogens are frequently detected in children with ACS, their respective role in triggering the disease is still unclear. We hypothesized that the incidence of ACS followed the unprecedented population-level changes in respiratory pathogen dynamics after COVID-19-related nonpharmaceutical interventions (NPIs).

RESEARCH QUESTION

What is the respective role of respiratory pathogens in ACS epidemiology?

STUDY DESIGN AND METHODS

This study was an interrupted time series analysis of patient records from a national hospital-based surveillance system. All children aged < 18 years with SCD hospitalized for ACS in France between January 2015 and May 2022 were included. The monthly incidence of ACS per 1,000 children with SCD over time was analyzed by using a quasi-Poisson regression model. The circulation of 12 respiratory pathogens in the general pediatric population over the same period was included in the model to assess the fraction of ACS potentially attributable to each respiratory pathogen.

RESULTS

Among the 55,941 hospitalizations of children with SCD, 2,306 episodes of ACS were included (median [interquartile range] age, 9 [5-13] years). A significant decrease was observed in ACS incidence after NPI implementation in March 2020 (-29.5%; 95% CI, -46.8 to -12.2; P = .001) and a significant increase after lifting of the NPIs in April 2021 (24.4%; 95% CI, 7.2 to 41.6; P = .007). Using population-level incidence of several respiratory pathogens, Streptococcus pneumoniae accounted for 30.9% (95% CI, 4.9 to 56.9; P = .02) of ACS incidence over the study period and influenza 6.8% (95% CI, 2.3 to 11.3; P = .004); other respiratory pathogens had only a minor role.

INTERPRETATION

NPIs were associated with significant changes in ACS incidence concomitantly with major changes in the circulation of several respiratory pathogens in the general population. This unique epidemiologic situation allowed determination of the contribution of these respiratory pathogens, in particular S pneumoniae and influenza, to the burden of childhood ACS, highlighting the potential benefit of vaccine prevention in this vulnerable population.

Characteristics of respiratory viruses' circulation through a six-year period (2016-2022) in a pediatric population in Normandy, France, and the impact of COVID-19 pandemic

IMPORTANCE

The report highlights an epidemiological change in the circulation of respiratory viruses in pediatric populations due to strategies adopted against COVID-19 pandemic. COVID-19 has resulted in a significant increase in requests for multiplex respiratory research to identify the virus responsible for the symptoms. The diagnostic needs have increased, and the number of samples analyzed in 2021-2022 is equal to the samples analyzed over the four epidemic periods preceding the pandemic. The report suggests the importance of active surveillance of respiratory viruses' circulation and new recommendations for respiratory virus detection in pediatric patients.

Positive and negative viral associations in patients with acute respiratory tract infections in primary care: the ECOVIR study

Introduction

Acute respiratory infections (ARIs) are the most common viral infections encountered in primary care settings. The identification of causal viruses is still not available in routine practice. Although new strategies of prevention are being identified, knowledge of the relationships between respiratory viruses remains limited.

Materials and methods

ECOVIR was a multicentric prospective study in primary care, which took place during two pre-pandemic seasons (2018-2019 and 2019-2020). Patients presenting to their General practitioner (GP) with ARIs were included, without selecting for age or clinical conditions. Viruses were detected on nasal swab samples using a multiplex Polymerase Chain Reaction test focused on 17 viruses [Respiratory Syncytial Virus-A (RSV-A), RSV-B, Rhinovirus/Enterovirus (HRV), human Metapneumovirus (hMPV), Adenovirus (ADV), Coronaviruses (CoV) HKU1, NL63, 229E, OC43, Influenza virus (H1 and H3 subtypes), Influenza virus B, Para-Influenza viruses (PIVs) 1-4, and Bocavirus (BoV)].

Results

Among the 668 analyzed samples, 66% were positive for at least one virus, of which 7.9% were viral codetections. The viral detection was negatively associated with the age of patients. BoV, ADV, and HRV occurred more significantly in younger patients than the other viruses (p < 0.05). Codetections were significantly associated with RSV, HRV, BoV, hMPV, and ADV and not associated with influenza viruses, CoV, and PIVs. HRV and influenza viruses were negatively associated with all the viruses. Conversely, a positive association was found between ADV and BoV and between PIVs and BoV.

Conclusion

Our study provides additional information on the relationships between respiratory viruses, which remains limited in primary care.

The Design and Implementation of the ECOVIR Project: A Primary Health Care Surveillance System to Strengthen Co-Detection of Respiratory Viruses in Normandy

Acute respiratory infections (ARIs) need to be better understood and treated, as they are critical to public health, especially during crises such as the SARS-CoV2 pandemic. These are the most abundant infections in the general population and are seen primarily in primary care by general practitioners (GPs). Many different viruses are involved, according to epidemic variations. Viral co-detections account for a significant proportion of ARIs in hospital cohorts. The objective of the ECOVIR cohort was to study viral co-detections by setting up a biobank of respiratory tract samples from patients consulting their general practitioner for ARI symptoms. We report here on the course of the study: the design, the conduct, and the difficulties encountered. ECOVIR (Etude des CO-detections VIrales dans les prélèvements Respiratoires) was a prospective, multicenter cohort conducted in France during two epidemic seasons (2018-2019 and 2019-2020). We recruited GPs. Each GP investigator (GPI) saw patients weekly for examination, clinical data collection, and nasopharyngeal swabbing. Each sample was sent to the virology unit for biobanking and molecular analysis. Clinical and sociodemographic data were collected 7 days after inclusion. ECOVIR involved 36 GPIs. Patients with symptoms of an ARI were included (n = 685). The median number of inclusions was 16 patients per GPI over both seasons (IC_25-75% [4.75; 27]). Patients aged 18 to 64 years were the most numerous (57%), followed by children (30%), and the elderly (13% over 65 years). This age distribution emphasizes the young adult and middle-aged population. Residents participated in the project and called patients on day 7 to obtain clinical and sociodemographic data. Our study triggered the creation of an original network, which plans to establish a functional link between research and primary health care. Primary care is unfortunately poorly represented in research protocols, particularly in respiratory infections, even though it is a cornerstone of our French health care system, as demonstrated every day in this period of crisis.

Use of LoopDeelab during the COVID-19 Pandemic: An Innovative Device for Field Diagnosis

Rapid and accurate diagnosis of SARS-CoV-2 infection is essential for the management of the COVID-19 outbreak. RT-LAMP LoopDeetect COVID-19 (LoopDeescience, France) is a rapid molecular diagnostic tool which operates with the LoopDeelab (LoopDeescience, France) device. RAPID COVID is a prospective double-blind research protocol which was conducted to evaluate the concordance between Loopdeetect COVID-19 and RT-PCR Allplex 2019 n-Cov (Seegene, Korea). Between 11 May 2020 and 14 June 2021, a total of 1122 nasopharyngeal swab specimens were collected, of which 741 were finally analysed. There were 32 “positive” and “indeterminate” RT-PCR results. The intrinsic performances of Loopdeetect COVID-19 are equivalent to other commercial RT-LAMP PCR COVID-19 kits, with a sensitivity and specificity of 69.23% [CI 95%: 48.21–85.67] and 100% [CI 95%: 99.58–100.00], respectively. To the best of our knowledge, LoopDeelab is the only LAMP PCR diagnostic device allowing such a fast and reliable analysis with low-cost equipment; this makes it a new and innovative technology, designed for field use. This device being portable, the development of other detection kits will be useful for the management of epidemics with a high attack rate and would facilitate the rapid application of health measures.

[ECOVIR: Study of a primary care cohort in of patients with Acute Respiratory Infections in Normandy, an example of pluri-professional hospital-primary care coordination]

Acute Respiratory Infections (ARI) need be better understood and more effectively treated, especially insofar as they are of pivotal importance in public health, particularly during a crisis such as the SARS-CoV2 pandemic. The prospective, multicentric cohort study of viral codetections in respiratory samples study known as ECOVIR was conducted in Normandy, France during two winters (2018-2019, 2019-2020). The objective of the project was to create a biobank of respiratory tract samples from patients consulting their general practitioner (GP) for ARI symptoms. ECOVIR involved 36 GP investigators (GPI), from 8 health care centers throughout Normandy. Six hundred and eighty-five patients with ARI symptoms were included; naso-pharyngeal samples were taken by the GPIs and subsequently analyzed in virology laboratories for the purposes of viral codetection. The median of inclusions was 16 patients for each of the 31 actively participating GPIs over the two winters (CI25-75% [4.75; 27]). By D7, 92% of the patients contacted had responded to our call for participation, enabling us to obtain clinical, environmental and socio-demographic data. Through this study, we created an original functional network, thereby establishing a viable link between research and primary care, which is generally underrepresented in research protocols, even though it constitutes the cornerstone of the French health care system, especially during this prolonged period of sanitary crisis.

Clinical course and cost assessment of infants with a first episode of acute bronchiolitis presenting to the emergency department: Data from the GUERANDE clinical trial

INTRODUCTION

Bronchiolitis is the leading cause of hospitalization for infants but its economic burden is not well documented. Our objective was to describe the clinical evolution and to assess the 1-month cost of a first episode of acute bronchiolitis presenting to the emergency department (ED).

METHODS

Our study was an epidemiologic analysis and a cost study of the cohort drawn from the clinical trial GUERANDE, conducted in 24 French pediatric EDs. Infants of 6 weeks to 12 months of age presenting at pediatric EDs with a first episode of bronchiolitis were eligible. The costs considered were collected from a societal viewpoint, according to the recommendations of the French National Health Authority.

RESULTS

A total of 777 infants were included with a median age of 4 months. A total of 57% were hospitalized during the month following the first consultation in the ED, including 28 (3.6%) in an intensive care unit. The mean length of stay was 4.2 days (SD = 3.7). The average time to relief of all symptoms was 13 days (SD = 7). Average total cost per patient was €1919 (95% confidence interval: 1756-2138) from a societal perspective, mostly due to hospitalization cost. The estimated annual cost of bronchiolitis in infants was evaluated to be between €160 and €273 million in France.

DISCUSSION

Bronchiolitis represent a high cost for the health care system and broadly for society, with hospitalizations costs being the main cost driver. Thus significant investments should be made to develop innovative therapies, to reduce the number of hospitalizations and length of stay.

Diagnostic accuracy and acceptability of molecular diagnosis of COVID-19 on saliva samples relative to nasopharyngeal swabs in tropical hospital and extra-hospital contexts: The COVISAL study

A prospective study was conducted among different intra and extra-hospital populations of French Guiana to evaluate the performance of saliva testing compared to nasopharyngeal swabs. Persons aged 3 years and older with mild symptoms suggestive of COVID-19 and asymptomatic persons with a testing indication were prospectively enrolled. Nasopharyngeal and salivary samples were stored at 4°C before analysis. Both samples were analyzed with the same Real-time PCR amplification of E gene, N gene, and RdRp gene. Between July 22th and October 28th, 1159 persons were included, of which 1028 were analyzed. When only considering as positives those with 2 target genes with Ct values <35, the sensitivity of RT-PCR on saliva samples was 100% relative to nasopharyngeal samples. Specificity positive and negative predictive values were above 90%. Across a variety of cultures and socioeconomic conditions, saliva tests were generally much preferred to nasopharyngeal tests and persons seemed largely confident that they could self-sample. For positive patients defined as those with the amplification of 2 specific target genes with Ct values below 35, the sensitivity and specificity of RT-PCR on saliva samples was similar to nasopharyngeal samples despite the broad range of challenging circumstances in a tropical environment.

Effect of Tenofovir Disoproxil Fumarate and Emtricitabine on nasopharyngeal SARS-CoV-2 viral load burden amongst outpatients with COVID-19: A pilot, randomized, open-label phase 2 trial

BACKGROUND

Tenofovir and emtricitabine interfere with the SARS CoV-2 ribonucleic acid (RNA)-dependent RNA polymerase (RdRp). Several cohorts reported that people treated by tenofovir disoproxil fumarate and emtricitabine are less likely to develop SARS CoV-2 infection and related severe COVID-19.

METHODS

We conducted a pilot randomized, open-label, controlled, phase 2 trial at two hospitals in France. Eligible patients were consecutive outpatients (aged ≥18 years) with RT-PCR-confirmed SARS-CoV-2 infection and an interval from symptom onset to enrolment of 7 days or less. Patients were randomly assigned in a 1:1 ratio to receive oral tenofovir disoproxil fumarate and emtricitabine (2 pills on day 1 followed by 1 pill per day on days 2-7) or the standard of care. The primary and secondary endpoints were SARS-CoV-2 viral clearance from baseline assessed by cycle threshold (Ct) RT-PCR on nasopharyngeal swab collected at day 4 and day 7, respectively. A higher Ct corresponds to a lower SARS CoV-2 viral burden. Other endpoints were the time to recovery and the number of adverse events. This trial is registered with ClinicalTrials.gov, NCT04685512.

FINDINGS

From November, 20^th 2020 to March, 19^th 2021, 60 patients were enrolled and randomly assigned to a treatment group (30 to tenofovir disoproxil fumarate and emtricitabine and 30 to standard of care). The median number of days from symptom onset to inclusion was 4 days (IQR 3-5) in both groups. Amongst patients who received tenofovir disoproxil fumarate, the difference from standard of care in the increase in Ct RT-PCR from baseline was 2.3 (95% confidence interval [-0.6 to 5.2], p = 0.13) at day 4 and 2.9 (95% CI [0.1 to 5.2], p = 0.044) at day 7. At day 7, 6/30 in the tenofovir disoproxil fumarate and emtricitabine group and 3/30 in the standard of care group reported no COVID-related symptoms. Adverse events included 11 cases of gastrointestinal side effects (grade ≤ 2), three of which leaded to drug discontinuation. Three patients had COVID-19 related hospitalisation, no participant died.

INTERPRETATION

In this pilot study of outpatients adult with recent non-severe COVID-19, tenofovir disoproxil fumarate plus emtricitabine appeared to accelerate the natural clearance of nasopharyngeal SARS-CoV-2 viral burden. These findings support the conduct of larger trials of tenofovir-based therapies for the prevention and early treatment of COVID-19.

FUNDING

No external funding.

Fatal Measles Inclusion-Body Encephalitis in Adult with Untreated AIDS, France

We report a fatal case of measles inclusion-body encephalitis occurring in a woman from Romania with AIDS. After an extensive but unsuccessful diagnostic evaluation, a pan-pathogen shotgun metagenomic approach revealed a measles virus infection. We identified no mutations previously associated with neurovirulence.

Prolonged Maternal Shedding and Maternal-fetal Transmission of Measles Virus

Prolonged measles virus detection in maternal saliva and blood was evidenced in 6 pregnant women. Maternal-fetal transmission was evidenced in 2 of 4 infants who were asymptomatic at birth, 21-24 weeks after maternal infection. Whereas peripartum congenital measles is severe, asymptomatic measles virus vertical transmission can occur earlier in pregnancy.

Molecular epidemiology of Enteroviruses and Rhinoviruses in patients with acute respiratory infections in Yaounde, Cameroon

Background

Acute respiratory infections (ARI) are associated with a huge morbidity and mortality worldwide. Rhinoviruses (RVs) and Enteroviruses (EVs) are recognized as leading causes of ARI.

Objectives

The present study describes the molecular epidemiology of RVs and EVs in Cameroon over a 3‐year surveillance period.

Methods

From September 2011 to October 2014, nasopharyngeal swabs were collected from patients with influenza‐like illness (ILI) and severe acute respiratory infections (SARI). Two sub‐genomic regions of the EVs and RVs were targeted for molecular characterization. These included the most conserved 5′‐untranslated region (5′UTR) and the viral protein 4/viral protein 2 transition region (VP4/VP2).

Results

A total of 974 samples were collected. Children ≤5 years accounted for 85.7% (835/974) of all participants. Among them, 160 (16.4%) were positive for RVs and/or EVs. RVs and/or EVs were significantly more identified in ILI compared to SARI patients (P = .015). Both viruses co‐circulated all year long with a marked increase of occurrence during rainy and cold season. All RV species were found to circulate in Cameroon, with 6, 10 and 6 virus types belonging to the RV‐A, RV‐B and RV‐C, respectively. EV species identified comprised EV‐A (1 Coxsackie virus A5), EV‐B (1 Coxsackie virus A9 and 2 Coxsackie virus B1) and EV‐C (1 EV‐C117).

Conclusions

This study indicates a strong year‐round occurrence of EV and RV associated respiratory infections in Cameroon. Molecular characterization identified a wide variety of RVs and EVs in patients with ARI in Cameroon.

Prospective Comparison of Saliva and Nasopharyngeal Swab Sampling for Mass Screening for COVID-19

Current testing for COVID-19 relies on reverse-transcriptase polymerase chain reaction from a nasopharyngeal swab specimen. Saliva samples have advantages regarding ease and painlessness of collection, which does not require trained staff and may allow self-sampling. We enrolled 776 persons at various field-testing sites and collected nasopharyngeal and pooled saliva samples. One hundred sixty two had a positive COVID-19 RT-PCR, 61% were mildly symptomatic and 39% asymptomatic. The sensitivity of RT-PCR on saliva samples vs. nasopharygeal swabs varied depending on the patient groups considered or on Ct thresholds. There were 10 (6.2%) patients with a positive saliva sample and a negative nasopharyngeal swab, all of whom had Ct values <25 for three genes. For symptomatic patients for whom the interval between symptoms onset and sampling was <10 days sensitivity was 77% but when excluding persons with isolated N gene positivity (54/162), sensitivity was 90%. In asymptomatic patients, the sensitivity was only 24%. When we looked at patients with Cts <30, sensitivity was 83 or 88.9% when considering two genes. The relatively good performance for patients with low Cts suggests that Saliva testing could be a useful and acceptable tool to identify infectious persons in mass screening contexts, a strategically important task for contact tracing and isolation in the community.

Anti-GnRH vaccination of stallions shedding equine arteritis virus in their semen: a field study

Stallions are natural reservoirs of equine arteritis virus (EAV) in their semen, representing a potential source of outbreaks. The carrier-state is testosterone-dependent, and clears spontaneously in 4 to 40% stallions. Reduction of testosterone secretion may be obtained with the anti-GnRH vaccine Equity. In this report, 16 naturally infected stallions excreting EAV in their semen were vaccinated twice with the vaccine EquityTM and monitored irregularly under field conditions for EAV viral load in their semen and plasmatic testosterone concentration. The results are indicated in months (M) after the first vaccine injection. Testosterone concentrations decreased from 1.7 to 0.2 ng/mL (P<0.002) after 3M. The EAV viral load decreased from 3.2×109 to 1.1×106 RNA copy/mL of semen (P<0.001) after 5M. One stallion died at 7M for other reason. At M3-10, 12/15 stallions ceased to shed the virus in their semen. At M5-10, 9/15 stallions had plasmatic testosterone concentrations of ≥ 0.5 ng/mL but the 6 others showed a persistently low testosterone concentration (≤0.3 ng/mL). Of the 14 stallions that were expected to recover their reproductive activity at the time of the next breeding season (<M12), 8 were EAV negative and produced foals, and 6 were not usable (4 for reproductive deficiency and 2 for EAV positivity). All the stallions were EAV negative at M22, with one stallion being vaccinated a third time at M15. These results suggest that the anti-GnRH vaccination could help to clear EAV shedding in stallions, without a significant effect on reproductive capacity for most of them, but some present a long lasting reduced testosterone secretion.

When a viral eruption hides another one: intrafamilial outbreak of parvovirus B19 and measles virus co-infections: case report

Background

Despite high overall population vaccine coverage, identified clusters of persons refraining from vaccination interfere with pursued measles elimination. Clinical diagnosis of measles is often obvious due to its typical rash. Yet, febrile rashes may occur during many viral infections. Misdiagnosis of a specific primary viral infection may have severe consequences, particularly in immunocompromised subjects or pregnant women. To our knowledge, this case presentation is the first description of a measles and parvovirus B19 coinfection outbreak. Analysis of this outbreak underlines rash diagnosis difficulties and potential serology interpretation pitfalls. This case report is helpful for the clinicians in the context of measles re-emergence and proposes several methods to improve the diagnosis approach.

Case presentation

We investigated an outbreak of rash in 6 out of 8 Traveler family members presenting to Rennes University Hospital (West of France). Anti-B19V and measles IgM/IgG antibodies were measured and detection of Parvovirus B19 and measles virus genomes were done on blood and/or respiratory samples. Virological investigations finally documented 6 cases of parvovirus B19 infections, including 4 associated with measles. Interestingly, in the four coinfection cases, the rash was typical of B19V primary infection for the two children but typical of measles for the two adults. Clinical diagnosis of rash may be misleading and thorough virological investigations may be required to avoid misdiagnosis.

Conclusions

This investigation first reports an intra-familial outbreak of MeV/B19V coinfections highlighting the high transmissibility of both viruses and the diagnostic challenges of dual rash-associated infections. This report also underlines the potential deleterious consequences of failure to identify measles cases, especially in a community with low vaccination coverage.

Sustained Response and Rationale of Programmed Cell Death-1-Targeting for Progressive Multifocal Leukoencephalopathy

In this study, we report a complete (clinical, radiological, and virological) sustained (1 year) response after nivolumab salvage therapy in a progressive multifocal leukoencephalopathy patient. Analyses of the cells infiltrate in a pretreatment brain biopsy suggest that parenchymal programmed cell death-L1⁺ macrophages could be the T-cells partnership in immune exhaustion and virus escape.

Sequencing and analysis of globally obtained human parainfluenza viruses 1 and 3 genomes

Human Parainfluenza viruses (HPIV) type 1 and 3 are important causes of respiratory tract infections in young children globally. HPIV infections do not confer complete protective immunity so reinfections occur throughout life. Since no effective vaccine is available for the two virus subtypes, comprehensive understanding of HPIV-1 and HPIV-3 genetic and epidemic features is important for diagnosis, prevention, and treatment of HPIV-1 and HPIV-3 infections. Relatively few whole genome sequences are available for both HPIV-1 and HPIV-3 viruses, so our study sought to provide whole genome sequences from multiple countries to further the understanding of the global diversity of HPIV at a whole-genome level. We collected HPIV-1 and HPIV-3 samples and isolates from Argentina, Australia, France, Mexico, South Africa, Switzerland, and USA from the years 2003-2011 and sequenced the genomes of 40 HPIV-1 and 75 HPIV-3 viruses with Sanger and next-generation sequencing with the Ion Torrent, Illumina, and 454 platforms. Phylogenetic analysis showed that the HPIV-1 genome is evolving at an estimated rate of 4.97 × 10-4 mutations/site/year (95% highest posterior density 4.55 × 10-4 to 5.38 × 10-4) and the HPIV-3 genome is evolving at a similar rate (3.59 × 10-4 mutations/site/year, 95% highest posterior density 3.26 × 10-4 to 3.94 × 10-4). There were multiple genetically distinct lineages of both HPIV-1 and 3 circulating on a global scale. Further surveillance and whole-genome sequencing are greatly needed to better understand the spatial dynamics of these important respiratory viruses in humans.

[Virus and Atypical Pathogens Detected in Community-Acquired Lower Respiratory Tract Infection in Infants and Children of Sfax Region, Tunisia]

Little is known about viral and atypical bacteria pathogen spectra of community-acquired lower respiratory tract infection in children in Tunisia. Thus, a prospective study was carried out between January 2009 and March 2010 in Sfax. Nasopharyngeal aspirates collected from 368 patients (78 with pneumonia and 290 with acute bronchiolitis) were analyzed by indirect immunofluorescence assay and PCR to detect influenza viruses, parainfluenza viruses, respiratory syncytial virus (RSV), human metapneumovirus, human rhinovirus, human enterovirus, adenovirus, coronavirus, Mycoplasma pneumonia (Mpn) and Chlamydia pneumonia (Cpn). One or more etiology was documented in 319 cases (86.7%). The most detected viruses were RSV (42.7%), rhinovirus (32.9%) and adenovirus (28.5%). Co-detection of two or three pathogens was found in 40% of positive samples. This study highlights the importance of respiratory viruses in lower respiratory tract infection in children of Sfax region as well as the high rate of co-detection of multiple viruses, resulting in challenges in clinical interpretation.

Effectiveness of an intervention campaign on influenza vaccination of professionals in nursing homes: A cluster-randomized controlled trial

BACKGROUND

Seasonal influenza has a major individual and collective impact, especially among the elderly living in nursing homes. To prevent infection by influenza viruses, vaccination of residents and professionals is an essential measure. However, while the vaccination rates of residents are generally high (>85%), rates among professionals are generally approximately 20%. To evaluate the effectiveness of an intervention campaign on the improvement of the influenza vaccination rate of professionals, a regional intervention study was proposed for nursing homes during the 2014-15 season.

METHODS

Cluster-randomized controlled trial (with a nursing home representing a cluster). In the intervention group, a campaign on influenza vaccination was offered to staff, combining different teaching aids in a multimodal approach. In the control group, no intervention was proposed. The primary endpoint was the rate of influenza vaccination among staff. Before and after the study, professionals were asked to complete short questionnaires on their perceptions of influenza vaccination. A multilevel analysis was carried out to compare the vaccination rates between the 2 groups and their evolution before/after the winter period.

RESULTS

A total of 32 nursing homes were randomized, and 6 were excluded. Initial vaccination rates were 27.6% in the intervention group and 24.2% in the control group (p = 0.16). After the study, these rates increased to 33.7% and 22.9%, respectively, which was a relative difference of +22.1% in the intervention group compared to -5.4% in the control group, p = 0.0025.

CONCLUSIONS

Despite professionals' reluctance to be vaccinate, participation in a promotional campaign with a pragmatic approach has increased the rate of influenza vaccination. The approach will be offered to all nursing homes in the region after revision of the tools to enhance their ease of use and pedagogical messages focused on the direct benefits to professionals.

p53 regulates CD46 expression and measles virus infection in myeloma cells

In this study, we assessed the sensitivity of myeloma cells to the oncolytic measles virus (MV) in relation to p53 using 37 cell lines and 23 primary samples. We showed that infection and cell death were correlated with CD46 expression, which was associated with TP53 status; TP53 abn cell lines highly expressed CD46 and were preferentially infected by MV when compared with the TP53 wt cell lines (P = .046 and P = .045, respectively). Infection of myeloma cells was fully dependent on CD46 expression in both cell lines and primary cells. In the TP53 wt cell lines, but not the TP53 abn cell lines, activation of the p53 pathway with nutlin3a inhibited both CD46 expression and MV infection, while TP53 silencing reciprocally increased CD46 expression and MV infection. We showed using a p53 chromatin immunoprecipitation assay and microRNA assessment that CD46 gene expression was directly and indirectly regulated by p53. Primary myeloma cells overexpressed CD46 as compared with normal cells and were highly infected and killed by MV. CD46 expression and MV infection were inhibited by nutlin3a in primary p53-competent myeloma cells, but not in p53-deficient myeloma cells, and the latter were highly sensitive to MV infection. In summary, myeloma cells were highly sensitive to MV and infection inhibition by the p53 pathway was abrogated in p53-deficient myeloma cells. These results argue for an MV-based clinical trial for patients with p53 deficiency.

[State of immunization against measles among health professionals in at-risk units of the Caen University Hospital]

BACKGROUND

France is facing a new resurgence of measles. Since November 2017, the number of cases has been increasing sharply. Immunization coverage in the general population, all ages combined, is below the threshold required for a rapid decline of the virus propagation. Regarding health professionals, the rate of immunization against this disease is insufficiently documented. In this context, the Occupational Health Service of the University Hospital of Caen has carried out an inventory of health personnel knowledge of immunization against measles in the units the most exposed to risk.

METHODS

Knowledge of immunization against measles was studied in pediatric, imaging, and pediatric and adult emergencies departments of the University Hospital of Caen, and the Hematology Institute of Lower Normandy (IHBN). The analysis included all health professionals present within these units during the study period: March and April 2018. Data collection was carried out by consulting the medical files of the occupational health unit and considering the set of responses to postal inquiries sent to staff.

RESULTS

Measured immunization status data refer to 1017 health professionals. Based on the criteria specific to the recommendations, 234 (50.6%) of the 462 professionals born before 1980 and 437 (78.7%) of the 555 professionals born in or after 1980 could be considered as immune. Of the total sample, 115 (11.3%) had positive measles serology. Among these 1017 professionals, information on the state of immunization against measles was lacking for 174 (17.1%).

CONCLUSION

The state of immunization of the nursing staff remains insufficient to prevent the occurrence of measles cases and the staff is also insufficiently informed. It is essential to have knowledge of the immunization status of this population, to organize the vaccination of non-immunized personnel within the occupational health unit, to prevent the emergence of new cases of measles and to reinforce the information regarding the importance of precautions related to airborne transmission in case of measles.

Prevalence of human respiratory syncytial virus infection in people with acute respiratory tract infections in Africa: A systematic review and meta-analysis

AIM

The epidemiology of human respiratory syncytial virus (HRSV) infection has not yet been systematically investigated in Africa. This systematic review and meta-analysis are to estimate the prevalence of HRSV infections in people with acute respiratory tract infections (ARTI) in Africa.

METHOD

We searched PubMed, EMBASE, Africa Journal Online, and Global Index Medicus to identify observational studies published from January 1, 2000, to August 1, 2017. We used a random-effects model to estimate the prevalence across studies. Heterogeneity (I2 ) was assessed via the chi-square test on Cochran's Q statistic. Review registration: PROSPERO CRD42017076352.

RESULTS

A total of 67 studies (154 000 participants) were included. Sixty (90%), seven (10%), and no studies had low, moderate, and high risk of bias, respectively. The prevalence of HRSV infection varied widely (range 0.4%-60.4%). The pooled prevalence was 14.6% (95% CI 13.0-16.4, I2  = 98.8%). The prevalence was higher in children (18.5%; 95% CI 15.8-21.5) compared to adults (4.0%; 95% CI 2.2-6.1) and in people with severe respiratory tract infections (17.9%; 95% CI 15.8-20.1) compared to those with benign forms (9.4%; 95% CI 7.4-11.5); P-values <0.0001. The HRSV prevalence was not associated with sex, subregion in Africa, setting, altitude, latitude, longitude, and seasonality.

CONCLUSION

This study suggests a high prevalence of HRSV in people with ARTI in Africa, particularly among children and people with severe clinical form. All innovative strategies to curb the burden should first focus on children which present the highest HRSV-related burden.

Molecular characterization of human adenovirus associated with acute respiratory infections in Cameroon from 2011 to 2014

Background

Human adenoviruses (HAdVs) cause a wide range of diseases worldwide, including respiratory infections. Studies on HAdV molecular epidemiology are limited in Cameroon. The purpose of this study is to document the different types HAdV circulating in Cameroon in children with acute respiratory infections.

Methods

Nasopharyngeal swabs were collected from 811 children under 15 years from 2011 to 2014. The HAdV detection was assessed by semi-quantitative generic PCR r-gene®. The HAdV-positive samples were typed by amplification and sequencing of partial hexon gene and a real-time PCR. Demographic data were collected and analyzed. The infection and hospitalization risk factors were assessed thought the Chi-square test.

Results

A total of 137/220 HAdV-positive samples were amplified successfully. Six species of HAdV (Mastadenovirus A to F) were detected with B (108/220) and C (47/220) being the predominant strains. Hospitalization and age were significantly associated to HAdV-B and HAdV-C respectively. Phylogenetic analysis of HAdV-B3 virus (18) and B7 (5) shows a conserved and a significant temporal stability in relation to the reference sequence (99.1 to 100% of similarity).

Conclusion

This study reported HAdV species and types detected in children with acute respiratory infections in Cameroon between September 2011 and July 2014. These results support further evaluation of the spatio-temporal circulation pattern of HAdV species and types in Cameroon.

Contemporaneous data on the prevalence of Human Respiratory Syncytial Virus infection in people with acute respiratory tract infections in Africa (2000-2017)

Availability of accurate data on the burden of the Human Respiratory Syncytial Virus (HRSV) can help to implement better strategies to curb this burden in Africa continent among people with acute respiratory tract infections (ARTI). We summarize here available contemporaneous data published from January 1, 2000 to August 31, 2017 on the prevalence of HSRV infection among people with ARTI in the continent.

Genetic diversity of human respiratory syncytial virus isolated among children with acute respiratory infections in Southern Cameroon during three consecutive epidemic seasons, 2011-2013

Background

Human respiratory syncytial virus (HRSV) is the main viral cause of severe lower respiratory tract disease in infants and young children. The aim of this study was to describe for the first time the genetic variability of HRSV in Cameroonian patients living in Yaounde for three consecutive epidemic seasons.

Methods

HRSV-positive nasopharyngeal samples detected in children less than 15 years in Yaounde were collected from September 2011 to December 2013. Semi-nested RT-PCR, sequencing, and phylogenetic analyses of the second hypervariable region of the G gene were performed.

Results

A total of 57 HRSV-positive samples were collected during the study period. Among these, 46 (80.7%) could be amplified in the G gene. HRSV group A (HRSV-A) and group B (HRSV-B) co-circulated in this population at 17.4 and 82.6%, respectively. HRSV-A strains clustered in the NA-1 genotype while HRSV-B strains clustered in the BA-9 genotype. HRSV-A strains accounted for 33.3% (2/6), 4.3% (1/23), and 29.4% (5/17) of the viruses isolated in 2011, 2012, and 2013, respectively.

Conclusions

This study reports molecular epidemiology data of HRSV in Cameroon for the first time. Additional studies are required to clarify evolutionary patterns of HRSV throughout sub-Saharan Africa to support antiviral and vaccine development.

SARS-CoV related Betacoronavirus and diverse Alphacoronavirus members found in western old-world

The emergence of SARS-CoV and MERS-CoV, triggered the discovery of a high diversity of coronaviruses in bats. Studies from Europe have shown that coronaviruses circulate in bats in France but this reflects only a fraction of the whole diversity. In the current study the diversity of coronaviruses circulating in western Europe was extensively explored. Ten alphacoronaviruses in eleven bat species belonging to the Miniopteridae, Vespertilionidae and Rhinolophidae families and, a SARS-CoV-related Betacoronavirus in Rhinolophus ferrumequinum were identified. The diversity and prevalence of bat coronaviruses presently reported from western Europe is much higher than previously described and includes a SARS-CoV sister group. This diversity demonstrates the dynamic evolution and circulation of coronaviruses in this species. That said, the identified coronaviruses were consistently associated with a particular bat species or genus, and these relationships were maintained no matter the geographic location. The observed phylogenetic grouping of coronaviruses from the same species in Europe and Asia, emphasizes the role of host/pathogen coevolution in this group.

Prevalence of HIV-1 drug resistance in treated patients with viral load >50 copies/mL: a 2014 French nationwide study

Background

Surveillance of HIV-1 resistance in treated patients with a detectable viral load (VL) is important to monitor, in order to assess the risk of spread of resistant viruses and to determine the proportion of patients who need new antiretroviral drugs with minimal cross-resistance.

Methods

The HIV-1 protease and reverse transcriptase (RT) and integrase genes were sequenced in plasma samples from 782 consecutive patients on failing antiretroviral regimens, seen in 37 specialized centres in 2014. The genotyping results were interpreted using the ANRS v24 algorithm. Prevalence rates were compared with those obtained during a similar survey conducted in 2009.

Results

The protease and RT sequences were obtained in 566 patients, and the integrase sequence in 382 patients. Sequencing was successful in 60%, 78%, 78% and 87% of patients with VLs of 51-200, 201-500, 501-1000 and >1000 copies/mL, respectively. Resistance to at least one antiretroviral drug was detected in 56.3% of samples. Respectively, 3.9%, 8.7%, 1.5% and 3.4% of patients harboured viruses that were resistant to any NRTI, NNRTI, PI and integrase inhibitor (INI). Resistance rates were lower in 2014 than in 2009. Resistance was detected in 48.5% of samples from patients with a VL between 51 and 200 copies/mL.

Conclusion

In France in 2014, 90.0% of patients in AIDS care centres were receiving antiretroviral drugs and 12.0% of them had VLs >50 copies/mL. Therefore, this study suggests that 6.7% of treated patients in France might transmit resistant strains. Resistance testing may be warranted in all treated patients with VL > 50 copies/mL.

Performance of influenza case definitions for influenza community surveillance: based on the French influenza surveillance network GROG, 2009-2014

International case definitions recommended by the Centers for Disease Control and Prevention (CDC), the European Centre for Disease Prevention and Control (ECDC), and the World Health Organization (WHO) are commonly used for influenza surveillance. We evaluated clinical factors associated with the laboratory-confirmed diagnosis of influenza and the performance of these influenza case definitions by using a complete dataset of 14,994 patients with acute respiratory infection (ARI) from whom a specimen was collected between August 2009 and April 2014 by the Groupes Régionaux d'Observation de la Grippe (GROG), a French national influenza surveillance network. Cough and fever ≥ 39 °C most accurately predicted an influenza infection in all age groups. Several other symptoms were associated with an increased risk of influenza (headache, weakness, myalgia, coryza) or decreased risk (adenopathy, pharyngitis, shortness of breath, otitis/otalgia, bronchitis/ bronchiolitis), but not throughout all age groups. The WHO case definition for influenza-like illness (ILI) had the highest specificity with 21.4%, while the ECDC ILI case definition had the highest sensitivity with 96.1%. The diagnosis among children younger than 5 years remains challenging. The study compared the performance of clinical influenza definitions based on outpatient surveillance and will contribute to improving the comparability of data shared at international level.

Single reaction, real time RT-PCR detection of all known avian and human metapneumoviruses

•

Detection of all known avian and human MPV subgroups in a single reaction rRT-PCR.

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Highly sensitive and specific method using SYBR Green I technology.

•

Complete validation of the method for detection of avian metapneumoviruses.

Current molecular methods for the detection of avian and human metapneumovirus (AMPV, HMPV) are specifically targeted towards each virus species or individual subgroups of these. Here a broad range SYBR Green I real time RT-PCR was developed which amplified a highly conserved fragment of sequence in the N open reading frame. This method was sufficiently efficient and specific in detecting all MPVs. Its validation according to the NF U47-600 norm for the four AMPV subgroups estimated low limits of detection between 1000 and 10 copies/μL, similar with detection levels described previously for real time RT-PCRs targeting specific subgroups. RNA viruses present a challenge for the design of durable molecular diagnostic test due to the rate of change in their genome sequences which can vary substantially in different areas and over time. The fact that the regions of sequence for primer hybridization in the described method have remained sufficiently conserved since the AMPV and HMPV diverged, should give the best chance of continued detection of current subgroups and of potential unknown or future emerging MPV strains.

[Rhinovirus: Underestimated pathogens in patients during the neonatal period]

INTRODUCTION

In recent years, developments in virological tools have led to the easy detection of rhinoviruses and enteroviruses (E/RV). Their detection is very frequent in cases of airway involvement in children and their demonstrated causality. But the morbidity of E/RV in the neonatal period is unknown due to lack of epidemiological data. The objective of this study was to evaluate the incidence and clinical characteristics of these infections in hospitalized neonates.

MATERIALS AND METHODS

We retrospectively analyzed the virology specimens of all neonates hospitalized at the Caen University Hospital between 2006 and 2011. Clinical characteristics were obtained from the charts.

RESULTS

During the study period, 4544 infants aged less than 28 days were hospitalized: 4159 in the neonatal ward and 385 in the pediatric ward. Among these, 711 virology specimens were available, 31 % of which identified at least one virus. An E/RV was identified in 87 patients (1.9 % of the neonates admitted during the study period): 52 in the pediatric ward (13.5 % of 385), and 35 in the neonatal ward (0.8 % of 4159). The mean gestational age was 39 weeks in the pediatric cohort and 35 weeks in the neonatal cohort. The main indication for virological analysis was persistent drowsiness (28 %), temperature above 38°C (25 %), an apparently life-threatening event (23 %), bradycardia (20.5 %), and pallor (20.5 %). Respiratory symptoms associated with E/RV infection were coryza (74 %), cough (35 %), hypoxemia (32 %), accessory muscle use, and recession (31 %). Digestive symptoms were poor feeding (59 %), regurgitation (38 %), abdominal distension (24 %), and projectile vomiting (17 %). Twenty-three percent of the patients required admission to the neonatal ICU or pediatric ICU. Respiratory treatments included oxygen (24 % of 87 patients), continuous positive airway pressure (11 %), and ventilation (5 %). Antibiotics were prescribed in 41 % of the patients (46), but only 10 % (9) had an identified concomitant bacterial infection. In the neonatal department, nosocomial acquisition was suspected in 50 % of E/RV infections.

CONCLUSION

E/RV infections have a significant morbidity in neonates, and nosocomial transmission of the virus is underestimated. We recommend that respiratory viruses, including E/RV, be tested for in any unexplained signs in a neonate. Better identification of viruses might shorten the duration of unnecessary antibiotics.

Effect of Nebulized Hypertonic Saline Treatment in Emergency Departments on the Hospitalization Rate for Acute Bronchiolitis: A Randomized Clinical Trial

IMPORTANCE

Acute bronchiolitis is the leading cause of hospitalization among infants. Previous studies, underpowered to examine hospital admission, have found a limited benefit of nebulized hypertonic saline (HS) treatment in the pediatric emergency department (ED).

OBJECTIVE

To examine whether HS nebulization treatment would decrease the hospital admission rate among infants with a first episode of acute bronchiolitis.

DESIGN, SETTING, AND PARTICIPANTS

The Efficacy of 3% Hypertonic Saline in Acute Viral Bronchiolitis (GUERANDE) study was a multicenter, double-blind randomized clinical trial on 2 parallel groups conducted during 2 bronchiolitis seasons (October through March) from October 15, 2012, through April 15, 2014, at 24 French pediatric EDs. Among the 2445 infants (6 weeks to 12 months of age) assessed for inclusion, 777 with a first episode of acute bronchiolitis with respiratory distress and no chronic medical condition were included.

INTERVENTIONS

Two 20-minute nebulization treatments of 4 mL of HS, 3%, or 4 mL of normal saline (NS), 0.9%, given 20 minutes apart.

MAIN OUTCOMES AND MEASURES

Hospital admission rate in the 24 hours after enrollment.

RESULTS

Of the 777 infants included in the study (median age, 3 months; interquartile range, 2-5 months; 468 [60.2%] male), 385 (49.5%) were randomized to the HS group and 387 (49.8%) to the NS group (5 patients did not receive treatment). By 24 hours, 185 of 385 infants (48.1%) in the HS group were admitted compared with 202 of 387 infants (52.2%) in the NS group. The risk difference for hospitalizations was not significant according to the mixed-effects regression model (adjusted risk difference, -3.2%; 95% CI, -8.7% to 2.2%; P = .25). The mean (SD) Respiratory Distress Assessment Instrument score improvement was greater in the HS group (-3.1 [3.2]) than in the NS group (-2.4 [3.3]) (adjusted difference, -0.7; 95% CI, -1.2 to -0.2; P = .006) and similarly for the Respiratory Assessment Change Score. Mild adverse events, such as worsening of cough, occurred more frequently among children in the HS group (35 of 392 [8.9%]) than among those in the NS group (15 of 384 [3.9%]) (risk difference, 5.0%; 95% CI, 1.6%-8.4%; P = .005), with no serious adverse events.

CONCLUSIONS AND RELEVANCE

Nebulized HS treatment did not significantly reduce the rate of hospital admissions among infants with a first episode of acute moderate to severe bronchiolitis who were admitted to the pediatric ED relative to NS, but mild adverse events were more frequent in the HS group.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01777347.

Phylogenic analysis of human bocavirus detected in children with acute respiratory infection in Yaounde, Cameroon

Objective

Human Bocavirus (HBoV) was first identified in 2005 and has been shown to be a common cause of respiratory infections and gastroenteritis in children. In a recent study, we found that 10.7% of children with acute respiratory infections (ARI) were infected by HBoV. Genetic characterization of this virus remains unknown in Central Africa, particularly in Cameroon Leeding us to evaluate the molecular characteristics of HBoV strains in Cameroonian children with ARI.

Results

Phylogenetic analysis of partial HBoV VP1/2 sequences showed a low level of nucleotide variation and the circulation of HBoV genotype 1 (HBoV-1) only. Three clades were obtained, two clustering with each of the reference strains ST1 and ST2, and a third group consisting of only Cameroon strains. By comparing with the Swedish reference sequences, ST1 and ST2, Cameroon sequences showed nucleotide and amino acid similarities of respectively 97.36–100% and 98.35–100%. These results could help improve strategies for monitoring and control of respiratory infections in Cameroon.

SOFIA®RSV: prospective laboratory evaluation and implementation of a rapid diagnostic test in a pediatric emergency ward

Background

Respiratory syncytial virus (RSV) is responsible for severe respiratory infections and higher costs in medical care. The two aims of this work were to assess the performances of SOFIA^®RSV tests in “real-life-laboratory” conditions (study 1) and implemented at point-of-care testing in a pediatric emergency department (ED, study 2), during two consecutive winter seasons.

Methods

In study 1, fresh nasopharyngeal swabs from patients of all ages were sampled in 1.5 ml of Universal virological Transport Medium (UTM) and prospectively tested using SOFIA^®RSV tests. In study 2, conducted in a pediatric ED, nasopharyngeal swabs were placed in 3 ml of UTM. All SOFIA^®RSV tests were confirmed by molecular testing, considered as reference method. The epidemiological and clinical features of tested patients, as well as the care of these patients after obtaining quick results were evaluated.

Results

The sensitivities of SOFIA^®RSV in infants (aged under 24 months) performed in the laboratory and in the pediatric ED were respectively 95% (95% CI: 86.8–98.1) and 74.8% (95% CI: 68.0–80.9) compared to PCR. In study 1, the sensitivity among children (from 2 to 15 years old) and adults (above 15 years old) dropped to 45% (95% CI: 23.1–68.5) and 59% (95% CI: 32.9–81.6), respectively. In study 2, there were some differences in bed-management of SOFIA^®RSV positive compared to SOFIA^®RSV negative infants.

Conclusions

SOFIA^®RSV tests performed in the laboratory and in the pediatric ED show high and satisfactory sensitivities among young children under 24 months, which supports its robustness and reliability. However, the impact of these tests on patient care at point-of-care cannot be clearly assessed when considering the limits of the study 2 design.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2557-8) contains supplementary material, which is available to authorized users.

[The interactions between microorganisms and the small airways. A paediatric focus]

The spectrum of respiratory viruses is expanding and emerging diseases have been described regularly over the last fifteen years. The origin of these emerging respiratory viruses may be zoonotic (by crossing species barrier, after changes to RNA viruses such as avian influenza virus type A or coronaviruses), or related to the use of new identification techniques (metapneumovirus, bocavirus). The relationship between bronchiolitis and asthma is now better understood thanks to prospective follow up of birth cohorts. The role of rhinovirus has become predominant with respect to respiratory syncytial virus. The identification of predisposing factors immunological, functional, atopic and genetic, for the onset of asthma after rhinovirus infection suggests that viral infection reveals a predisposition rather than itself being a cause of asthma. The role of bacteria in the natural history of asthma is also beginning to be better understood. The results of the COPSAC Danish cohort have shown the frequency of bacterial identification during wheezy episodes before 3 years, and the impact of bacterial colonization at the age of one month on the onset of asthma by age 5 years. The role of bacterial infections in severe asthma in young children is also discussed.

[New therapies against HCV]

Human coronaviruses (HCoV) are single strand RNA viruses. To date, there are four so-called « classical » or « novel » HCoVs, characterized by a winter circulation. These coronaviruses are responsible for mild respiratory infection in general population. However, HCoVs are associated to more severe respiratory tract infection among susceptible population. Indeed, HCoVs account for 2 to 7% of hospitalizations due to a respiratory infection, particularly among children, immunocompromised or elderly people. Thereby, HCoVs are included in the panel of respiratory viruses detected in routine using molecular biology tools. These four circulating HCoVs have to be distinguished from the two emerging HCoVs: SARS-CoV and MERS-CoV. These later are associated to a more severe respiratory infection and differ from other HCoVs by their increased epidemic potential, their more important health impact, and their atypical circulation. Such as paramyxoviruses and Influenza viruses, coronaviruses have to be monitored due to their associated risk of emergence in human population from animal reservoirs.

[Not Available]

Bronchiolitis epidemiology. Respiratory syncytial virus is the most important viral pathogen causing acute lower respiratory infection and infants hospitalizations. Other viruses are also identified (métapneumovirus, rhino/enterovirus, coronavirus, influenza, parainfluenza, adenovirus …). The research develops on new therapies and prevention.

Viral etiology of severe acute respiratory infections in hospitalized children in Cameroon, 2011-2013

BACKGROUND

Severe acute respiratory illness (SARI) is recognized as an important cause of morbidity, mortality, and hospitalization among children in developing countries. Little is known, however, in tropical countries like Cameroon about the cause and seasonality of respiratory infections, especially in hospitalized settings.

OBJECTIVES

Our study investigates the viral etiology and seasonality of SARI in hospitalized children in Yaounde, Cameroon.

METHODS

Prospective clinic surveillance was conducted to identify hospitalized children aged ≤15 years presenting with respiratory symptoms ≤5-day duration. Demographic and clinical data, and respiratory specimens were collected. Nasopharyngeal samples were tested for 17 respiratory viruses using a multiplex polymerase chain reaction. The viral distribution and demographic data were statistically analyzed.

RESULTS

From September 2011 through September 2013, 347 children aged ≤15 years were enrolled. At least one virus was identified in each of 65·4% children, of which 29·5% were coinfections; 27·3% were positive for human adenovirus (hAdV), 13·2% for human respiratory syncytial virus (hRSV), 11·5% for rhinovirus/enterovirus (RV/EV), 10·6% for human bocavirus (hBoV), 9·8% for influenza virus (Inf), 6·6% for human parainfluenza virus (hPIV), 5·7% for human coronavirus (hCoV), and 2·3% for human metapneumovirus (hMPV). While hRSV showed seasonal patterns, hAdV and RV/EV were detected throughout the year and no evident temporal patterns were observed for the remaining viruses.

CONCLUSION

Respiratory viruses were associated with a high burden of hospitalizations among children in Cameroon. Nevertheless, additional studies evaluating asymptomatic Cameroonian children will be important in understanding the relationship between viral carriage and disease.

Performance Evaluation of the VIDAS(®) Measles IgG Assay and Its Diagnostic Value for Measuring IgG Antibody Avidity in Measles Virus Infection

The objective of this study is primarily to compare the performance of the VIDAS(®) Measles immunoglobulin (Ig)G assay to that of two other serological assays using an immunoassay technique, Enzygnost(®) Anti-measles Virus/IgG (Siemens) and Measles IgG CAPTURE EIA(®) (Microimmune). The sensitivity and the agreement of the VIDAS(®) Measles IgG assay compared to the Enzygnost(®) Anti-measles Virus/IgG assay and the Measles IgG CAPTURE EIA(®) assay are 100%, 97.2% and 99.0%, 98.4%, respectively. The very low number of negative sera for IgG antibodies does not allow calculation of specificity. As a secondary objective, we have evaluated the ability of the VIDAS(®) Measles IgG assay to measure anti-measles virus IgG antibody avidity with the help of the VIDAS(®) CMV IgG Avidity reagent, using 76 sera from subjects with measles and 238 other sera. Different groups of populations were analyzed. In the primary infection measles group, the mean IgG avidity index was 0.16 (range of 0.07 to 0.93) compared to 0.79 (range of 0.25 to 1) in the serum group positive for IgG antibodies and negative for IgM. These data allow to define a weak anti-measles virus IgG antibody avidity as an avidity index (AI) < 0.3 and a strong avidity as an AI > 0.6. The VIDAS(®) Measles IgG assay has a performance equivalent to that of other available products. Its use, individual and quick, is well adapted to testing for anti-measles immunity in exposed subjects.