Herpes simplex virus lung infection in patients undergoing prolonged mechanical ventilation

Herpesviridae and Atypical Bacteria Co-Detections in Lower Respiratory Tract Samples of SARS-CoV-2-Positive Patients Admitted to an Intensive Care Unit

Shortly after the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cases of viral, bacterial, and fungal coinfections in hospitalized patients became evident. This retrospective study investigates the prevalence of multiple pathogen co-detections in 1472 lower respiratory tract (LRT) samples from 229 SARS-CoV-2-positive patients treated in the largest intensive care unit (ICU) in Slovenia. In addition to SARS-CoV-2, (rt)RT-PCR tests were used to detect cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2), varicella zoster virus (VZV), and atypical bacteria: Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila/spp. At least one co-detection was observed in 89.1% of patients. EBV, HSV-1, and CMV were the most common, with 74.7%, 58.1%, and 38.0% of positive patients, respectively. The median detection time of EBV, HSV-1, and CMV after initial SARS-CoV-2 confirmation was 11 to 20 days. Bronchoalveolar lavage (BAL) and tracheal aspirate (TA) samples showed equivalent performance for the detection of EBV, CMV, and HSV-1 in patients with both available samples. Our results indicate that SARS-CoV-2 infection could be a risk factor for latent herpesvirus reactivation, especially HSV-1, EBV, and CMV. However, additional studies are needed to elucidate the clinical importance of these findings.

New findings on CD16brightCD62Ldim neutrophil subtypes in sepsis-associated ARDS: an observational clinical study

Background

The CD16brightCD62Ldim neutrophil subtype is a recently identified neutrophil subtype. The aim of this study was to evaluate changes of peripheral blood CD16brightCD62Ldim neutrophils in patients with sepsis-associated ARDS.

Methods

We prospectively recruited adult patients with sepsis-associated ARDS in the intensive care unit (ICU). Patient demographic data, medical history information, and laboratory data were collected within 48 hours of enrollment, and flow cytometry was applied to analyze the CD16brightCD62Ldim neutrophil subtype in the patients' peripheral blood. Multifactor COX regression models were used to analyze factors affecting prognosis, and Spearman correlation coefficients were used to analyze clinical and laboratory indicators affecting complications of infection.

Results

Of the 40 patients, 9 patients died by the 28-day follow-up, indicating a mortality rate of 22.5%. Patients in the nonsurvival group had higher CD16brightCD62Ldim neutrophil levels. Patients with sepsis-associated ARDS who had a baseline proportion of CD16brightCD62Ldim neutrophil subtypes to total neutrophils in peripheral blood >3.73% had significantly higher 28-day mortality, while patients with CD16brightCD62Ldim neutrophil subtypes counts >2.62×109/L were also associated with significantly higher 28-day mortality. The percentage of the CD16brightCD62Ldim neutrophil subtype (HR=5.305, 95% CI 1.986-14.165, p=0.001) and IL-8 (HR=3.852, 95% CI 1.561-9.508, p=0.003) were independent risk factors for the development of infectious complications in patients with sepsis-related ARDS. The percentage of CD16brightCD62Ldim neutrophil subtypes predicted an AUC of 0.806 (95% CI 0.147-0.964, P=0.003) for the development of infectious complications, and 0.742 (95% CI 0.589-0.895, P=0.029) for the prediction of death within 28 days.

Conclusion

We identified for the first time that CD16brightCD62Ldim neutrophils are elevated in patients with sepsis-associated ARDS and are associated with infectious complications and poor prognosis. The percentage of CD16brightCD62Ldim neutrophil subtypes may serve as a predictor of the development of infectious complications in patients with ARDS.

Herpes Simplex Virus Bronchopneumonitis in Critically Ill Patients with Acute on Chronic Liver Failure: A Retrospective Analysis

(1) Background: Critically ill patients are frequently diagnosed with pulmonary Herpes simplex virus-1 (HSV) reactivation, which then can lead to HSV bronchopneumonitis and is associated with higher mortality and longer mechanical ventilation. For the particular subgroup of critically ill patients with acute on chronic liver failure (ACLF), however, the impact of HSV reactivation is unknown. We investigated the impact of HSV reactivation in these patients. (2) Methods: We conducted a retrospective analysis, evaluating data from 136 mechanically ventilated patients with ACLF between January 2016 and August 2023. Clinical parameters were compared between patients with and without HSV bronchopneumonitis. (3) Results: 10.3% were diagnosed with HSV bronchopneumonitis (HSV group). Mortality did not differ between the HSV and non-HSV group (85.7% vs. 75.4%, p = 0.52). However, the clinical course in the HSV group was more complicated as patients required significantly longer mechanical ventilation (14 vs. 21 days, p = 0.04). Furthermore, fungal superinfections were significantly more frequent in the HSV group (28.6% vs. 6.6%, p = 0.006). (4) Conclusions: Mortality of critically ill patients with ACLF with HSV bronchopneumonitis was not increased in spite of the cirrhosis-associated immune dysfunction. Their clinical course, however, was more complicated with significantly longer mechanical ventilation.

Advances and Challenges in Sepsis Management: Modern Tools and Future Directions

Sepsis, a critical condition marked by systemic inflammation, profoundly impacts both innate and adaptive immunity, often resulting in lymphopenia. This immune alteration can spare regulatory T cells (Tregs) but significantly affects other lymphocyte subsets, leading to diminished effector functions, altered cytokine profiles, and metabolic changes. The complexity of sepsis stems not only from its pathophysiology but also from the heterogeneity of patient responses, posing significant challenges in developing universally effective therapies. This review emphasizes the importance of phenotyping in sepsis to enhance patient-specific diagnostic and therapeutic strategies. Phenotyping immune cells, which categorizes patients based on clinical and immunological characteristics, is pivotal for tailoring treatment approaches. Flow cytometry emerges as a crucial tool in this endeavor, offering rapid, low cost and detailed analysis of immune cell populations and their functional states. Indeed, this technology facilitates the understanding of immune dysfunctions in sepsis and contributes to the identification of novel biomarkers. Our review underscores the potential of integrating flow cytometry with omics data, machine learning and clinical observations to refine sepsis management, highlighting the shift towards personalized medicine in critical care. This approach could lead to more precise interventions, improving outcomes in this heterogeneously affected patient population.

Viral Pneumonias

Viral pneumonia is usually community acquired and caused by influenza, parainfluenza, respiratory syncytial virus, human metapneumovirus, and adenovirus. Many of these infections are airway centric and chest imaging demonstrates bronchiolitis and bronchopneumonia, With the exception of adenovirus infections, the presence of lobar consolidation usually suggests bacterial coinfection. Community-acquired viral pathogens can cause more severe pneumonia in immunocompromised hosts, who are also susceptible to CMV and varicella infection. These latter 2 pathogens are less likely to manifest the striking airway-centric pattern. Airway-centric pattern is distinctly uncommon in Hantavirus pulmonary syndrome, a rare environmentally acquired infection with high mortality.

Destabilisation of T cell-dependent humoral immunity in sepsis

Sepsis is a heterogeneous condition defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. For some, sepsis presents as a predominantly suppressive disorder, whilst others experience a pro-inflammatory condition which can culminate in a 'cytokine storm'. Frequently, patients experience signs of concurrent hyper-inflammation and immunosuppression, underpinning the difficulty in directing effective treatment. Although intensive care unit mortality rates have improved in recent years, one-third of discharged patients die within the following year. Half of post-sepsis deaths are due to exacerbation of pre-existing conditions, whilst half are due to complications arising from a deteriorated immune system. It has been suggested that the intense and dysregulated response to infection may induce irreversible metabolic reprogramming in immune cells. As a critical arm of immune protection in vertebrates, alterations to the adaptive immune system can have devastating repercussions. Indeed, a marked depletion of lymphocytes is observed in sepsis, correlating with increased rates of mortality. Such sepsis-induced lymphopenia has profound consequences on how T cells respond to infection but equally on the humoral immune response that is both elicited by B cells and supported by distinct CD4+ T follicular helper (TFH) cell subsets. The immunosuppressive state is further exacerbated by functional impairments to the remaining lymphocyte population, including the presence of cells expressing dysfunctional or exhausted phenotypes. This review will specifically focus on how sepsis destabilises the adaptive immune system, with a closer examination on how B cells and CD4+ TFH cells are affected by sepsis and the corresponding impact on humoral immunity.

Diagnostic Value and Clinical Application of Metagenomic Next-Generation Sequencing for Infections in Critically Ill Patients

Objective

To evaluate the diagnostic value and clinical application of metagenomic next-generation sequencing (mNGS) for infections in critically ill patients.

Methods

Comparison of diagnostic performance of mNGS and conventional microbiological testing for pathogens was analyzed in 234 patients. The differences between immunocompetent and immunocompromised individuals in mNGS-guided anti-infective treatment adjustment were also analyzed.

Results

The sensitivity and specificity of mNGS for bacterial and fungal detection were 96.6% (95% confidence interval [CI], 93.5%-99.6%) and 83.1% (95% CI, 75.2%-91.1%), and 85.7% (95% CI, 71.9%-99.5%) and 93.2% (95% CI, 89.7%-96.7%), respectively. Overall, 152 viruses were detected by mNGS, but in which 28 viruses were considered causative agents. The proportion of mNGS-guided beneficial anti-infective therapy adjustments in the immunocompromised group was greater than in the immunocompetent group (48.5% vs 30.1%; P=0.008). In addition, mNGS-guided anti-infective regimens with peripheral blood and BALF specimens had the highest proportion (39.0%; 40.0%), but the proportion of patients not helpful due to peripheral blood mNGS was also as high as 22.0%.

Conclusion

mNGS might be a promising technology to provide precision medicine for critically ill patients with infection.

The Diagnosis and Management of Herpes Simplex Pneumonia in the Critical Care Setting: A Comprehensive Review

Herpes simplex virus (HSV) belongs to the Herpesviridae family and is divided into two subtypes: HSV-1 and HSV-2. It is known that herpesviruses lie dormant in neural ganglion cells and are reactivated during times of stress, trauma, fever, and immunosuppression. While HSV primarily causes mucosal infections such as cold sores or upper respiratory tract manifestations, it can also lead to serious, life-threatening infections, particularly in immunocompromised patients. Although HSV is occasionally detected in airway samples from critically ill patients, true HSV pneumonia is rare. HSV pneumonia is thought to result from the aspiration of salivary secretions that can travel from the pharynx and tracheobronchial areas to the lungs. It can be difficult to diagnose, and the presence of HSV in respiratory specimens does not necessarily indicate true infection. Treatment with antiviral drugs such as acyclovir should be considered based on the clinical presentation, corroborative findings, and the presence of cytopathological changes in the bronchoalveolar specimen. The prognosis of HSV pneumonia is generally poor and early detection is critical for better outcomes. This review discusses the risk factors, clinical presentation, diagnosis, treatment, and prognosis of HSV pneumonia and emphasizes the importance of distinguishing between true infection and carrier status.

Risk Stratification for Herpes Simplex Virus Pneumonia Using Elastic Net Penalized Cox Proportional Hazard Algorithm with Enhanced Explainability

Herpes simplex virus (HSV) pneumonia is a serious and often fatal respiratory tract infection that occurs in immunocompromised individuals. The early detection of accurate risk stratification is essential in identifying patients who are at high risk of mortality and may benefit from more aggressive treatment. In this study, we developed and validated a risk stratification model for HSV bronchopneumonia using an elastic net penalized Cox proportional hazard algorithm. We analyzed data from a cohort of 104 critically ill patients with HSV bronchopneumonia identified in Chang Gung Memorial Hospital, Linkou, Taiwan: one of the largest tertiary medical centers in the world. A total of 109 predictors, both clinical and laboratory, were identified in this process to develop a risk stratification model that could accurately predict mortality in patients with HSV bronchopneumonia. This model was able to differentiate the risk of death and predict mortality in patients with HSV bronchopneumonia compared to the APACHE II score in the early stage of ICU admissions. Both hazard ratio coefficient and selection frequency were used as the metrics to enhance the explainability of the informative predictors. Our findings suggest that the elastic net penalized Cox proportional hazard algorithm is a promising tool for risk stratification in patients with HSV bronchopneumonia and could be useful in identifying those at high risk of mortality.

Incidence and clinical features of HHV-7 detection in lower respiratory tract in patients with severe pneumonia: a multicenter, retrospective study

PURPOSE

The significance of detecting human herpesvirus 7 (HHV-7) in the lower respiratory tract of patients with severe pneumonia is unclear. This study aims to evaluate the clinical characteristics and prognosis of detecting HHV-7 in the lower respiratory tract of patients with severe pneumonia.

METHODS

Patients with severe pneumonia requiring invasive mechanical ventilation and underwent commercial metagenomic next-generation sequencing (mNGS) testing of bronchoalveolar lavage fluid from January 2019 to March 2023 were enrolled in 12 medical centers. Clinical data of patients were collected retrospectively, and propensity score matching was used for subgroup analysis and mortality assessment.

RESULTS

In a total number of 721 patients, 45 cases (6.24%) were identified with HHV-7 positive in lower respiratory tract. HHV-7 positive patients were younger (59.2 vs 64.4, p = 0.032) and had a higher rate of co-detection with Cytomegalovirus (42.2% vs 20.7%, p = 0.001) and Epstein-Barr virus (35.6% vs 18.2%, p = 0.008). After propensity score matching for gender, age, SOFA score at ICU admission, and days from ICU admission to mNGS assay, there was no statistically significant difference in the 28-day mortality rate between HHV-7 positive and negative patients (46.2% vs 36.0%, p = 0.395). Multivariate Cox regression analysis adjusting for gender, age, and SOFA score showed that HHV-7 positive was not an independent risk factor for 28-day mortality (HR 1.783, 95%CI 0.936-3.400, p = 0.079).

CONCLUSION

HHV-7 was detected in the lungs of 6.24% of patients with severe pneumonia. The presence of HHV-7 in patients with severe pneumonia requiring invasive mechanical ventilation is associated with a younger age and co-detected of Cytomegalovirus and Epstein-Barr virus. While HHV-7 positivity was not found to be an independent risk factor for mortality in this cohort, this result may have been influenced by the relatively small sample size of the study.

Infections in Burn Patients

Infections are the leading cause of mortality in burn patients who survive their initial resuscitation. Burn injury leads to immunosuppression and a dysregulated inflammatory response which can have a prolonged impact. Early surgical excision along with support of the multidisciplinary burn team has improved mortality in burn patients. The authors review diagnostic and therapeutic challenges as well as strategies for management of burn related infections.

Persistently Elevated Soluble Triggering Receptor Expressed on Myeloid Cells 1 and Decreased Monocyte Human Leucocyte Antigen DR Expression Are Associated With Nosocomial Infections in Septic Shock Patients

Sepsis-acquired immunosuppression may play a major role in patients' prognosis through increased risk of secondary infections. Triggering receptor expressed on myeloid cells 1 (TREM-1) is an innate immune receptor involved in cellular activation. Its soluble form (sTREM-1) has been described as a robust marker of mortality in sepsis. The objective of this study was to evaluate its association with the occurrence of nosocomial infections alone or in combination with human leucocyte antigen-DR on monocytes (mHLA-DR).

DESIGN

Observational study.

SETTING

University Hospital in France.

PATIENTS

One hundred sixteen adult septic shock patients as a post hoc study from the IMMUNOSEPSIS cohort (NCT04067674).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma sTREM-1 and monocyte HLA-DR were measured at day 1 or 2 (D1/D2), D3/D4, and D6/D8 after admission. Associations with nosocomial infection were evaluated through multivariable analyses. At D6/D8, both markers were combined, and association with increased risk of nosocomial infection was evaluated in the subgroup of patients with most deregulated markers in a multivariable analysis with death as a competing risk. Significantly decreased mHLA-DR at D6/D8 and increased sTREM-1 concentrations were measured at all time points in nonsurvivors compared with survivors. Decreased mHLA-DR at D6/D8 was significantly associated with increased risk of secondary infections after adjustment for clinical parameters with a subdistribution hazard ratio of 3.61 (95% CI, 1.39-9.34; p = 0.008). At D6/D8, patients with persistently high sTREM-1 and decreased mHLA-DR presented with a significantly increased risk of infection (60%) compared with other patients (15.7%). This association remained significant in the multivariable model (subdistribution hazard ratio [95% CI], 4.65 [1.98-10.9]; p < 0.001).

CONCLUSIONS

In addition to its prognostic interest on mortality, sTREM-1, when combined with mHLA-DR, may help to better identify immunosuppressed patients at risk of nosocomial infections.

Ventilator-Associated Pneumonia in Immunosuppressed Patients

Immunocompromised patients-including patients with cancer, hematological malignancies, solid organ transplants and individuals receiving immunosuppressive therapies for autoimmune diseases-account for an increasing proportion of critically-ill patients. While their prognosis has improved markedly in the last decades, they remain at increased risk of healthcare- and intensive care unit (ICU)-acquired infections. The most frequent of these are ventilator-associated lower respiratory tract infections (VA-LTRI), which include ventilator-associated pneumonia (VAP) and tracheobronchitis (VAT). Recent studies have shed light on some of the specific features of VAP and VAT in immunocompromised patients, which is the subject of this narrative review. Contrary to previous belief, the incidence of VAP and VAT might actually be lower in immunocompromised than non-immunocompromised patients. Further, the relationship between immunosuppression and the incidence of VAP and VAT related to multidrug-resistant (MDR) bacteria has also been challenged recently. Etiological diagnosis is essential to select the most appropriate treatment, and the role of invasive sampling, specifically bronchoscopy with bronchoalveolar lavage, as well as new molecular syndromic diagnostic tools will be discussed. While bacteria-especially gram negative bacteria-are the most commonly isolated pathogens in VAP and VAT, several opportunistic pathogens are a special concern among immunocompromised patients, and must be included in the diagnostic workup. Finally, the impact of immunosuppression on VAP and VAT outcomes will be examined in view of recent papers using improved statistical methodologies and treatment options-more specifically empirical antibiotic regimens-will be discussed in light of recent findings on the epidemiology of MDR bacteria in this population.

Next-Generation Sequencing in Critically Ill COVID-19 Patients with Suspected Bloodstream Infections: A Retrospective Cohort Study

BACKGROUND

Rapid pathogen identification and appropriate antimicrobial therapy are crucial in critically ill COVID-19 patients with bloodstream infections (BSIs). This study aimed to evaluate the diagnostic performance and potential therapeutic benefit of additional next-generation sequencing (NGS) of microbial DNA from plasma in these patients.

METHODS

This monocentric descriptive retrospective study reviewed clinical data and pathogen diagnostics in COVID-19 ICU patients. NGS (DISQVER^®) and blood culture (BC) samples were obtained on suspicion of BSIs. Data were reviewed regarding the adjustment of antimicrobial therapy and diagnostic procedures seven days after sampling and analyzed using the Chi²-test.

RESULTS

Twenty-five cases with simultaneous NGS and BC sampling were assessed. The NGS positivity rate was 52% (13/25) with the detection of 23 pathogens (14 bacteria, 1 fungus, 8 viruses), and the BC positivity rate was 28% (7/25, 8 bacteria; p = 0.083). The NGS-positive patients were older (75 vs. 59.5 years; p = 0.03) with a higher prevalence of cardiovascular disease (77% vs. 33%; p = 0.03). These NGS results led to diagnostic procedures in four cases and to the commencement of four antimicrobial therapies in three cases. Empirical treatment was considered appropriate and continued in three cases.

CONCLUSIONS

In COVID-19 patients with suspected BSIs, NGS may provide a higher positivity rate than BC and enable new therapeutic approaches.

Herpes Simplex Virus and Varicella Zoster Virus Infections in Cancer Patients

Herpes simplex virus (HSV) and varicella zoster virus (VZV) are alpha herpesviruses that establish life-long latent infection in neuronal ganglia after primary infection. Periodic reactivation of these viruses results in recurrent infections that can have significant impact on patients' quality of life. HSV commonly causes oral and genital mucocutaneous infections whereas VZV is responsible for varicella/chickenpox and herpes zoster/shingles, but cancer patients are at particularly higher risk of complications including disseminated and visceral infections due to impaired cell-mediated immunity. While diagnosis of more common HSV and/or VZV infections is frequently clinically based, immunocompromised hosts may have atypical skin presentation or visceral involvement. Thus, diagnostic confirmation using virus-specific tests such as polymerase chain reaction or immunohistochemical staining is crucial in some cases. Oral acyclovir, valacyclovir and famciclovir are usually used for mild to moderate infections and intravenous acyclovir is the drug of choice for severe or disseminated infections. Foscarnet can be used when acyclovir-resistance is confirmed or suspected. Pharmaceutical prophylaxis against HSV and/or VZV should be considered in high-risk cancers patients. Currently, there is no commercially available vaccine against HSV, but VZV vaccines are available to prevent varicella and zoster.

Host-Derived Cytotoxic Agents in Chronic Inflammation and Disease Progression

At inflammatory sites, cytotoxic agents are released and generated from invading immune cells and damaged tissue cells. The further fate of the inflammation highly depends on the presence of antagonizing principles that are able to inactivate these host-derived cytotoxic agents. As long as the affected tissues are well equipped with ready-to-use protective mechanisms, no damage by cytotoxic agents occurs and resolution of inflammation is initiated. However, long-lasting and severe immune responses can be associated with the decline, exhaustion, or inactivation of selected antagonizing principles. Hence, cytotoxic agents are only partially inactivated and contribute to damage of yet-unperturbed cells. Consequently, a chronic inflammatory process results. In this vicious circle of permanent cell destruction, not only novel cytotoxic elements but also novel alarmins and antigens are liberated from affected cells. In severe cases, very low protection leads to organ failure, sepsis, and septic shock. In this review, the major classes of host-derived cytotoxic agents (reactive species, oxidized heme proteins and free heme, transition metal ions, serine proteases, matrix metalloproteases, and pro-inflammatory peptides), their corresponding protective principles, and resulting implications on the pathogenesis of diseases are highlighted.

[Herpes simplex virus type 1 (HSV-1) over-infection in patients with acute respiratory distress syndrome secondary to COVID-19 pneumonia: Impact on mortality]

OBJECTIVE

Herpes simplex virus type1 (HSV-1) reactivation have been described in patients with invasive mechanical ventilation and recently in patients with acute respiratory distress syndrome (ARDS) secondary to COVID-19 with higher rates of reactivation than were detected previously in critical care, and although the diagnosis of HSV-1 pneumonia is not easy, its presence is associate with an increase in morbidity and mortality. The objective of this study is to determinate if the identification of HSV-1 in lower airway of patients with ARDS secondary to COVID-19 have influence in clinical outcome and mortality.

METHOD

Two hundred twenty-four admitted patients in intensive care unit (ICU) of Complejo Hospitalario Universitario de Toledo diagnosed of severe acute respiratory syndrome coronavirus2 (SARS-CoV-2) were reviewed and were selected those with mechanical ventilation who had undergone (BAL). It was registered all results of HSV-1 PCR (negative and positive).

RESULTS

During the study period (November 28, 2020 to April 13, 2021) was admitted 224 patients in ICU diagnosed of SARS-CoV-2 pneumonia. Eighty-three patients of them had undergone BAL, with HSV-1 PCR positive result in 47 (56%), and negative result in 36 (43.4%). We performed pathological anatomy study in BAL samples on 26 of the total BAL realized. Typical cytopathic characteristics of HSV-1 were found in 13 samples (50%) and 11 of them (84.6%) have had HSV-1 PCR positive result. Thirty days mortality was significantly higher in the group of patients with HSV-1 PCR positive result (33.5% vs. 57.4%, P=.015). This difference was stronger in the group of patients with HSV-1 findings in the pathological anatomy study (30.8% vs. 69.2%, P=.047).

CONCLUSION

Our results suggest that ARDS secondary to SARS-CoV-2 pneumonia is highly associated to HSV-1 reactivation and that the finding of HSV-1 in lower airway is associated with a worst prognostic and with significantly mortality increase. It is necessary to carry out more extensive studies to determinate if treatment with acyclovir can improve the prognosis of these patients.

Herpes simplex virus type 1 (HSV-1) over-infection in patients with acute respiratory distress syndrome secondary to COVID-19 pneumonia: Impact on mortality

Objective

Herpes simplex virus type 1 (HSV-1) reactivation have been described in patients with invasive mechanical ventilation and recently in patients with acute respiratory distress syndrome (ARDS) secondary to COVID-19 with higher rates of reactivation than were detected previously in critical care, and although the diagnosis of HSV-1 pneumonia is not easy, its presence is associate with an increase in morbidity and mortality. The objective of this study is to determinate if the identification of HSV-1 in lower airway of patients with ARDS secondary to COVID-19 have influence in clinical outcome and mortality.

Method

Two hundred twenty-four admitted patients in intensive care unit (ICU) of Complejo Hospitalario Universitario de Toledo diagnosed of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were reviewed and were selected those with mechanical ventilation who had undergone (BAL). It was registered all results of HSV-1 PCR (negative and positive).

Results

During the study period (November 28, 2020 to April 13, 2021) was admitted 224 patients in ICU diagnosed of SARS-CoV-2 pneumonia. Eighty-three patients of them had undergone BAL, with HSV-1 PCR positive result in 47 (56%), and negative result in 36 (43.4%). We performed pathological anatomy study in BAL samples on 26 of the total BAL realized. Typical cytopathic characteristics of HSV-1 were found in 13 samples (50%) and 11 of them (84.6%) have had HSV-1 PCR positive result. Thirty days mortality was significantly higher in the group of patients with HSV-1 PCR positive result (33.5% vs. 57.4%, p = 0.015). This difference was stronger in the group of patients with HSV-1 findings in the pathological anatomy study (30.8% vs. 69.2%, p = 0.047).

Conclusion

Our results suggest that ARDS secondary to SARS-CoV-2 pneumonia is highly associated to HSV-1 reactivation and that the finding of HSV-1 in lower airway is associated with a worst prognostic and with significantly mortality increase. It is necessary to carry out more extensive studies to determinate if treatment with acyclovir can improve the prognosis of these patients.

Inefficient Recovery of Repeatedly Stimulated Memory CD8 T Cells after Polymicrobial Sepsis Induction Leads to Changes in Memory CD8 T Cell Pool Composition

Long-lasting sepsis-induced immunoparalysis has been principally studied in primary (1°) memory CD8 T cells; however, the impact of sepsis on memory CD8 T cells with a history of repeated cognate Ag encounters is largely unknown but important in understanding the role of sepsis in shaping the pre-existing memory CD8 T cell compartment. Higher-order memory CD8 T cells are crucial in providing immunity against common pathogens that reinfect the host or are generated by repeated vaccination. In this study, we analyzed peripheral blood from septic patients and show that memory CD8 T cells with defined Ag specificity for recurring CMV infection proliferate less than bulk populations of central memory CD8 T cells. Using TCR-transgenic T cells to generate 1° and higher-order (quaternary [4°]) memory T cells within the same host, we demonstrate that the susceptibility and loss of both memory subsets are similar after sepsis induction, and sepsis diminished Ag-dependent and -independent (bystander) functions of these memory subsets equally. Both the 1° and 4° memory T cell populations proliferated in a sepsis-induced lymphopenic environment; however, due to the intrinsic differences in baseline proliferative capacity, expression of receptors (e.g., CD127/CD122), and responsiveness to homeostatic cytokines, 1° memory T cells become overrepresented over time in sepsis survivors. Finally, IL-7/anti-IL-7 mAb complex treatment early after sepsis induction preferentially rescued the proliferation and accumulation of 1° memory T cells, whereas recovery of 4° memory T cells was less pronounced. Thus, inefficient recovery of repeatedly stimulated memory cells after polymicrobial sepsis induction leads to changes in memory T cell pool composition, a notion with important implications in devising strategies to recover the number and function of pre-existing memory CD8 T cells in sepsis survivors.

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.

Updates in the management of respiratory virus infections in ICU patients: revisiting the non-SARS-CoV-2 pathogens

INTRODUCTION

Although viruses are an underestimated cause of community-acquired pneumonias (CAP) and hospital-acquired pneumonias (HAP)/ventilator-associated pneumonias (VAP) in intensive care unit (ICU) patients, they have an impact on morbidity and mortality.

AREAS COVERED

In this perspective article, we discuss the available data regarding the management of severe influenza CAP and herpesviridae HAP/VAP. We review diagnostic and therapeutic strategies in order to give clear messages and address unsolved questions.

EXPERT OPINION

Influenza CAP affects yearly thousands of people; however, robust data regarding antiviral treatment in the most critical forms are scarce. While efficacy of oseltamivir has been investigated in randomized controlled trials (RCT) in uncomplicated influenza, only observational data are available in ICU patients. Herpesviridae are an underestimated cause of HAP/VAP in ICU patients. Whilst incidence of herpesviridae identification in samples from lower respiratory tract of ICU patients is relatively high (from 20% to 50%), efforts should be made to differentiate local reactivation from true lung infection. Only few randomized controlled trials evaluated the efficacy of antiviral treatment in herpesviridae reactivation/infection in ICU patients and all were exploratory or negative. Further studies are needed to evaluate the impact of such treatment in specific populations.

Herpes Simplex Virus Type 1 with Concomitant Pneumonia and Urinary Tract Infection in an Older Patient: A Case Report

A 76-year-old female patient was unable to ambulate due to sequelae of cerebrovascular disease and had been living in a healthcare facility. On admission, the patient was diagnosed with sepsis and a urinary tract infection caused by Candida tropicalis. Chest radiography showed right lung atelectasis, while bronchoscopy showed bronchial stenosis with anthracotic pigmentation in both bronchi. Bronchial washing cytology revealed herpes simplex virus (HSV) type 1-infected cells with intranuclear inclusions and multinucleation on the 7th day. Moreover, the patient showed microscopic hematuria. Urine cytology also revealed HSV type 1-infected cells. The patient was treated with antiviral (acyclovir), antifungal, and antibiotic agents. One week later, follow-up urine cytology revealed the absence of HSV infection, and her condition was stabilized. However, her clinical condition deteriorated due to an infection caused by multidrug-resistant bacterial pathogens, and she eventually died 4 weeks after admission. We describe a case of HSV type 1 pneumonia and urinary tract infection in an older adult patient.

Upper Airways Spray for Viral Infections Prevention

Aim

Several studies emphasized the antiviral properties of many natural compounds enclosed in nutraceuticals formulas and quite effective to prevent the respiratory infections. The rationale of our investigation has been to achieve protection from common cold viruses' infection of the upper airways pooling together and dispensing different active principles on a multistep defense basis. Material and Methods. 30 patients affected by sudden aspecific viral-induced sore throat rhinitis were divided in two groups: (1) the first group included 15 patients which were administered with our spray formula and (2) the second group included 15 patients with the commercial nasal lavage kit. The mucous smear was stained with May Grunwald-Giemsa to exclude eosinophilic infiltrate and confirm the prevalence of granulocytes and lympho-monocytes typical of viral seasonal inflammatory upper airways conditions.

Results

The symptomatic relieve is remarkedly evident in the treated group with our spray compared to the second group treated with commercial nasal lavage kit.

Conclusions

The open case-control retrospective observational study showed a definite benefit of the spray based on natural herbal extracts to take control of the upper airways respiratory distress due to viral infections.

Herpesviridae lung reactivation and infection in patients with severe COVID-19 or influenza virus pneumonia: a comparative study

Background

Lung reactivations of Herpesviridae, herpes simplex virus (HSV) and cytomegalovirus (CMV) have been reported in COVID-19 patients. Whether or not those viral reactivations are more frequent than in other patients is not known.

Methods

Retrospective monocentric cohort study of 145 patients with severe COVID-19 pneumonia requiring invasive mechanical ventilation and who were tested for HSV and CMV in bronchoalveolar lavage performed during fiberoptic bronchoscopy for ventilator-associated pneumonia suspicion. Rates of HSV and CMV lung reactivations, and HSV bronchopneumonitis were assessed and compared with an historical cohort of 89 patients with severe influenza pneumonia requiring invasive mechanical ventilation.

Results

Among the 145 COVID-19 patients included, 50% and 42% had HSV and CMV lung reactivations, respectively, whereas among the 89 influenza patients, 63% and 28% had HSV and CMV lung reactivations, respectively. Cumulative incidence of HSV lung reactivation (taking into account extubation and death as competing events) was higher in influenza than in COVID-19 patients (p = 0.03), whereas the rate of HSV bronchopneumonitis was similar in both groups (31% and 25%, respectively). Cumulative incidence of CMV lung reactivation (taking into account extubation and death as competing events) was similar in COVID-19 and influenza patients (p = 0.07). Outcomes of patients with HSV or CMV lung reactivations were similar to that of patients without, whatever the underlying conditions, i.e., in COVID-19 patients, in influenza patients, or when all patients were grouped.

Conclusions

HSV and CMV lung reactivations are frequent in COVID-19 patients, but not more frequent than in patients with influenza-associated severe pneumonia, despite a higher severity of illness at intensive care unit admission of the latter and a longer duration of mechanical ventilation of the former. Although no impact on outcome of HSV and CMV lung reactivations was detected, the effect of antiviral treatment against these Herpesviridae remains to be determined in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01062-0.

Characteristics and prognosis of Herpesviridae-related pneumonia in critically ill burn patients

BACKGROUND

The aim of this study was to describe the prevalence, characteristics and outcome of critically burn patients with pulmonary HSV reactivation.

METHODS

Retrospective, single-center cohort study in a burn critical care unit in a tertiary center, including all consecutive severely burn patients with bronchoalveolar lavage performed for pneumoniae suspicion and screened for HSV from January 2013 and April 2017. We used logistic regression to identify factors associated with HSV reactivation and outcomes.

RESULTS

94 patients were included, mean age was 51 (39-64) years; median total body surface area burned was 36 (25-54)% and ICU mortality 38%. Fifty-five patients (59%) had pulmonary HSV reactivation and 30 (55%) were treated with acyclovir. Patients with HSV reactivation were more severely ill with higher SOFA score at admission compared to patient without HSV reactivation (6 [3-8] vs. 2 [1-4], p < 0.0001 respectively). In multivariate analysis, sex, SOFA score at admission and smoke inhalation were significantly associated with HSV reactivation. Only septic shock was associated with 90-day mortality when HSV reactivation was not.

CONCLUSIONS

Pulmonary HSV reactivation is frequent among severely ill burn patients. Initial severity and smoke inhalation are risk factors. Antiviral treatment was not associated with outcome.

Herpes Simplex Virus 1 (HSV-1) Reactivation in Critically Ill COVID-19 Patients: A Brief Narrative Review

Systemic or pulmonary reactivations of herpes simplex virus 1 (HSV-1) have been reported in critically ill patients with COVID-19, posing a dilemma for clinicians in terms of their diagnostic and clinical relevance. Prevalence of HSV-1 reactivation may be as high as > 40% in this population, but with large heterogeneity across studies, likely reflecting the different samples and/or cut-offs for defining reactivation. There is frequently agreement on the clinical significance of HSV-1 reactivation in the presence of severe manifestations clearly attributable to the virus. However, the clinical implications of HSV-1 reactivations in the absence of manifest signs and symptoms remain controversial. Our review aims at providing immunological background and at reviewing clinical findings on HSV-1 reactivations in critically ill patients with COVID-19.

Nosocomial Pneumonia in the Mechanically Ventilated Patient

Ventilator-associated pneumonia (VAP) is a common complication occurring in critically ill patients who are mechanically ventilated and is the leading cause of nosocomial infection-related death. Etiologic agents for VAP widely differ based on the population of intensive care unit patients, duration of hospital stay, and prior antimicrobial therapy. VAP due to multidrug-resistant pathogens is associated with the highest morbidity and mortality, likely due to delays in appropriate antimicrobial treatment. International guidelines are currently available to guide diagnostic and therapeutic strategies. VAP can be prevented through various pharmacological and non-pharmacological interventions, which are more effective when grouped as bundles. When VAP is clinically suspected, diagnostic strategies should include early collection of respiratory samples to guide antimicrobial therapy. Empirical treatment should be based on the most likely etiologic microorganisms and antibiotics likely to be active against these microorganisms. Response to therapy should be reassessed after 3 to 5 days and antimicrobials adjusted or de-escalated to reduce the burden of the disease. Finally, considering that drug resistance is increasing worldwide, several novel antibiotics are being tested to efficiently treat VAP in the coming decades.

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.

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.

Monocyte Signature Associated with Herpes Simplex Virus Reactivation and Neurological Recovery After Brain Injury

RATIONALE

Brain injury induces systemic immunosuppression increasing the risk of viral reactivations and altering neurological recovery.

OBJECTIVES

To determine if systemic immune alterations and lung replication of Herpesviridae are associated and can help predict outcomes after brain injury.

METHODS

We collected peripheral blood mononuclear cells in severely brain-injured patients requiring invasive mechanical ventilation. We systematically searched for respiratory Herpes Simplex Virus (HSV) replications in tracheal aspirates. We also performed CHiP-sequencing, RNA-sequencing and in vitro functional assays of monocytes and CD4 T cells collected on day 1 to characterize immune response to severe acute brain injury. The primary outcome was the Glasgow outcome scale Extended (GOS-E) at 6 months.

MEASUREMENTS AND MAIN RESULTS

In 344 severe brain-injured patients, lung HSV reactivations were observed in 39% of patients seropositive for HSV, and independently associated with poor neurological recovery at six months (hazard ratio 1.90, 95%CI 1.08-3.57). WGNA analyses of the transcriptomic response of monocytes to brain injury defined a module of 721 genes, including PD-L1 and CD80, enriched for the binding DNA motif of the transcriptional factor Zeb2, and whose ontogenic analyses revealed decreased interferon--mediated and anti-viral response signaling pathways. This monocyte signature was preserved in a validation cohort and predicted the neurological outcome at 6 months with good accuracy (AUC 0.786, 95%CI 0.593-0.978).

CONCLUSIONS

A specific monocyte signature is associated with HSV reactivation and predicts recovery after brain injury. The alterations of the immune control of Herpesviridae replication are understudied and represent a novel therapeutic target.

Incidence and Outcome of Patients with Cardiogenic Shock and Detection of Herpes Simplex Virus in the Lower Respiratory Tract

(1) Herpes simplex virus (HSV) reactivation in critically ill patients can cause infection in the lower respiratory tract, prolonging mechanical ventilation. However, the association of HSV reactivation with cardiogenic shock (CS) is unclear. As CS is often accompanied by pulmonary congestion and reduced immune system activity, the aim of our study was to determine the incidence and outcome of HSV reactivation in these patients. (2) In this retrospective, single-center study, bronchial lavage (BL) was performed on 181 out of 837 CS patients with mechanical ventilation. (3) In 44 of those patients, HSV was detected with a median time interval of 11 days since intubation. The occurrence of HSV was associated with an increase in C-reactive protein and the fraction of inspired oxygen at the time of HSV detection. Arterial hypertension, bilirubin on ICU admission, the duration of mechanical ventilation and out-of-hospital cardiac arrest were associated with HSV reactivation. (4) HSV reactivation could be detected in 24.3% of patients with CS on whom BL was performed, and its occurrence should be considered in patients with prolonged mechanical ventilation. Due to the limited current evidence, the initiation of treatment for these patients remains an individual choice. Dedicated randomized studies are necessary to investigate the efficacy of antiviral therapy.

Clinical Value of Metagenomics Next-Generation Sequencing in Bronchoalveolar Lavage Fluid for Patients with Severe Hospital-Acquired Pneumonia: A Nested Case–Control Study

Background

Metagenomics next-generation sequencing (mNGS) is more efficient in identifying pathogens responsible for pneumonia. However, whether these patients ultimately benefit from this improvement remains unknown.

Methods

In this retrospective, nested, case–control study, patients with severe hospital-acquired pneumonia (HAP) who had undergone mNGS of bronchoalveolar lavage fluid while in our intensive care unit from March 2017 to December 2020 (n = 33) were matched in a ratio of 1 to 2 (n = 66) by sex, age, comorbidities, immune status, Acute Physiology and Chronic Health Evaluation II score, severity of pulmonary infection, and use of extracorporeal life support with patients who had undergone conventional microbiological testing only. The primary outcome was 90-day mortality; secondary outcomes being length of intensive care unit stay, duration of mechanical ventilation support, 7-day and 28-day mortality, and efficacy of treatment of pulmonary infection.

Results

In the CMT group, 17 patients (25.8%) had negative results, whereas only one (3.0%) had negative results in the mNGS group (P < 0.001). After receipt of microbiology results, antibiotics were altered in 23/33 patients (70.0%) in the mNGS group, but in only 29/66 (43.9%) in the CMT group (P = 0.016). Pulmonary infection-related findings improved in 20/33 patients (60.6%) in the mNGS group in the subsequent 7 days, but in only 25/66 (37.9%) in the CMT group (P = 0.032). However, the 28-day (33.3% vs 31.2%, P = 1.0) and 90-day (48.5% vs 45.5%, P = 0.78) mortality rates did not differ significantly between the two groups. These findings were supported by Cox-regression and Kaplan–Meier survival curve analyses.

Conclusion

mNGS is helpful in the treatment of severe HAP but does not improve medium or long-term survival rates, especially in patients with severe comorbidities.

Risk factors for <em>Herpes simplex</em> virus (HSV) and <em>Cytomegalovirus</em> (CMV) infections in critically-ill COVID-19 patients

Background

To assess the prevalence of Herpes simplex and Cytomegalovirus infection in respiratory samples of critically-ill COVID-19 patients, its role in outcome and mortality and the influence of dexamethasone treatment in the early stage of SARS-CoV-2 infection.

Methods

All mechanically ventilated COVID-19 patients treated on ICU between March 2020 and January 2021 were included. Respiratory specimens were tested for Herpes simplex virus (HSV) type 1, 2 and Cytomegalovirus (CMV) by quantitative real-time PCR. Clinical parameters were compared in the cohorts with and without HSV-1- infection.

Results

134 patients with a median age of 72.5 years (73.0% male, n=98) were included. HSV-1 reactivation occurred in 61 patients (45.5%), after median 9 (7-13) days of mechanical ventilation. The main factor for reactivation was length of stay on ICU (24 days vs 13 days, p<0.001) and duration of mechanical ventilation (417 vs 214 hours, p<0.001). Treatment with dexamethasone and a history of immunosuppression did not associate with HSV-infection in the univariate analysis (39 vs 41, p=0.462 and 27.9% vs 23.3%, p=0.561, respectively). Both ICU and hospital mortality were not significantly different in the cohorts with and without HSV-infection (57.4% vs 45.2%, p=0.219).

Conclusions

Our study shows a high prevalence of HSV-infection in critically-ill COVID-19 patients which was unexpectedly higher than the prevalence of CMV-infections and unrelated to dexamethasone treatment. The main risk factors for HSV and CMV in the studied cohorts were the length of ICU stay and duration of mechanical ventilation. Therefore, we recommend routine monitoring of critically ill COVID-19 patients for these viral co-infections and consider treatment in those patients.

Herpes simplex virus reactivation in patients with COVID-19 and acute respiratory distress syndrome: a prospective cohort study

Background

There is a paucity of data about the occurrence and risk factors of herpes simplex virus (HSV) reactivation among patients with severe COVID-19 presenting with acute respiratory distress syndrome (ARDS).

Methods

We performed a nested case-control study among a cohort of SARS-CoV-2 infected patients with ARDS. Between March and April 2020, all consecutive mechanically ventilated patients ≥18 years old with a positive PCR for SARS-CoV-2 on mucocutaneous samples were included in the study. We collected data on demographics, medical history, laboratory variables, administration of antivirals and other agents, respiratory and organ support procedures, microbiological results, and management of ARDS with prone positioning and the use of steroids. Univariate and multivariable Cox regression models were performed in order to identify predictors of HSV reactivation.

Results

Eighty-three patients with laboratory-confirmed SARS-CoV-2 infection were admitted to the ICU for mechanical ventilation. 18/83 (21.7%) patients developed mucocutaneous herpes simplex virus reactivation after a median of 17 days (IQR, 14–20). Prone positioning was the only independent risk factor for HSV reactivation (adj. hazard ratios, 1.60; 95% CI, 1.11–2.30; P = 0.009). All patients with mucocutaneous HSV reactivation were treated with antivirals. The outcome in terms of ventilator-associated pneumonia, catheter-related bloodstream infections, and in-hospital mortality was similar for patients with and without HSV reactivation.

Conclusions

HSV reactivation is frequent in COVID-19 patients with ARDS, especially if prolonged invasive mechanical ventilation with prone positioning is needed. Prompt testing for HSV and initiation of antiviral therapy should be performed in case of mucocutaneous lesions in this population.

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.

Preemptive acyclovir to prevent herpes simplex virus bronchopneumonitis in mechanically ventilated patients with herpes simplex virus oropharyngeal reactivation: An ancillary study of the preemptive treatment for herpesviridae trial

Background

To evaluate the impact of preemptive acyclovir treatment on herpes simplex virus (HSV) bronchopneumonitis in mechanically ventilated patients with HSV oropharyngeal reactivation.

Methods

Ancillary study of the Preemptive Treatment for Herpesviridae (PTH) clinical trial. Patients included in that trial from one centre (Pitié-Salpêtrière Hospital) and in whom at least one bronchoalveolar lavage (BAL) was performed for ventilator-associated pneumonia suspicion were included in the present study. Rate of HSV bronchopneumonitis, defined as clinical symptoms suggesting of pneumonia and presence of HSV in BAL fluid ≥105 copies of HSV/106 cells, were compared in patients who received either acyclovir or placebo.

Results

Eighty-three patients were included; 40 having received preemptive acyclovir and 43 having received a placebo, without differences between groups at admission or at randomization. The number of patients who developed HSV bronchopneumonitis was lower among acyclovir-treated patients than among placebo-treated patients (40% vs. 72%, respectively, p = .003). Results were similar when restricted to patients without HSV detected in the lower respiratory tract at randomization (31% vs. 61%, respectively, p = .03).

Conclusions

Preemptive acyclovir treatment in mechanically ventilated patients with HSV oropharyngeal reactivation reduces HSV bronchopneumonitis rate.

Reactivation of Herpes Simplex Virus Type 1 (HSV-1) Detected on Bronchoalveolar Lavage Fluid (BALF) Samples in Critically Ill COVID-19 Patients Undergoing Invasive Mechanical Ventilation: Preliminary Results from Two Italian Centers

Reactivation of herpes simplex virus type 1 (HSV-1) has been described in critically ill patients with coronavirus disease 2019 (COVID-19) pneumonia. In the present two-center retrospective experience, we primarily aimed to assess the cumulative risk of HSV-1 reactivation detected on bronchoalveolar fluid (BALF) samples in invasively ventilated COVID-19 patients with worsening respiratory function. The secondary objectives were the identification of predictors for HSV-1 reactivation and the assessment of its possible prognostic impact. Overall, 41 patients met the study inclusion criteria, and 12/41 patients developed HSV-1 reactivation (29%). No independent predictors of HSV-1 reactivation were identified in the present study. No association was found between HSV-1 reactivation and mortality. Eleven out of 12 patients with HSV-1 reactivation received antiviral therapy with intravenous acyclovir. In conclusion, HSV-1 reactivation is frequently detected in intubated patients with COVID-19. An antiviral treatment in COVID-19 patients with HSV-1 reactivation and worsening respiratory function might be considered.

Secondary Immunodeficiency Related to Kidney Disease (SIDKD)-Definition, Unmet Need, and Mechanisms

Kidney disease is a known risk factor for poor outcomes of COVID-19 and many other serious infections. Conversely, infection is the second most common cause of death in patients with kidney disease. However, little is known about the underlying secondary immunodeficiency related to kidney disease (SIDKD). In contrast to cardiovascular disease related to kidney disease, which has triggered countless epidemiologic, clinical, and experimental research activities or interventional trials, investments in tracing, understanding, and therapeutically targeting SIDKD have been sparse. As a call for more awareness of SIDKD as an imminent unmet medical need that requires rigorous research activities at all levels, we review the epidemiology of SIDKD and the numerous aspects of the abnormal immunophenotype of patients with kidney disease. We propose a definition of SIDKD and discuss the pathogenic mechanisms of SIDKD known thus far, including more recent insights into the unexpected immunoregulatory roles of elevated levels of FGF23 and hyperuricemia and shifts in the secretome of the intestinal microbiota in kidney disease. As an ultimate goal, we should aim to develop therapeutics that can reduce mortality due to infections in patients with kidney disease by normalizing host defense to pathogens and immune responses to vaccines.

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.

Outcomes of Herpes Simplex Virus Pneumonitis in Critically Ill Patients

Critically ill patients, such as those in intensive care units (ICUs), can develop herpes simplex virus (HSV) pneumonitis. Given the high prevalence of acute respiratory distress syndrome (ARDS) and multiple pre-existing conditions among ICU patients with HSV pneumonitis, factors predicting mortality in this patient population require further investigation. In this retrospective study, the bronchoalveolar lavage or sputum samples of ICU patients were cultured or subjected to a polymerase chain reaction for HSV detection. Univariable and multivariable Cox regressions were conducted for mortality outcomes. The length of hospital stay was plotted against mortality on Kaplan–Meier curves. Among the 119 patients with HSV pneumonitis (age: 65.8 ± 14.9 years), the mortality rate was 61.34% (73 deaths). The mortality rate was significantly lower among patients with diabetes mellitus (odds ratio [OR] 0.12, 95% confidence interval [CI]: 0.02–0.49, p = 0.0009) and significantly higher among patients with ARDS (OR: 4.18, 95% CI: 1.05–17.97, p < 0.0001) or high (≥30) Acute Physiology and Chronic Health Evaluation II scores (OR: 1.08, 95% CI: 1.00–1.18, p = 0.02). Not having diabetes mellitus (DM), developing ARDS, and having a high Acute Physiology and Chronic Health Evaluation II (APACHE II) score were independent predictors of mortality among ICU patients with HSV pneumonitis.

Herpesviruses in Critically Ill Patients With ARDS

Reactivation of herpsviruses, mainly HSV, CMV and EBV, are frequent among critically ill patients. Although they are not immunocompromised from a classical point of view, these patients often present an alteration of their immune system favoring viral reactivation. Seropositive patients with sepsis and under mechanical ventilation are particularly at risk. Herpesviruses have a pulmonary tropism and can be responsible for non-resolving forms of acute respiratory distress syndrome with high mortality. However, the direct causality between herpesviruses reactivation and impaired outcomes among severely ill patients remains under debate.

Lung Microbiome in Critically Ill Patients

The historical hypothesis of sterility of the lungs was invalidated over a decade ago when studies demonstrated the existence of sparse but very diverse bacterial populations in the normal lung and the association between pulmonary dysbiosis and chronic respiratory diseases. Under mechanical ventilation, dysbiosis occurs rapidly with a gradual decline in diversity over time and the progressive predominance of a bacterial pathogen (mainly Proteobacteria) when lung infection occurs. During acute respiratory distress syndrome, an enrichment in bacteria of intestinal origin, mainly Enterobacteriaceae, is observed. However, the role of this dysbiosis in the pathogenesis of ventilator-associated pneumonia and acute respiratory distress syndrome is not yet fully understood. The lack of exploration of other microbial populations, viruses (eukaryotes and prokaryotes) and fungi is a key issue. Further analysis of the interaction between these microbial kingdoms and a better understanding of the host−microbiome interaction are necessary to fully elucidate the role of the microbiome in the pathogenicity of acute diseases. The validation of a consensual and robust methodology in order to make the comparison of the different studies relevant is also required. Filling these different gaps should help develop preventive and therapeutic strategies for both acute respiratory distress syndrome and ventilator-associated pneumonia.

HSV-1 reactivation is associated with an increased risk of mortality and pneumonia in critically ill COVID-19 patients

BACKGROUND

Data in the literature about HSV reactivation in COVID-19 patients are scarce, and the association between HSV-1 reactivation and mortality remains to be determined. Our objectives were to evaluate the impact of Herpes simplex virus (HSV) reactivation in patients with severe SARS-CoV-2 infections primarily on mortality, and secondarily on hospital-acquired pneumonia/ventilator-associated pneumonia (HAP/VAP) and intensive care unit-bloodstream infection (ICU-BSI).

METHODS

We conducted an observational study using prospectively collected data and HSV-1 blood and respiratory samples from all critically ill COVID-19 patients in a large reference center who underwent HSV tests. Using multivariable Cox and cause-specific (cs) models, we investigated the association between HSV reactivation and mortality or healthcare-associated infections.

RESULTS

Of the 153 COVID-19 patients admitted for ≥ 48 h from Feb-2020 to Feb-2021, 40/153 (26.1%) patients had confirmed HSV-1 reactivation (19/61 (31.1%) with HSV-positive respiratory samples, and 36/146 (24.7%) with HSV-positive blood samples. Day-60 mortality was higher in patients with HSV-1 reactivation (57.5%) versus without (33.6%, p = 0.001). After adjustment for mortality risk factors, HSV-1 reactivation was associated with an increased mortality risk (hazard risk [HR] 2.05; 95% CI 1.16-3.62; p = 0.01). HAP/VAP occurred in 67/153 (43.8%) and ICU-BSI in 42/153 (27.5%) patients. In patients with HSV-1 reactivation, multivariable cause-specific models showed an increased risk of HAP/VAP (csHR 2.38, 95% CI 1.06-5.39, p = 0.037), but not of ICU-BSI.

CONCLUSIONS

HSV-1 reactivation in critically ill COVID-19 patients was associated with an increased risk of day-60 mortality and HAP/VAP.

Herpesvirus reactivation during severe COVID-19 and high rate of immune defect

OBJECTIVE

We assessed herpesvirus reactivation in severe SARS-CoV-2 infection.

METHODS

Retrospective study including consecutive patients admitted to an onco-hematology intensive care unit (ICU) for severe COVID-19. Replication of EBV, CMV, and HSV was evaluated. Competing risk analyses were used to assess the cumulative risk of viral reactivation, and time-dependent Cox and Fine and Gray models to assess risk factors for viral reactivation.

RESULTS

Among 100 patients, 38 were immunocompromised. Sixty-three patients presented viral reactivation (12% for HSV, 58% EBV and 19% CMV). Symptomatic patients received treatment. Overall cumulative incidence of viral reactivation was 56.1% [55.9-56.4] at 10 days. After adjustment, a preexisting hematological malignancy (sHR [95%CI]=0.31 [0.11-0.85]) and solid organ transplantation (sHR [95% CI]=2.09 [1.13-3.87]) remained independently associated with viral reactivation. Viral reactivation (P=0.34) was not associated with mortality.

CONCLUSIONS

Incidence of herpesvirus reactivation in patients admitted to the ICU for severe COVID-19 was high, but rarely required antiviral treatment.

[Management of infectious complications associated with coronavirus infection in severe patients admitted to ICU]

Infections have become one of the main complications of patients with severe SARS-CoV-2 pneumonia admitted in ICU. Poor immune status, frequent development of organic failure requiring invasive supportive treatments, and prolonged ICU length of stay in saturated structural areas of patients are risk factors for infection development. The Working Group on Infectious Diseases and Sepsis GTEIS of the Spanish Society of Intensive Medicine and Coronary Units SEMICYUC emphasizes the importance of infection prevention measures related to health care, the detection and early treatment of major infections in the patient with SARS-CoV-2 infections. Bacterial co-infection, respiratory infections related to mechanical ventilation, catheter-related bacteremia, device-associated urinary tract infection and opportunistic infections are review in the document.

Herpes Simplex Virus Re-Activation in Patients with SARS-CoV-2 Pneumonia: A Prospective, Observational Study

Background: Herpes simplex 1 co-infections in patients with COVID-19 are considered relatively uncommon; some reports on re-activations in patients in intensive-care units were published. The aim of the study was to analyze herpetic re-activations and their clinical manifestations in hospitalized COVID-19 patients, performing HSV-1 PCR on plasma twice a week. Methods: we conducted a prospective, observational, single-center study involving 70 consecutive patients with severe/critical SARS-CoV-2 pneumonia tested for HSV-1 hospitalized at Azienda Ospedaliero-Universitaria of Modena. Results: of these 70 patients, 21 (30.0%) showed detectable viremia and 13 (62%) had clinically relevant manifestations of HSV-1 infection corresponding to 15 events (4 pneumonia, 5 herpes labialis, 3 gingivostomatitis, one encephalitis and two hepatitis). HSV-1 positive patients were more frequently treated with steroids than HSV-1 negative patients (76.2% vs. 49.0%, p = 0.036) and more often underwent mechanical ventilation (IMV) (57.1% vs. 22.4%, p = 0.005). In the unadjusted logistic regression analysis, steroid treatment, IMV, and higher LDH were significantly associated with an increased risk of HSV1 re-activation (odds ratio 3.33, 4.61, and 16.9, respectively). The association with the use of steroids was even stronger after controlling for previous use of both tocilizumab and IMV (OR = 5.13, 95% CI:1.36–19.32, p = 0.016). The effect size was larger when restricting to participants who were treated with high doses of steroids while there was no evidence to support an association with the use of tocilizumab Conclusions: our study shows a high incidence of HSV-1 re-activation both virologically and clinically in patients with SARS-CoV-2 severe pneumonia, especially in those treated with steroids.