Addressing the public health burden of respiratory viruses: the Battle against Respiratory Viruses (BRaVe) Initiative

Intranasal Vaccination with a Respiratory-Syncytial-Virus-Based Virus-like Particle Displaying the G Protein Conserved Region Induces Severe Weight Loss and Pathology upon Challenge with Wildtype Respiratory Syncytial Virus

Respiratory syncytial virus (RSV) is a major cause of severe respiratory tract disease worldwide, and a pediatric vaccine is not available. We generated a filamentous RSV-based virus-like particle (VLP) that presents the central conserved region of the attachment protein G. This was achieved by co-expressing the matrix protein, phosphoprotein, nucleoprotein, and a hybrid fusion protein in which the F ectodomain was replaced with the G central region (GCR). The latter is relatively conserved and contains a receptor binding site and hence is a logical vaccine target. The immunogenicity and efficacy of the resulting VLP, termed VLP-GCR, were examined in mice using intranasal application without adjuvant. VLP-GCR induced substantial anti-N antibody levels but very low anti-G antibody levels, even after three vaccinations. In contrast, a VLP presenting prefusion-stabilized fusion (preF) protein instead of GCR induced both high anti-F and anti-nucleoprotein antibody levels, suggesting that our GCR antigen was poorly immunogenic. Challenge of VLP-GCR-vaccinated mice caused increased weight loss and lung pathology, and both VLPs induced mucus in the lungs. Thus, neither VLP is suitable as a vaccine for RSV-naive individuals. However, VLP-preF enhanced the proportion of preF antibodies and could serve as a multi-antigen mucosal booster vaccine in the RSV-experienced population.

Ingredients of Vicks VapoRub inhibit rhinovirus-induced ATP release

Background

Over-the-counter therapies, such as Vicks VapoRub, are frequently used in the management of upper respiratory tract infection symptoms. Of these, acute cough is the most bothersome; however, the mechanisms involved have not been fully elucidated. The temperature-sensitive transient receptor potential (TRP) channels, including TRPA1, TRPV1, TRPM8 and TRPV4, are potential candidates. TRPV4 is also thought to be involved in cough through the TRPV4-ATP-P2X3 pathway. Here, we hypothesise that Vicks VapoRub ingredients (VVRIs) modulate the TRP cough channels.

Methods

Stably transfected HEK cells expressing TRP channels were challenged with VVRIs, individually or in combination, and the agonist and antagonist effects were measured using calcium signalling responses. In addition, rhinovirus serotype-16 (RV16)-infected A549 airway epithelial cells were pre-incubated with individual or combinations of VVRIs prior to hypotonic challenge and extracellular ATP release analysis.

Results

Calcium signalling reconfirmed some previously defined activation of TRP channels by specific VVRIs. The combined VVRIs containing menthol, camphor and eucalyptus oil activated TRPV1, TRPV4, TRPM8 and untransfected wild-type HEK293 cells. However, pre-incubation with VVRIs did not significantly inhibit any of the channels compared with the standard agonist responses. Pre-incubation of RV16-infected A549 cells with individual or combined VVRIs, except menthol, resulted in a 0.45-0.55-fold reduction in total ATP release following hypotonic stimulation, compared with infected cells not treated with VVRIs.

Conclusion

These findings suggest that some VVRIs may reduce symptoms associated with upper respiratory tract infection by modulating specific TRP receptors and by reducing RV16-induced ATP release.

Etiology, clinical characteristics, and risk factors associated with severe influenza-like illnesses in Mexican adults

Objective

The aim of this study was to determine the risk factors associated with severe influenza-like illness (ILI) in Mexican adults that could be useful to clinicians when assessing patients with ILI.

Methods

Data from adult patients enrolled from 2010 through 2014 in ILI002 - a prospective hospital-based observational cohort study - were analyzed. Etiology and clinical characteristics were compared between cases of severe ILI (defined as hospitalization and/or death) and cases of non-severe ILI.

Results

Overall, 1428 (39.0%) out of a total 3664 cases of ILI were classified as severe. Adjusted analyses showed a higher risk of severe ILI associated with signs and symptoms related to lower tract infection, i.e. cough with sputum (odds ratio (OR) 2.037, 95% confidence interval (CI) 1.206-3.477; P = 0.008), dyspnea (OR 5.044, 95% CI 2.99-8.631; and shortness of breath (OR 5.24, 95% CI 3.0839.124; P < 0.001), and with increases in lactate dehydrogenase (OR 4.426, 95% CI 2.321-8.881; P < 0.001) and C-reactive protein (OR 3.618, 95% CI 2.5955.196; P < 0.001). Further, there was an increased risk of severe ILI with a longer time between symptom onset and inclusion (OR 1.108, 95% CI 1.049-1.172; P < 0.001) and with chronic steroid use (OR 14.324, 95% CI 8.059-26.216; P < 0.001).

Conclusions

Respiratory viruses can cause severe ILI. The results of this study highlight the importance of evaluating data compatible with lower tract involvement and previous use of immunosuppressants at baseline, because patients meeting these conditions may develop severe illness.

Rhinovirus/enterovirus was the most common respiratory virus detected in adults with severe acute respiratory infections pre-COVID-19 in Kuala Lumpur, Malaysia

Background

Severe acute respiratory infections (SARI) pose a great global burden. The contribution of respiratory viruses to adult SARI is relatively understudied in Asia. We aimed to determine viral aetiology of adult SARI patients in Kuala Lumpur, Malaysia.

Methods

The prevalence of 20 common (mainly viral) respiratory pathogens, and MERS-CoV, SARS-CoV and 5 bacterial select agents was investigated from May 2017 to October 2019 in 489 SARI adult patients in Kuala Lumpur, Malaysia, using molecular assays (Luminex NxTAG-RPP kit and qPCR assays). Viral metagenomics analysis was performed on 105 negative samples.

Results

Viral respiratory pathogens were detected by PCR in 279 cases (57.1%), including 10 (2.0%) additional detections by metagenomics analysis. The most detected viruses were rhinovirus/enterovirus (RV/EV) (49.1%) and influenza virus (7.4%). Three melioidosis cases were detected but no SARS-CoV, MERS-CoV or other bacterial select agents. Bacterial/viral co-detections and viral co-detections were found in 44 (9.0%) and 27 (5.5%) cases respectively, mostly involving RV/EV. Independent predictors of critical disease were male gender, chronic lung disease, lack of runny nose and positive blood culture with a significant bacterial pathogen. Asthma and sore throat were associated with increased risk of RV/EV detection, while among RV/EV cases, males and those with neurological disease were at increased risk of critical disease.

Conclusions

Prior to the COVID-19 pandemic, the high prevalence of respiratory viruses in adults with SARI was mainly attributed to RV/EV. Continued surveillance of respiratory virus trends contributes to effective diagnostic, prevention, and treatment strategies.

Severe Acute Respiratory Infection Surveillance in Brazil: the Role of Public, Private, and Philanthropic Health Care Units

Epidemiological surveillance and notification of respiratory infections are important for management and control of epidemics and pandemics. Fact-based decisions, like social distancing policies and preparation of hospital beds, are taken based on several factors, including case numbers; hence, health authorities need quick access to reliable and well-analysed data. We aimed to analyse the role of the Brazilian public health system in the notification and hospitalization of patients with severe acute respiratory infection (SARI). Data of SARI cases in Brazil (2013–20) were obtained from SIVEP-Gripe platform, and legal status of each healthcare unit (HCU) responsible for case notification and hospitalization was obtained from the National Registry of Health Facilities (CNES) database. HCUs that are part of the hospital network were classified as ‘Public Administration’, ‘Business Entities’, ‘Philanthropic Entities’ or ‘Individuals’. SARI notification data from Brazilian macro-regions (North, Northeast, Midwest, Southeast and South) were analysed and compared between administrative spheres. This study reveals that hospitalizations due to SARI increased significantly in Brazil during the coronavirus disease 2019 (COVID-19) pandemic, especially in HCUs of Public Administration. In the Southeast and South, where incidence of SARI is high, philanthropic HCUs also contribute to hospitalization of SARI cases and attend up to 7.4% of the cases notified by the Public Administration. The number of cases is usually lower in other regions, but in 2020 the Northeast showed more hospitalizations than the South. In the South, SARI season occurs later; however, in 2020, an early peak was observed because of COVID-19. Notably, the contribution of each administrative sphere that manages hospital networks in Brazil in the control and management of SARI varies between regions. Our approach will allow managers to assess the use of public resources, given that there are different profiles of healthcare in each region of Brazil and that the public health system has a major role in notifying and attending SARI cases.

MicroRNA let-7 and viral infections: focus on mechanisms of action

MicroRNAs (miRNAs) are fundamental post-transcriptional modulators of several critical cellular processes, a number of which are involved in host defense mechanisms. In particular, miRNA let-7 functions as an essential regulator of the function and differentiation of both innate and adaptive immune cells. Let-7 is involved in several human diseases, including cancer and viral infections. Several viral infections have found ways to dysregulate the expression of miRNAs. Extracellular vesicles (EV) are membrane-bound lipid structures released from many types of human cells that can transport proteins, lipids, mRNAs, and miRNAs, including let-7. After their release, EVs are taken up by the recipient cells and their contents released into the cytoplasm. Let-7-loaded EVs have been suggested to affect cellular pathways and biological targets in the recipient cells, and can modulate viral replication, the host antiviral response, and the action of cancer-related viruses. In the present review, we summarize the available knowledge concerning the expression of let-7 family members, functions, target genes, and mechanistic involvement in viral pathogenesis and host defense. This may provide insight into the development of new therapeutic strategies to manage viral infections.

Identifying the research, advocacy, policy and implementation needs for the prevention and management of respiratory syncytial virus lower respiratory tract infection in low- and middle-income countries

INTRODUCTION

The high burden of respiratory syncytial virus (RSV) infection in young children disproportionately occurs in low- and middle-income countries (LMICs). The PROUD (Preventing RespiratOry syncytial virUs in unDerdeveloped countries) Taskforce of 24 RSV worldwide experts assessed key needs for RSV prevention in LMICs, including vaccine and newer preventive measures.

METHODS

A global, survey-based study was undertaken in 2021. An online questionnaire was developed following three meetings of the Taskforce panellists wherein factors related to RSV infection, its prevention and management were identified using iterative questioning. Each factor was scored, by non-panellists interested in RSV, on a scale of zero (very-low-relevance) to 100 (very-high-relevance) within two scenarios: (1) Current and (2) Future expectations for RSV management.

RESULTS

Ninety questionnaires were completed: 70 by respondents (71.4% physicians; 27.1% researchers/scientists) from 16 LMICs and 20 from nine high-income (HI) countries (90.0% physicians; 5.0% researchers/scientists), as a reference group. Within LMICs, RSV awareness was perceived to be low, and management was not prioritised. Of the 100 factors scored, those related to improved diagnosis particularly access to affordable point-of-care diagnostics, disease burden data generation, clinical and general education, prompt access to new interventions, and engagement with policymakers/payers were identified of paramount importance. There was a strong need for clinical education and local data generation in the lowest economies, whereas upper-middle income countries were more closely aligned with HI countries in terms of current RSV service provision.

CONCLUSION

Seven key actions for improving RSV prevention and management in LMICs are proposed.

Seroprevalence and molecular characterization of human respiratory syncytial virus and human adenovirus among children in Ado-Ekiti, Nigeria

In children, the respiratory syncytial virus and adenovirus majorly cause acute respiratory infections. The study evaluated the seroprevalence and conducted the molecular characterization of human respiratory syncytial virus (HRSV) and human adenovirus (HAdV) among children. Venous blood, nasopharyngeal, and oropharyngeal swabs were collected from children presenting with acute respiratory infections in a tertiary health facility in Ado-Ekiti, Nigeria. A serological investigation was carried out on the sera samples for the detection of anti-HRSV immunoglobulin M (IgM), anti-HRSV IgG, anti-HAdV IgM, and anti-HAdV IgG using ELISA (enzyme-linked immunosorbent assay) kits. The amplification and sequencing of HRSV and HAdV were carried out using specific primer pairs that targeted the glycoprotein (G) gene of HRSV and the hexon gene of HAdV, respectively. The seroprevalence of HRSV IgG and IgM was 73% and 7.5%, respectively, while the seroprevalence of HAdV IgG and IgM was 98.5% and 8.5%, respectively. The age of enrolled children, presence of fever, and cough were associated (p < 0.05) with the infection. HRSV subtype B (HRSV-B) (13.3%), and species of HAdV (Mastadenovirus B and C) (11.7%) were detected among the studied population. There was no viral coinfection with both HRSV and HAdV. In infancy and early childhood, HRSV-B, HAdV species B and C are common etiologic agents of respiratory infections as reported in this study. Further studies on molecular characterization of respiratory tract viruses including circulating respiratory syncytial virus and adenovirus are hereby advocated.

Added value of rapid respiratory syndromic testing at point of care versus central laboratory testing: a controlled clinical trial

Background

Virus-associated respiratory infections are in the spotlight with the emergence of SARS-CoV-2 and the expanding use of multiplex PCR (mPCR). The impact of molecular testing as a point-of-care test (POCT) in the emergency department (ED) is still unclear.

Objectives

To compare the impact of a syndromic test performed in the ED as a POCT and in the central laboratory on length of stay (LOS), antibiotic use and single-room assignment.

Methods

From 19 November 2019 to 9 March 2020, adults with acute respiratory illness seeking care in the ED of a large hospital were enrolled, with mPCR performed with a weekly alternation in the ED as a POCT (week A) or in the central laboratory (week B).

Results

474 patients were analysed: 275 during A weeks and 199 during B weeks. Patient characteristics were similar. The hospital LOS (median 7 days during week A versus 7 days during week B, P = 0.29), the proportion of patients with ED-LOS <1 day (63% versus 60%, P = 0.57) and ED antibiotic prescription (59% versus 58%, P = 0.92) were not significantly different. Patients in the POCT arm were more frequently assigned a single room when having a positive PCR for influenza, respiratory syncytial virus and metapneumovirus [52/70 (74%) versus 19/38 (50%) in the central testing arm, P = 0.012].

Conclusions

Syndromic testing performed in the ED compared with the central laboratory failed to reduce the LOS or antibiotic consumption in patients with acute respiratory illness, but was associated with an increased single-room assignment among patients in whom a significant respiratory pathogen was detected.

Differentiating impacts of non-pharmaceutical interventions on non-coronavirus disease-2019 respiratory viral infections: Hospital-based retrospective observational study in Taiwan

BACKGROUND

Physical distancing and facemask use are worldwide recognized as effective non-pharmaceutical interventions (NPIs) against the coronavirus disease-2019 (COVID-19). Since January 2020, Taiwan has introduced both NPIs but their effectiveness on non-COVID-19 respiratory viruses (NCRVs) remain underexplored.

METHODS

This retrospective observational study examined electronic records at a tertiary hospital in northern Taiwan from pre-COVID (January-December 2019) to post-COVID period (January-May 2020). Patients with respiratory syndromes were tested for both enveloped (eg, influenza virus and seasonal coronavirus) and non-enveloped RVs (eg, enterovirus and rhinovirus) using multiplex reverse transcription polymerase chain reaction assays. Monthly positivity rates of NCRVs among adult and pediatric patients were analyzed with comparison between pre- and post-COVID periods.

RESULTS

A total of 9693 patients underwent 12 127 multiplex RT-PCR tests. The average positivity rate of NCRVs reduced by 11.2% (25.6% to 14.4%) after nationwide PHIs. Despite the COVID-19 pandemic, the most commonly identified enveloped and non-enveloped viruses were influenza virus and enterovirus/rhinovirus, respectively. Observed reduction in NCRV incidence was predominantly contributed by enveloped NCRVs including influenza viruses. We did not observe epidemiological impacts of NPIs on non-enveloped viruses but an increasing trend in enterovirus/rhinovirus test positivity rate among pediatric patients. Our data were validated using Taiwan's national notification database.

CONCLUSIONS

Our frontline investigation suggests that the current NPIs in Taiwan might not effectively control the transmission of non-enveloped respiratory viruses, despite their protective effects against influenza and seasonal coronavirus. Health authorities may consider using hydrogen peroxide or chloride-based disinfectants as additional preventative strategies against non-enveloped respiratory viruses in the post-COVID-19 era.

The epidemiology and etiologies of respiratory tract infection in Northern Taiwan during the early phase of coronavirus disease 2019 (COVID-19) outbreak

Background

Coronavirus disease 2019 (COVID-19) manifests symptoms as common etiologies of respiratory tract infections (RTIs). During the pandemic of COVID-19, identifying the etiologies correctly from patients with RTI symptoms was crucial in not only disease control but preventing healthcare system from collapsing. By applying sensitive PCR-based molecular assays, we detected the etiologic agents and delineated the epidemiologic picture of RTIs in the early phase of COVID-19 pandemic.

Methods

From December 2019 to February 2020, we screened patients presented with RTIs using multiplex PCR-based diagnostic assays. Data from pediatric and adult patients were compared with different months and units in the hospital.

Results

Of all 1631 patients including 1445 adult and 186 pediatric patients screened, 8 viruses and 4 bacteria were identified. Positive rates were 25% in December, 37% in January, and 20% in February, with pediatric patients having higher positive rates than adults (Ps < 0.001). In pediatric patients, RhV/EnV was the most commonly detected, followed by parainfluenza viruses. Most Mycoplasma pneumoniae infection occurred in pediatric patients. RhV/EnV was the most commonly detected agent in pediatric patients admitted to intensive care units (ICUs), while influenza accounted for the majority of adult cases with critical illness. Noticeably, seasonal coronavirus ranked second in both adult and pediatric patients with ICU admission.

Conclusion

While we focused on the pandemic of COVID-19, common etiologies still accounted for the majority of RTIs and lead to severe diseases, including other seasonal coronaviruses.

PACIFIC: a lightweight deep-learning classifier of SARS-CoV-2 and co-infecting RNA viruses

Viral co-infections occur in COVID-19 patients, potentially impacting disease progression and severity. However, there is currently no dedicated method to identify viral co-infections in patient RNA-seq data. We developed PACIFIC, a deep-learning algorithm that accurately detects SARS-CoV-2 and other common RNA respiratory viruses from RNA-seq data. Using in silico data, PACIFIC recovers the presence and relative concentrations of viruses with > 99% precision and recall. PACIFIC accurately detects SARS-CoV-2 and other viral infections in 63 independent in vitro cell culture and patient datasets. PACIFIC is an end-to-end tool that enables the systematic monitoring of viral infections in the current global pandemic.

The effect of vitamin D supplementation on acute respiratory tract infection in older Australian adults: an analysis of data from the D-Health Trial

BACKGROUND

Observational studies have linked vitamin D deficiency with acute respiratory tract infection, but results from randomised controlled trials are heterogeneous. We analysed data from the D-Health Trial to determine whether supplementing older Australian adults, recruited from the general population, with monthly doses of vitamin D reduced the risk, duration, and severity of acute respiratory tract infections.

METHODS

We used data from the D-Health Trial, a randomised, double-blind, placebo-controlled trial of monthly vitamin D supplementation, for which acute respiratory infection was a pre-specified trial outcome. Participants were supplemented and followed for up to 5 years. The trial was set within the Australian general population, using the Commonwealth Electoral Roll as the sampling frame, but also allowing some volunteers to participate. Participants were men and women aged 60 to 79 years (with volunteers up to age 84 years). Participants were randomly assigned to receive either vitamin D or placebo (1:1) using computer-generated permuted block randomisation, which was stratified by age, sex, and state. This was an automated process and the assignment list was not visible to study staff or investigators. Active and placebo gel capsules, identical in appearance to ensure masking, were labelled A and B and the code was not available to study staff or investigators. Participants were asked to report occurrence of acute respiratory symptoms over the previous month via annual surveys, and a subset of participants completed 8-week respiratory symptom diaries in winter. As part of our process to maintain blinding, a random sample of participants was selected for analysis of survey data and a separate sample selected for analysis of diary data. Blood samples were obtained from a random sample of participants (about 450 per group per year) and serum 25-hydroxy vitamin D (25[OH]D) concentrations were measured to monitor adherence. We used regression models to estimate odds ratios (OR), rate ratios, and rate differences. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12613000743763.

FINDINGS

Between Jan 13, 2014, and May 26, 2015, 421 207 invitations were sent, 40 824 people were interested in participating, and 21 315 participants were recruited and randomised. Of the 16 000 participants selected for potential analysis of survey data, 15 373 were included in the analysis; 295 in the vitamin D group and 332 in the placebo group who were missing data for all five annual surveys were excluded from the analysis. Of the 3800 selected for potential analysis of diary data, 3070 were invited to complete the diaries because 730 had already withdrawn. 2598 people were included in the analysis; 218 people in the vitamin D group and 254 in the placebo group were missing data and were therefore excluded from the analysis. In blood samples collected from randomly sampled participants throughout the trial, the mean serum 25(OH)D concentration was 114·8 (SD 30·3) nmol/L in the vitamin D group and 77·5 (25·2) nmol/L in the placebo group. Vitamin D supplementation did not reduce the risk of acute respiratory tract infection (survey OR 0·98, 95% CI 0·93 to 1·02; diary OR 0·98, 0·83 to 1·15). Analyses of diary data showed reductions in the overall duration of symptoms and of severe symptoms, but these were small and unlikely to be clinically significant.

INTERPRETATION

Monthly bolus doses of 60 000 IU of vitamin D did not reduce the overall risk of acute respiratory tract infection, but could slightly reduce the duration of symptoms in the general population. These findings suggest that routine vitamin D supplementation of a population that is largely vitamin D replete is unlikely to have a clinically relevant effect on acute respiratory tract infection.

FUNDING

National Health and Medical Research Council.

Viral Infections of the Upper Airway in the Setting of COVID-19: A Primer for Rhinologists

BACKGROUND

Viral respiratory tract infections are associated with a significant burden of disease and represent one of the leading causes of mortality worldwide. The current Coronavirus Disease 2019 (COVID-19) pandemic highlights the devastating toll that respiratory viruses have on humanity and the desperate need to understand the biological characteristics that define them in order to develop efficacious treatments and vaccines. To date, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has infected nearly 600 times more people and resulted in 200 times more deaths relative to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle Eastern Respiratory Syndrome Coronavirus (MERS-CoV) combined.

OBJECTIVE

Through this review, we aim to summarize the key characteristics of respiratory viruses that hold global significance, with a focus on SARS-CoV-2. Our goal is to disseminate our current knowledge of these infectious agents to otolaryngologists, in particular rhinologists, practicing in the COVID-19 era.

METHODS

The general and clinical characteristics of selected respiratory viruses along with available viral treatments and vaccines are reviewed.

RESULTS

There has been significant progress in our understanding of the epidemiology and pathogenesis of various respiratory viruses. However, despite the advancement in knowledge, efficacious vaccines and antiviral treatments remain elusive for most respiratory viruses. The dire need for these scientific discoveries is highlighted by the recent COVID-19 pandemic, which has prompted investigators worldwide to conduct clinical trials at an accelerated timeline in an effort to reduce the morbidity and mortality associated with SARS-CoV-2 infection. Rhinologists will continue to remain on the front-lines of pandemics associated with respiratory viruses.

CONCLUSION

In light of these unprecedented times, the need to understand the nuances of these viral respiratory pathogens, especially SARS-CoV-2, cannot be overemphasized. This knowledge base is of particular importance to otolaryngologists, whose expertise in the upper airway coincides with the anatomic tropism of these infectious agents.

Challenges in the prevention or treatment of RSV with emerging new agents in children from low- and middle-income countries

INTRODUCTION

Respiratory syncytial virus (RSV) causes approximately 120,000 deaths annually in children <5 years, with 99% of fatalities occurring in low- and middle-income countries (LMICs).

AREAS COVERED

There are numerous RSV interventions in development, including long-acting monoclonal antibodies, vaccines (maternal and child) and treatments which are expected to become available soon. We reviewed the key challenges and issues that need to be addressed to maximize the impact of these interventions in LMICs. The epidemiology of RSV in LMICs was reviewed (PubMed search to 30 June 2020 inclusive) and the need for more and better-quality data, encompassing hospital admissions, community contacts, and longer-term respiratory morbidity, emphasized. The requirement for an agreed clinical definition of RSV lower respiratory tract infection was proposed. The pros and cons of the new RSV interventions are reviewed from the perspective of LMICs.

EXPERT OPINION

We believe that a vaccine (or combination of vaccines, if practicable) is the only viable solution to the burden of RSV in LMICs. A coordinated program, analogous to that with polio, involving governments, non-governmental organizations, the World Health Organization, the manufacturers and the healthcare community is required to realize the full potential of vaccine(s) and end the devastation of RSV in LMICs.

Surveillance of respiratory viruses among children attending a primary school in rural coastal Kenya

Background: Respiratory viruses are primary agents of respiratory tract diseases. Knowledge on the types and frequency of respiratory viruses affecting school-children is important in determining the role of schools in transmission in the community and identifying targets for interventions. Methods: We conducted a one-year (term-time) surveillance of respiratory viruses in a rural primary school in Kilifi County, coastal Kenya between May 2017 and April 2018. A sample of 60 students with symptoms of ARI were targeted for nasopharyngeal swab (NPS) collection weekly.  Swabs were screened for 15 respiratory virus targets using real time PCR diagnostics. Data from respiratory virus surveillance at the local primary healthcare facility was used for comparison. Results: Overall, 469 students aged 2-19 years were followed up for 220 days. A total of 1726 samples were collected from 325 symptomatic students; median age of 7 years (IQR 5-11). At least one virus target was detected in 384 (22%) of the samples with a frequency of 288 (16.7%) for rhinovirus, 47 (2.7%) parainfluenza virus, 35 (2.0%) coronavirus, 15 (0.9%) adenovirus, 11 (0.6%) respiratory syncytial virus (RSV) and 5 (0.3%) influenza virus.  The proportion of virus positive samples was higher among lower grades compared to upper grades (25.9% vs 17.5% respectively; χ 2 = 17.2, P -value <0.001). Individual virus target frequencies did not differ by age, sex, grade, school term or class size. Rhinovirus was predominant in both the school and outpatient setting. Conclusion: Multiple respiratory viruses circulated in this rural school population.  Rhinovirus was dominant in both the school and outpatient setting and RSV was of notably low frequency in the school. The role of school children in transmitting viruses to the household setting is still unclear and further studies linking molecular data to contact patterns between the school children and their households are required.

Respiratory viruses in pediatric emergency department patients and their family members

Background

Respiratory viral infections account for a substantial fraction of pediatric emergency department (ED) visits. We examined the epidemiological patterns of seven common respiratory viruses in children presenting to EDs with influenza‐like illness (ILI). Additionally, we examined the co‐occurrence of viral infections in the accompanying adults and risk factors associated with the acquisition of these viruses.

Methods

Nasopharyngeal swab were collected from children seeking medical care for ILI and their accompanying adults (Total N = 1315). Study sites included New York Presbyterian, Bellevue, and Tisch hospitals in New York City. PCR using a respiratory viral panel was conducted, and data on symptoms and medical history were collected.

Results

Respiratory viruses were detected in 399 children (62.25%) and 118 (17.5%) accompanying adults. The most frequent pathogen detected was human rhinovirus (HRV) (28.81%). Co‐infection rates were 14.79% in children and 8.47% in adults. Respiratory syncytial virus (RSV) and parainfluenza infections occurred more often in younger children. Influenza and HRV occurred more often in older children. Influenza and coronavirus were mostly isolated in winter and spring, RSV in fall and winter and HRV in fall and spring. Children with HRV were more likely to have history of asthma. Adults with the same virus as their child often accompanied ≤ 2‐year‐old‐positive children and were more likely to be symptomatic compared to adults with different viruses.

Conclusions

Respiratory viruses, while presenting the same suite of symptoms, possess distinct seasonal cycles and affect individuals differently based on a number of identifiable factors, including age and history of asthma.

Dynamics of IFN-β Responses during Respiratory Viral Infection. Insights for Therapeutic Strategies

Rationale: Viral infections are major drivers of exacerbations and clinical burden in patients with asthma and chronic obstructive pulmonary disease (COPD). IFN-β is a key component of the innate immune response to viral infection. To date, studies of inhaled IFN-β treatment have not demonstrated a significant effect on asthma exacerbations.Objectives: The dynamics of exogenous IFN-β activity were investigated to inform on future clinical indications for this potential antiviral therapy.Methods: Monocyte-derived macrophages (MDMs), alveolar macrophages, and primary bronchial epithelial cells (PBECs) were isolated from healthy control subjects and patients with COPD and infected with influenza virus either prior to or after IFN-β stimulation. Infection levels were measured by the percentage of nucleoprotein 1-positive cells using flow cytometry. Viral RNA shedding and IFN-stimulated gene expression were measured by quantitative PCR. Production of inflammatory cytokines was measured using MSD.Measurements and Main Results: Adding IFN-β to MDMs, alveolar macrophages, and PBECs prior to, but not after, infection reduced the percentage of nucleoprotein 1-positive cells by 85, 56, and 66%, respectively (P < 0.05). Inhibition of infection lasted for 24 hours after removal of IFN-β and was maintained albeit reduced up to 1 week in MDMs and 72 hours in PBECs; this was similar between healthy control subjects and patients with COPD. IFN-β did not induce inflammatory cytokine production by MDMs or PBECs but reduced influenza-induced IL-1β production by PBECs.Conclusions: In vitro modeling of IFN-β dynamics highlights the potential for intermittent prophylactic doses of exogenous IFN-β to modulate viral infection. This provides important insights to aid the future design of clinical trials of IFN-β in asthma and COPD.

The Multifarious Role of 14-3-3 Family of Proteins in Viral Replication

The 14-3-3 proteins are a family of ubiquitous and exclusively eukaryotic proteins with an astoundingly significant number of binding partners. Their binding alters the activity, stability, localization, and phosphorylation state of a target protein. The association of 14-3-3 proteins with the regulation of a wide range of general and specific signaling pathways suggests their crucial role in health and disease. Recent studies have linked 14-3-3 to several RNA and DNA viruses that may contribute to the pathogenesis and progression of infections. Therefore, comprehensive knowledge of host-virus interactions is vital for understanding the viral life cycle and developing effective therapeutic strategies. Moreover, pharmaceutical research is already moving towards targeting host proteins in the control of virus pathogenesis. As such, targeting the right host protein to interrupt host-virus interactions could be an effective therapeutic strategy. In this review, we generated a 14-3-3 protein interactions roadmap in viruses, using the freely available Virusmentha network, an online virus-virus or virus-host interaction tool. Furthermore, we summarize the role of the 14-3-3 family in RNA and DNA viruses. The participation of 14-3-3 in viral infections underlines its significance as a key regulator for the expression of host and viral proteins.

Surveillance of respiratory viruses among children attending a primary school in rural coastal Kenya

Background: Respiratory viruses are primary agents of respiratory tract diseases. Knowledge on the types and frequency of respiratory viruses affecting school-children is important in determining the role of schools in transmission in the community and identifying targets for interventions. Methods: We conducted a one-year (term-time) surveillance of respiratory viruses in a rural primary school in Kilifi County, coastal Kenya between May 2017 and April 2018. A sample of 60 students with symptoms of ARI were targeted for nasopharyngeal swab (NPS) collection weekly.  Swabs were screened for 15 respiratory virus targets using real time PCR diagnostics. Data from respiratory virus surveillance at the local primary healthcare facility was used for comparison. Results: Overall, 469 students aged 2-19 years were followed up for 220 days. A total of 1726 samples were collected from 325 symptomatic students; median age of 7 years (IQR 5-11). At least one virus target was detected in 384 (22%) of the samples with a frequency of 288 (16.7%) for rhinovirus, 47 (2.7%) parainfluenza virus, 35 (2.0%) coronavirus, 15 (0.9%) adenovirus, 11 (0.6%) respiratory syncytial virus (RSV) and 5 (0.3%) influenza virus.  The proportion of virus positive samples was higher among lower grades compared to upper grades (25.9% vs 17.5% respectively; χ 2 = 17.2, P -value <0.001). Individual virus target frequencies did not differ by age, sex, grade, school term or class size. Rhinovirus was predominant in both the school and outpatient setting. Conclusion: Multiple respiratory viruses circulated in this rural school population.  Rhinovirus was dominant in both the school and outpatient setting and RSV was of notably low frequency in the school. The role of school children in transmitting viruses to the household setting is still unclear and further studies linking molecular data to contact patterns between the school children and their households are required.

Pragmatic multicentre randomised controlled trial evaluating the impact of a routine molecular point-of-care 'test-and-treat' strategy for influenza in adults hospitalised with acute respiratory illness (FluPOC): trial protocol

BACKGROUND

Influenza infections often remain undiagnosed in patients admitted to hospital due to lack of routine testing. When tested for, the diagnosis and treatment of influenza are often delayed due to the slow turnaround times of centralised laboratory PCR testing. Newer molecular systems, have comparable accuracy to laboratory PCR testing, and can generate a result in under 1 hour, making them potentially deployable as point-of-care tests (POCTs). High-quality evidence for the impact of routine POCT for influenza on clinical outcomes is, however, currently lacking. This large pragmatic multicentre randomised controlled trial aims to address this evidence gap.

METHODS AND ANALYSIS

The FluPOC trial is a pragmatic, multicentre, randomised controlled trial evaluating adults admitted to a large teaching hospital and a district general hospital with an acute respiratory illness, during influenza season and defined by Public Health England. Up to 840 patients will be recruited over up to three influenza seasons, and randomised (1:1) to receive either POCT using the FilmArray respiratory panel, or routine clinical care. Clinical and infection control teams will be informed of the results in real time and where influenza is detected clinical teams will be encouraged to offer neuraminidase inhibitor (NAI) treatment in accordance with national guidelines. Those allocated to standard clinical care will have a swab taken for later analysis to allow assessment of missed diagnoses. The outcomes assessment will be by retrospective case note analysis. The outcome measures include the proportion of influenza-positive patients detected and appropriately treated with NAIs, isolation facility use, antibiotic use, length of hospital stay, complications and mortality.

ETHICS AND DISSEMINATION

Prior to commencing the study, approval was obtained from the South Central Hampshire A Ethics Committee (reference 17/SC/0368, granted 7 September 2017). Results generated from this protocol will be published in peer-reviewed scientific journals and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN17197293.

INDUCTION OF SECONDARY BACTERIAL PNEUMONIA IN MICE INFECTED WITH PANDEMIC AND LABORATORY STRAINS OF THE H1N1 INFLUENZA VIRUS

Aim.In this study we developed and characterized a mouse model of secondary S. aureus and S. pneumoniae pneumonia following influenza virus infection with H1N1 pandemic and laboratory strains and their reassortment.Materials and methods. BALB/с mice were infected intranasally with A/California/04/2009/(H1N1 pndm), A/Puerto Rico/8/34 or their reassortment NIBRG-121xp followed by different strains of S. аureus и S. pneumoniae. The pathogenicity of infection was assessed by mouse survival and weight change, viral titre and bacterial count in the lungs.Results.It was shown that the infection of mice with three strains of the H1N1 influenza virus with a comparable level of pathogenicity leads to a different severity of secondary bacterial infection. The mouse adapted A/California/04/2009 pandemic strain possessed the greatest ability to alter antibacterial immunity.Conclusion. An experimental model of post-influenza bacterial pneumonia utilizing three strains of the H1N1 influenza virus and various strains of S. aureus or S. pneumoniae was established. The ability of viruses to provoke bacterial superinfection of different severity is characterized.

High Prevalence of Viral Infections Among Hospitalized Pneumonia Patients in Equatorial Sarawak, Malaysia

Background

Although pneumonia is a known cause of morbidity and mortality in Sarawak, Malaysia, the etiology and epidemiology of pneumonia are not well described in this equatorial region. Routine clinical diagnostics for pneumonia etiology at government hospitals in Sarawak had historically involved only bacterial diagnostics. Viral diagnostics were only obtained through outside consultations.

Methods

From June 15, 2017 to May 14, 2018, we collected nasopharyngeal swabs from 600 patients of all ages older than 1 month hospitalized with pneumonia at Sibu and Kapit Hospitals. Specimens were examined at our collaborating institutions with a panel of molecular assays for viral pathogens including influenza A (IAV), IBV, ICV, and IDV, human adenovirus (AdV), human enterovirus (EV), human coronavirus (CoV), respiratory syncytial virus subtype A (RSV-A) or RSV-B, and parainfluenza virus (PIV) types 1–4.

Results

Of 599 samples examined, 288 (48%) had molecular evidence of 1 or more respiratory viruses. Overall, the most prevalent virus detected was RSV-A (14.2%) followed by AdV (10.4%) and IAV (10.4%), then RSV-B (6.2%), EV (4.2%), IBV (2.2%), PIV-3 (1.7%), CoV (1.0%), PIV-1 (1.0%), PIV-4 (0.7%), and PIV-2 (0.2%). No specimens were confirmed positive for ICV or IDV.

Conclusions

The high prevalence of viruses detected in this study suggest that respiratory viruses may be responsible for considerable morbidity in equatorial regions such as Sarawak. Access to viral diagnostics are very necessary for medical staff to determine appropriate pneumonia treatments.

The epidemiology and severity of respiratory viral infections in a tropical country: Ecuador, 2009-2016

BACKGROUND

Respiratory viral infections (RVI) are a leading cause of mortality worldwide. We compared the epidemiology and severity of RVI in Ecuador during 2009-2016.

METHODS

Respiratory specimens collected within the national surveillance system were tested for influenza viruses, respiratory syncytial virus (RSV), adenovirus, parainfluenza virus, and human metapneumovirus. Overall and virus-specific positive detection rate (PDR) were calculated and compared the timing of epidemics caused by the different viruses. Logistic regression models were used to compare the age distribution and risk of death across respiratory viruses.

RESULTS

A total of 41,172 specimens were analyzed: influenza (PDR=14.3%) and respiratory syncytial virus (RSV) (PDR=9.5%) were the most frequently detected viruses. Influenza epidemics typically peaked in December-January and RSV epidemics in March; seasonality was less evident for the other viruses. Compared to adults, children were more frequently infected with RSV, adenovirus, parainfluenza, and influenza B, while the elderly were less frequently infected with influenza A(H1N1)p. The age-adjusted risk of death was highest for A(H1N1)p (odds ratio [OR] 1.73, 95% confidence intervals [CI] 1.38-2.17), and lowest for RSV (OR 0.75, 95%CI 0.57-0.98).

CONCLUSIONS

Whilst influenza and RSV were the most frequently detected pathogens, the risk of death differed by RVI, being highest for pandemic influenza and lowest for RSV.

Acute respiratory infections in hospitalized children in Vientiane, Lao PDR - the importance of Respiratory Syncytial Virus

The Human respiratory syncytial virus (RSV) is one of the most important viral pathogens, causing epidemics of acute respiratory infection (ARI), especially bronchiolitis and pneumonia, in children worldwide. To investigate the RSV burden in Laos, we conducted a one-year study in children <5 years old admitted to Mahosot Hospital, Vientiane Capital, to describe clinical and epidemiological characteristics and predictive factors for severity of RSV-associated ARI. Pooled nasal and throat swabs were tested using multiplex real-time PCR for 33 respiratory pathogens (FTD® kit). A total of 383 patients were included, 277 (72.3%) of whom presented with pneumonia. 377 (98.4%) patients were positive for at least one microorganism, of which RSV was the most common virus (41.0%), with a peak observed between June and September, corresponding to the rainy season. Most RSV inpatients had pneumonia (84.1%), of whom 35% had severe pneumonia. Children <3-months old were a high-risk group for severe pneumonia, independently of RSV infection. Our study suggests that RSV infection is frequent in Laos and commonly associated with pneumonia in hospitalized young children. Further investigations are required to provide a better overall view of the Lao nationwide epidemiology and public health burden of RSV infection over time.

Comparison of three multiplex PCR assays for detection of respiratory viruses: Anyplex II RV16, AdvanSure RV, and Real-Q RV

Background

Due to its great sensitivity, the nucleic acid amplification test (NAAT) is widely used for detection of respiratory viruses (RV). However, few reports have described a direct comparison between multiplex RT‐PCR assays for RV. The objective of this study was to perform a direct comparison of three multiplex RT‐PCR assays for the detection of respiratory viruses.

Methods

A total of 201 respiratory samples (161 nasopharyngeal swab samples and 40 sputum samples) were tested with three commercial RV assays: Seegene Anyplex II RV16 (AP), LG AdvanSure RV (AD), and Biosewoom Real‐Q RV (RQ). The additional tests for the discrepant results were conducted by repeat RV assay or monoplex PCR coupled direct sequencing. Data analysis using percent agreement, kappa, and prevalence‐adjusted and bias‐adjusted kappa (PABAK) values was performed for comparisons among the three RV assays.

Results

Of the 201 samples, AP, AD, and RQ detected 105 (52.2%), 99 (49.3%), and 95 (47.3%) positive cases respectively. The overall agreement, kappa, and PABAK values for the three assays ranged between 97%‐98%, 0.76‐0.86, and 0.93‐0.96 respectively. The performance of the three assays was very similar, with 94%‐100% agreement for all comparisons, each virus types. The additional testing of samples showed discrepant results demonstrating that AD assay had the highest rate of concordance with original results.

Conclusions

We suggest that all multiplex assay would be suitable for the detection of for respiratory viruses in clinical setting.

Molecular point-of-care testing for respiratory viruses versus routine clinical care in adults with acute respiratory illness presenting to secondary care: a pragmatic randomised controlled trial protocol (ResPOC)

BACKGROUND

Respiratory viruses are associated with a huge socio-economic burden and are responsible for a large proportion of acute respiratory illness in hospitalised adults. Laboratory PCR is accurate but takes at least 24 h to generate a result to clinicians and antigen-based point-of-care tests (POCT) lack sensitivity. Rapid molecular platforms, such as the FilmArray Respiratory Panel, have equivalent diagnostic accuracy to laboratory PCR and can generate a result in 1 h making them deployable as POCT. Molecular point-of-care testing for respiratory viruses in hospital has the potential to improve the detection rate of respiratory viruses, improve the use of influenza antivirals and reduce unnecessary antibiotic use, but high quality randomised trials with clinically relevant endpoints are needed.

METHODS

The ResPOC study is a pragmatic randomised controlled trial of molecular point-of-care testing for respiratory viruses in adults with acute respiratory illness presenting to a large teaching hospital in the United Kingdom. Eligible participants are adults presenting with acute respiratory illness to the emergency department or the acute medicine unit. Participants are allocated 1:1 by internet-based randomisation service to either the intervention of a nose and throat swab analysed immediately on the FilmArray Respiratory Panel as a POCT or receive routine clinical care. The primary outcome is the proportion of patients treated with antibiotics. Secondary outcomes include turnaround time, virus detection, neuraminidase inhibitor use, length of hospital stay and side room use. Analysis of the primary outcome will be by intention-to-treat and all enrolled participants will be included in safety analysis.

DISCUSSION

Multiple novel molecular POCT platforms for infections including respiratory viruses have been developed and licensed in the last few years and many more are in development but the evidence base for clinical benefit above standard practice is minimal. This randomised controlled trial aims to close this evidence gap by generating high quality evidence for the clinical impact of molecular POCT for respiratory viruses in secondary care and to act as an exemplar for future studies of molecular POCT for infections. This study has the potential to change practice and improve patient care for patients presenting to hospital with acute respiratory illness.

TRIAL REGISTRATION

This study was registered with ISRCTN, number ISRCTN90211642 , on 14th January 2015.

The Clinical Significance of FilmArray Respiratory Panel in Diagnosing Community-Acquired Pneumonia

AIM

FilmArray Respiratory Panel (FilmArray RP) test is an emerging diagnostic method in fast detecting multiple respiratory pathogens; the methodology and clinical significance of FilmArray RP in community-acquired pneumonia (CAP) diagnosis were evaluated in this study.

METHODS

Specimens from 74 patients with CAP were analyzed and compared using FilmArray RP, traditional multiple PCR assay, bacterial (or fungal) culture, and serological detection.

RESULTS

FilmArray RP and multiplex PCR showed 100% coincidence rate in detecting coronaviruses 229E, OC43, HKU1, and NL63, human metapneumovirus, influenza A and B, and parainfluenza viruses (PIV1, PIV2, and PIV4). There were 15 viral specimens tested as disagreement positive results. FilmArray RP had higher detection rate in detecting dual viral and Mycoplasma pneumoniae infection. The positive bacteria (or fungi) were found in 25 specimens.

CONCLUSIONS

This study demonstrated the capability of FilmArray RP for simultaneous detection of broad-spectrum respiratory pathogens and potential use in facilitating better patient care.

Influence of meteorological conditions on RSV infection in Portugal

Acute viral bronchiolitis is a common cause for infant hospital admissions. Of all etiological agents, respiratory syncytial virus (RSV) is commonly the most frequent. The present study assesses relationships between atmospheric factors and RSV infections in under 3-year-old patients admitted to the Inpatient Paediatric Service of Vila Real (North of Portugal). For this purpose, (1) clinical files of children admitted with a diagnosis of acute bronchiolitis from September 2005 to December 2015 (>10 years) were scrutinised and (2) local daily temperature/precipitation series, as well as six weather types controlling meteorological conditions in Portugal, were used. Fifty-five percent of all 770 admitted children were effectively infected with a given virus, whilst 48 % (367) were RSV+, i.e. 87 % of virus-infected children were RSV+. The bulk of incidence is verified in the first year of age (82 %, 302), slightly higher in males. RSV outbreaks are typically from December to March, but important inter-annual variability is found in both magnitude and shape. Although no clear connections were found between monthly temperatures/precipitation and RSV outbreaks apart from seasonality, a linkage to wintertime cold spells is apparent on a daily basis. Anomalously low minimum temperatures from the day of admittance back to 10 days before are observed. This relationship is supported by anomalously high occurrences of the E and AA weather types over the same period, which usually trigger dry and cold weather. These findings highlight some predictability in the RSV occurrences, revealing potential for modelling and risk assessments.

The role of microRNAs in respiratory viral infection: friend or foe?

MicroRNAs (miRNAs) have emerged as a class of regulatory RNAs in host-pathogen interactions. Aberrant miRNA expression seems to play a central role in the pathology of several respiratory viruses, promoting development and progression of infection. miRNAs may thus serve as therapeutic and prognostic factors for respiratory viral infectious disease caused by a variety of agents. We present a comprehensive review of recent findings related to the role of miRNAs in different respiratory viral infections and discuss possible therapeutic opportunities aiming to attenuate the burden of viral infections. Our review supports the emerging concept that cellular and viral-encoded miRNAs might be broadly implicated in human respiratory viral infections, with either positive or negative effects on virus life cycle. Copyright © 2016 John Wiley & Sons, Ltd.

A UK general practice population cohort study investigating the association between lipid lowering drugs and 30-day mortality following medically attended acute respiratory illness

Background. Cholesterol lowering drugs HMG-CoA reductase inhibitors (statins) and PPARα activators (fibrates) have been shown to reduce host inflammation via non-disease specific immunomodulatory mechanisms. Recent studies suggest that commonly prescribed drugs in general practice, statins and fibrates, may be beneficial in influenza-like illness related mortality. This retrospective cohort study examines the association between two lipid lowering drugs, statins and fibrates, and all-cause 30-day mortality following a medically attended acute respiratory illness (MAARI). Methods. Primary care patient data were retrospectively extracted from the UK Clinical Practice Research Datalink (CPRD) database. The sample comprised 201,179 adults aged 30 years or older experiencing a MAARI episode. Patient exposure to statins or fibrates was coded as separate dichotomous variables and deemed current if the most recent GP prescription was issued in the 30 days prior to MAARI diagnosis. Multivariable logistic regression and Cox regression were used for analyses. Adjustment was carried out for chronic lung disease, heart failure, metformin and glitazones, comorbidity burden, socio-demographic and lifestyle variables such as smoking status and body mass index (BMI). Statistical interaction tests were carried out to check for effect modification by gender, body mass index, smoking status and comorbidity. Results. A total of 1,096 (5%) patients died within the 30-day follow up period. Of this group, 213 (19.4%) were statin users and 4 (0.4%) were fibrate users. After adjustment, a significant 35% reduction in odds [adj OR; 0.65 (95% CI [0.52-0.80])] and a 33% reduction in the hazard [adj HR: 0.67 (95% CI [0.55-0.83])] of all-cause 30-day mortality following MAARI was observed in statin users. A significant effect modification by comorbidity burden was observed for the association between statin use and MAARI-related mortality. Fibrate use was associated with a non-significant reduction in 30-day MAARI-related mortality. Conclusion. This study suggests that statin use may be associated with a reduction in 30-day mortality following acute respiratory illness that is severe enough to merit medical consultation. Findings from this study support and strengthen similar observational research while providing a strong rationale for a randomised controlled trial investigating the potential role of statins in acute respiratory infections.

[Modulation of transcriptomic signature of the infected host: a new therapeutic strategy for the management of severe viral infections? Example of the flu]

Ces dernières décennies ont été marquées par l’émergence ou la réémergence de virus responsables d’épidémies ou de pandémies plus ou moins sévères. Les stratégies préventives sont prises à défaut, et l’arsenal antiviral curatif est limité d’autant plus que les résistances virales peuvent apparaître rapidement. Par ailleurs, le développement de nouvelles molécules nécessite un délai incompatible avec la réponse rapide nécessaire lors d’une épidémie d’envergure ou d’une pandémie. C’est la raison pour laquelle de nouvelles approches thérapeutiques sont nécessaires. Un concept novateur est le repositionnement de molécules déjà sur le marché en exploitant leur capacité à inverser la réponse transcriptomique cellulaire de l’hôte infecté. En identifiant des molécules qui visent l’hôte et non le virus, cette stratégie permet d’avoir un large spectre d’action et d’être potentiellement actif sur de nouveaux variants. La mise en place de cette stratégie nécessite de caractériser les réponses cellulaires spécifiques de l’infection virale d’intérêt, de cribler in silico des molécules candidates, de les tester sur modèles cellulaires et animaux, avant d’envisager des essais cliniques chez l’homme. Nous présenterons cette démarche en prenant pour exemple l’infection grippale.

Novel insights into human respiratory syncytial virus-host factor interactions through integrated proteomics and transcriptomics analysis

The lack of vaccine and limited antiviral options against respiratory syncytial virus (RSV) highlights the need for novel therapeutic strategies. One alternative is to develop drugs that target host factors required for viral replication. Several microarray and proteomics studies had been published to identify possible host factors that are affected during RSV replication. In order to obtain a comprehensive understanding of RSV-host interaction, we integrated available proteome and transcriptome datasets and used it to construct a virus-host interaction network. Then, we interrogated the network to identify host factors that are targeted by the virus and we searched for drugs from the DrugBank database that interact with these host factors, which may have potential applications in repositioning for future treatment options of RSV infection.

Point-of-care testing for respiratory viruses in adults: The current landscape and future potential

Respiratory viruses are responsible for a large proportion of acute respiratory illness in adults as well as children, and are associated with a huge socio-economic burden worldwide. Development of accurate point-of-care tests (POCT) for respiratory viruses has been listed as a priority by the World Health Organisation and replacing the current paradigm of empirical antimicrobial use with directed use is a listed goal of the movement for reduction in antimicrobial resistance. POCTs for respiratory viruses have previously been limited by the poor sensitivity of antigen detection based tests and by a limited range of detectable viruses. Highly accurate molecular platforms are now able to test for a comprehensive range of viruses, can be operated by non-laboratory staff and can generate a result in approximately 1 h, making them potentially deployable as POCTs. The potential clinical benefits of POC testing for respiratory viruses in adults include a reduction in unnecessary antibiotic use, improved antiviral prescribing for influenza and rationalisation of isolation facilities. We review here the burden of disease, the currently available molecular platforms with potential for POCT use and the existing evidence for clinical and economic benefits of testing for respiratory viruses in adults.

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There is a large burden of respiratory virus infection in hospitalised adults.

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Replacing empirical antimicrobials with pathogen directed use is a global priority.

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Molecular platforms now exist with potential for use as point-of-care tests (POCT).

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Potential benefits of POCT include a reduction in unnecessary antibiotic use.

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High quality trials evaluating clinically relevant outcomes are urgently needed.

Modulation of the immune response to respiratory viruses by vitamin D

Background: Vitamin D deficiency has been shown to be independently associated with increased risk of viral acute respiratory infection (ARI) in a number of observational studies, and meta-analysis of clinical trials of vitamin D supplementation for prevention of ARI has demonstrated protective effects. Several cellular studies have investigated the effects of vitamin D metabolites on immune responses to respiratory viruses, but syntheses of these reports are lacking. Scope: In this article, we review the literature reporting results of in vitro experiments investigating immunomodulatory actions of vitamin D metabolites in human respiratory epithelial cells infected with respiratory viruses. Key findings: Vitamin D metabolites do not consistently influence replication or clearance of rhinovirus, respiratory syncytial virus (RSV) or influenza A virus in human respiratory epithelial cell culture, although they do modulate expression and secretion of type 1 interferon, chemokines including CXCL8 and CXCL10 and pro-inflammatory cytokines, such as TNF and IL-6. Future research: More studies are needed to clarify the effects of vitamin D metabolites on respiratory virus-induced expression of cell surface markers mediating viral entry and bacterial adhesion to respiratory epithelial cells.

Challenges and opportunities in developing respiratory syncytial virus therapeutics

Two meetings, one sponsored by the Wellcome Trust in 2012 and the other by the Global Virology Foundation in 2013, assembled academic, public health and pharmaceutical industry experts to assess the challenges and opportunities for developing antivirals for the treatment of respiratory syncytial virus (RSV) infections. The practicalities of clinical trials and establishing reliable outcome measures in different target groups were discussed in the context of the regulatory pathways that could accelerate the translation of promising compounds into licensed agents. RSV drug development is hampered by the perceptions of a relatively small and fragmented market that may discourage major pharmaceutical company investment. Conversely, the public health need is far too large for RSV to be designated an orphan or neglected disease. Recent advances in understanding RSV epidemiology, improved point-of-care diagnostics, and identification of candidate antiviral drugs argue that the major obstacles to drug development can and will be overcome. Further progress will depend on studies of disease pathogenesis and knowledge provided from controlled clinical trials of these new therapeutic agents. The use of combinations of inhibitors that have different mechanisms of action may be necessary to increase antiviral potency and reduce the risk of resistance emergence.

Emerging novel and antimicrobial-resistant respiratory tract infections: new drug development and therapeutic options

The emergence and spread of antimicrobial-resistant bacterial, viral, and fungal pathogens for which diminishing treatment options are available is of major global concern. New viral respiratory tract infections with epidemic potential, such as severe acute respiratory syndrome, swine-origin influenza A H1N1, and Middle East respiratory syndrome coronavirus infection, require development of new antiviral agents. The substantial rise in the global numbers of patients with respiratory tract infections caused by pan-antibiotic-resistant Gram-positive and Gram-negative bacteria, multidrug-resistant Mycobacterium tuberculosis, and multiazole-resistant fungi has focused attention on investments into development of new drugs and treatment regimens. Successful treatment outcomes for patients with respiratory tract infections across all health-care settings will necessitate rapid, precise diagnosis and more effective and pathogen-specific therapies. This Series paper describes the development and use of new antimicrobial agents and immune-based and host-directed therapies for a range of conventional and emerging viral, bacterial, and fungal causes of respiratory tract infections.