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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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). What is the respective role of respiratory pathogens in ACS epidemiology? 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. 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. 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. [Display omitted] [ABSTRACT FROM AUTHOR]

Background. No information is available on the viral etiology of upper respiratory tract infections in Cameroon.Methods. We prospectively enrolled outpatients with influenza-like illness (ILI) presenting at 14 sentinel clinics located across the country from January through December 2009. The specimens were tested using real-time and multiplex reverse-transcription polymerase chain reaction methods for the detection of 15 RNA respiratory viruses.Results. We detected at least 1 respiratory virus in 365 of 561 specimens (65.1%). Overall, influenza virus was the most commonly detected virus (28.2% of specimens), followed by human rhinovirus (17.8%); parainfluenza virus (PIV) types 1–4 (7.5%); enterovirus (5.9%); respiratory syncytial virus (RSV; 5.7%); human coronavirus (HCoV) OC43, 229E, NL63, and HKU1 (5.3%); and human metapneumovirus (HMPV; 5.0%). RSV (26 of 31 specimens [83.9%]), PIV (30 of 39 [76.9%]), and HRV (64 of 99 [64.6%]) were most common among children <5 years of age. Coinfections were found in 53 of 365 positive specimens (14.5%), and most (71.7%) were in children <5 years of age. While influenza virus, enterovirus, RSV, and HMPV had a defined period of circulation, the other viruses were detected throughout the year.Conclusions. We found that respiratory viruses play an important role in the etiology of ILI in Cameroon, particularly in children <5 years of age. [ABSTRACT FROM AUTHOR]

The highly contagious respiratory syncytial virus (RSV) is responsible for up to approximately 50,000 hospitalisations during each RSV season in children aged under 5 years in France, with the burden greatest in infants younger than 1 year who were born at term. There is a need for a strategy to universally protect young children from RSV infection, and thereby reduce the pressure that RSV places every year on RSV-infected children, their parents, and French healthcare systems. Potential strategies currently undergoing clinical investigation include passive immunisation via maternal vaccination or administration of long-acting monoclonal antibodies at or soon after birth, followed by vaccination later in infancy or childhood. An ongoing partnership and collaboration between parents, public health authorities, and frontline primary healthcare will need to be reinforced once these new RSV prevention strategies are available, to facilitate their use and ensure that all children receive adequate protection from the start of their first RSV season. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: To determine the incidence, risk factors, and clinical relevance of viral ventilator-associated pneumonia (VAP) in an adult intensive care unit (ICU).Design: Prospective observational study.Setting: A 22-bed adult medical ICU in a university hospital.Patients: All consecutive adult patients ventilated more than 48 h in a 9-month period including regular seasonal viral infections.Interventions: A tracheobronchial aspirate upon enrollment and at the time of VAP suspicion.Measurements and Results: All respiratory specimens were tested in culture, indirect immunofluorescence assay, and PCR or RT-PCR for virological assessment. Patients were followed until ICU discharge or death. One hundred thirty-nine patients were included. Upon enrollment, a respiratory virus was detected in the tracheobronchial aspirate in 25% of patients (35 of 139). The incidence of VAP, defined according to clinical daily evaluation, was 28% (39 of 139 patients). A bacteria was documented in 74% of cases, whereas no case of a causative viral infection was encountered among VAP patients; however, herpes simplex virus type-1 (HSV 1) infection was detected in respiratory specimens of 31% of VAP (12 of 39).Conclusions: We found a high incidence of HSV-1 infection in VAP patients; however, nosocomial viral VAP is likely to be rare in ICU, as assessed by the absence of respiratory virus-induced VAP identified in this prospective cohort study. [ABSTRACT FROM AUTHOR]

Examines the association of coronavirus strains 229E and OC43 with various respiratory illnesses in the U.S. Amplification of the viral genome by reverse transcriptase-polymerase chain reaction; Normalization the levels of liver enzyme; Presence of coronavirus RNA in bronchoalveolar lavage.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

There is imperious need for efficient therapies against ubiquitous and life-threatening respiratory viruses, foremost among them being the human respiratory syncytial virus (hRSV). Several research groups who performed functional screens for broad-spectrum antivirals identified compounds targeting the de novo pyrimidine biosynthesis pathway. Despite their strong antiviral activity in vitro , whether such antimetabolites are effective in vivo remains highly controversial. Here, we evaluated two potent pyrimidine biosynthesis inhibitors developed in our laboratory, IPPA17-A04 and GAC50, in a model of mild hRSV-infection in cynomolgus macaques. In this model, hRSV replication is restricted to the epithelium of the upper respiratory tract, and is compatible with a topical treatment by intranasal sprays. The local administration of palivizumab, a neutralizing anti-hRSV antibody used in clinics, significantly reduced virus replication. In contrast, pyrimidine biosynthesis inhibitors did not show any inhibitory effect on hRSV growth when delivered topically as experimented in our model. Our results should help to better define the potential applications of this class of antimetabolites in the treatment of viral infections. [ABSTRACT FROM AUTHOR]

Abstract: A method was developed for the detection and quantitation of HAdV (human adenovirus) and HBoV (human bocavirus) based on a duplex real-time PCR, the AB PCR, using a Smartcycler instrument. A control real-time PCR was carried out on albumin DNA to standardise the non-homogenous respiratory samples. No cross-reactivity was observed with viruses or bacteria that could be found in the respiratory tract. The diagnosis rate using the AB PCR on clinical samples was 10.7%: 3.4% for HBoV detection, 6.9% for HAdV detection and 0.3% double detection HBoV–HAdV. The clinical and epidemiological characteristics of the HAdV- and HBoV-infected patients were evaluated. In the HAdV-positive group and the HBoV-positive group the samples were classified according to the severity of the disease. The HAdV viral load did not appear to be linked to the severity of the disease. Conversely, the difference between the two HBoV groups, severe and non-severe, was significant statistically when the comparison was based on the viral load (P =0.006) or after adjustment of the viral load to the number of cells in the samples (P =0.02). [Copyright &y& Elsevier]

Abstract: A 4-tube multiplex RT-PCR (mRT-PCR), which showed higher sensitivity over conventional methods, was previously developed for the diagnosis of 14 viral pathogens of the respiratory tract. Herein the mRT-PCR was compared to the commercial Luminex mPCR-microsphere flow cytometry assay (Resplex II) which allows the detection of 12 different viruses. Eleven different viruses were identified in 91 nasopharyngeal swabs of children with acute respiratory infection, influenza A (IAV) and B, respiratory syncytial virus (RSV), human rhinovirus (hRhV), human echovirus, parainfluenza viruses (PIV) 1, 2, 3 and 4, human metapneumovirus (hMPV), and human coronavirus NL63. The results of the two techniques showed 53 and 40 positive patients by the Resplex II assay and mRT-PCR, respectively, with a concordance in 35 positive and 33 negative patients (74.7%). Individual RT-PCR tests were performed to control viruses not simultaneously detected by the two multiplex assays. The major virus misdiagnosed by mRT-PCR was IAV whereas the major viruses misdiagnosed by Resplex II were PIV1, 3 and 4. The mRT-PCR remains a simple, rapid, and specific assay for the specific detection of respiratory viruses, and can be easily implemented with standards in clinical laboratories at a low cost. [Copyright &y& Elsevier]

Resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs) increases with the wider use of this class of antiretroviral therapy. The association between adherence and resistance to NNRTI-based regimens is poorly understood. Predictors of virologic failure and resistance according to a baseline evaluation of nonadherence risk factors were determined in a cohort of 71 human immunodeficiency virus (HIV)-infected patients with early virologic response who received an NNRTI-based regimen. During the median follow-up of 29 months, 20 (28%) of 71 patients experienced virologic failure with an NNRTI-based regimen. Virologic failure was associated with repeated drug holidays (≥48 h of unplanned drug cessation), depression, younger age, and low adherence to therapy during baseline evaluation. Moreover, repeated drug holidays was the only risk factor for developing a major mutation conferring cross-resistance to the NNRTI class (hazard ratio, 22.5; 95% confidence interval, 2.8-180.3; P < .0001). Patients' previous adherence to therapy and drugs genetic barriers, not only the number of pills or doses involved, should be taken into consideration in the decision to simplify highly active antiretroviral therapy. [ABSTRACT FROM AUTHOR]

Over two years (2012–2014), 719 nasopharyngeal samples were collected from 6-week- to 12-month-old infants presenting at the emergency department with moderate to severe acute bronchiolitis. Viral testing was performed, and we found that 98% of samples were positive, including 90% for respiratory syncytial virus, 34% for human rhino virus, and 55% for viral co-detections, with a predominance of RSV/HRV co-infections (30%). Interestingly, we found that the risk of being infected by HRV is higher in the absence of RSV, suggesting interferences or exclusion mechanisms between these two viruses. Conversely, coronavirus infection had no impact on the likelihood of co-infection involving HRV and RSV. Bronchiolitis is the leading cause of hospitalizations in infants before 12 months of age, and many questions about its role in later chronic respiratory diseases (asthma and chronic obstructive pulmonary disease) exist. The role of virus detection and the burden of viral codetections need to be further explored, in order to understand the physiopathology of chronic respiratory diseases, a major public health issue. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Responds to the comments made by Leen Vijgen et al. regarding the genetic variability of human respiratory coronavirus OC43. Different arguments to underline the hypothesis about the genetic stability of the human coronaviruses HCo-V-OC43; Statistical arguments presented by Vijgen et al; Possible contamination of the HRT-18 cell line used to propagate the HCo-V-OC43-ATCC variant.

Background: Human metapneumovirus (hMPV) is one of the leading respiratory viruses. This prospective observational study aimed to describe the clinical features and the outcomes of hMPV-associated lower respiratory tract infections in adult inpatients., Methods: Consecutive adult patients admitted to one of the 31 participating centers with an acute lower respiratory tract infection and a respiratory multiplex PCR positive for hMPV were included. A primary composite end point of complicated course (hospital death and/or the need for invasive mechanical ventilation) was used., Results: Between March 2018 and May 2019, 208 patients were included. The median age was 74 [62-84] years. Ninety-seven (47 %) patients were men, 187 (90 %) had at least one coexisting illness, and 67 (31 %) were immunocompromised. Median time between first symptoms and hospital admission was 3 [2-7] days. The two most frequent symptoms were dyspnea (86 %) and cough (85 %). The three most frequent clinical diagnoses were pneumonia (42 %), acute bronchitis (20 %) and acute exacerbation of chronic obstructive pulmonary disease (16 %). Among the 52 (25 %) patients who had a lung CT-scan, the most frequent abnormality was ground glass opacity (41 %). While over four-fifths of patients (81 %) received empirical antibiotic therapy, a bacterial coinfection was diagnosed in 61 (29 %) patients. Mixed flora (16 %) and enterobacteria (5 %) were the predominant documentations. The composite criterion of complicated course was assessable in 202 (97 %) patients, and present in 37 (18 %) of them. In the subpopulation of pneumonia patients (42 %), we observed a more complicated course in those with a bacterial coinfection (8/24, 33 %) as compared to those without (5/60, 8 %) (p = 0.02). Sixty (29 %) patients were admitted to the intensive care unit. Among them, 23 (38 %) patients required invasive mechanical ventilation. In multivariable analysis, tachycardia and alteration of consciousness were identified as risk factors for complicated course., Conclusion: hMPV-associated lower respiratory tract infections in adult inpatients mostly involved elderly people with pre-existing conditions. Bacterial coinfection was present in nearly 30 % of the patients. The need for mechanical ventilation and/or the hospital death were observed in almost 20 % of the patients., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Astrid VABRET disclosed payment or honoraria for lectures, presentations and support for attending meetings and/or travel from ANOFI, 10.13039/501100003103ASTRA ZENECA, MODERNA, and participation on a Data Safety Monitoring Board from SANOFI, 10.13039/100030732MSD, MODERNA and GSK. Frederic Schlemmer disclosed consulting fees from 10.13039/100004319Pfizer, payment or honoraria for lectures, presentations from 10.13039/100005564Gilead, and participation on a Data Safety Monitoring Board from Boerhinger Ingelheim, 10.13039/100019719Chiesi, Elivie, 10.13039/100005564Gilead, 10.13039/100004330GlaxoSmithKline and Oxyvie. Anne Bergeron disclosed payment or honoraria for lectures, presentations and support for attending meetings and/or travel from Astra Zeneca and 10.13039/100004336Novartis, and participation on a Data Safety Monitoring Board from Enanta. Anahita Rouzé disclosed payment or honoraria for lectures, presentations and support for attending meetings and/or travel from 10.13039/100030732MSD, 10.13039/100005564Gilead, Mundipharma. Blandine RAMMAERT disclosed payment or honoraria for lectures, presentations from Gilead. Cedric Daubin disclosed support for attending meetings and/or travel from 10.13039/100005564Gilead. Nicolas Terzi disclosed payment or honoraria for lectures, presentations from 10.13039/100004319Pfizer and Boehringher Inghelheim, and support for attending meetings and/or travel from 10.13039/100005564Gilead. Quentin Philippot disclosed payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from 10.13039/100005564Gilead and Elsevier, and grants or contracts from APHP, 10.13039/501100017007ARS Ile de France and 10.13039/501100001677Inserm 10.13039/501100007492Fondation Bettencourt Schueller, and support for the present manuscript from SOS Oxygen. Other authors did not disclose competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

Introduction: Acute respiratory infections (ARI) are the most common infections in the general population and are mainly caused by respiratory viruses. Detecting several viruses in a respiratory sample is common. To better understand these viral codetections and potential interferences, we tested for the presence of viruses and developed quantitative PCR (Polymerase Chain Reaction) for the viruses most prevalent in coinfections: human rhinovirus (HRV) and respiratory syncytial virus (RSV), and quantified their viral loads according to coinfections and health status, age, cellular abundance and other variables., Materials and Methods: Samples from two different cohorts were analyzed: one included hospitalized infants under 12 months of age with acute bronchiolitis (n=719) and the other primary care patients of all ages with symptoms of ARI (n=685). We performed Multiplex PCR on nasopharyngeal swabs, and quantitative PCR on samples positive for HRV or/and RSV to determine viral loads (VL). Cellular abundance (CA) was also estimated by qPCR targeting the GAPDH gene. Genotyping was performed either directly from first-line molecular panel or by PCR and sequencing for HRV., Results: The risks of viral codetection were 4.1 (IC 95 [1.8; 10.0]) and 93.9 1 (IC 95 [48.7; 190.7]) higher in infants hospitalized for bronchiolitis than in infants in primary care for RSV and HRV respectively (p<0.001). CA was higher in samples positive for multiple viruses than in mono-infected or negative samples (p<0.001), and higher in samples positive for RSV (p<0.001) and HRV (p<0.001) than in negative samples. We found a positive correlation between CA and VL for both RSV and HRV. HRV VL was higher in children than in the elderly (p<0.05), but not RSV VL. HRV VL was higher when detected alone than in samples coinfected with RSV-A and with RSV-B. There was a significant increase of RSV-A VL when codetecting with HRV (p=0.001) and when co-detecting with RSV-B+HRV versus RSV-A+ RSV-B (p=0.02)., Conclusions: Many parameters influence the natural history of respiratory viral infections, and quantifying respiratory viral loads can help disentangle their contributions to viral outcome., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Petat, Corbet, Leterrier, Vabret and Ar Gouilh.)

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., (© International Society of Travel Medicine 2023. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Petat, Schuers, Marguet, Humbert, Le Bas, Rabiaza, Corbet, Leterrier, Vabret and Ar Gouilh.)

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., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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., (© 2021 Wiley Periodicals LLC.)

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., Competing Interests: The authors have declared that no competing interests exist.

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., Competing Interests: J.-JP reports personal fees and grant support from Gilead Sciences, Merck Sharp & Dohme and ViiV Healthcare outside the submitted work. L.H. reports personal fees and non-financial support from Gilead Sciences, Janssen-Cilag, Merck Sharp & Dohme and ViiV Healthcare outside the submitted work. Other authors declare no competing interests., (© 2021 The Author(s).)

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Nacher, Mergeay-Fabre, Blanchet, Benoit, Pozl, Mesphoule, Sainte-Rose, Vialette, Toulet, Moua, Saout, Simon, Guidarelli, Galindo, Biche, Faurous, Chaizemartin, Fahrasmane, Rochemont, Vignier, Vabret and Demar.)

Background: Identified in 2001, Human Metapneumovirus (HMPV) is a Pneumovirus associated with acute lower and upper respiratory infections in all age groups and especially in newborns, elderly and immunocompromised subjects. Data are still limited in sub-Saharan African countries genetic characterization of this respiratory virus. This study reports the genetic variability of HMPV strains in Cameroonian children for 3 consecutive epidemic seasons (September 2011-October 2014)., Methods: A prospective surveillance was conducted to identify inpatient and outpatient children less than 15 years with respiratory symptoms ≤5 days. The nasopharyngeal samples were tested for HMPV using a multiplex polymerase chain reaction. Viral distribution and demographic data were analyzed statistically. Positive samples for HMPV were amplified by semi-nested polymerize chain reaction and then partially sequenced at the G gene. Phylogenetic analyzes were performed on the partial nucleotide and protein sequences of the G gene., Results: From September 2011 to October 2014, 822 children under 15 years were enrolled in the study. HMPV was identified in each of 3.9% (32/822) of children. HMPV were detected throughout the year. HMPV-A (73.3%; 11/15) was predominant compared to HMPV-B (26.7; 4/15). Cameroonian HMPV strains are grouped among the members of genotype A2b (for HMPV-A), B1 and B2 (for HMPV-B)., Conclusion: This study suggests that about 4% of ARI recorded in children in Cameroon are caused by HMPV. The present study is also the first report on the genetic variability of the G gene of HMPV strains in the region. Although this work partially fills gaps for some information, additional studies are required to clarify the molecular epidemiology and evolutionary pattern of HMPV in sub-Saharan Africa in general and more particularly in Cameroon., (Copyright © 2019 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

We described nosocomially clustered cases of measles secondary to a nonvaccinated index case occurring in a teenage psychiatric unit despite optimum vaccine coverage. Surveillance of this fully vaccinated closed cohort showed a 7% attack rate. Vaccination limited the risk of complicated measles and the onset of a large outbreak.

Background: Prodromal symptoms are frequently reported in the atypical form of Hemolytic uremic syndrome (aHUS) suggesting implication of infectious triggers. Some pathogens may also play a role in the mechanisms of production of autoantibody directed against Factor H (FH), a complement regulator, leading to aHUS., Methods: The presence of 15 gastrointestinal (GI) pathogens was investigated by using xTAG-based multiplex PCR techniques on stools collected at the acute phase in a cohort of Indian HUS children classified according to the presence or absence of anti-FH autoantibodies., Results: Prevalence of pathogens in patients with anti-FH antibody (62.5%) was twice that in those without (31.5%). Different pathogens were detected, the most frequent being Clostridium difficile, Giardia intestinalis, Salmonella, Shigella, Rotavirus, Norovirus and Entamoeba histolytica. No stool was positive for Shigatoxin., Conclusion: This study reveals a higher prevalence of GI pathogens in anti-FH positive than in negative patients. No single pathogen was implicated exclusively in one form of HUS. These pathogens may play a role in the disease initiation by inducing complement activation or an autoimmune response.

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., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

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., Competing Interests: J. Brouard déclare des interventions ponctuelles pour Novartis ( board « Asthme grave et mucoviscidose ») et Astra-Zeneca ( board « Grippe enfant »), Pasteur-Merrieux, MSD et ALK ; et avoir été pris en charge lors de congrès par ALK, Astra-Zeneca, Nestlé et Novartis. L. Tran, A. Flammang et A. Vabret déclarent n’avoir aucun lien d’intérêts.

Competing Interests: J. Brouard déclare des interventions ponctuelles pour Novartis ( board « Asthme grave et mucoviscidose ») et AstraZeneca ( board « Grippe enfant »), Pasteur/Merrieux, MSD et ALK ; et avoir été pris en charge lors de congrès par ALK, AstraZeneca, Nestlé et Novartis. L. Tran, A. Flammang et A. Vabret déclarent n’avoir aucun lien d’intérêts.

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis, a disease observed only in equids. EAV is the prototype of the family Arteriviridæ within the order Nidovirales. EAV is an enveloped, positive-sense, single-stranded RNA virus with a considerable variation in the genome as observed in other RNA viruses. During natural infections, EAV may cause abortion and persistent subclinical infections in stallions which can shed the virus in the semen for years, or even lifetime. Chronically infected stallions represent the natural reservoir of the virus. They ensure the persistence and the evolution of the virus, making possible the emergence of new variants potentially virulent. The genetic heterogeneity of EAV during persistent infection in the stallion is considerably greater than that generated during epidemics. Recent studies facilitated the understanding of EAV evolution and genetic variability. With recent advances in molecular biological techniques and the increasing number of sequences available in databases, molecular epidemiological studies have reported specific molecular hallmarks of EAV strains during and outside of epidemics. These new data should facilitate a better understanding and the determination of the origin of new EAV outbreaks.

To optimize standard treatment of chronic hepatitis C in responder patients who have achieved undetectable viral load, a prospective study was conducted to determine the factors and kinetics of virologic relapse. Responder patients were monitored 2, 4, 8, 12, 16, and 24 weeks after the end of treatment with pegylated interferon and ribavirin. Forty-seven of the 154 patients (30.5%) relapsed. Relapse was significantly associated with absence of rapid virologic response (RVR), retreatment, higher baseline viral load, older age, and lower weight-based dose of pegylated interferon. Relapse was more frequent in patients failing to achieve a RVR after receiving pegylated interferon alpha 2a < 2.5 µg/week or alpha 2b < 1.5 µg/week (P = 0.002). Among patients infected with hepatitis C virus (HCV) genotype 1 with non-CC IL-28B polymorphism (rs12979860), viral decay during treatment was lower in relapsers (P = 0.003 at week 4). Relapse was detected at weeks 2, 4, 8, and 12 after the end of treatment for 5, 8, 10, and 6 patients infected with HCV genotype 1, respectively. Positive predictive values for sustained virologic response were 70.9%, 80.2%, 91.9%, and 98.8% at weeks 2, 4, 8, and 12, respectively. Only one patient relapsed beyond 24 weeks. Closer follow-up and treatment adaptation in patients failing to achieve RVR may decrease the relapse rate in slower responders and heavier patients. Monitoring viral load as early as 1 month after the end of treatment could be useful to assess virologic response., (Copyright © 2013 Wiley Periodicals, Inc.)

During the 2011 measles outbreak in Paris (France), patients with clinical suspicion of measles were tested for virological confirmation of measles virus (MV) infection. To assess the practical value of molecular diagnosis in an epidemic setting, 171 oral fluid samples and 235 serum samples collected from 270 patients were tested prospectively for MV-RNA using a novel one-step real-time RT-PCR assay including an internal control. Serum samples were also tested for MV-specific IgG and IgM antibodies. MV infection was confirmed by detection of MV-RNA and/or MV-IgM for 229 of the 270 patients. The results for the 102 cases with both serum and oral fluid samples available were used to compare the techniques. The detection rate of MV-RNA by RT-PCR was 98% (100/102) for oral fluid and 95% (97/102) for serum samples. The detection rate of MV-IgM was 85% (87/102). Negative MV-IgM results were observed mostly for serum samples collected early after the onset of the rash. A MV-RNA standard of known concentration obtained by in vitro transcription was used to quantify MV-RNA in samples. MV-RNA copy numbers were significantly higher in oral fluid than in serum samples, but did not correlate with time of sampling (within 1 week after the onset of the rash), patient age, or vaccination status. During the early stage of infection, the MV-RNA viral load in serum was lower in patients positive than in those negative for MV-IgG. In conclusion, the one-step real-time RT-PCR assay is a simple and sensitive tool suitable for MV diagnosis within hours., (Copyright © 2013 Wiley Periodicals, Inc.)

After the huge decrease of measles thanks to vaccination, measles reappeared in 2008, with 604 cases reported at the Institut national de veille sanitaire (InVS), then 1,544 cases in 2009 and 2,605 cases up to 2010, June. At the same time, 86 viral strains were detected from saliva samples at the Centre national de référence de la rougeole et des Paramyxoviridae respiratoires (CNR) in 2008, 316 in 2009 and 946 up to August 2010. The reality of the outbreak was confirmed by the increase of the endemic cases: 0.0009% cases in 2008 and 0.004% in 2010, the diffusion to all parts of France, and the more specific attack of infants: 4% in 2008 and 9% in 2010, and of young adults: 17% in 2008 and 38% in 2010. Most of the cases (82%) occurred in non-vaccinated people. The number of hospitalised cases has increased as well, going from 18% in 2008 to 34% in 2010. The strain of this outbreak is a genotype D4. It appeared in 2008 then it spread in 2009 and 2010, representing 19, 75 and 99% of the strains, respectively. All the viruses in this genotype belonged to the Montreal-like cluster described in 1989: Montréal.CAN/89xD4. At the beginning of the outbreak some were closed to a variant which appeared in England in 2007 MVs/Enfield.GBR/14.07(D4), but most of them (95%) are nowidentical to a strain which caused a small focus of measles in the region Vendee at the last trimester 2008: MVs/Montaigu.FRA/43.08(D4). The salivary diagnosis of measles, which was introduced in France in 2005, in parallel to the obligation of reporting measles cases, has been proved very efficient: 75% of saliva are collected in the first four days, and viral RNA was detected in 536 (81%) out the 660 samples received at the CNR up to now in 2010; 136 (21%) saliva had IgM specific antibodies and 18% had neither RNA, nor IgM.

Viral tropism is defined as the group of target cells which can be infected by this virus. Knowing viral tropism is knowing the target organ, and the animal species used as host. The variation of tropism allow for virus to evolve, cross species barriers, and infect a new host. Coronavirus family is a very large group of viruses which infect birds and mammals. These RNA viruses can rapidly evolve. In the history of coronaviruses, several examples of variations of tropism have been described, and have as consequences the emergence of a new infection (coronavirus associated with SARS, porcine respiratory coronavirus), or a new expression of the clinical presentation of the infection (fatal infectious peritonitis in cats and ferrets)., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

Individuals with viral infection could possibly emit an infectious aerosol. The distinction between exhaled breaths of infected and healthy individuals should facilitate an understanding of the airborne transmission of infections. In this context, the present study is aimed at distinguishing healthy individuals from symptomatic ones by the study of their exhaled breath. A setup composed of a modified hood connected to an electrical low pressure impactor, which allows for the study of a wide range of particle sizes (from 7 nm to 10 μm), has been developed in order to collect exhaled breaths. This setup has been used with seventy eight volunteers. The results obtained using Principal Component Analysis (PCA) showed that exhaled breaths of individuals without symptoms have statistical similarities and are different from those of individuals with symptoms. This separation was made by the greater proportional emission by individuals with symptoms of particles collected on stages 3 ( D 50 = 0.09 μm), 6 ( D 50 = 0.38 μm), 8 ( D 50 = 0.95 μm), 10 ( D 50 = 2.40 μm), and 12 ( D 50 = 4.02 μm) of the impactor. There was not a specific size distribution obtained for the individuals with symptoms. As a consequence, further research on the exhaled breath should be undertaken with symptomatic volunteers and would require the analysis of this wide range of particle sizes., (Copyright © 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)

The objective of this work was to define the etiology of viral pneumopathies at the patients from reanimation section being under mechanical ventilation, making reference to viruses with respiratory tropism, and also to Chlamydia Pneumoniae and Mycoplasma pneumoniae. The subjects were 36 patients hospitalized into Service of Medical Reanimation from CHU Caen and who needed mechanical ventilation more than 48 hours. The samples from the patients were mostly nasal aspirate, 1 bronchial aspirate and 2 tracheal aspirates. The diagnosis tests were: the test of direct immunofluorescence (DIF) from the samples (for Influenza viruses A and B, Parainfluenza 1,2,3, Adenovirus and Respiratory Syncytial Virus (RSV), inoculation on the tissue culture of diploid cells MRC5, and at the appearance of cythopatic effect specific for Herpes Simplex Virus (HSV), it was made DIF for the detection of type 1 or 2, and also there were made 6 techniques of Polymerase Chain Reaction (PCR). The results of the tests were: at admission before installing the mechanical ventilation, 6 patients presented an infection with Rhinoviruses (RV), 3 with Influenza type A, 3 with HSV type 1 and 2 with Enterovirus. After a period of time from installing the mechanical ventilation, 8 patients presented an infection with HSV typel, among who 1 presented at admission an infection with RV, and 1 patient presented at 7 days from installing the mechanical ventilation an infection with RSV, and at 16 days an infection with HSV type 1. Thus, it could be concluded that in 25% from the cases of viral pneumopathies from patients being under mechanical ventilation it was an endogen reactivation of HSV type1 and only into a single case was diagnosed initially with an infection with RSV, after that it appeared also an infection with HSV typel.

Techniques used for the diagnostic of upper and lower respiratory tract viral infections Techniques used for the diagnostic of upper and lower respiratory tract viral infections include conventional procedures and the new molecular tools. Serology has no interest for diagnosis. Antigen detection can be carried out by simple, easy and cheap tools. They are available at hospital and in community practice as well for the detection of influenza virus, RSV, hMPV, parainfluenza virus and adenovirus. To look for viruses which are non detectable by antigen detection assays (rhinovirus, coronavirus, bocavirus, polyomavirus...) or in severe or complicated respiratory lower infections, the use of molecular tools is highly indicated.

More than 200 antigenically distinct viruses have been documented as causes of sporadic or epidemic respiratory infections in infants and children. The lung itself is rarely sampled directly, and sputum representing lower-airway secretions can rarely be obtained from children. In addition culture of secretions from upper respiratory tract is not useful since the normal flora includes the bacteria commonly responsible for pneumonia. Clinical and radiology data only suggest the diagnosis. The development of techniques to detect antigens of the causative agent in nasopharyngeal secretions, nucleic acid by means of the polymerise-chain reaction assays has significantly improved the identification of the responsible pathogen and the choice of appropriate treatment. Since more 30 years rhinovirus, coronavirus, enterovirus, parainfluenza virus and respiratory syncytial virus were added to influenza, adenovirus and measles virus as causes of respiratory tract infections. This list of pathogens was extended last years with the discovery of human metapneumovirus, bocavirus, polyomavirus. In restricted patient groups, such as the immunocompromised, members of the family of herpesvirus have also been associated with respiratory disease.

The nucleocapsid (N) gene of human coronavirus strain OC43 (HCoV-OC43) was amplified by reverse transcriptase-polymerase chain reaction, and cloned in pENTR/D-TOPO plasmid. This plasmid containing the N gene was recombined with in a BaculoDirect baculovirus DNA designed in order to express N protein in fusion with a C-terminal polyhistidine tag containing V5 epitope. Sf21 cells were transfected with recombinant baculovirus DNA. Recombinant N protein was extracted from infected cells, analysed by SDS-PAGE and Western blot, and purified by Ni2+ affinity procedure. Sera from 100 healthcare workers and five 2-3-year-old children were tested in a Western blot assay using the purified recombinant N protein. All of the sera from adults and two of the sera from children have a positive result.