Impact of respiratory viruses in hospital-acquired pneumonia in the intensive care unit: A single-center retrospective study

HAP-FAST: a feasibility study incorporating qualitative, mechanistic and costing sub-studies alongside a randomised pilot trial comparing chest x-ray to low-dose CT scan and empirical antibiotics to antibiotics guided by the BIOFIRE® FILM ARRAY® pneumonia plus panel in adults with suspected non-ventilator-associated hospital-cquired pneumonia

INTRODUCTION

Non-ventilator-associated hospital-acquired pneumonia (nv-HAP) is the most common healthcare-associated infection (HCAI), is associated with high mortality and morbidity and places a major burden on healthcare systems. Diagnosis currently relies on chest x-rays to confirm pneumonia and sputum cultures to determine the microbiological cause. This approach leads to over-diagnosis of pneumonia, rarely identifies a causative pathogen and perpetuates unnecessary and imprecise antibiotic use. The HAP-FAST study aims to evaluate the feasibility of a randomised trial to evaluate the clinical impact of low-dose, non-contrast-enhanced thoracic CT scans and rapid molecular sputum analysis using the BIOFIRE® FILMARRAY® pneumonia plus panel (FAPP) for patients suspected with nv-HAP.

METHODS AND ANALYSIS

The HAP-FAST feasibility study consists of a pilot randomised trial, a qualitative study, a costing analysis and exploratory analyses of clinical samples to investigate the immune-pathophysiology of HAP. Participants are identified and recruited from four acute hospitals in the Northwest of the UK. Using a Research Without Prior Consent model, the pilot trial will recruit 220 adult participants, with or without mental capacity, and with suspected HAP. HAP-FAST is a non-blinded, sequential, multiple assignment, randomised trial with two possible stages of randomisation: first, chest x-ray (CXR) or CT; second, if treated as nv-HAP, FAPP or standard microbiological processing alone (no FAPP). Pathogen-specific antibiotic guidance will be provided for FAPP results. Randomisation uses a web-based platform and followed up for 90 days. The feasibility of a future trial will be determined by assessing trial processes, outcome measures and patient and staff experiences.

ETHICS AND DISSEMINATION

This study has undergone combined review by the UK NHS Research Ethics Committee and Health Research Authority. Results will be disseminated via peer-reviewed journals, via the funders' website and through a range of media to engage the public.

TRIAL REGISTRATION NUMBER

NCT05483309.

Viral Pneumonia: From Influenza to COVID-19

Respiratory viruses are increasingly recognized as a cause of community-acquired pneumonia (CAP). The implementation of new diagnostic technologies has facilitated their identification, especially in vulnerable population such as immunocompromised and elderly patients and those with severe cases of pneumonia. In terms of severity and outcomes, viral pneumonia caused by influenza viruses appears similar to that caused by non-influenza viruses. Although several respiratory viruses may cause CAP, antiviral therapy is available only in cases of CAP caused by influenza virus or respiratory syncytial virus. Currently, evidence-based supportive care is key to managing severe viral pneumonia. We discuss the evidence surrounding epidemiology, diagnosis, management, treatment, and prevention of viral pneumonia.

Impact of Multiplex PCR in the Therapeutic Management of Severe Bacterial Pneumonia

Pneumonia is a common and severe illness that requires prompt and effective management. Advanced, rapid, and accurate tools are needed to diagnose patients with severe bacterial pneumonia, and to rapidly select appropriate antimicrobial therapy, which must be initiated within the first few hours of care. Two multiplex molecular tests, Unyvero HPN and FilmArray Pneumonia+ Panel, have been developed using the multiplex polymerase chain reaction (mPCR) technique to rapidly identify pathogens and their main antibiotic resistance mechanisms from patient respiratory specimens. Performance evaluation of these tests showed strong correlations with reference techniques. However, good knowledge of their indications, targets, and limitations is essential. Collaboration with microbiologists is, therefore, crucial for their appropriate use. Under these conditions, and with standardized management, these rapid tests can improve the therapeutic management of severe pneumonia faster, more precisely, and with narrow-spectrum antibiotic therapy. Further randomized controlled trials are needed to address the many unanswered questions about multiplex rapid molecular testing during the diagnosis and the management of severe pneumonia. This narrative review will address the current knowledge, advantages, and disadvantages of these tests, and propose solutions for their routine use.

Severe Parainfluenza Viral Infection-A Retrospective Study of Adult Intensive Care Patients

There is little known about parainfluenza virus (PIV) infection in adult intensive care unit (ICU) patients. Here, we aim to describe the characteristics, clinical course and outcomes of PIV infection in adults requiring intensive care. In this retrospective study of consecutive patients admitted to our ICU with confirmed PIV infection over a 7-year period, we report the patient characteristics, laboratory tests and prognostic scores on ICU admission. The main outcomes reported are 30-day mortality and organ support required. We included 50 patients (52% male, mean age 67.6 years). The mean PaO2/FiO2 and neutrophil/lymphocyte ratios on ICU admission were 198 ± 82 mmHg and 15.7 ± 12.5. Overall, 98% of patients required respiratory support and 24% required cardiovascular support. The median length of ICU stay was 5.9 days (IQR 3.7-9.1) with a 30-day mortality of 40%. In conclusion, PIV infection in adult ICU patients is associated with significant mortality and morbidity. There were significant differences between patients who presented with primary hypoxemic respiratory failure and hypercapnic respiratory failure.

Society of Critical Care Medicine and the Infectious Diseases Society of America Guidelines for Evaluating New Fever in Adult Patients in the ICU

RATIONALE

Fever is frequently an early indicator of infection and often requires rigorous diagnostic evaluation.

OBJECTIVES

This is an update of the 2008 Infectious Diseases Society of America and Society (IDSA) and Society of Critical Care Medicine (SCCM) guideline for the evaluation of new-onset fever in adult ICU patients without severe immunocompromise, now using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology.

PANEL DESIGN

The SCCM and IDSA convened a taskforce to update the 2008 version of the guideline for the evaluation of new fever in critically ill adult patients, which included expert clinicians as well as methodologists from the Guidelines in Intensive Care, Development and Evaluation Group. The guidelines committee consisted of 12 experts in critical care, infectious diseases, clinical microbiology, organ transplantation, public health, clinical research, and health policy and administration. All task force members followed all conflict-of-interest procedures as documented in the American College of Critical Care Medicine/SCCM Standard Operating Procedures Manual and the IDSA. There was no industry input or funding to produce this guideline.

METHODS

We conducted a systematic review for each population, intervention, comparison, and outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the GRADE approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak or as best-practice statements.

RESULTS

The panel issued 12 recommendations and 9 best practice statements. The panel recommended using central temperature monitoring methods, including thermistors for pulmonary artery catheters, bladder catheters, or esophageal balloon thermistors when these devices are in place or accurate temperature measurements are critical for diagnosis and management. For patients without these devices in place, oral or rectal temperatures over other temperature measurement methods that are less reliable such as axillary or tympanic membrane temperatures, noninvasive temporal artery thermometers, or chemical dot thermometers were recommended. Imaging studies including ultrasonography were recommended in addition to microbiological evaluation using rapid diagnostic testing strategies. Biomarkers were recommended to assist in guiding the discontinuation of antimicrobial therapy. All recommendations issued were weak based on the quality of data.

CONCLUSIONS

The guidelines panel was able to formulate several recommendations for the evaluation of new fever in a critically ill adult patient, acknowledging that most recommendations were based on weak evidence. This highlights the need for the rapid advancement of research in all aspects of this issue-including better noninvasive methods to measure core body temperature, the use of diagnostic imaging, advances in microbiology including molecular testing, and the use of biomarkers.

Respiratory Viruses in Nosocomial Pneumonia: An Evolving Paradigm

Nosocomial pneumonia (NP) represents a leading cause of morbidity and mortality in hospitalized patients. Historically, clinicians have considered hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), which comprise NP, to be essentially bacterial processes. As such, patients suspected of having either HAP or VAP are initially treated with broad-spectrum antibiotics, and few clinicians search for a possible culprit virus. Recent reports which build on earlier studies, however, indicate that viruses likely play an important role in NP. Studies employing viral diagnostics as part of the evaluation for NP indicate that common respiratory viruses can spread nosocomially and lead to HAP and VAP. Similarly, studies of the general epidemiology of respiratory viral infections, such as influenza, respiratory syncytial virus, adenovirus, and rhinovirus, confirm that these pathogens are important causes of NP, especially among immunosuppressed and pediatric patients. More importantly, these more contemporary analyses reveal that one cannot, based on clinical characteristics, distinguish a viral from a bacterial cause of NP. Additionally, viral HAP and VAP result in crude mortality rates that rival or exceed those reported in bacterial NP. Rigorous prospective, multicenter trials are needed to confirm the significance of respiratory viruses in NP, as are studies of novel therapeutics for these viral infections.

The importance of viruses in ventilator-associated pneumonia

OBJECTIVE

Ventilator-associated pneumonia (VAP) remains a challenge. The importance of viruses in VAP is not established. We sought to determine the prevalence of viruses in VAP and the outcomes of viral VAP.

DESIGN

Retrospective study of VAP over 3 years. The frequency of a viral process represented the primary endpoint. Clinical outcomes served as secondary endpoints. We identified variables independently associated with a virus and conducted sensitivity analyses to assess the interaction between type of infection and patient characteristics.

SETTING

Tertiary-care referral center.

PATIENTS

The final cohort consisted of 710 patients and a virus was isolated in 5.1%.

INTERVENTIONS

None.

RESULTS

The most common viruses included: rhinovirus, influenza A, and cytomegalovirus. Baseline characteristics were similar between those with and without viral infections. In logistic regression, immunosuppression (adjusted odds ratio [aOR], 2.97; 95% confidence interval [CI], 1.44-6.14) and stem-cell transplantation (SCT, aOR, 3.58; 95% CI, 1.17-10.99) were independently associated with a virus. The presence of either variable performed poorly as a screening test for a virus. In-hospital (22.4% vs 21.6%; P = .869) and 30-day (32.8% vs 27.9%; P = .448) mortality rates were similar between the cohorts, respectively. Sensitivity analyses restricted to patients without a mixed viral and bacterial infection or those who were immunocompetent yielded similar results.

CONCLUSION

Although infrequent, a range of viruses may cause VAP. Viruses more often complicate SCT and immunosuppression, but one can isolate viruses in immunocompetent subjects. Viral VAP produces severe infection and results in high mortality rates. Clinical features do not differentiate viral from nonviral VAP.

Impact of Enhanced in-Hospital Infection Prevention During the COVID-19 Pandemic on Postoperative Pneumonia in Older Surgical Patients

Purpose

We aimed to investigate the impact of enhanced in-hospital infection prevention during the coronavirus disease 2019 (COVID-19) pandemic on postoperative pneumonia in older surgical patients.

Patients and Methods

We retrospectively reviewed the electronic medical records of consecutive patients ≥70 years who underwent elective surgery between 2017 and 2021 at our institution. All perioperative variables were retrieved from the electronic medical records. The primary outcome was new-onset postoperative pneumonia during the hospitalization period. Since February 2020, our institution implemented a series of policies to enhance infection prevention, hence patients were divided into groups according to whether they underwent surgery before or during the COVID-19 pandemic. An interrupted time series analysis was performed to evaluate the difference between pre- and post-intervention slopes of the primary outcome.

Results

Among the 29,387 patients included in the study, 10,547 patients underwent surgery during the COVID-19 pandemic. Although there was a decreasing trend of the monthly incidence rate of postoperative pneumonia compared to before the COVID-19 pandemic, there was no statistical significance in the trend (slope before COVID-19 period: β-coefficient, -0.007; 95% CI, -0.022 to 0.007).

Conclusion

Our study revealed that enhanced in-hospital infection prevention implemented to manage the COVID-19 pandemic did not significantly affect the decreasing trend of postoperative pneumonia at our institution.

Ultra-Short-Course Antibiotics for Suspected Pneumonia With Preserved Oxygenation

BACKGROUND

Suspected pneumonia is the most common indication for antibiotics in hospitalized patients but is frequently overdiagnosed. We explored whether normal oxygenation could be used as an indicator to support early discontinuation of antibiotics.

METHODS

We retrospectively identified all patients started on antibiotics for pneumonia in 4 hospitals with oxygen saturations ≥95% on ambient air, May 2017-February 2021. We propensity-matched patients treated 1-2 days vs 5-8 days and compared hospital mortality and time to discharge using subdistribution hazard ratios (SHRs). Secondary outcomes included readmissions, 30-day mortality, Clostridioides difficile infections, hospital-free days, and antibiotic-free days.

RESULTS

Among 39 752 patients treated for possible pneumonia, 10 012 had median oxygen saturations ≥95% without supplemental oxygen. Of these, 2871 were treated 1-2 days and 2891 for 5-8 days; 4478 patients were propensity-matched. Patients treated 1-2 vs 5-8 days had similar hospital mortality (2.1% vs 2.8%; SHR, 0.75 [95% confidence interval {CI}, .51-1.09]) but less time to discharge (6.1 vs 6.6 days; SHR, 1.13 [95% CI, 1.07-1.19]) and more 30-day hospital-free days (23.1 vs 22.7; mean difference, 0.44 [95% CI, .09-.78]). There were no significant differences in 30-day readmissions (16.0% vs 15.8%; odds ratio [OR], 1.01 [95% CI, .86-1.19]), 30-day mortality (4.6% vs 5.1%; OR, 0.91 [95% CI, .69-1.19]), or 90-day C. difficile infections (1.3% vs 0.8%; OR, 1.67 [95% CI, .94-2.99]).

CONCLUSIONS

One-quarter of hospitalized patients treated for pneumonia had oxygenation saturations ≥95% on ambient air. Outcomes were similar with 1-2 vs 5-8 days of antibiotics. Normal oxygenation levels may help identify candidates for early antibiotic discontinuation. Prospective trials are warranted.

Respiratory viruses: their importance and lessons learned from COVID-19

Respiratory virus infection can cause severe illnesses capable of inducing acute respiratory failure that can progress rapidly to acute respiratory distress syndrome (ARDS). ARDS is related to poor outcomes, especially in individuals with a higher risk of infection, such as the elderly and those with comorbidities, i.e. obesity, asthma, diabetes mellitus and chronic respiratory or cardiovascular disease. Despite this, effective antiviral treatments available for severe viral lung infections are scarce. The coronavirus disease 2019 (COVID-19) pandemic demonstrated that there is also a need to understand the role of airborne transmission of respiratory viruses. Robust evidence supporting this exists, but better comprehension could help implement adequate measures to mitigate respiratory viral infections. In severe viral lung infections, early diagnosis, risk stratification and prognosis are essential in managing patients. Biomarkers can provide reliable, timely and accessible information possibly helpful for clinicians in managing severe lung viral infections. Although respiratory viruses highly impact global health, more research is needed to improve care and prognosis of severe lung viral infections. In this review, we discuss the epidemiology, diagnosis, clinical characteristics, management and prognosis of patients with severe infections due to respiratory viruses.

PCR-based diagnosis of respiratory virus in postsurgical septic patients: A preliminary study before SARS-CoV-2 pandemic

Respiratory viruses are part of the normal microbiota of the respiratory tract, which sometimes cause infection with/without respiratory insufficiency and the need for hospital or ICU admission. The aim of this study is to determine the prevalence of respiratory viruses in nontransplanted postoperative septic patients as well as lymphocyte count influence in their presence and its relationship to mortality. 223 nontransplanted postsurgical septic patients were recruited on the Intensive Care Unit (ICU) at Hospital Clínico Universitario de Valladolid prior to the SARS-COV-2 pandemic. Patients were split into 2 groups according to the presence/absence of respiratory viruses. Multivariate logistic regression analysis was used to identify independent factors related to positive respiratory virus PCR test. Respiratory viruses were isolated in 28.7% of patients. 28-day mortality was not significantly different between virus-positive and virus-negative groups. Logistic regression analysis revealed that lymphocyte count ≤ 928/µl is independently associated with a positive PCR result [OR 3.76, 95% CI (1.71-8.26), P = .001] adjusted by platelet count over 128,500/µL [OR 4.27, 95% CI (1.92-9.50) P < .001] and the presence of hypertension [OR 2.69, 95% CI (1.13-6.36) P = .025] as confounding variables. Respiratory viruses' detection by using PCR in respiratory samples of nontransplanted postoperative septic patients is frequent. These preliminary results revealed that the presence of lymphopenia on sepsis diagnosis is independently associated to a positive virus result, which is not related to a higher 28-day mortality.

Correlation between Platelet miRNA Expression and Coagulation Function in Children with Severe Pneumonia

Objective

To investigate the relationship between expression levels of platelet miRNAs and severe pneumonia (SP) in children.

Methods

A randomized controlled trial was conducted in 129 children with SP hospitalized from May 2018 to May 2020. All children joined the study group and were divided into the mild infection group, moderate infection group, and severe infection group according to the diagnostic criteria, 43 cases in each group. Besides, 129 healthy children were selected as the control group. The expression levels of platelet miR-223 and miR-192 were detected by real-time quantitative polymerase chain reaction (qPCR). The prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (FIB) were detected by the Sysmex CA-1500 System (Sysmex Corporation, Japan). The Pearson analysis was conducted to evaluate the correlation between coagulation function and the levels of miR-223 and miR-192.

Results

Compared with the control group, miR-223 in the study group was significantly higher and miR-192 was significantly lower (P < 0.05). Compared with the mild infection group, miR-223 was significantly higher and miR-192 was significantly lower in the moderate infection group and severe infection group (P < 0.05). Compared with the control group, PT and APTT were significantly lower and FIB was significantly higher in the study group (P < 0.05). Pearson correlation analysis revealed that miR-223 was positively correlated with PT and APTT (P < 0.05) and negatively correlated with FIB (P < 0.05); miR-192 was negatively correlated with PT and APTT (P < 0.05) and positively correlated with FIB (P < 0.05).

Conclusion

miR-223 and miR-192 can reflect coagulation function in children with SP, which can provide a certain reference basis for clinical guidance and treatment and prognosis.

Healthcare-associated infections in adult intensive care unit patients: Changes in epidemiology, diagnosis, prevention and contributions of new technologies

Patients in intensive care units (ICUs) are at high risk for healthcare-acquired infections (HAI) due to the high prevalence of invasive procedures and devices, induced immunosuppression, comorbidity, frailty and increased age. Over the past decade we have seen a successful reduction in the incidence of HAI related to invasive procedures and devices. However, the rate of ICU-acquired infections remains high. Within this context, the ongoing emergence of new pathogens, further complicates treatment and threatens patient outcomes. Additionally, the SARS-CoV-2 (COVID-19) pandemic highlighted the challenge that an emerging pathogen provides in adapting prevention measures regarding both the risk of exposure to caregivers and the need to maintain quality of care. ICU nurses hold a special place in the prevention and management of HAI as they are involved in basic hygienic care, steering and implementing quality improvement initiatives, correct microbiological sampling, and aspects antibiotic stewardship. The emergence of more sensitive microbiological techniques and our increased knowledge about interactions between critically ill patients and their microbiota are leading us to rethink how we define HAIs and best strategies to diagnose, treat and prevent these infections in the ICU. This multidisciplinary expert review, focused on the ICU setting, will summarise the recent epidemiology of ICU-HAI, discuss the place of modern microbiological techniques in their diagnosis, review operational and epidemiological definitions and redefine the place of several controversial preventive measures including antimicrobial-impregnated medical devices, chlorhexidine-impregnated washcloths, catheter dressings and chlorhexidine-based mouthwashes. Finally, general guidance is suggested that may reduce HAI incidence and especially outbreaks in ICUs.

Epidemiologic Characteristics and Clinical Significance of Respiratory Viral Infections Among Adult Patients Admitted to the Intensive Care Unit

Background

The diagnosis of respiratory viral infections (RVIs) in critically ill patients is important for determining treatment options and adhering to infection-control protocols. However, data on the incidence and occurrence patterns of RVIs are scarce. We investigated the epidemiology and clinical impact of RVIs in critically ill patients.

Methods

This retrospective observational study was conducted in a tertiary hospital in South Korea between November 2014 and September 2020. Adult patients (≥ 18 years of age) who tested positive for an RVI by multiplex polymerase chain reaction (mPCR) and were admitted to the intensive care unit (ICU) were included in the study. Clinical characteristics and outcomes were obtained by reviewing electronic medical records. Pearson's χ2 test and Fisher's exact test, Mann-Whitney U test was used to compare between groups of patients. Trend analysis and the χ2-based Q test was used to analyze test behavior of physicians performing mPCR test.

Results

Among 22,517 patients admitted to the ICU during the study period, 2,222 (9.9%) underwent mPCR testing for an RVI. The median timing of mPCR testing after ICU admission was 1 day (IQR, 0-2). A total of 335 (15.1%) non-duplicative RVI-positive cases were included in the analysis. The incidence rate of RVIs in ICU patients was 30.45 per 10,000 patient-days. The most frequently detected RVI was influenza A (27.8%), followed by rhinovirus (25.4%). Thirty-two (9.6%) RVI-positive patients were diagnosed with upper respiratory infections, 193 (64.1%) with community-acquired, and 108 (35.9%) with hospital-acquired pneumonia. All-cause mortality and mortality related to respiratory tract infection (RTI) were 30.7% and 22.1%, respectively. The initial presentation of septic shock, requirement for mechanical ventilation, and lymphocytopenia were significant predictors of RTI-related mortality. Of the RVI-positive patients, 151 (45.1%) had nonviral coinfections and presented with higher clinical severity and longer hospital stays than patients infected solely with viral pathogens.

Conclusion

The incidence of RVIs in ICU patients is common. ICU patients with RVIs had high mortality and frequently presented with coinfections with nonviral pathogens, which were associated with a higher clinical severity than sole RVI. Increased testing for RVIs will enhance infection-control efforts and improve patient care.

Ventilator-associated pneumonia in critically ill patients with COVID-19 infection, a narrative review

COVID pneumonitis can cause patients to become critically ill. They may require intensive care and mechanical ventilation. Ventilator-associated pneumonia is a concern. This review aims to discuss the topic of ventilator-associated pneumonia in this group. Several reasons have been proposed to explain the elevated rates of VAP in critically ill COVID patients compared to non-COVID patients. Extrinsic factors include understaffing, lack of PPE and use of immunomodulating agents. Intrinsic factors include severe parenchymal damage, immune dysregulation, along with pulmonary vascular endothelial inflammation and thrombosis. The rate of VAP has been reported at 45.4%, with an ICU mortality rate of 42.7%. Multiple challenges to diagnosis exist. Other conditions such as acute respiratory distress syndrome, pulmonary oedema and atelectasis can present with similar features. Frequent growth of gram-negative bacteria has been shown in multiple studies, with particularly high rates of pseudomonas aeruginosa. The rate of invasive pulmonary aspergillosis has been reported at 4–30%. We would recommend the use of invasive techniques when possible. This will enable de-escalation of antibiotics as soon as possible, decreasing overuse. It is also important to keep other possible causes of ventilator-associated pneumonia in mind, such as COVID-19 associated pulmonary aspergillosis, cytomegalovirus, etc. Diagnostic tests such as galactomannan and B-D-glucan should be considered. These patients may face a long treatment course, with risk of re-infection, along with prolonged weaning, which carries its own long-term consequences.

Severe COVID‐19 pneumonia in an intensive care setting and comparisons with historic severe viral pneumonia due to other viruses

Purpose

Severe viral pneumonia is associated with significant morbidity and mortality. Recent COVID‐19 pandemic continues to impose significant health burden worldwide, and individual pandemic waves often lead to a large surge in the intensive care unit (ICU) admissions for respiratory support. Comparisons of severe SARS‐CoV‐2 pneumonia with other seasonal and nonseasonal severe viral infections are rarely studied in an intensive care setting.

Methods

A retrospective cohort study comparing patients admitted to ICU with COVID‐19 between March and June 2020 and those with viral pneumonias between January and December 2019. We compared patient specific demographic variables, duration of illness, ICU organ supportive measures and outcomes between both groups.

Results

Analysis of 93 COVID‐19 (Group 1) and 52 other viral pneumonia patients (Group 2) showed an increased proportion of obesity (42% vs. 23%, p = 0.02), non‐White ethnicities (41% vs. 6%, p < 0.001) and diabetes mellitus (30% vs. 13%, p = 0.03) in Group 1, with lower prevalence of chronic obstructive pulmonary disease (COPD)/asthma (16% vs. 34%, p = 0.02). In Group 1, the neutrophil to lymphocyte ratio was much lower (6.7 vs. 10, p = 0.006), and invasive mechanical ventilation (58% vs. 26%, p < 0.001) was more common. Length of ICU (8 vs. 4, p < 0.001) and hospital stay (22 vs. 11, p < 0.001) was prolonged in Group 1, with no significant difference in mortality. Influenza A and rhinovirus were the most common pathogens in Group 2 (26% each).

Conclusions

Key differences were identified within demographics (obesity, ethnicity, age, ICU scores, comorbidities) and organ support. Despite these variations, there were no significant differences in mortality between both groups. Further studies with larger sample sizes would allow for further assessment of clinical parameters in these patients.

How common is ventilator-associated pneumonia after coronavirus disease 2019?

PURPOSE OF REVIEW

The first studies on COVID-19 patients with acute respiratory distress syndrome (ARDS) described a high rate of secondary bacterial ventilator-associated pneumonia (VAP). The specificity of VAP diagnoses in these patients are reviewed, including their actual rate.

RECENT FINDINGS

Published studies described high rates of bacterial VAP among COVID-19 patients with ARDS, and these VAP episodes are usually severe and of specifically poor prognosis with high mortality. Indeed, Severe acute respiratory syndrome - coronavirus disease 19 (SARS-CoV2) infection elicits alterations that may explain a high risk of VAP. In addition, breaches in the aseptic management of patients might have occurred when the burden of care was heavy. In addition, VAP in these patients is more frequently suspected, and more often investigated with diagnostic tools based on molecular techniques.

SUMMARY

VAP is frequented and of particularly poor prognosis in COVID-19 patients with ARDS. It can be explained by SARS-CoV-2 pathophysiology, and also breaches in the aseptic procedures. In addition, tools based on molecular techniques allow an early diagnosis and unmask VAP usually underdiagnosed by traditional culture-based methods. The impact of molecular technique-based diagnostics in improving antibacterial therapy and COVID-19 prognosis remain to be evaluated.

Rhinoviruses: molecular diversity and clinical characteristics

BACKGROUND

Rhinoviruses are commonly considered simple "common cold" agents. The link between their molecular epidemiology and patient clinical presentation and outcomes remains unclear in adult populations.

MATERIALS/METHODS

All nasopharyngeal or bronchoalveolar lavages were screened using multiplex PCR in three Parisian hospitals from January to September 2018. For all detected rhinoviruses, the VP2/VP4 region was subtyped by sequencing.

RESULTS

The study included 178 human rhinovirus (HRV) positive unique patients. They were primarily male (56%), with a median age of 62.2 [IQR: 46.8-71.4], frequently presenting chronic respiratory diseases (56%) and/or immunosuppression (46%). Of these, 63% were admitted for respiratory distress, including pneumonia for 25%; 95 (53%), 27 (15%), and 56 (32%) were positive for HRV-A, -B, and -C, respectively. HRV-B appeared more associated with immunosuppressive treatments (58% vs. 30% and 36% of patients for HRV-A and -C, respectively, p = 0.038), higher coinfection rates (54% vs. 34% and 23%, p = 0.03), and higher ICU admission rates (35% vs. 17% and 13%, p = 0.048). Conversely, HRV-A was more frequently associated with pneumonia (54% vs. 31% and 11% for HRV-B and -C, respectively, p = 0.01).

CONCLUSIONS

This study highlights the high proportion of chronic respiratory diseases or immunosuppression among hospitalized patients infected with a rhinovirus.

Severe Infections Due to Respiratory Viruses

Severe viral infections may result in severe illnesses capable of causing acute respiratory failure that could progress rapidly to acute respiratory distress syndrome (ARDS), related to worse outcomes, especially in individuals with a higher risk of infection, including the elderly and those with comorbidities such as asthma, diabetes mellitus and chronic respiratory or cardiovascular disease. In addition, in cases of severe viral pneumonia, co-infection with bacteria such as Streptococcus pneumoniae and Staphylococcus aureus is related to worse outcomes. Respiratory viruses like influenza, rhinovirus, parainfluenza, adenovirus, metapneumovirus, respiratory syncytial virus, and coronavirus have increasingly been detected. This trend has become more prevalent, especially in critically ill patients, due to the availability and implementation of molecular assays in clinical practice. Respiratory viruses have been diagnosed as a frequent cause of severe pneumonia, including cases of community-acquired pneumonia, hospital-acquired pneumonia, and ventilator-associated pneumonia. In this review, we will discuss the epidemiology, diagnosis, clinical characteristics, management, and prognosis of patients with severe infections due to respiratory viruses, with a focus on influenza viruses, non-influenza viruses, and coronaviruses.

Viral Ventilator-Associated Pneumonia/Hospital-Acquired Pneumonia

Among the viruses possibly responsible for hospital-acquired and ventilator-associated pneumonia, herpes simplex virus (HSV) is probably the most often involved: HSV reactivation is frequent in intensive care unit patients, and lung parenchymal infection (HSV bronchopneumonitis) has been well described, either using cytological signs of parenchymal involvement in cells obtained during bronchoalveolar lavage or using HSV virus load in the lower respiratory tract. Although treating patients with HSV bronchopneumonitis may be recommended, based on expert opinion, prophylactic or preemptive treatment of HSV reactivation should be avoided. Ventilator-associated pneumonia due to cytomegalovirus (CMV) is less frequent than HSV bronchopneumonitis, and more difficult to diagnose. No data exists on the impact of antiviral treatment on CMV pneumonia. The involvement of respiratory viruses has been described in patients with healthcare-associated pneumonia and hospital-acquired pneumonia, but their role in ventilator-associated pneumonia is not clear.

"HAP and VAP after Guidelines"

Nosocomial pneumonia is associated with worsened prognosis when diagnosed in intensive care unit (ICU), ranging from 12 to 48% mortality. The incidence rate of ventilation-acquired pneumonia tends to decrease below 15/1,000 intubation-day. Still, international guidelines are heterogeneous about diagnostic criteria because of inaccuracy of available methods. New entities have thus emerged concerning lower respiratory tract infection, namely ventilation-acquired tracheobronchitis (VAT), or ICU-acquired pneumonia (ICUAP), eventually requiring invasive ventilation (v-ICUAP), according to the type of ventilation support. The potential discrepancy with non-invasive methods could finally lead to underdiagnosis in almost two-thirds of non-intubated patients. Delayed diagnostic could explain in part the 2-fold increase in mortality of penumonia when invasive ventilation is initiated. Here we discuss the rationale underlying this new classification.Many situations can lead to misdiagnosis, even more when the invasive mechanical ventilation is initiated. The chest radiography lacks sntivity and specificity for diagnosing pneumonia. The place of chest computed tomography and lung ultrasonography for routine diagnostic of new plumonary infiltrate remain to be evaluated.Microbiological methods used to confirm the diagnostic can be heterogeneous. The development of molecular diagnostic tools may improve the adequacy of antimicrobial therapies of ventilated patients with pneumonia, but we need to further assess its impact in non-ventilated pneumonia.In this review we introduce distinction between hospital-acquired pneumonia according to the localization in the hospital and the oxygenation/ventilation mode. A clarification of definition is the first step to develop more accurate diagnostic strategies and to improve the patients' prognosis.

Place des virus respiratoires dans les pneumonies aiguës communautaires de l'adulte : quels changements depuis la Covid-19 ?

L’émergence du SARS-CoV-2 a renforcé l'intérêt pour la place des virus respiratoires, dans les pneumonies aiguës communautaires, en mettant en exergue de nombreux points encore mal connus tels que la part des infections asymptomatiques, les interactions entre virus respiratoires et pathogènes non viraux, leurs périodes d'incubation, leur pathogénicité ou encore la durée d'excrétion variable.

La présentation clinique et radiologique des pneumonies aiguës communautaires ne permet pas toujours de distinguer l'origine virale de l'origine bactérienne.

L'absence de réelle conséquence thérapeutique semble un frein à l'utilisation des PCR multiplex dans la pratique quotidienne. Toutefois, l'amélioration en termes de délai de rendu des résultats et du nombre de pathogènes inclus dans les panels, ainsi que l'accumulation récente de données épidémiologiques et cliniques, devraient aider à rationaliser l'utilisation de ces tests, faciliter l'interprétation de leurs résultats et guider l'utilisation des molécules antivirales en développement.

Respiratory viral infections in pragmatically selected adults in intensive care units

Respiratory viruses can be detected in 18.3 to 48.9% of critically ill adults with severe respiratory tract infections (RTIs). The present study aims to assess the clinical significance of respiratory viruses in pragmatically selected adults in medical intensive care unit patients and to identify factors associated with viral respiratory viral tract infections (VRTIs). We conducted a prospective study on critically ill adults with suspected RTIs without recognized respiratory pathogens. Viral cultures with monoclonal antibody identification, in-house real-time polymerase chain reaction (PCR) for influenza virus, and FilmArray respiratory panel were used to detect viral pathogens. Multivariable logistic regression was applied to identify factors associated with VRTIs. Sixty-four (40.5%) of the included 158 critically ill adults had respiratory viruses detected in their respiratory specimens. The commonly detected viruses included influenza virus (20), followed by human rhinovirus/enterovirus (11), respiratory syncitial virus (9), human metapneumovirus (9), human parainfluenza viruses (8), human adenovirus (7), and human coronaviruses (2). The FilmArray respiratory panel detected respiratory viruses in 54 (34.6%) patients, but showed negative results for seven of 13 patients with influenza A/H3 infection. In the multivariable logistic regression model, patient characters associated with VRTIs included those aged < 65 years, household contact with individuals with upper RTI, the presence of fever, cough with sputum production, and sore throat. Respiratory viruses were not uncommonly detected in the pragmatically selected adults with critical illness. The application of multiplex PCR testing for respiratory viruses in selected patient population is a practical strategy, and the viral detection rate could be further improved by the patient characters recognized in this study.

New insights and antimicrobial stewardship opportunities in viral pneumonia: five lung ultrasound cases

Background

Antimicrobial stewardship is crucial to avoid antimicrobial resistance in microbes and adverse drug effects in patients. In respiratory infections, however, viral pneumonia is difficult to distinguish from bacterial pneumonia, which explains the overuse of antibiotic therapy in this indication.

Cases

Five cases of lung consolidation are presented. Lung ultrasound, in conjunction with procalcitonin levels, were used to exclude or corroborate bacterial pneumonia.

Conclusion

Lung ultrasound is easy to learn and perform and is helpful in guiding diagnosis in unclear cases of pneumonia and may also offer new insights into the spectrum of certain virus diseases. The use of lung ultrasound can raise awareness in clinicians of the need for antimicrobial stewardship and may help to avoid the unnecessary use of antibiotics.

Supplementary Information

The online version of this article (10.1007/s00508-021-01946-4) contains supplementary material, which is available to authorized users.

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.

Molecular diagnostic methods for pneumonia: how can they be applied in practice?

PURPOSE OF REVIEW

Pneumonia represents a major burden in clinical practice. A rapid etiological diagnosis is critical for optimizing the antibiotic use. Owing to the variety of possible pathogens and the time needed for bacterial cultures or usual polymerase chain reaction (PCR) assays, timely and precise diagnosis is a huge challenge. Several new rapid multiplex assays have been developed in the last decade to resolve these issues. This review aims to provide an overview of recent evidence on improvements and limitations of new rapid molecular assays for pneumonia.

RECENT FINDINGS

Several rapid multiplex-PCR assays are commercially available for upper or lower respiratory tract samples, allowing detection of a wide range of respiratory viruses, bacteria, and, in some cases, of several antibiotic resistance genes. Clinical evaluations demonstrated their good correlation with gold-standard assays but their lack of exhaustiveness, especially for hospital-acquired pneumonia. Studies that evaluated their potential benefits on antibiotic use suffered from important weaknesses with conflicting and limited results.

SUMMARY

New molecular assays may enable improvements in patient management and antibiotic use. Available studies highlight several benefits and the strong interrelations needed between microbiologists and physicians for their implementation and interpretation according to the clinical and epidemiological context.

Associations of influenza, chronic comorbid conditions, and severe maternal morbidity among U.S. pregnant women with influenza at delivery hospitalization, 2000-2015

BACKGROUND

Chronic comorbid conditions increase the risk of influenza-related morbidity. Whether this holds for pregnant women who are at high risk of complications from influenza remains to be determined.

OBJECTIVES

To determine whether chronic comorbid conditions are associated with an increased risk of severe maternal morbidity (SMM) among pregnant women with an influenza diagnosis at delivery hospitalization.

STUDY DESIGN

We performed a cross-sectional analysis of delivery hospitalizations complicated by an influenza diagnosis using the National Inpatient Sample from 2000-2015. We assessed four prevalent chronic comorbid conditions associated with increased influenza-complications outside of pregnancy, obstructive lung disease (asthma and chronic obstructive pulmonary disease [COPD]), chronic hypertension, obesity, and pregestational diabetes, overall and individually. The primary outcome was SMM excluding transfusion as defined by the Centers for Disease Control and Prevention, and secondarily, specific SMM measures recognized as influenza-related complications, acute respiratory distress syndrome (ARDS), mechanical intubation and ventilation, and sepsis and shock. Multivariable survey-weighted log linear models were used, adjusting for patient, hospital, and clinical characteristics.

RESULTS

Of 62.7 million delivery hospitalizations, 0.2% (n=144,572) were complicated by an influenza diagnosis at delivery hospitalization (23 cases of influenza per 10,000 delivery hospitalizations), and 24.9% (n=36,054) with 1 or more chronic comorbid conditions, of which 77.4% included obstructive lung disease. Pregnant women with an influenza diagnosis at delivery hospitalization with a chronic comorbid condition had a slightly higher risk of SMM compared to those without (2.6% vs. 1.7%; adjusted risk ratio (aRR): 1.11; 95% CI: 1.03, 1.21), as well as ARDS (0.9% vs. 0.5%; aRR: 1.42; 95% CI: 1.23, 1.64) and mechanical intubation and ventilation (0.2% vs. 0.1%; aRR: 1.92; 95% CI: 1.37, 2.69), but a lower risk of sepsis and shock (0.2% vs. 0.3%; aRR: 0.57; 95% CI: 0.45, 0.73). Regarding specific conditions, obstructive lung disease was associated with an increased risk of SMM (adjusted risk ratio (aRR): 1.21; 95% CI: 1.11, 1.32), as well as ARDS (aRR: 1.54; 95% CI: 1.32, 1.79) and mechanical intubation and ventilation (aRR: 2.80; 95% CI: 2.00, 3.91). Chronic hypertension was associated with an increased risk of ARDS (aRR: 1.70; 95% CI: 1.16, 2.49), but a lower risk of sepsis and shock (aRR: 0.34; 95% CI: 0.13, 0.85). Obesity was associated with a lower risk of SMM (aRR: 0.84; 95% CI: 0.74, 0.97). Pregestational diabetes was not associated with SMM.

CONCLUSIONS

Among women with a diagnosis of influenza at delivery hospitalization, chronic comorbid conditions may increase the risk of SMM, and in particular, those outcomes related to influenza. These results can inform efforts to increase influenza vaccination for pregnant women with chronic comorbidities.

Outcomes of respiratory viral-bacterial co-infection in adult hospitalized patients

BACKGROUND

Viral infections of the respiratory tract represent a major global health concern. Co-infection with bacteria may contribute to severe disease and increased mortality in patients. Nevertheless, viral-bacterial co-infection patterns and their clinical outcomes have not been well characterized to date. This study aimed to evaluate the clinical features and outcomes of patients with viral-bacterial respiratory tract co-infections.

METHODS

We included 19,361 patients with respiratory infection due to respiratory viruses [influenza A and B, respiratory syncytial virus (RSV), parainfluenza] and/or bacteria in four tertiary hospitals in Hong Kong from 2013 to 2017 using a large territory-wide healthcare database. All microbiological tests were conducted within 48 h of hospital admission. Four etiological groups were included: (1) viral infection alone; (2) bacterial infection alone; (3) laboratory-confirmed viral-bacterial co-infection and (4) clinically suspected viral-bacterial co-infection who were tested positive for respiratory virus and negative for bacteria but had received at least four days of antibiotics. Clinical features and outcomes were recorded for laboratory-confirmed viral-bacterial co-infection patients compared to other three groups as control. The primary outcome was 30-day mortality. Secondary outcomes were intensive care unit (ICU) admission and length of hospital stay. Propensity score matching estimated by binary logistic regression was used to adjust for the potential bias that may affect the association between outcomes and covariates.

FINDINGS

Among 15,906 patients with respiratory viral infection, there were 8451 (53.1%) clinically suspected and 1,087 (6.8%) laboratory-confirmed viral-bacterial co-infection. Among all the bacterial species, Haemophilus influenzae (226/1,087, 20.8%), Pseudomonas aeruginosa (180/1087, 16.6%) and Streptococcus pneumoniae (123/1087, 11.3%) were the three most common bacterial pathogens in the laboratory-confirmed co-infection group. Respiratory viruses co-infected with non-pneumococcal streptococci or methicillin-resistant Staphylococcus aureus was associated with the highest death rate [9/30 (30%) and 13/48 (27.1%), respectively] in this cohort. Compared with other infection groups, patients with laboratory-confirmed co-infection had higher ICU admission rate (p < 0.001) and mortality rate at 30 days (p = 0.028), and these results persisted after adjustment for potential confounders using propensity score matching. Furthermore, patients with laboratory-confirmed co-infection had significantly higher mortality compared to patients with bacterial infection alone.

INTERPRETATION

In our cohort, bacterial co-infection is common in hospitalized patients with viral respiratory tract infection and is associated with higher ICU admission rate and mortality. Therefore, active surveillance for bacterial co-infection and early antibiotic treatment may be required to improve outcomes in patients with respiratory viral infection.

Update in Viral Infections in the Intensive Care Unit

The advent of highly sensitive molecular diagnostic techniques has improved our ability to detect viral pathogens leading to severe and often fatal infections that require admission to the Intensive Care Unit (ICU). Viral infections in the ICU have pleomorphic clinical presentations including pneumonia, acute respiratory distress syndrome, respiratory failure, central or peripheral nervous system manifestations, and viral-induced shock. Besides de novo infections, certain viruses fall into latency and can be reactivated in both immunosuppressed and immunocompetent critically ill patients. Depending on the viral strain, transmission occurs either directly through contact with infectious materials and large droplets, or indirectly through suspended air particles (airborne transmission of droplet nuclei). Many viruses can efficiently spread within hospital environment leading to in-hospital outbreaks, sometimes with high rates of mortality and morbidity, thus infection control measures are of paramount importance. Despite the advances in detecting viral pathogens, limited progress has been made in antiviral treatments, contributing to unexpectedly high rates of unfavorable outcomes. Herein, we review the most updated data on epidemiology, common clinical features, diagnosis, pathogenesis, treatment and prevention of severe community- and hospital-acquired viral infections in the ICU settings.

[Virological diagnosis of lower respiratory tract infections]

INTRODUCTION

The etiological diagnosis of bronchopulmonary infections cannot be assessed with clinical, radiological and epidemiological data alone. Viruses have been demonstrated to cause a large proportion of these infections, both in children and adults.

BACKGROUND

The diagnosis of viral bronchopulmonary infections is based on the analysis of secretions, collected from the lower respiratory tract when possible, by techniques that detect either influenza and respiratory syncytial viruses, or a large panel of viruses that can be responsible for respiratory disease. The latter, called multiplex PCR assays, allow a syndromic approach to respiratory infection. Their high cost for the laboratory raises the question of their place in the management of patients in terms of antibiotic economy and isolation. In the absence of clear recommendations, the strategy and equipment are very unevenly distributed in France.

OUTLOOK

Medico-economic analyses need to be performed in France to evaluate the place of these tests in the management of patients. The evaluation of the role of the different viruses often detected in co-infection, especially in children, also deserves the attention of virologists and clinicians.

CONCLUSIONS

The availability of new diagnostic technologies, the recent emergence of SARS-CoV-2, together with the availability of new antiviral drugs are likely to impact future recommendations for the management of viral bronchopulmonary infections.

Pulmonary infections complicating ARDS

Pulmonary infection is one of the main complications occurring in patients suffering from acute respiratory distress syndrome (ARDS). Besides traditional risk factors, dysregulation of lung immune defenses and microbiota may play an important role in ARDS patients. Prone positioning does not seem to be associated with a higher risk of pulmonary infection. Although bacteria associated with ventilator-associated pneumonia (VAP) in ARDS patients are similar to those in patients without ARDS, atypical pathogens (Aspergillus, herpes simplex virus and cytomegalovirus) may also be responsible for infection in ARDS patients. Diagnosing pulmonary infection in ARDS patients is challenging, and requires a combination of clinical, biological and microbiological criteria. The role of modern tools (e.g., molecular methods, metagenomic sequencing, etc.) remains to be evaluated in this setting. One of the challenges of antimicrobial treatment is antibiotics diffusion into the lungs. Although targeted delivery of antibiotics using nebulization may be interesting, their place in ARDS patients remains to be explored. The use of extracorporeal membrane oxygenation in the most severe patients is associated with a high rate of infection and raises several challenges, diagnostic issues and pharmacokinetics/pharmacodynamics changes being at the top. Prevention of pulmonary infection is a key issue in ARDS patients, but there is no specific measure for these high-risk patients. Reinforcing preventive measures using bundles seems to be the best option.

Respiratory virus-associated infections in HIV-infected adults admitted to the intensive care unit for acute respiratory failure: a 6-year bicenter retrospective study (HIV-VIR study)

Introduction

Acute respiratory failure is the main reason for admission to the intensive care unit (ICU) in HIV-infected adults. There is little data about the epidemiology of respiratory viruses in this population.

Methods

HIV-infected adults admitted to two intensive care units over a 6-year period for an acute respiratory failure and explored for respiratory viruses with multiplex polymerase chain reaction (mPCR) were retrospectively selected. Objectives were to describe the prevalence of respiratory viruses, coinfections with non-viral pathogens, and hospital outcome.

Results

A total of 123 episodes were included. An HIV infection was newly diagnosed in 9% of cases and 72% of the population were on antiretroviral therapy. Real-time mPCR tests identified at least one respiratory virus in the respiratory tract of 33 (27%) patients, but with a non-viral copathogen in two-thirds of cases. Rhinovirus was predominant, documented in 15 patients, followed by Influenza and Respiratory Syncytial Viruses (both n = 6). The prevalence of respiratory virus-associated infection did not vary along with the level of the CD4 T-cell deficiency, except for Rhinovirus which was more prevalent in patients with a CD4 lymphocyte count below 200 cells/µL (n = 13 (20%) vs. n = 2 (4%), p < 0.01). In multivariate analysis, respiratory virus-associated infection was not associated with a worse prognosis.

Conclusions

Viruses are frequently identified in the respiratory tract of HIV-infected patients with acute respiratory failure that requires ICU admission, but with a non-viral copathogen in two-thirds of cases. Rhinovirus is the predominant viral specie; its prevalence is highest in patients with a CD4 lymphocyte count below 200 cells/µL.

Evaluation of the FilmArray® Pneumonia Plus Panel for Rapid Diagnosis of Hospital-Acquired Pneumonia in Intensive Care Unit Patients

The FilmArray^® Pneumonia plus Panel (FAPP) is a new multiplex molecular test for hospital-acquired pneumonia (HAP), which can rapidly detect 18 bacteria, 9 viruses, and 7 resistance genes. We aimed to compare the diagnosis performance of FAPP with conventional testing in 100 intensive care unit (ICU) patients who required mechanical ventilation, with clinically suspected HAP. A total of 237 samples [76 bronchoalveolar lavages (BAL_DS) and 82 endotracheal aspirates (ETA_DS) obtained at HAP diagnosis, and 79 ETA obtained during follow-up (ETA_TT)], were analyzed independently by routine microbiology testing and FAPP. 58 patients had paired BAL_DS and ETA_DS. The positivity thresholds of semi-quantified bacteria were 10³–10⁴ CFUs/mL or 10⁴ copies/mL for BAL, and 10⁵ CFUs/mL or copies/mL for ETA. Respiratory commensals (H. influenzae, S. aureus, E. coli, S. pneumoniae) were the most common pathogens. Discordant results for bacterial identification were observed in 33/76 (43.4%) BAL_DS and 36/82 (43.9%) ETA_DS, and in most cases, FAPP identified one supplemental bacteria (23/33 BAL_DS and 21/36 ETA_DS). An absence of growth, or polybacterial cultures, explained almost equally the majority of the non-detections in culture. No linear relationship was observed between bin and CFUs/mL variables. Concordant results between paired BAL_DS and ETA_DS were obtained in 46/58 (79.3%) patients with FAPP. One of the 17 resistance genes detected with FAPP (mecA/C and MREJ) was not confirmed by conventional testing. Overall, FAPP enhanced the positivity rate of diagnostic testing, with increased recognition of coinfections. Implementing this strategy may allow clinicians to make more timely and informed decisions.

Detection of community-acquired respiratory viruses in allogeneic stem-cell transplant recipients and controls-A prospective cohort study

Background

Community‐acquired respiratory viruses (CARV) cause upper and lower respiratory tract infections (URTI/LRTI) and may be life‐threatening for recipients of an allogeneic stem cell transplantation (allo‐SCT).

Methods

In a prospective study encompassing 4 winter‐seasons, we collected throat gargles (TG) at random time points from allo‐SCT recipients (patients) and controls and followed them up for at least 3 weeks including repetitive sampling and documentation of symptoms. A Multiplex‐PCR system to identify 20 CARV and Mycoplasma pneumoniae was used to detect CARV.

Results

One hundred ninety‐four patients with 426 TG and 273 controls with 549 TG were included. There were more patients with a positive test result (25% vs 11% in the controls), and the patients had a higher number of positive TG (70 = 16%) compared to controls (32 = 6%) (P < .001). Altogether, 115 viruses were detected. Multiple viruses in one TG (11/48, 34%) and prolonged shedding were only observed in patients (13/48, 27%). Patients had more RSV (18/83, 26%) and adenovirus (15/83, 21%) than controls (both viruses 2/32, 6%). Independent risk factors for the detection of CARV included age >40 years (OR 3.38, 95% CI 1.8‐6.4, P < .001) and presence of URTI‐symptoms (OR 3.22, 95% CI 1.9‐5.5, P < .001). No controls developed a LRTI or died whereas 4/48 (8%) patients developed a LRTI (coronavirus in 2, RSV in 1 and influenza A H1N1 in 1 patient). One patient died of CARV (influenza A H1N1).

Conclusion

Allo‐SCT‐recipients have more CARV‐infections, exhibit a different epidemiology, have more cases of co‐infection or prolonged shedding and have a higher rate of LRTI and mortality.

Viruses of Respiratory Tract: an Observational Retrospective Study on Hospitalized Patients in Rome, Italy

Respiratory tract infections account for high morbidity and mortality around the world. Fragile patients are at high risk of developing complications such as pneumonia and may die from it. Limited information is available on the extent of the circulation of respiratory viruses in the hospital setting. Most knowledge relates to influenza viruses (FLU) but several other viruses produce flu-like illness. The study was conducted at the University Hospital Policlinico Tor Vergata, Rome, Italy. Clinical and laboratory data from hospitalized patients with respiratory tract infections during the period October 2016-March 2019 were analysed. The retrospective analysis included 17 viral agents detected by FilmArray test and clinical data from medical records and hospital discharge sheets. Models were adjusted for relevant confounders such as clinical severity and risk of death, socio-demographic characteristics and surgical procedures. From a total of 539 specimens analysed, 180 (33.39%) were positive for one or more respiratory viruses. Among them, 83 (46.1 %) were positive for influenza viruses (FLU), 36 (20%) rhino/enteroviruses (RHV/EV), 17 (9.44%) human coronaviruses (HCOV-229E, -HKU1, -NL63, and -OC43), 17 (9.44%) respiratory syncytial virus, 15 (8.33%) human metapneumovirus (HMPV), 8 (4.44%) parainfluenza viruses (PIV) and 4 (2.22%) adenoviruses (ADV). The distribution of viral agents varied across age groups and month of detection. The positive specimens were from 168 patients [102 M, 66 F; median age (range): 64 years (19-93)]. Overall, 40% of them had a high-grade clinical severity and a 27% risk of death; 27 patients died and 22 of them (81.5%) had received a clinical diagnosis of pneumonia. Respiratory viral infections may have a severe course and a poor prognosis in hospitalized patients, due to underlying comorbidities. Monitoring the circulation of respiratory viruses in hospital settings is important to improve diagnosis, prevention and treatment.

Multicenter evaluation of the QIAstat Respiratory Panel-A new rapid highly multiplexed PCR based assay for diagnosis of acute respiratory tract infections

Acute respiratory tract infections (ARTI), including the common cold, pharyngitis, sinusitis, otitis media, bronchiolitis and pneumonia are the most common diagnoses among patients seeking medical care in western countries, and account for most antibiotic prescriptions. While a confirmed and fast ARTI diagnosis is key for antibiotic prescribing, empiric antimicrobial treatment remains common, because viral symptoms are often clinically similar and difficult to distinguish from those caused by bacteria. As a result, inappropriate antibiotic prescriptions are high and in certain settings likely higher than the commonly estimated 30%. The QIAstat Respiratory Panel^® assay (QIAstat RP) is a multiplexed in vitro diagnostics test for the rapid simultaneous detection of 21 pathogens directly from respiratory samples, including human mastadenovirus A-G, primate bocaparvovirus 1+2, human coronavirus (HKU1, NL63, OC43, 229E), human metapneumovirus A/B, rhinovirus/enterovirus, influenza A virus (no subtype, subtype H1, H1N1/2009, H3), influenza B virus, human respirovirus 1+3, human orthorubulavirus 2+4, human orthopneumovirus, Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila. We describe the first multicenter study of 445 respiratory samples, collected through the 2016–2017 and 2018 respiratory seasons, with performance compared against BioFire FilmArray RP v1.7 and discrepancy testing by Seegene Allplex RP. The QIAstat RP demonstrated a positive percentage of agreement of 98.0% (95% CI: 96.0–99.1%) and a negative percentage agreement of 99.8% (95% CI: 99.6–99.9%). With use of this comprehensive and rapid test, improved patient outcomes and antimicrobial stewardship may potentially be achieved.

Ventilator-associated pneumonia in adults: a narrative review

Ventilator-associated pneumonia (VAP) is one of the most frequent ICU-acquired infections. Reported incidences vary widely from 5 to 40% depending on the setting and diagnostic criteria. VAP is associated with prolonged duration of mechanical ventilation and ICU stay. The estimated attributable mortality of VAP is around 10%, with higher mortality rates in surgical ICU patients and in patients with mid-range severity scores at admission. Microbiological confirmation of infection is strongly encouraged. Which sampling method to use is still a matter of controversy. Emerging microbiological tools will likely modify our routine approach to diagnosing and treating VAP in the next future. Prevention of VAP is based on minimizing the exposure to mechanical ventilation and encouraging early liberation. Bundles that combine multiple prevention strategies may improve outcomes, but large randomized trials are needed to confirm this. Treatment should be limited to 7 days in the vast majority of the cases. Patients should be reassessed daily to confirm ongoing suspicion of disease, antibiotics should be narrowed as soon as antibiotic susceptibility results are available, and clinicians should consider stopping antibiotics if cultures are negative.

A Comparison of the Mortality Risk Associated With Ventilator-Acquired Bacterial Pneumonia and Nonventilator ICU-Acquired Bacterial Pneumonia

OBJECTIVES

To investigate the respective impact of ventilator-associated pneumonia and ICU-hospital-acquired pneumonia on the 30-day mortality of ICU patients.

DESIGN

Longitudinal prospective studies.

SETTING

French ICUs.

PATIENTS

Patients at risk of ventilator-associated pneumonia and ICU-hospital-acquired pneumonia.

INTERVENTIONS

The first three episodes of ventilator-associated pneumonia or ICU-hospital-acquired pneumonia were handled as time-dependent covariates in Cox models. We adjusted using the case-mix, illness severity, Simplified Acute Physiology Score II score at admission, and procedures and therapeutics used during the first 48 hours before the risk period. Baseline characteristics of patients with regard to the adequacy of antibiotic treatment were analyzed, as well as the Sequential Organ Failure Assessment score variation in the 2 days before the occurrence of ventilator-associated pneumonia or ICU-hospital-acquired pneumonia. Mortality was also analyzed for Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species(ESKAPE) and P. aeruginosa pathogens.

MEASUREMENTS AND MAIN RESULTS

Of 14,212 patients who were admitted to the ICUs and who stayed for more than 48 hours, 7,735 were at risk of ventilator-associated pneumonia and 9,747 were at risk of ICU-hospital-acquired pneumonia. Ventilator-associated pneumonia and ICU-hospital-acquired pneumonia occurred in 1,161 at-risk patients (15%) and 176 at-risk patients (2%), respectively. When adjusted on prognostic variables, ventilator-associated pneumonia (hazard ratio, 1.38 (1.24-1.52); p < 0.0001) and even more ICU-hospital-acquired pneumonia (hazard ratio, 1.82 [1.35-2.45]; p < 0.0001) were associated with increased 30-day mortality. The early antibiotic therapy adequacy was not associated with an improved prognosis, particularly for ICU-hospital-acquired pneumonia. The impact was similar for ventilator-associated pneumonia and ICU-hospital-acquired pneumonia mortality due to P. aeruginosa and the ESKAPE group.

CONCLUSIONS

In a large cohort of patients, we found that both ICU-hospital-acquired pneumonia and ventilator-associated pneumonia were associated with an 82% and a 38% increase in the risk of 30-day mortality, respectively. This study emphasized the importance of preventing ICU-hospital-acquired pneumonia in nonventilated patients.

Use of whole-genome sequencing in the molecular investigation of care-associated HCoV-OC43 infections in a hematopoietic stem cell transplant unit

•

HCoV−OC43 is involved in healthcare–associated infections.

•

HCoV−OC43 genotypes B, E, F and G are identified.

•

Asian and European strains of HCoV−OC43 circulate among patients.

Background

While respiratory viral infections are recognized as a frequent cause of illness in hematopoietic stem cell transplantation (HSCT) recipients, HCoV−OC43 infections have rarely been investigated as healthcare-associated infections in this population.

Objectives

In this report, HCoV−OC43 isolates collected from HSCT patients were retrospectively characterized to identify potential clusters of infection that may stand for a hospital transmission.

Study design

Whole-genome and S gene sequences were obtained from nasal swabs using next-generation sequencing and phylogenetic trees were constructed. Similar identity matrix and determination of the most common ancestor were used to compare clusters of patient’s sequences. Amino acids substitutions were analysed.

Results

Genotypes B, E, F and G were identified. Two clusters of patients were defined from chronological data and phylogenetic trees. Analyses of amino acids substitutions of the S protein sequences identified substitutions specific for genotype F strains circulating among European people.

Conclusions

HCoV−OC43 may be implicated in healthcare-associated infections.

Influenza virus-related critical illness: pathophysiology and epidemiology

Influenza virus affects the respiratory tract by direct viral infection or by damage from the immune system response. In humans, the respiratory epithelium is the only site where the hemagglutinin (HA) molecule is effectively cleaved, generating infectious virus particles. Virus transmission occurs through a susceptible individual's contact with aerosols or respiratory fomites from an infected individual. The inability of the lung to perform its primary function of gas exchange can result from multiple mechanisms, including obstruction of the airways, loss of alveolar structure, loss of lung epithelial integrity from direct epithelial cell killing, and degradation of the critical extracellular matrix.Approximately 30-40% of hospitalized patients with laboratory-confirmed influenza are diagnosed with acute pneumonia. These patients who develop pneumonia are more likely to be < 5 years old, > 65 years old, Caucasian, and nursing home residents; have chronic lung or heart disease and history of smoking, and are immunocompromised.Influenza can primarily cause severe pneumonia, but it can also present in conjunction with or be followed by a secondary bacterial infection, most commonly by Staphylococcus aureus and Streptococcus pneumoniae. Influenza is associated with a high predisposition to bacterial sepsis and ARDS. Viral infections presenting concurrently with bacterial pneumonia are now known to occur with a frequency of 30-50% in both adult and pediatric populations. The H3N2 subtype has been associated with unprecedented high levels of intensive care unit (ICU) admission.Influenza A is the predominant viral etiology of acute respiratory distress syndrome (ARDS) in adults. Risk factors independently associated with ARDS are age between 36 and 55 years old, pregnancy, and obesity, while protective factors are female sex, influenza vaccination, and infections with Influenza A (H3N2) or Influenza B viruses.In the ICU, particularly during the winter season, influenza should be suspected not only in patients with typical symptoms and epidemiology, but also in patients with severe pneumonia, ARDS, sepsis with or without bacterial co-infection, as well as in patients with encephalitis, myocarditis, and rhabdomyolysis.

Approche syndromique multiplexe en réanimation

Le développement récent des nouveaux tests de diagnostic rapide par PCR multiplexe à visée syndromique, capables de détecter plusieurs dizaines de pathogènes en quelques heures, a entraîné un changement de paradigme en microbiologie et en pratique clinique. Plusieurs d’entre eux, comme les panels pour détecter les germes en cause dans les bactériémies, les infections respiratoires hautes ou basses et les méningoencéphalites, sont déjà disponibles et peuvent apporter une aide dans le diagnostic des infections chez les patients de réanimation. Bien que ces nouvelles techniques présentent des avantages évidents pour le dénombrement de micro-organismes et parfois pour la détection simultanée de gènes de résistance, pour les délais d’exécution et de rendus de résultats, elles présentent cependant certains défis, comme l’évaluation de leurs performances réelles, leur coût très élevé, le choix des stratégies d’utilisation et l’interprétation clinicobiologique des résultats. Dans cet article, nous avons passé en revue les différents tests qui peuvent ou pourront aider les réanimateurs dans leur pratique quotidienne, relevé leurs limites et leur impact bénéfique potentiel sur le soin des patients.

Effect of Influenza Vaccination Against Postoperative Pneumonia and Mortality for Geriatric Patients Receiving Major Surgery: A Nationwide Matched Study

Background

Limited information is available on the association between influenza vaccination and postoperative outcomes.

Methods

Using Taiwan's National Health Insurance Research Database reimbursement claims data from 2008-2013, we conducted a matched cohort study of 16903 patients aged >66 years who received influenza vaccinations and later underwent major surgery. Using a propensity score matching procedure adjusted for sociodemographic characteristics, medical condition, surgery type, and anesthesia type, 16903 controls who underwent surgery but were not vaccinated were selected. Logistic regressions were used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for postoperative pneumonia and in-hospital mortality associated with influenza vaccination.

Results

Patients who received preoperative influenza vaccination had a lower risk of postoperative pneumonia (OR, 0.60; 95% CI, .56-.64) and in-hospital mortality (OR, 0.46; 95% CI, .39-.56), compared with unvaccinated patients, in both sexes and every age group. Vaccinated patients who underwent surgery also had a decreased risk of postoperative intensive care unit admission (OR, 0.56; 95% CI, .53-.60), shorter hospital stays (P < .0001), and lower medical expenditures (P < .0001) than nonvaccinated controls.

Conclusions

Vaccinated geriatric patients who underwent surgery had lower risks of pneumonia and in-hospital mortality, compared with unvaccinated patients who underwent similar major surgeries. Further studies are needed to explain how preoperative influenza vaccination improves perioperative outcomes.

Rationalizing antimicrobial therapy in the ICU: a narrative review

The massive consumption of antibiotics in the ICU is responsible for substantial ecological side effects that promote the dissemination of multidrug-resistant bacteria (MDRB) in this environment. Strikingly, up to half of ICU patients receiving empirical antibiotic therapy have no definitively confirmed infection, while de-escalation and shortened treatment duration are insufficiently considered in those with documented sepsis, highlighting the potential benefit of implementing antibiotic stewardship programs (ASP) and other quality improvement initiatives. The objective of this narrative review is to summarize the available evidence, emerging options, and unsolved controversies for the optimization of antibiotic therapy in the ICU. Published data notably support the need for better identification of patients at risk of MDRB infection, more accurate diagnostic tools enabling a rule-in/rule-out approach for bacterial sepsis, an individualized reasoning for the selection of single-drug or combination empirical regimen, the use of adequate dosing and administration schemes to ensure the attainment of pharmacokinetics/pharmacodynamics targets, concomitant source control when appropriate, and a systematic reappraisal of initial therapy in an attempt to minimize collateral damage on commensal ecosystems through de-escalation and treatment-shortening whenever conceivable. This narrative review also aims at compiling arguments for the elaboration of actionable ASP in the ICU, including improved patient outcomes and a reduction in antibiotic-related selection pressure that may help to control the dissemination of MDRB in this healthcare setting.

Superinfection and cell regeneration can lead to chronic viral coinfections

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Clinical researchers have found that coinfection of the respiratory tract can cause distinct disease outcome, sometimes leading to long-lasting infection, compared to single viral infection.

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The impact of coinfections in human respiratory tract have not yet been evaluated in either theoretical or experimental studies on a large scale.

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A few experiments confirm that different respiratory viruses can infect the same cell (superinfection).

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Superinfection alone cannot cause long-lasting viral coinfections.

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The combined mechanism of superinfection and cell regeneration provides a plausible mechanism for chronic viral coinfections.

Molecular diagnostic techniques have revealed that approximately 43% of the patients hospitalized with influenza-like illness are infected by more than one viral pathogen, sometimes leading to long-lasting infections. It is not clear how the heterologous viruses interact within the respiratory tract of the infected host to lengthen the duration of what are usually short, self-limiting infections. We develop a mathematical model which allows for single cells to be infected simultaneously with two different respiratory viruses (superinfection) to investigate the possibility of chronic coinfections. We find that a model with superinfection and cell regeneration has a stable chronic coinfection fixed point, while superinfection without cell regeneration produces only acute infections. This analysis suggests that both superinfection and cell regeneration are required to sustain chronic coinfection via this mechanism since coinfection is maintained by superinfected cells that allow slow-growing infections a chance to infect cells and continue replicating. This model provides a possible mechanism for chronic coinfection independent of any viral interactions via the immune response.

Pneumonia with bacterial and viral coinfection

PURPOSE OF REVIEW

We aim to review the epidemiology of pneumonia with bacterial and viral coinfection, the pathogenesis and clinical impact of coinfection along with the current state of treatment and outcomes.

RECENT FINDINGS

Emphasis is given to the pathogenesis of bacterial and viral co-infection including specific highlighting on influenza, rhinovirus, respiratory syncytial virus and cytomegalovirus. Updates on the current state of diagnosis and management are included, as well as on areas where future research can be directed to improve patient clinical outcomes regarding viral and bacterial coinfection.

SUMMARY

Bacterial and viral coinfection is increasingly recognized as an underlying etiology for community- and hospital-acquired infections. Coinfections may be a risk factor for ICU admission, severity of disease, and mortality. Clinicians must be aware of these coinfections for appropriate management and prognostication, as well as for the prevention of nosocomial spread of viral illness.

Virus respiratoires dans les pneumonies associées aux soins

Les pneumonies acquises à l’hôpital (PAH) sont fréquentes. À l’ère des techniques diagnostiques de biologie moléculaire (multiplex polymerase chain reaction), les rares données disponibles estiment que les virus respiratoires sont impliqués dans 22 à 32 % des épisodes. Les patients immunodéprimés constituent probablement la population la plus à risque. La présentation clinique et radiologique ne diffère pas entre pneumonies bactériennes, virales et mixtes (virus–bactérie). L’excrétion prolongée de virus respiratoires dans les voies aériennes a été rapportée chez les patients immunodéprimés. Elle pourrait promouvoir la co-infection bactérienne, associée à des durées d’hospitalisation prolongées. L’acquisition intrahospitalière a été démontrée chez tous les virus respiratoires. Elle encourage la mise en œuvre et le respect des mesures d’hygiène et de confinement, dans l’objectif de protéger soignants, visiteurs et patients. De nombreux points restent largement méconnus, relatifs aux interactions entre virus respiratoires et pathogènes non viraux, aux périodes d’incubation, ou encore aux durées d’excrétion virale. L’amélioration des techniques diagnostiques et l’accumulation de données épidémiologiques et cliniques devraient permettre de mieux appréhender le rôle des virus respiratoires dans les PAH. Cette meilleure connaissance aidera à rationaliser l’utilisation des tests de détection et facilitera l’interprétation de leurs résultats. Elle guidera aussi le clinicien dans l’utilisation future des nombreuses molécules antivirales actuellement en développement clinique chez l’homme.

Healthcare-associated infections: potential for prevention through vaccination

The challenge of healthcare-associated infections is compounded by the higher incidence of resistant organisms and the decreasing utility of antimicrobial agents. Historic and current vaccines have already contributed to reductions in healthcare-associated infections, and future vaccines have the potential to reduce these infections further. Through examples of bacterial and viral vaccines, this review will attempt to chart the way forward.

Prevalence of respiratory viruses among adults, by season, age, respiratory tract region and type of medical unit in Paris, France, from 2011 to 2016

BACKGROUND

Multiplex PCR tests have improved our understanding of respiratory viruses' epidemiology by allowing their wide range detection. We describe here the burden of these viruses in hospital settings over a five-year period.

METHODS

All respiratory samples from adult patients (>20 years old) tested by multiplex-PCR at the request of physicians, from May 1 2011 to April 30 2016, were included retrospectively. Viral findings are reported by season, patient age group, respiratory tract region (upper or lower) and type of clinical unit (intensive care unit, pneumology unit, lung transplantation unit and other medical units).

RESULTS

In total, 7196 samples (4958 patients) were included; 29.2% tested positive, with viral co-infections detected in 1.6% of samples. Overall, two viral groups accounted for 60.2% of all viruses identified: picornaviruses (rhinovirus or enterovirus, 34.3%) and influenza (26.6%). Influenza viruses constituted the group most frequently identified in winter (34.4%), in the upper respiratory tract (32%) and in patients over the age of 70 years (36.4%). Picornavirus was the second most frequently identified viral group in these populations and in all other groups, including lower respiratory tract infections (41.3%) or patients in intensive care units (37.6%).

CONCLUSION

This study, the largest to date in Europe, provides a broad picture of the distribution of viruses over seasons, age groups, types of clinical unit and respiratory tract regions in the hospital setting. It highlights the burden associated with the neglected picornavirus group. These data have important implications for the future development of vaccines and antiviral drugs.