Influenza A (H1N1pdm09)-Related Critical Illness and Mortality in Mexico and Canada, 2014

Long-term outcomes of survivors with influenza A H1N1 virus-induced severe pneumonia and ARDS: a single-center prospective cohort study

Introduction

Systematic evaluation of long-term outcomes in survivors of H1N1 is still lacking. This study aimed to characterize long-term outcomes of severe H1N1-induced pneumonia and acute respiratory distress syndrome (ARDS).

Method

This was a single-center, prospective, cohort study. Survivors were followed up for four times after discharge from intensive care unit (ICU) by lung high-resolution computed tomography (HRCT), pulmonary function assessment, 6-minute walk test (6MWT), and SF-36 instrument.

Result

A total of 60 survivors of H1N1-induced pneumonia and ARDS were followed up for four times. The carbon monoxide at single breath (DLCO) of predicted values and the 6MWT results didn't continue improving after 3 months. Health-related quality of life didn't change during the 12 months after ICU discharge. Reticulation or interlobular septal thickening on HRCT did not begin to improve significantly until the 12-month follow-up. The DLCO of predicted values showed negative correlation with the severity degree of primary disease and reticulation or interlobular septal thickening, and a positive correlation with physical functioning. The DLCO of predicted values and reticulation or interlobular septal thickening both correlated with the highest tidal volume during mechanical ventilation. Levels of fibrogenic cytokines had a positive correlation with reticulation or interlobular septal thickening.

Conclusion

The improvements in pulmonary function and exercise capacity, imaging, and health-related quality of life had different time phase and impact on each other during 12 months of follow-up. Long-term outcomes of pulmonary fibrosis might be related to the lung injury and excessive lung fibroproliferation at the early stage during ICU admission.

Bioinformatics analysis identifies a key gene HLA_DPA1 in severe influenza-associated immune infiltration

BACKGROUND

Severe influenza is a serious global health issue that leads to prolonged hospitalization and mortality on a significant scale. The pathogenesis of this infectious disease is poorly understood. Therefore, this study aimed to identify the key genes associated with severe influenza patients necessitating invasive mechanical ventilation.

METHODS

The current study utilized two publicly accessible gene expression profiles (GSE111368 and GSE21802) from the Gene Expression Omnibus database. The research focused on identifying the genes exhibiting differential expression between severe and non-severe influenza patients. We employed three machine learning algorithms, namely the Least Absolute Shrinkage and Selection Operator regression model, Random Forest, and Support Vector Machine-Recursive Feature Elimination, to detect potential key genes. The key gene was further selected based on the diagnostic performance of the target genes substantiated in the dataset GSE101702. A single-sample gene set enrichment analysis algorithm was applied to evaluate the participation of immune cell infiltration and their associations with key genes.

RESULTS

A total of 44 differentially expressed genes were recognized; among them, we focused on 10 common genes, namely PCOLCE2, HLA_DPA1, LOC653061, TDRD9, MPO, HLA_DQA1, MAOA, S100P, RAP1GAP, and CA1. To ensure the robustness of our findings, we employed overlapping LASSO regression, Random Forest, and SVM-RFE algorithms. By utilizing these algorithms, we were able to pinpoint the aforementioned 10 genes as potential biomarkers for distinguishing between both cases of influenza (severe and non-severe). However, the gene HLA_DPA1 has been recognized as a crucial factor in the pathological condition of severe influenza. Notably, the validation dataset revealed that this gene exhibited the highest area under the receiver operating characteristic curve, with a value of 0.891. The use of single-sample gene set enrichment analysis has provided valuable insights into the immune responses of patients afflicted with severe influenza that have further revealed a categorical correlation between the expression of HLA_DPA1 and lymphocytes.

CONCLUSION

The findings indicated that the HLA_DPA1 gene may play a crucial role in the immune-pathological condition of severe influenza and could serve as a promising therapeutic target for patients infected with severe influenza.

Continuous Positive Airway Pressure (CPAP) for severe pneumonia in low- and middle-income countries: A systematic review of contextual factors

Background

Continuous positive airway pressure (CPAP) may have a role in reducing the high mortality in children less than 5 years with World Health Organization (WHO) severe pneumonia. More evidence is needed to understand important contextual factors that impact on implementation, effectiveness, and safety in low resource settings.

Methods

We conducted a systematic review of Medline, Embase and Pubmed (January 2000 to August 2020) with terms of "pneumonia", "CPAP" and "child". We included studies that provided original clinical or non-clinical data on the use of CPAP in children (28 days-4 years) with pneumonia in low- or middle-income countries. We used standardised tools to assess study quality, and grade levels of evidence for clinical conclusions. Results are presented as a narrative synthesis describing context, intervention, and population alongside outcome data.

Results

Of 902 identified unique references, 23 articles met inclusion criteria, including 6 randomised controlled trials, one cluster cross over trial, 12 observational studies, 3 case reports and 1 cost-effectiveness analysis. There was significant heterogeneity in patient population, with wide range in mortality among participants in different studies (0%-55%). Reporting of contextual factors, including staffing, costs, and details of supportive care was patchy and non-standardised. Current evidence suggests that CPAP has a role in the management of infants with bronchiolitis and as escalation therapy for children with pneumonia failing standard-flow oxygen therapy. However, CPAP must be implemented with appropriate staffing (including doctor oversight), intensive monitoring and supportive care, and technician and infrastructure capacity. We provide practical guidance and recommendations based on available evidence and published expert opinion, for the adoption of CPAP into routine care in low resource settings and for reporting of future CPAP studies.

Conclusions

CPAP is a safe intervention in settings that can provide intensive monitoring and supportive care, and the strongest evidence for a benefit of CPAP is in infants (aged less than 1 year) with bronchiolitis. The available published evidence and clinical experience can be used to help facilities assess appropriateness of implementing CPAP, guide health workers in refining selection of patients most likely to benefit from it, and provide a framework for components of safe and effective CPAP therapy.

Protocol registration

PROSPERO registration: CRD42020210597.

Co-expression network analysis identifies potential candidate hub genes in severe influenza patients needing invasive mechanical ventilation

BACKGROUND

Influenza is a contagious disease that affects people of all ages and is linked to considerable mortality during epidemics and occasional outbreaks. Moreover, effective immunological biomarkers are needed for elucidating aetiology and preventing and treating severe influenza. Herein, we aimed to evaluate the key genes linked with the disease severity in influenza patients needing invasive mechanical ventilation (IMV). Three gene microarray data sets (GSE101702, GSE21802, and GSE111368) from blood samples of influenza patients were made available by the Gene Expression Omnibus (GEO) database. The GSE101702 and GSE21802 data sets were combined to create the training set. Hub indicators for IMV patients with severe influenza were determined using differential expression analysis and Weighted correlation network analysis (WGCNA) from the training set. The receiver operating characteristic curve (ROC) was also used to evaluate the hub genes from the test set's diagnostic accuracy. Different immune cells' infiltration levels in the expression profile and their correlation with hub gene markers were examined using single-sample gene set enrichment analysis (ssGSEA).

RESULTS

In the present study, we evaluated a total of 447 differential genes. WGCNA identified eight co-expression modules, with the red module having the strongest correlation with IMV patients. Differential genes were combined to obtain 3 hub genes (HLA-DPA1, HLA-DRB3, and CECR1). The identified genes were investigated as potential indicators for patients with severe influenza who required IMV using the least absolute shrinkage and selection operator (LASSO) approach. The ROC showed the diagnostic value of the three hub genes in determining the severity of influenza. Using ssGSEA, it has been revealed that the expression of key genes was negatively correlated with neutrophil activation and positively associated with adaptive cellular immune response.

CONCLUSION

We evaluated three novel hub genes that could be linked to the immunopathological mechanism of severe influenza patients who require IMV treatment and could be used as potential biomarkers for severe influenza prevention and treatment.

[Clinical characteristics of influenza pneumonia in the elderly and relationship between D-dimer and disease severity]

OBJECTIVE

To clarify the clinical characteristics of influenza pneumonia in the elderly patients and the relationship between D-dimer and the severity of influenza pneumonia.

METHODS

In the study, 52 hospitalized patients older than 65 years with confirmed influenza pneumonia diagnosed in Peking University People's Hospital on 5 consecutive influenza seasons from 2014 were retrospectively analyzed. General information, clinical symptoms, laboratory data, treatment methods and prognosis of the patients were collected. The relationship between D-dimer and pneumonia severity was analyzed, and receiver operating characteristic (ROC) curve was used to evaluate the predictive value of D-dimer.

RESULTS

Among the 52 patients, 31 were male (31/52, 59.6%), the average age was (77.1±7.4) years, and 19 of them (36.5%) were diagnosed with severe pneumonia. About 70% patients presenting with fever. In the severe group, the patients were more likely to complain of dyspnea than in the non-severe group (14/19, 73.7% vs. 10/33, 30.3%, P=0.004), severe pneumonia group had higher level of CURB-65 (confusion, urea, respiratory rate, blood pressure, and age>65), pneumonia severity index (PSI), C-reactive protein, urea nitrogen, lactate dehydrogenase, fasting glucose, and D-dimer (P value was 0.004, < 0.001, < 0.001, 0.003, 0.038, 0.018, and < 0.001, respectively), albumin was lower than that in the non-severe group [(35.8±5.6) g/L vs. (38.9±3.5) g/L, t=-2.348, P=0.018]. There was a significant positive correlation between the D-dimer at the first admission and PSI score (r=0.540, 95%CI: 0.302 to 0.714, P < 0.001), while a significant negative correlation with PaO₂/FiO₂ (r=-0.559, 95%CI: -0.726 to -0.330, P < 0.001). Area under the curve of D-dimer was 0.765 (95%CI: 0.627 to 0.872). Area under the curve of PSI was 0.843 (95%CI: 0.716 to 0.929). There was no statistically significant difference in test efficacy between the two (Z=2.360, P=0.174). D-dimer level over 1 225 μg/L had a positive predict value for influenza pneumonia in hospital death with a sensitivity of 76.92% and a specificity of 74.36%.

CONCLUSION

Influenza pneumonia in the elderly always has atypical symptoms, dyspnea is a prominent feature in severe cases, D-dimer level is associated with the severity of influenza pneumonia, and greater than 1 200 μg/L has a good predictive value for in-hospital death in the elderly.

Flu-IV score: a predictive tool for assessing the risk of invasive mechanical ventilation in patients with influenza-related pneumonia

Background

The need for invasive mechanical ventilation (IMV) is linked to significant morbidity and mortality in patients with influenza-related pneumonia (Flu-p). We aimed to develop an assessment tool to predict IMV among Flu-p patients within 14 days of admission.

Methods

In total, 1107 Flu-p patients from five teaching hospitals were retrospectively enrolled from January 2012 to December 2019, including 895 patients in the derivation cohort and 212 patients in the validation cohort. The predictive model was established based on independent risk factors for IMV in the Flu-p patients from the derivation cohort.

Results

Overall, 10.6% (117/1107) of patients underwent IMV within 14 days of admission. Multivariate regression analyses revealed that the following factors were associated with IMV: early neuraminidase inhibitor use (− 3 points), lymphocytes < 0.8 × 10⁹/L (1 point), multi-lobar infiltrates (1 point), systemic corticosteroid use (1 point), age ≥ 65 years old (1 points), PaO₂/FiO₂ < 300 mmHg (2 points), respiratory rate ≥ 30 breaths/min (3 points), and arterial PH < 7.35 (4 points). A total score of five points was used to identify patients at risk of IMV. This model had a sensitivity of 85.5%, a specificity of 88.8%, and exhibited better predictive performance than the ROX index (AUROC = 0.909 vs. 0.594, p = 0.004), modified ROX index (AUROC = 0.909 vs. 0.633, p = 0.012), and HACOR scale (AUROC = 0.909 vs. 0.622, p < 0.001) using the validation cohort.

Conclusions

Flu-IV score is a valuable prediction rule for 14-day IMV rates in Flu-p patients. However, it should be validated in a prospective study before implementation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01833-2.

Epigenetic susceptibility to severe respiratory viral infections and its therapeutic implications: a narrative review

The emergence of highly pathogenic strains of influenza virus and coronavirus (CoV) has been responsible for large epidemic and pandemic outbreaks characterised by severe pulmonary illness associated with high morbidity and mortality. One major challenge for critical care is to stratify and minimise the risk of multi-organ failure during the stay in the intensive care unit (ICU). Epigenetic-sensitive mechanisms, including deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) methylation, histone modifications, and non-coding RNAs may lead to perturbations of the host immune-related transcriptional programmes by regulating chromatin structure and gene expression patterns. Viruses causing severe pulmonary illness can use epigenetic-regulated mechanisms during host-pathogen interaction to interfere with innate and adaptive immunity, adequacy of inflammatory response, and overall outcome of viral infections. For example, Middle East respiratory syndrome-CoV and H5N1 can affect host antigen presentation through DNA methylation and histone modifications. The same mechanisms would presumably occur in patients with coronavirus disease 2019, in which tocilizumab may epigenetically reduce microvascular damage. Targeting epigenetic pathways by immune modulators (e.g. tocilizumab) or repurposed drugs (e.g. statins) may provide novel therapeutic opportunities to control viral-host interaction during critical illness. In this review, we provide an update on epigenetic-sensitive mechanisms and repurposed drugs interfering with epigenetic pathways which may be clinically suitable for risk stratification and beneficial for treatment of patients affected by severe viral respiratory infections.

A retrospective comparison between influenza and COVID-19-associated ARDS in a Croatian tertiary care center

BACKGROUND

Since the beginning of the Corona virus disease 2019 (COVID-19) pandemic the new Severe acute respiratory syndrome coronoavirus 2 (SARS-CoV‑2) virus has been repeatedly compared to the influenza virus; however, the comparison of invasively mechanically ventilated patients with acute respiratory distress syndrome (ARDS) caused by these viruses is very scarce. The purpose of this study was to compare clinical course and laboratory parameters between the most severely ill flu and COVID 19 patients treated with invasive mechanical ventilation (IMV).

METHODS

The study was conducted at the intensive care unit (ICU) of the tertiary care hospital in Zagreb, Croatia in the period between November 2018 and July 2020. Investigation included 72 adult patients requiring IMV due to influenza or SARS-CoV‑2 virus infection and 42 patients had influenza and 30 had SARS-CoV‑2 virus infection and the comparison between two etiological groups was conducted.

RESULTS

Invasively mechanically ventilated patients with COVID 19 and influenza differ in certain aspects. COVID 19 patients are older, male, have lower C-reactive protein (CRP) levels and have less need for extracorporeal membrane oxygenation (ECMO) support. In other measured variables, including mortality, the difference between influenza or SARS-CoV‑2 etiology was not significant.

CONCLUSION

High mortality of IMV patients with influenza and COVID 19 with 55% and 63%, respectively, challenges and urges medical and especially ICU community to expand our quest for further treatments, especially since ECMO use that is scarcely required in COVID 19 patients probably has limited impact in reducing mortality in COVID 19 patients.

Lapiferin protects against H1N1 virus-induced pulmonary inflammation by negatively regulating NF-kB signaling

H1N1 virus-induced excessive inflammatory response contributes to severe disease and high mortality rates. There is currently no effective strategy against virus infection in lung. The present study evaluated the protective roles of a natural compound, lapiferin, in H1N1 virus-induced pulmonary inflammation in mice and in cultured human bronchial epithelial cells. Initially, Balb/C mice were grouped as Control, H1N1 infection (intranasally infected with 500 plaque-forming units of H1N1 virus), lapiferin (10 mg/kg), and H1N1+lapiferin (n=10/group). Lung histology, expression of inflammatory factors, and survival rates were assessed after 14 days of exposure. Administration of lapiferin significantly alleviated the virus-induced inflammatory infiltrate in lung tissues. Major pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, were decreased at both mRNA and protein levels by lapiferin administration in the lung homogenate. Lapiferin also reduced inflammatory cell numbers in bronchoalveolar fluid. Mechanistically, lapiferin suppressed the transcriptional activity and protein expression of NF-κB p65, causing inhibition on NF-κB signaling. Pre-incubation of human bronchial epithelial cells with an NF-κB signaling specific activator, ceruletide, significantly blunted lapiferin-mediated inhibition of pro-inflammatory cytokines secretion in an air-liquid-interface cell culture experiment. Activation of NF-κB signaling also blunted lapiferin-ameliorated inflammatory infiltrate in lungs. These results suggested that lapiferin was a potent natural compound that served as a therapeutic agent for virus infection in the lung.

Defining Community-Acquired Pneumonia as a Public Health Threat: Arguments in Favor from Spanish Investigators

Despite advances in its prevention, pneumonia remains associated with high morbidity, mortality, and health costs worldwide. Studies carried out in the last decade have indicated that more patients with community-acquired pneumonia (CAP) now require hospitalization. In addition, pneumonia management poses many challenges, especially due to the increase in the number of elderly patients with multiple comorbidities, antibiotic-resistant pathogens, and the difficulty of rapid diagnosis. In this new call to action, we present a wide-ranging review of the information currently available on CAP and offer some reflections on ways to raise awareness of this disease among the general public. We discuss the burden of CAP and the importance of attaining better, faster microbiological diagnosis and initiating appropriate treatment. We also suggest that closer cooperation between health professionals and the population at large could improve the management of this largely preventable infectious disease that takes many lives each year.

Prone ventilation in H1N1 virus-associated severe acute respiratory distress syndrome: A case series

Background:

Management of H1N1 viral infection-associated acute respiratory distress syndrome (ARDS) has primarily been focused on lung protective ventilation strategies, despite that mortality remains high (up to 45%). Other measures to improve survival are prone position ventilation (PPV) and extracorporeal membrane oxygenation. There is scarcity of literature on the use of prone ventilation in H1N1-associated ARDS patients.

Methods:

In this retrospective study, all adult patients admitted to medical intensive care unit (ICU) with H1N1 viral pneumonia having severe ARDS and requiring prone ventilation as a rescue therapy for severe hypoxemia were reviewed. The patients were considered to turn prone if PaO₂/FiO₂ ratio was <100 cmH₂O and PaCO₂ was >45 cmH₂O; if no progressive improvement was seen in PaO₂/FiO₂ over a period of 4 h, then patients were considered to turn back to supine. Measurements were obtained in supine (baseline) and PPV, after 30–60 min and then 4–6 hourly.

Results:

Eleven adult patients with severe ARDS were ventilated in prone position. Their age range was 26–59 years. The worst PaO₂/FiO₂ ratio range on the day of invasive ventilation was 48–100 (median 79). A total of 39 PPV sessions were done, with a range of 1–8 prone sessions per patient (median three sessions). Out of the 39 PPV sessions, PaO₂/FiO₂ ratio and PaCO₂ responder were 38 (97.4%) and 27 (69.2%) sessions, respectively. The median ICU stay and mechanical ventilation days were 15 (range: 3–26) and 12 (range: 2–22) days, respectively. The common complication observed due to PPV was pressure ulcer. At ICU discharge, all except two patients survived.

Conclusion:

PPV improves oxygenation when started early with adequate duration and should be considered in all severe ARDS cases secondary to H1N1 viral infection.

Provision of Care for Critically Ill Children in Disasters

Children are affected by all types of disasters disproportionately compared with adults. Despite this, planning and readiness to care for children in disasters is suboptimal locally, nationally, and internationally. These planning gaps increase the likelihood that a disaster will have a greater negative impact on children when compared with adults. New voluntary regional coalitions have been developed to fill this gap. Some are pediatric focused or have pediatrics well integrated into the greater coalition. This article discusses key points of pediatric disaster planning, specific vulnerabilities, and the care of children in general and in specific disaster situations.

Corticosteroids as adjunctive therapy in the treatment of influenza

BACKGROUND

Specific treatments for influenza are limited to neuraminidase inhibitors and adamantanes. Corticosteroids show evidence of benefit in sepsis and related conditions, most likely due to their anti-inflammatory and immunomodulatory properties. Although commonly prescribed for severe influenza, there is uncertainty over their potential benefits or harms. This is an update of a review first published in 2016.

OBJECTIVES

To systematically assess the effectiveness and potential adverse effects of corticosteroids as adjunctive therapy in the treatment of influenza, taking into account differences in timing and doses of corticosteroids.

SEARCH METHODS

We searched CENTRAL (2018, Issue 9), which includes the Cochrane Acute Respiratory infections Group's Specialised Register, MEDLINE (1946 to October week 1, 2018), Embase (1980 to 3 October 2018), CINAHL (1981 to 3 October 2018), LILACS (1982 to 3 October 2018), Web of Science (1985 to 3 October 2018), abstracts from the last three years of major infectious disease and microbiology conferences, and references of included articles. We also searched the World Health Organization International Clinical Trials Registry Platform, ClinicalTrials.gov, and the ISRCTN registry on 3 October 2018.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), quasi-RCTs, and observational studies that compared corticosteroid treatment with no corticosteroid treatment for influenza or influenza-like illness. We did not restrict studies by language of publication, influenza subtypes, clinical setting, or age of participants. We selected eligible studies in two stages: sequential examination of title and abstract, followed by full text.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. We pooled estimates of effect using a random-effects model, where appropriate. We assessed heterogeneity using the I² statistic and assessed the certainty of the evidence using the GRADE framework.

MAIN RESULTS

This updated review includes 30 studies (one RCT with two arms and 29 observational studies) with a total of 99,224 participants. We included 19 studies in the original review (n = 3459), all of which were observational, with 13 studies included in the meta-analysis for mortality. We included 12 new studies in this update (one RCT and 11 observational studies), and excluded one study in the original review as it has been superceded by a more recent analysis. Twenty-one studies were included in the meta-analysis (9536 individuals), of which 15 studied people infected with 2009 influenza A H1N1 virus (H1N1pdm09). Data specific to mortality were of very low quality, based predominantly on observational studies, with inconsistent reporting of variables potentially associated with the outcomes of interest, differences between studies in the way in which they were conducted, and with the likelihood of potential confounding by indication. Reported doses of corticosteroids used were high, and indications for their use were not well reported. On meta-analysis, corticosteroid therapy was associated with increased mortality (odds ratio (OR) 3.90, 95% confidence interval (CI) 2.31 to 6.60; I² = 68%; 15 studies). A similar increase in risk of mortality was seen in a stratified analysis of studies reporting adjusted estimates (OR 2.23, 95% CI 1.54 to 3.24; I² = 0%; 5 studies). An association between corticosteroid therapy and increased mortality was also seen on pooled analysis of six studies which reported adjusted hazard ratios (HRs) (HR 1.49, 95% CI 1.09 to 2.02; I² = 69%). Increased odds of hospital-acquired infection related to corticosteroid therapy were found on pooled analysis of seven studies (pooled OR 2.74, 95% CI 1.51 to 4.95; I² = 90%); all were unadjusted estimates, and we graded the data as of very low certainty.

AUTHORS' CONCLUSIONS

We found one RCT of adjunctive corticosteroid therapy for treating people with community-acquired pneumonia, but the number of people with laboratory-confirmed influenza in the treatment and placebo arms was too small to draw conclusions regarding the effect of corticosteroids in this group, and we did not include it in our meta-analyses of observational studies. The certainty of the available evidence from observational studies was very low, with confounding by indication a major potential concern. Although we found that adjunctive corticosteroid therapy is associated with increased mortality, this result should be interpreted with caution. In the context of clinical trials of adjunctive corticosteroid therapy in sepsis and pneumonia that report improved outcomes, including decreased mortality, more high-quality research is needed (both RCTs and observational studies that adjust for confounding by indication). The currently available evidence is insufficient to determine the effectiveness of corticosteroids for people with influenza.

Always ready, always prepared-preparing for the next pandemic

A future global pandemic is likely to occur and planning for the care of critically ill children is less robust than that for adults. This review covers the current state of federal and regional resources for pediatric care in pandemics, a strategy for pandemic preparation in pediatric intensive care units and regions focusing on stuff, space, staff and systems, considerations in developing surge capacity and triage protocols, special circumstances such as highly infectious and highly lethal pandemics, and a discussion of ethics in the setting of pediatric critical care in a pandemic.

Platelets in Immune Response to Virus and Immunopathology of Viral Infections

Platelets are essential effector cells in hemostasis. Aside from their role in coagulation, platelets are now recognized as major inflammatory cells with key roles in the innate and adaptive arms of the immune system. Activated platelets have key thromboinflammatory functions linking coagulation to immune responses in various infections, including in response to virus. Recent studies have revealed that platelets exhibit several pattern recognition receptors (PRR) including those from the toll-like receptor, NOD-like receptor, and C-type lectin receptor family and are first-line sentinels in detecting and responding to pathogens in the vasculature. Here, we review the main mechanisms of platelets interaction with viruses, including their ability to sustain viral infection and replication, their expression of specialized PRR, and activation of thromboinflammatory responses against viruses. Finally, we discuss the role of platelet-derived mediators and platelet interaction with vascular and immune cells in protective and pathophysiologic responses to dengue, influenza, and human immunodeficiency virus 1 infections.

Time required to initiate outbreak and pandemic observational research

PURPOSE

Observational research focused upon emerging infectious diseases such as Ebola virus, Middle East respiratory syndrome, and Zika virus has been challenging to quickly initiate. We aimed to determine the duration of start-up procedures and barriers encountered for an observational study focused upon such infectious outbreaks.

MATERIALS AND METHODS

At 1 pediatric and 5 adult intensive care units, we measured durations from protocol receipt to a variety of outbreak research milestones, including research ethics board (REB) approval, data sharing agreement (DSA) execution, and patient study screening initiation.

RESULTS

The median (interquartile range) time from site receipt of the protocol to REB submission was 73 (30-126) days; to REB approval, 158 (42-188) days; to DSA completion, 276 (186-312) days; and to study screening initiation, 293 (269-391) days. The median time from REB submission to REB approval was 43 (13-85) days. The median time for all start-up procedures was 335 (188-335) days.

CONCLUSIONS

There is a lengthy start-up period required for outbreak-focused research. Completing DSAs was the most time-consuming step. A reactive approach to newly emerging threats such as Ebola virus, Middle East respiratory syndrome, and Zika virus will likely not allow sufficient time to initiate research before most outbreaks are advanced.