Respiratory herpes simplex virus type 1 infection/colonisation in the critically ill: marker or mediator?

Multiple Organ Dysfunction Secondary to Herpes Simplex Virus -1 Reactivation After Treatment With Dexamethasone and Sarilumab for Covid-19 Disease

Introduction

The immunological response to the SARS-CoV-2 virus and the treatment of COVID-19 disease present a potential susceptibility to viral reactivation, particularly Herpes simplex virus-1 (HSV-1).

Case Presentation

A 49-year-old female presented to hospital with severe COVID-19 pneumonitis and was given sarilumab and dexamethasone. She was intubated and ventilated in the intensive care unit (ICU) and initially demonstrated biochemical and clinical evidence of improvement. This was followed by a severe acute deterioration in respiratory, renal, and cardiovascular function, accompanied by a vesicular rash on the face. Polymerase chain reaction confirmed HSV-1 reactivation and treatment with acyclovir was commenced. After 49 days in ICU the patient was successfully weaned from all organ support, and she made a satisfactory recovery.

Conclusions

HSV-1 reactivation is common in COVID-19 and likely contributes to poorer clinical outcomes. The mechanism causing susceptibility to viral reactivation is not clearly defined, however, the development of critical illness induced immunosuppression via dysfunction of interferon and interleukin pathways is a likely mechanism. This effect could be perpetuated with immunosuppressant medications, although further research is needed to characterise this phenomenon.

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.

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.

Efficacy and safety of antiviral therapy in critically ill patients with mechanical ventilation: a meta-analysis with trial sequential analysis of randomized controlled trials

BACKGROUND

Viral reactivation is frequently detected in critically ill patients with mechanical ventilation and is associated with worse outcomes. However, the efficacy and safety of antiviral therapy in these patients remain unknown.

OBJECTIVES

To assess the effects of antiviral therapy on mortality, viral reactivation, and adverse events in critically ill patients with mechanical ventilation.

DATA SOURCES

Medline, Embase, the Cochrane Library, and reference lists.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that compared antiviral therapy with placebo, standard care, or no treatment.

PARTICIPANTS

Critically ill patients with mechanical ventilation.

INTERVENTIONS

Antiviral therapy.

ASSESSMENT OF RISK OF BIAS

Cochrane risk of bias tool.

METHODS OF DATA SYNTHESIS

Risk ratios (RR) with 95% confidence intervals (CIs) were pooled using a random-effects model for meta-analysis with trial sequential analysis.

RESULTS

Nine trials with a broad spectrum of critically ill patients were included. No association was found between antiviral therapy and all-cause mortality at the longest follow-up (nine trials; 1790 patients; RR 0.93, 95% CI 0.79-1.11; I² = 3%). Trial sequential analysis showed that the cumulative Z-curve crossed the futility boundary establishing sufficient evidence. No association also was found between antiviral therapy and 28-day mortality, in-hospital mortality, 60-day mortality, or 90-day mortality. But antiviral therapy was associated with a reduction in viral reactivation (five trials; 644 patients; RR 0.23, 95% CI 0.14-0.37; I² = 0%). Trial sequential analysis showed that the cumulative Z-curve crossed the trial sequential monitoring boundary for benefit establishing sufficient evidence. Antiviral therapy was not associated with an increased risk of renal insufficiency (eight trials; 1574 patients; RR 0.88, 95% CI 0.73-1.05; I² =0%).

CONCLUSIONS

No association between antiviral therapy and mortality was found, but antiviral therapy reduced viral reactivation without increasing the risk of renal insufficiency in critically ill patients with mechanical ventilation.

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.

Theory: Treatments for Prolonged ICU Patients May Provide New Therapeutic Avenues for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

We here provide an overview of treatment trials for prolonged intensive care unit (ICU) patients and theorize about their relevance for potential treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Specifically, these treatment trials generally target: (a) the correction of suppressed endocrine axes, notably through a "reactivation" of the pituitary gland's pulsatile secretion of tropic hormones, or (b) the interruption of the "vicious circle" between inflammation, oxidative and nitrosative stress (O&NS), and low thyroid hormone function. There are significant parallels in the treatment trials for prolonged critical illness and ME/CFS; this is consistent with the hypothesis of an overlap in the mechanisms that prevent recovery in both conditions. Early successes in the simultaneous reactivation of pulsatile pituitary secretions in ICU patients-and the resulting positive metabolic effects-could indicate an avenue for treating ME/CFS. The therapeutic effects of thyroid hormones-including in mitigating O&NS and inflammation and in stimulating the adreno-cortical axis-also merit further studies. Collaborative research projects should further investigate the lessons from treatment trials for prolonged critical illness for solving ME/CFS.

Effect of antiviral therapy on the outcomes of mechanically ventilated patients with herpes simplex virus detected in the respiratory tract: a systematic review and meta-analysis

Background

Herpes simplex virus (HSV) is frequently detected in the respiratory tract of mechanically ventilated patients. The aim of this study was to assess current evidence to determine whether antiviral therapy is associated with better outcomes in these patients.

Methods

MEDLINE, ISI Web of Science, Cochrane Database and ClinicalTrials.gov were searched from inception to 25 May 2020. All clinical studies investigating the effects of antiviral therapy on the outcome of mechanically ventilated ICU patients in whom HSV was detected in the respiratory tract were eligible for inclusion, regardless of study design, publication status or language. Titles and abstracts were reviewed independently by two authors. If the articles seemed eligible, full-text articles were reviewed and data extracted.

We performed a random-effects meta-analysis to estimate relative risks (RRs) with corresponding 95% confidence intervals (CIs). The primary endpoint was hospital all-cause mortality.

Results

Nine studies were included in the meta-analysis (one randomized controlled trial, eight cohort studies). Antiviral treatment was associated with lower hospital mortality (with antiviral treatment, 40.6% (189 out of 465 patients); without, 52.7% (193 out of 366 patients); RR 0.74 [0.64, 0.85]; eight studies, low quality of evidence). Furthermore, antiviral treatment was associated with lower 30-day mortality (RR 0.75 [0.59, 0.94]; three studies, very low quality of evidence). We did not observe evidence for differences in ICU mortality (RR 0.73 [0.51, 1.05]; three studies, very low quality of evidence).

Conclusions

This meta-analysis of the available data shows that antiviral therapy might result in lower hospital and 30-day all-cause mortality in mechanically ventilated ICU patients who are positive for HSV in the respiratory tract. However, this result must be interpreted with great caution due to the high risk of bias and limited number of patients. Large, well-designed randomized controlled clinical trials are urgently needed.

Trial registration

The study was registered in advance on International Prospective Register of Systematic Reviews (CRD42020180053).

Effect of Antiviral Therapy on the Outcome of Mechanically Ventilated Patients With Herpes Simplex Virus Type 1 in BAL Fluid: A Retrospective Cohort Study

BACKGROUND

Herpes simplex virus type 1 (HSV-1) is frequently detected in the BAL fluid of patients on mechanical ventilation.

RESEARCH QUESTION

The aim of the study was to investigate whether antiviral therapy is associated with improved overall survival within 30 days.

STUDY DESIGN AND METHODS

This was a retrospective cohort study in four ICUs between January 2011 and December 2017. All adult patients on mechanical ventilation with a respiratory tract infection with positive polymerase chain reaction testing for HSV-1 in the BAL were included. Patients already receiving antiviral agents on the day BAL was performed were excluded. We performed uni- and multivariable Cox and logistic regression modeling.

RESULTS

Overall, 306 patients were included in the analysis. Among them, 177 patients (57.8%) received antiviral therapy (90.9% acyclovir, 6.2% ganciclovir, 2.9% both). The overall 30-day mortality rate was 42.4% (n = 75) in the antiviral treatment group and 50.4% (n = 65) in the control group. The adjusted hazard ratio (HR) for the primary outcome was 0.62 (95% CI, 0.44-0.87; P = .005), indicating better overall survival within 30 days for the antiviral-treated group than for the untreated group. This benefit was also present in the subgroup of patients without immunosuppression (n = 246; adjusted HR, 0.53; 95% CI, 0.36-0.78; P = .001). Overall, the median lengths of hospital stay (31 vs 24 days, P = .002) and ICU stay (24 vs 17 days, P < .001), and the duration of mechanical ventilation (18 vs 11 days, P < .001), were longer for patients with therapy. No evidence for the treatment-related deterioration of renal function was observed.

INTERPRETATION

These data suggest that detection of HSV-1 in the BAL of patients on mechanical ventilation may be of clinical significance and that specific antiviral treatment may improve clinical outcomes. However, this needs to be proven in multicenter randomized controlled trials before implementation into the clinical routine.

The clinical impact of pneumocystis and viral PCR testing on bronchoalveolar lavage in immunosuppressed patients

Introduction

Pulmonary infiltrates in immunosuppressed patients are common. Yields from bronchoscopy with bronchoalveolar lavage (BAL) has been reported to be between 31 and 65%. The clinical impact of pneumocystis and viral Polymerase chain reaction (PCR) testing on BAL has not been extensively evaluated in a mixed immunosuppressed patient population.

Methods

We performed a retrospective chart review of immunosuppressed adults with pulmonary infiltrates who underwent BAL at the University of Rochester Medical Center. Only one BAL per patient was included. We compared the rate of positive PCR testing to conventional testing. We then investigated factors associated with positive PCR testing. Finally, we assessed for changes in antimicrobial therapy after bronchoscopy.

Results

Three hundred and fifty-nine patients underwent BAL with 249 patients having pneumocystis PCR testing and 142 having viral PCR testing. Pneumocystis identification occurred in 43 patients and viral species identification occurred in 56 patients. PCR testing increased pneumocystis identification compared to microscopy, 14% vs. 5%, p = 0.01, and viral identification compared to culture, 25% vs. 6%, p = 0.0001. Of the patients with positive pneumocystis PCR testing 49% had antibiotics stopped, 66% were started on anti-pneumocystis therapy, and only 6% did not receive treatment. There was no difference in the number of patients with antibiotics stopped based on viral PCR testing results.

Discussion

PCR testing increases BAL yield in immunosuppressed patients compared to conventional testing. Pneumocystis identified by PCR only may cause a self-limited infection and may not require antimicrobial therapy. PCR testing should be included in the evaluation of pulmonary infiltrates in immunosuppressed patients.

•

Polymerase chain reaction testing has increased bronchoscopy yield.

•

Pneumocystis is now being identified in non-HIV/AIDS with negative microscopy.

•

Viruses are identified during bronchoscopy that were missed during nasal testing.

•

Antimicrobial therapies are being changed based on testing results.

Herpes simplex type 1 pneumonitis and acute respiratory distress syndrome in a patient with chronic lymphatic leukemia: a case report

Background

Pulmonary pathogenicity of herpes simplex virus type 1 in patients in intensive care without classic immunosuppression as well as the necessity of antiviral treatment in the case of herpes simplex virus detection in respiratory specimens in these patients is controversial. We present a case of acute respiratory distress syndrome in a patient with stable chronic lymphatic leukemia not requiring treatment, in whom we diagnosed herpes simplex virus type 1 bronchopneumonitis based on herpes simplex virus type 1 detection in bronchoalveolar lavage fluid and clinical response to antiviral treatment.

Case presentation

A 72-year-old white man presented with symptoms of lower respiratory tract infection. His medical history was significant for chronic lymphatic leukemia, which had been stable without treatment, arterial hypertension, multiple squamous cell carcinomas of the scalp, and alcohol overuse. Community-acquired pneumonia was suspected and appropriate broad-spectrum antibacterial treatment was initiated. Within a few hours, rapid respiratory deterioration led to cardiac arrest. He was successfully resuscitated, but developed acute respiratory distress syndrome. Furthermore, he remained febrile and inflammation markers remained elevated despite antibacterial treatment. Polymerase chain reaction from bronchoalveolar lavage fluid and viral culture from tracheobronchial secretions tested positive for herpes simplex virus type 1. We initiated antiviral treatment with acyclovir. Concomitantly we further escalated the antibacterial treatment, although no bacterial pathogen had been isolated at any point. Defervescence occurred rapidly and his C-reactive protein and leukocyte levels decreased. He was successfully weaned from mechanical ventilation, transferred to the ward, and eventually discharged to home.

Conclusions

Herpes simplex virus should be considered a cause for lower respiratory tract infection in critically ill patients, especially in the setting of an underlying disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s13256-017-1495-9) contains supplementary material, which is available to authorized users.

Resistant pathogens, fungi, and viruses

Although originally described in Staphylococcus aureus, resistance among bacteria has now become a race to determine which classes of bacteria will become more resistant. Availability of antibacterial agents has allowed the development of entirely new diseases caused by nonbacterial pathogens, related largely to fungi that are inherently resistant to antibacterials. This article presents the growing body of knowledge of the herpes family of viruses, and their occurrence and consequences in patients with concomitant surgical disease or critical illness. The focus is on previously immunocompetent patients, as the impact of herpes viruses in immunosuppressed patients has received thorough coverage elsewhere.

Herpes Simplex Pneumonia in an Immunocompetent Patient With Progression to Organizing Pneumonia

Background. Organizing pneumonia is an uncommon diffuse interstitial lung disease that affects the terminal and respiratory bronchioles, alveolar ducts, and alveoli. Most cases are idiopathic, but some are associated with infections. We present an uncommon case of organizing pneumonia associated with herpes simplex virus-1 (HSV-1). Case. A 39-year-old man with hypertension presented with dyspnea, fever, and productive cough for 2 weeks. He was treated for 5 days for acute bronchitis as an outpatient with no improvement. His examination revealed mild respiratory distress, O2 saturation 92% on room air, and right sided crackles. Labs included a white blood cell count of 19 300/µL. His chest x-ray showed bilateral infiltrates greater on the right. Bronchoalveolar lavage was positive for HSV-1; transbronchial biopsies showed focal pneumonitis with plentiful intra-alveolar macrophages. His respiratory status progressively deteriorated, and he was intubated for mechanical ventilation. He received 10 days of intravenous (IV) antibiotics and 14 days of IV acyclovir. He was readmitted 10 days later with worsening symptoms and was intubated for respiratory failure. His CT chest showed diffuse, patchy consolidation of both lungs, right more than left. Open lung biopsy showed extensive organizing pneumonia, diffuse alveolar damage, intra-alveolar macrophages, and pleural fibrosis; he was treated with IV corticosteroids. He was extubated after 10 days; within 2 weeks his chest x-ray was markedly improved. Discussion. Organizing pneumonia is usually idiopathic; infection is one of the secondary causes. To our knowledge this is only the second reported case associated with HSV. This association may have important pathogenic and therapeutic implications.

Fatal pulmonary disease and encephalic complication in a man with HSV-1 Infection: a case report

Herpes simplex virus type 1 (HSV-1) is associated with a large spectrum of pathologies i.e. pulmonary diseases. Although it has often been isolated from the lower respiratory tract of immunocompetent or immunosuppressed patients undergoing prolonged mechanical ventilation (MV), its causative role in serious lung infections is still unclear. Here we report the case of a 44-year-old man presenting seizures that followed an acute respiratory illness that occurred during hospitalization. The detection of HSV-1 DNA in bronchoalveolar lavage (BAL), in spinal fluid, and in blood samples, supported the evidence of a disseminated viral infection that strengthens the hypothesis of herpetic pneumonia as a possible triggering cause of neurological complications and fatal outcome. This observation draws attention to the opportunity of introducing tests for the detection of HSV-1 into the diagnostic protocols for such patients. In fact, adequate diagnostic tools would favor early diagnosis and correct therapy to HSV-1 that could reduce the possibility of either encephalic complications or the rate of mortality in critical long-term patients affected by respiratory pathologies who need assisted ventilation.

Clinical features and virological analysis of a case of Middle East respiratory syndrome coronavirus infection

BACKGROUND

The Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging virus involved in cases and case clusters of severe acute respiratory infection in the Arabian Peninsula, Tunisia, Morocco, France, Italy, Germany, and the UK. We provide a full description of a fatal case of MERS-CoV infection and associated phylogenetic analyses.

METHODS

We report data for a patient who was admitted to the Klinikum Schwabing (Munich, Germany) for severe acute respiratory infection. We did diagnostic RT-PCR and indirect immunofluorescence. From time of diagnosis, respiratory, faecal, and urine samples were obtained for virus quantification. We constructed a maximum likelihood tree of the five available complete MERS-CoV genomes.

FINDINGS

A 73-year-old man from Abu Dhabi, United Arab Emirates, was transferred to Klinikum Schwabing on March 19, 2013, on day 11 of illness. He had been diagnosed with multiple myeloma in 2008, and had received several lines of treatment. The patient died on day 18, due to septic shock. MERS-CoV was detected in two samples of bronchoalveolar fluid. Viral loads were highest in samples from the lower respiratory tract (up to 1·2 × 10(6) copies per mL). Maximum virus concentration in urine samples was 2691 RNA copies per mL on day 13; the virus was not present in the urine after renal failure on day 14. Stool samples obtained on days 12 and 16 contained the virus, with up to 1031 RNA copies per g (close to the lowest detection limit of the assay). One of two oronasal swabs obtained on day 16 were positive, but yielded little viral RNA (5370 copies per mL). No virus was detected in blood. The full virus genome was combined with four other available full genome sequences in a maximum likelihood phylogeny, correlating branch lengths with dates of isolation. The time of the common ancestor was halfway through 2011. Addition of novel genome data from an unlinked case treated 6 months previously in Essen, Germany, showed a clustering of viruses derived from Qatar and the United Arab Emirates.

INTERPRETATION

We have provided the first complete viral load profile in a case of MERS-CoV infection. MERS-CoV might have shedding patterns that are different from those of severe acute respiratory syndrome and so might need alternative diagnostic approaches.

FUNDING

European Union; German Centre for Infection Research; German Research Council; and German Ministry for Education and Research.

Viral infections in patients with an acute exacerbation of idiopathic interstitial pneumonia

Background

Patients with slowly progressive idiopathic interstitial pneumonia, including idiopathic pulmonary fibrosis, often deteriorate, thus suggesting that the clinical course may be unpredictable. Such episodes are termed acute exacerbation of idiopathic interstitial pneumonia. The etiology of an acute exacerbation of idiopathic interstitial pneumonia is unknown. In this study, we tested the hypothesis that an acute exacerbation of idiopathic interstitial pneumonia is induced by respiratory viral infections.

Methods

Bronchoalveolar lavage fluid obtained from patients with an acute exacerbation of idiopathic interstitial pneumonia was tested for viral nucleic acid using polymerase chain reaction.

Results

Only 1 of the 14 patients with an acute exacerbation of idiopathic interstitial pneumonia exhibited evidence of respiratory syncytial virus B, and 2 patients exhibited evidence of cytomegalovirus. Seven patients fulfilled the diagnostic criteria of idiopathic pulmonary fibrosis.

Conclusions

Most cases with an acute exacerbation of idiopathic interstitial pneumonia are not caused by a viral infection.

Clinical correlates of herpes simplex virus type 1 loads in the lower respiratory tract of critically ill patients

BACKGROUND

The significance of isolation of herpes simplex virus (HSV) type 1 from the lower respiratory tract in critically ill patients on mechanical ventilation is still unclear. In the current study, we used polymerase chain reaction techniques to quantify HSV-1 to further evaluate its role.

OBJECTIVES

The hypothesis was that high loads reflect invasive pulmonary disease related to prolonged mechanical ventilation and increased mortality, as opposed to shedding from the upper respiratory tract, which leads to lower viral loads.

STUDY DESIGN

We prospectively studied 77 consecutive patients admitted to the intensive care unit and analyzed 136 tracheal aspirates or bronchoalveolar lavage fluids, taken when clinically indicated in the diagnostic workup of fever, radiologic pulmonary infiltrates, progressive respiratory insufficiency or combinations. Samples were cultured for bacteria and yeasts according to routine microbiological methods and HSV-1 loads were determined by real time quantitative PCR. Viral loads were expressed per number of cells recovered.

RESULTS

HSV-1 load was directly related to the simplified acute physiology score II (rs=0.47, P=0.04) when the first specimen taken proved positive for HSV-1. HSV-1 positivity concurred with Candida spp. colonization. Patients with and without a HSV-1 load did not differ with respect to pulmonary and systemic courses and vital outcomes.

CONCLUSIONS

The data suggest that HSV-1 in the lower respiratory tract originates from shedding in the upper respiratory tract in about 30% of critically ill patients, following immune suppression and reactivation, without invasively infecting the lung. No attributable mortality was observed.

Clinical impact of HSV-1 detection in the lower respiratory tract from hospitalized adult patients

The occurrence and clinical impact of herpes simplex virus (HSV) were evaluated in 342 bronchoalveolar lavage specimens from 237 patients. HSV-1 and HSV-2 were detected in 32.1% and <1% of patients, respectively. A significant difference of HSV-1 prevalence and load was found in relation to admission to intensive care unit, mechanical ventilation and mortality within 28 days; in particular, a viral load ≥10(5) copies/mL bronchoalveolar lavage fluid was significantly associated with critical features. No association was found with immune status or other characteristics. Nine of 21 (42.9%) cases of ventilator-associated pneumonia were positive for HSV-1, with poor outcome in six.

Viral infections in septic shock (VISS-trial)-crosslinks between inflammation and immunosuppression

BACKGROUND

Recent investigations provided evidence that herpes simplex virus (HSV-1) and cytomegalovirus (CMV) are reactivated in critically ill individuals. However, at this time, it remains unclear whether these viral infections are of real pathogenetic relevance or represent innocent bystanders.

MATERIALS AND METHODS

In total, 60 patients with septic shock were enrolled. Blood samples and tracheal secretion were collected at the time of sepsis diagnosis (T0) as well as 7 d (T1), 14 d (T2), 21 d (T3), and 28 d (T4) later. The following virologic diagnostics were performed: (1) Viral load of herpes simplex virus type1 (HSV-1) and cytomegalovirus (CMV) in blood samples as well as tracheal secretion using polymerase chain reaction (PCR). (2) Detection of CMV-antigen (pp65) in blood samples using immunofluorescence microscopy. Furthermore plasma levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) were evaluated using ELISA-kits.

RESULTS

Thirty-one patients (51.7%) were found to be positive for HSV-1, whereas in 16 patients (26.7%) CMV could be identified. Patients with a positive PCR for HSV-1 and/or CMV showed a significantly prolonged length of hospital stay and absolute time of respirator-dependant ventilation. Furthermore, survival curves of patients with a high HSV-1-load (>10E8) in tracheal secretion in comparison with those with a lower HSV-1-load (<10E8) revealed a significantly impaired survival.

CONCLUSIONS

Viral superinfections with HSV-1 or CMV can frequently be observed in patients with septic shock, especially in those with increased disease severity and a prolonged need for respirator-dependant ventilation. In patients with a viral superinfection morbidity is increased, whereas differences in mortality seem to be dosage-dependant.

The potential influence of common viral infections diagnosed during hospitalization among critically ill patients in the United States

Viruses are the most common source of infection among immunocompetent individuals, yet they are not considered a clinically meaningful risk factor among the critically ill. This work examines the association of viral infections diagnosed during the hospital stay or not documented as present on admission to the outcomes of ICU patients with no evidence of immunosuppression on admission. This is a population-based retrospective cohort study of University HealthSystem Consortium (UHC) academic centers in the U.S. from the years 2006 to 2009. The UHC is an alliance of over 90% of the non-profit academic medical centers in the U.S. A total of 209,695 critically ill patients were used in this analysis. Eight hospital complications were examined. Patients were grouped into four cohorts: absence of infection, bacterial infection only, viral infection only, and bacterial and viral infection during same hospital admission. Viral infections diagnosed during hospitalization significantly increased the risk of all complications. There was also a seasonal pattern for viral infections. Specific viruses associated with poor outcomes included influenza, RSV, CMV, and HSV. Patients who had both viral and bacterial infections during the same hospitalization had the greatest risk of mortality RR 6.58, 95% CI (5.47, 7.91); multi-organ failure RR 8.25, 95% CI (7.50, 9.07); and septic shock RR 271.2, 95% CI (188.0, 391.3). Viral infections may play a significant yet unrecognized role in the outcomes of ICU patients. They may serve as biological markers or play an active role in the development of certain adverse complications by interacting with coincident bacterial infection.

Herpes simplex virus: a marker of severity in bacterial ventilator-associated pneumonia

PURPOSE

Ventilator-associated pneumonia (VAP) is the most frequent nosocomial infection in intensive care units and has a high morbidity and mortality rate. It is mainly a bacterial disease, although the potential role of viruses as pathogens or copathogens in VAP is under discussion. Our study aims were to determine the incidence of herpes simplex virus (HSV) in the lower respiratory tract (LRT) secretions in patients with bacterial VAP and to assess its potential clinical relevance.

MATERIAL AND METHODS

This is a prospective observational study carried out over a 14-month period. All LRT samples of adult patients with VAP were sent for bacterial culture and virus isolation. We compared patients with bacterial VAP with isolation of HSV and those without.

RESULTS

One-hundred seventy-seven patients had confirmed bacterial VAP. Herpes simplex virus was present in 13.4% of them. Patients with HSV had more severe underlying conditions and worse outcome. They consumed more antibiotics for the VAP episode, had more Clostridium difficile infection, spent a longer time on mechanical ventilation, had a longer intensive care unit and hospital stay, and had greater mortality than those without.

CONCLUSIONS

Herpes simplex virus excretion in LRT secretions is not infrequent in VAP, and it is associated with greater severity and worse prognosis.

Clinical course and spectrum of intensive care unit patients reactivating herpes simplex-1 virus: a retrospective analysis

Background:

Herpes simplex-1 virus (HSV-1) reactivation in the respiratory tract is common in intensive care unit (ICU) patients. However, susceptible ICU populations are poorly defined. Clinical recognition of HSV infection of the respiratory tract is difficult and the impact of such reactivation is not understood.

Materials and Methods:

A retrospective analysis of HSV-1 positive patients encountered over a 5-year period at a multispecialty ICU was carried out. HSV-1 was identified in respiratory secretions using a qualitative polymerase chain reaction (PCR) technique. Patient charts were reviewed for clinical features that would typify HSV-1 respiratory involvement, and the morbidity and mortality risks found with HSV-1 respiratory involvement.

Results:

A review of 48 HSV-1 positive ICU patients showed that patients reactivating HSV in the respiratory tract fell into one of the three categories: (1) septic elderly patients with and without ARDS, (2) immunosuppressed patients, especially those receiving high-dose steroids, and (3) post-thoracotomy patients. Abnormalities suggestive of HSV-1 reactivation in the respiratory tract included, haemorrhagic or excessive respiratory secretions, concomitant orofacial herpes (42%), and bronchoscopic abnormalities (hemorrhagic ulcers and mucosal friability) (83%). Twenty eight percent of the HSV-1 infected patients experienced postextubation stridor. HSV-1 reactivation was associated with extended ventilator stays, significant mortality (42%), and ventilator-associated pneumonias (52%).

Conclusions:

Identification of susceptible populations and definition of clinical features of HSV-1 related respiratory disease can enable diagnosis of HSV-1 infection in ICU patients. Although detection by a PCR technique can rapidly diagnose HSV-1 reactivation, prospective studies are required to clarify HSV disease versus mere shedding, and understand the impact of HSV-1 reactivation in hospitalized patients.

A detailed evaluation of acute respiratory decline in patients with fibrotic lung disease: aetiology and outcomes

BACKGROUND AND OBJECTIVE

A comprehensive diagnostic evaluation is recommended for all patients with fibrotic lung disease and acute respiratory decompensation. However, the effect on clinical outcomes of this evaluation remains unknown.

METHODS

We evaluated 27 consecutive patients with fibrotic lung disease who were hospitalized for an acute respiratory decline between June 2006 and April 2009. An interstitial lung disease expert assisted with the acute care of each patient. A retrospective review of the patient charts was performed to obtain demographic and clinical data, and to assess outcomes.

RESULTS

Using a strict definition of acute exacerbation (AE) of fibrotic lung disease derived from the IPF Network Pulmonary Perspective statement, 10 of the 27 patients were classified as definite AE and nine as suspected AE. In eight patients, infectious agents were identified as potential explanations for the respiratory decline. No patients with congestive heart failure or pulmonary embolism were identified. Overall survival to discharge was 37.0%. One-year survival was 14.8%. There were no differences in outcomes for patients with AE compared with those for whom potential infectious aetiologies were identified (log rank, P = 0.932). Patients with IPF showed a decreased rate of survival compared with patients with non-IPF fibrotic disease (1-year survival 0% vs 28.6%, log rank, P = 0.045).

CONCLUSIONS

In patients with fibrotic lung disease and an acute respiratory decline, a detailed diagnostic evaluation revealed a potential infectious aetiology in up to one-third of cases. However, there was no association between this finding and outcomes in these patients. One-year survival was dismal in patients who suffered an acute respiratory decompensation.

Microsatellite analysis of HSV-1 isolates: from oropharynx reactivation toward lung infection in patients undergoing mechanical ventilation

BACKGROUND

According to recent reports, herpes simplex virus type 1 (HSV-1) induces bronchopneumonitis (BPn) in immunocompetent patients undergoing prolonged mechanical ventilation (MV), whose respiratory functions deteriorate with a poor outcome. HSV-1 BPn is associated with HSV symptomatic or symptomless reactivation in the oropharynx.

OBJECTIVES

We sought to systematically and genetically characterize HSV-1 strains isolated from immunocompetent patients receiving prolonged MV and to characterize the genetic relationship of strains sequentially isolated from oropharyngeal samples (OPS) and broncho-alveolar liquids (BAL) to determine the natural course of HSV BPn.

STUDY DESIGN

In this molecular epidemiological study, microsatellite technology was used to determine genetic relationships between 211 HSV-1 strains isolated from OPS and/or BAL from 106 patients receiving MV.

RESULTS

Microsatellite haplotypes of HSV-1 strains sequentially isolated from the same individual were identical, and HSV-1 isolates from the lung were genetically indistinguishable from strains isolated from the oral cavity. Each patient was characterized by their own HSV-1 microsatellite haplotype, and no nosocomial transmission of strains between patients was observed.

CONCLUSION

Our results demonstrate that, in patients who receive MV, the HSV-1 pulmonary infection results from the reactivation of genetically related HSV-1 in the oropharynx, which progressively infects the lower respiratory tract.

Clinical relevance of and risk factors for HSV-related tracheobronchitis or pneumonia: results of an outbreak investigation

Introduction

Herpes simplex virus (HSV) type 1 was identified in respiratory specimens from a cluster of eight patients on a surgical intensive care unit within 8 weeks. Six of these patients suffered from HSV-related tracheobronchitis and one from HSV-related pneumonia only. Our outbreak investigation aimed to determine the clinical relevance of and risk factors associated with HSV-related tracheobronchitis or pneumonia in critically ill patients, and to investigate whether the cluster was caused by nosocomial transmission.

Methods

A retrospective cohort study was performed to identify risk factors for the outcomes of HSV-related tracheobronchitis or pneumonia and death using univariable analysis as well as logistic regression analysis. Viruses were typed by molecular analysis of a fragment of the HSV type 1 glycoprotein G.

Results

The cohort of patients covering the outbreak period comprised 53 patients, including six patients with HSV-related tracheobronchitis and one patient with pneumonia only. HSV-related tracheobronchitis or pneumonia was associated with increased mortality (100% in patients with versus 17.8% in patients without HSV-related tracheobronchitis or pneumonia; P < 0.0001). The interaction of longer duration of ventilation and tracheotomy was associated with HSV-related tracheobronchitis or pneumonia in multivariable analysis.

Identical HSV type 1 glycoprotein G sequences were found in three patients and in two patients. The group of three identical viral sequences belonged to a widely circulating strain. The two identical viral sequences were recovered from bronchoalveolar lavages of one patient with HSV-related tracheobronchitis and of one patient without clinical symptoms. These viral sequences showed unique polymorphisms, indicating probable nosocomial transmission.

Conclusion

HSV-related tracheobronchitis or pneumonia is associated with increased mortality in critically ill patients. Care should be taken to avoid nosocomial transmission and early diagnosis should be attempted.

Herpes simplex virus lung infection in patients undergoing prolonged mechanical ventilation

RATIONALE

It is not known whether the isolation of herpes simplex virus (HSV) from lower respiratory tract samples of nonimmunocompromised ventilated patients corresponds to bronchial contamination from the mouth and/or throat, local tracheobronchial excretion of HSV, or true HSV lung involvement (bronchopneumonitis) with its own morbidity/mortality.

OBJECTIVES

This prospective, single-center, observational study was conducted to define the frequency, risk factors, and relevance of HSV bronchopneumonitis.

METHODS

All consecutive nonimmunocompromised patients receiving mechanical ventilation for 5 days or more were evaluated. Bronchoalveolar lavage, oropharyngeal swabs, and bronchial biopsies (presence of macroscopic bronchial lesions) were obtained for all who deteriorated clinically with suspected lung infection. HSV bronchopneumonitis was defined as this deterioration, associated with HSV in bronchoalveolar lavage and HSV-specific nuclear inclusions in cells recovered during lavage or bronchial biopsies.

MEASUREMENTS AND MAIN RESULTS

HSV bronchopneumonitis was diagnosed in 42 (21%) of the 201 patients who deteriorated clinically, with a mean mechanical ventilation duration before diagnosis of 14 +/- 6 days. Risk factors associated with HSV bronchopneumonitis were oral-labial lesions, HSV in the throat, and macroscopic bronchial lesions seen during bronchoscopy. Patients with HSV bronchopneumonitis were comparable to those without at admission, but their courses were more complicated, with longer duration of mechanical ventilation and intensive care unit stays.

CONCLUSIONS

HSV bronchopneumonitis is common in nonimmunocompromised patients with prolonged mechanical ventilation, is associated with HSV reactivation or infection of the mouth and/or throat, and seems to be associated with poorer outcome.

Quantitative detection of herpes simplex virus DNA in the lower respiratory tract

Quantitation of herpes simplex virus (HSV) DNA in bronchoalveolar lavage specimens could indicate an infectious role in the lower respiratory tract. The aim of this study was to compare quantitative HSV DNA results from adult bronchoalveolar lavage specimens to clinical outcome. Quantitative real-time PCR assays targeting HSV and other herpes viruses were performed on adult bronchoalveolar lavage specimens obtained from a largely immunocompromised population during a 1-year period. The results were compared to patient characteristics and outcome. HSV DNA was detected in 11 (19%) of 57 bronchoalveolar lavage specimens with a mean viral level of 5.6 log genome equivalents/ml (range, 2.9-8.1 log). A threshold of HSV DNA levels equal or higher than 5.0 log (n = 7) was associated with mortality within 28 days following hospital admission (odds ratio [OR], 6.8; 95% confidence interval [CI], 1.2-39.2). A threshold level of 5.5 log was associated with mortality within 28 days of sampling (OR 8.5; 95% CI 1.2-62.1), only after excluding patients receiving specific antiviral medication. Patients with HSV DNA levels equal or higher than 7.5 log had severe respiratory failure. Viral pneumonia was histologically proven in one patient with 8.0 log at autopsy. No patient with HSV DNA levels below 5.5 log (n = 5) or DNA levels higher than 5.0 log of cytomegalovirus (CMV) (n = 3), Epstein-Barr virus (EBV) (n = 9), varicella-zoster virus (VZV) (n = 1), or human herpesvirus 6 (HHV-6) (n = 0) died within 28 days of hospital admission. We conclude that quantitative detection of HSV DNA in bronchoalveolar lavage fluid is a potential diagnostic tool for detection of relevant viral infection of the lower respiratory tract.

Herpes simplex virus type 1 and respiratory disease in critically-ill patients: real pathogen or innocent bystander?

Herpes simplex virus type 1 (HSV-1) has been associated with pulmonary disease, mostly in severely immunocompromised patients. After reactivation and shedding in the oropharynx, the virus may reach the lower respiratory tract by aspiration or by contiguous spread. HSV-1 can be detected in clinical specimens by virus culture or quantitatively by nucleic acid amplification techniques. With these techniques, HSV-1 is often detected in the respiratory secretions of critically-ill patients. However, a clear diagnosis of HSV-1 pneumonia is difficult to establish because clinical criteria, radiological features and laboratory findings all lack specificity. Lower respiratory tract HSV-1 infections have not been associated with specific risk-factors. There is also an absence of consistent data concerning the effect of antiviral treatment on the outcome of critically-ill patients. Further studies are needed to better define the pathogenic role of HSV-1 in the lower respiratory tract of these patients, to improve the diagnosis, and, especially, to assess the need for antiviral treatment in the individual patient.

NK cells contribute to the early clearance of HSV-1 from the lung but cannot control replication in the central nervous system following intranasal infection

While infection of the respiratory tract with herpes simplex virus type 1 (HSV-1) can have severe clinical complications, little is known of the immune mechanisms that control both the replication and spread of HSV-1 in this site. To better understand the contribution of innate immunity and in particular natural killer (NK) cells to the control of infection at this site, we have utilized a mouse model of intranasal HSV-1 infection. NK cell numbers increased in the lung following intranasal infection and they produced IFN-gamma and acquired an enhanced cytotoxic capacity. While depletion of NK cells resulted in increased HSV-1 titres in the lung, the time taken to clear the virus was unaffected. Interestingly, HSV-1 was also effectively cleared from the lungs of RAG-1-/- mice that lack both B and T cells. However, RAG-1-/- mice could not control the spread of virus to the central nervous system and its subsequent replication in the brain. Together, these data demonstrate that NK cells are recruited, activated and contribute to early protection of the lung during acute HSV-1 infection of the respiratory tract, but in the absence of adaptive immunity are unable to control the replication and spread of virus in the nervous system.

Herpes simplex virus type 1 and normal protein permeability in the lungs of critically ill patients: a case for low pathogenicity?

Introduction

The pathogenicity of late respiratory infections with herpes simplex virus type 1 (HSV-1) in the critically ill is unclear.

Methods

In four critically ill patients with persistent pulmonary infiltrates of unknown origin and isolation of HSV-1 from tracheal aspirate or bronchoalveolar lavage fluid, at 7 (1–11) days after start of mechanical ventilatory support, a pulmonary leak index (PLI) for ⁶⁷Gallium (⁶⁷Ga)-transferrin (upper limit of normal 14.1 × 10^-3/min) was measured.

Results

The PLI ranged between 7.5 and 14.0 × 10^-3/min in the study patients. Two patients received a course of acyclovir and all survived.

Conclusions

The normal capillary permeability observed in the lungs argues against pathogenicity of HSV-1 in the critically ill, and favors that isolation of the virus reflects reactivation in the course of serious illness and immunodepresssion, rather than primary or superimposed infection in the lungs.