Lung dendritic-cell metabolism underlies susceptibility to viral infection in diabetes.

People with diabetes feature a life-risking susceptibility to respiratory viral infection, including influenza and SARS-CoV-2 (ref. 1), whose mechanism remains unknown. In acquired and genetic mouse models of diabetes, induced with an acute pulmonary viral infection, we demonstrate that hyperglycaemia leads to impaired costimulatory molecule expression, antigen transport and T cell priming in distinct lung dendritic cell (DC) subsets, driving a defective antiviral adaptive immune response, delayed viral clearance and enhanced mortality. Mechanistically, hyperglycaemia induces an altered metabolic DC circuitry characterized by increased glucose-to-acetyl-CoA shunting and downstream histone acetylation, leading to global chromatin alterations. These, in turn, drive impaired expression of key DC effectors including central antigen presentation-related genes. Either glucose-lowering treatment or pharmacological modulation of histone acetylation rescues DC function and antiviral immunity. Collectively, we highlight a hyperglycaemia-driven metabolic-immune axis orchestrating DC dysfunction during pulmonary viral infection and identify metabolic checkpoints that may be therapeutically exploited in mitigating exacerbated disease in infected diabetics.

Indirect effects of the covid-19 pandemic on childhood infection in England: population based observational study.

OBJECTIVE: To assess the impact of the covid-19 pandemic on hospital admission rates and mortality outcomes for childhood respiratory infections, severe invasive infections, and vaccine preventable disease in England. DESIGN: Population based observational study of 19 common childhood respiratory, severe invasive, and vaccine preventable infections, comparing hospital admission rates and mortality outcomes before and after the onset of the pandemic in England. SETTING: Hospital admission data from every NHS hospital in England from 1 March 2017 to 30 June 2021 with record linkage to national mortality data. POPULATION: Children aged 0-14 years admitted to an NHS hospital with a selected childhood infection from 1 March 2017 to 30 June 2021. MAIN OUTCOME MEASURES: For each infection, numbers of hospital admissions every month from 1 March 2017 to 30 June 2021, percentage changes in the number of hospital admissions before and after 1 March 2020, and adjusted odds ratios to compare 60 day case fatality outcomes before and after 1 March 2020. RESULTS: After 1 March 2020, substantial and sustained reductions in hospital admissions were found for all but one of the 19 infective conditions studied. Among the respiratory infections, the greatest percentage reductions were for influenza (mean annual number admitted between 1 March 2017 and 29 February 2020 was 5379 and number of children admitted from 1 March 2020 to 28 February 2021 was 304, 94% reduction, 95% confidence interval 89% to 97%), and bronchiolitis (from 51 655 to 9423, 82% reduction, 95% confidence interval 79% to 84%). Among the severe invasive infections, the greatest reduction was for meningitis (50% reduction, 47% to 52%). For the vaccine preventable infections, reductions ranged from 53% (32% to 68%) for mumps to 90% (80% to 95%) for measles. Reductions were seen across all demographic subgroups and in children with underlying comorbidities. Corresponding decreases were also found for the absolute numbers of 60 day case fatalities, although the proportion of children admitted for pneumonia who died within 60 days increased (age-sex adjusted odds ratio 1.71, 95% confidence interval 1.43 to 2.05). More recent data indicate that some respiratory infections increased to higher levels than usual after May 2021. CONCLUSIONS: During the covid-19 pandemic, a range of behavioural changes (adoption of non-pharmacological interventions) and societal strategies (school closures, lockdowns, and restricted travel) were used to reduce transmission of SARS-CoV-2, which also reduced admissions for common and severe childhood infections. Continued monitoring of these infections is required as social restrictions evolve.

Immunopathogenesis of Different Emerging Viral Infections: Evasion, Fatal Mechanism, and Prevention.

Different emerging viral infections may emerge in different regions of the world and pose a global pandemic threat with high fatality. Clarification of the immunopathogenesis of different emerging viral infections can provide a plan for the crisis management and prevention of emerging infections. This perspective article describes how an emerging viral infection evolves from microbial mutation, zoonotic and/or vector-borne transmission that progresses to a fatal infection due to overt viremia, tissue-specific cytotropic damage or/and immunopathology. We classified immunopathogenesis of common emerging viral infections into 4 categories: 1) deficient immunity with disseminated viremia (e.g., Ebola); 2) pneumocytotropism with/without later hyperinflammation (e.g., COVID-19); 3) augmented immunopathology (e.g., Hanta); and 4) antibody-dependent enhancement of infection with altered immunity (e.g., Dengue). A practical guide to early blocking of viral evasion, limiting viral load and identifying the fatal mechanism of an emerging viral infection is provided to prevent and reduce the transmission, and to do rapid diagnoses followed by the early treatment of virus neutralization for reduction of morbidity and mortality of an emerging viral infection such as COVID-19.

New Parvoviruses and Picornavirus in Tissues and Feces of Foals with Interstitial Pneumonia.

Six foals with interstitial pneumonia of undetermined etiology from Southern California were analyzed by viral metagenomics. Spleen, lung, and colon content samples obtained during necropsy from each animal were pooled, and nucleic acids from virus-like particles enriched for deep sequencing. The recently described equine copiparvovirus named eqcopivirus, as well as three previously uncharacterized viruses, were identified. The complete ORFs genomes of two closely related protoparvoviruses, and of a bocaparvovirus, plus the partial genome of a picornavirus were assembled. The parvoviruses were classified as members of new ungulate protoparvovirus and bocaparvovirus species in the Parvoviridae family. The picornavirus was classified as a new species in the Salivirus genus of the Picornaviridae family. Spleen, lung, and colon content samples from each foal were then tested for these viral genomes by nested PCR and RT-PCR. When present, parvoviruses were detected in both feces and spleen. The picornavirus, protoparvovirus, and eqcopivirus genomes were detected in the lungs of one animal each. Three foals were co-infected with the picornavirus and either a protoparvovirus, bocaparvovirus, or eqcopivirus. Two other foals were infected with a protoparvovirus only. No viral infection was detected in one animal. The complete ORFs of the first equine protoparvoviruses and bocaparvovirus, the partial ORF of the third equine picornavirus, and their detection in tissues of foals with interstitial pneumonia are described here. Testing the involvement of these viruses in fatal interstitial pneumonia or other equine diseases will require larger epidemiological and/or inoculation studies.

Immune Dysregulation and the Increased Risk of Complications and Mortality Following Respiratory Tract Infections in Adults With Down Syndrome.

The risk of severe outcomes following respiratory tract infections is significantly increased in individuals over 60 years, especially in those with chronic medical conditions, i.e., hypertension, diabetes, cardiovascular disease, dementia, chronic respiratory disease, and cancer. Down Syndrome (DS), the most prevalent intellectual disability, is caused by trisomy-21 in ~1:750 live births worldwide. Over the past few decades, a substantial body of evidence has accumulated, pointing at the occurrence of alterations, impairments, and subsequently dysfunction of the various components of the immune system in individuals with DS. This associates with increased vulnerability to respiratory tract infections in this population, such as the influenza virus, respiratory syncytial virus, SARS-CoV-2 (COVID-19), and bacterial pneumonias. To emphasize this link, here we comprehensively review the immunobiology of DS and its contribution to higher susceptibility to severe illness and mortality from respiratory tract infections.

14-3-3 is a VP3-binding protein involved in Macrobrachium rosenbergii Taihu virus infection in shrimp.

Macrobrachium rosenbergii Taihu virus (MrTV) is a fierce pathogen that causes high mortality in M. rosenbergii larvae. Little is known about the pathogenesis of MrTV and host-virus interactions. In this study, a virus overlay protein binding assay (VOPBA), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, was carried out to search for novel host molecules that bind with VP3, one of the main capsid proteins of MrTV. Macrobrachium rosenbergii 14-3-3 protein (Mr14-3-3) was identified as the binding protein of VP3, which was further confirmed by co-immunoprecipitation (Co-IP) and co-localization assay. A preincubation assay was developed, which indicated that preincubation with recombinant Mr14-3-3 (rMr14-3-3) could significantly decrease the expression level of VP3 in MrTV-infected M. rosenbergii larvae, suggesting that preincubation with rMr14-3-3 could partially block MrTV infection. This study revealed that Mr14-3-3 acts as a binding protein for MrTV-VP3 and plays an important role in MrTV infection, offering a potential target for the development of anti-MrTV therapies.

Prevalence and outcomes of co-infection and superinfection with SARS-CoV-2 and other pathogens: A systematic review and meta-analysis.

INTRODUCTION: The recovery of other pathogens in patients with SARS-CoV-2 infection has been reported, either at the time of a SARS-CoV-2 infection diagnosis (co-infection) or subsequently (superinfection). However, data on the prevalence, microbiology, and outcomes of co-infection and superinfection are limited. The purpose of this study was to examine the occurrence of co-infections and superinfections and their outcomes among patients with SARS-CoV-2 infection. PATIENTS AND METHODS: We searched literature databases for studies published from October 1, 2019, through February 8, 2021. We included studies that reported clinical features and outcomes of co-infection or superinfection of SARS-CoV-2 and other pathogens in hospitalized and non-hospitalized patients. We followed PRISMA guidelines, and we registered the protocol with PROSPERO as: CRD42020189763. RESULTS: Of 6639 articles screened, 118 were included in the random effects meta-analysis. The pooled prevalence of co-infection was 19% (95% confidence interval [CI]: 14%-25%, I2 = 98%) and that of superinfection was 24% (95% CI: 19%-30%). Pooled prevalence of pathogen type stratified by co- or superinfection were: viral co-infections, 10% (95% CI: 6%-14%); viral superinfections, 4% (95% CI: 0%-10%); bacterial co-infections, 8% (95% CI: 5%-11%); bacterial superinfections, 20% (95% CI: 13%-28%); fungal co-infections, 4% (95% CI: 2%-7%); and fungal superinfections, 8% (95% CI: 4%-13%). Patients with a co-infection or superinfection had higher odds of dying than those who only had SARS-CoV-2 infection (odds ratio = 3.31, 95% CI: 1.82-5.99). Compared to those with co-infections, patients with superinfections had a higher prevalence of mechanical ventilation (45% [95% CI: 33%-58%] vs. 10% [95% CI: 5%-16%]), but patients with co-infections had a greater average length of hospital stay than those with superinfections (mean = 29.0 days, standard deviation [SD] = 6.7 vs. mean = 16 days, SD = 6.2, respectively). CONCLUSIONS: Our study showed that as many as 19% of patients with COVID-19 have co-infections and 24% have superinfections. The presence of either co-infection or superinfection was associated with poor outcomes, including increased mortality. Our findings support the need for diagnostic testing to identify and treat co-occurring respiratory infections among patients with SARS-CoV-2 infection.

Myocarditis Presenting as Sudden Death in Infants and Children: A Single Centre Analysis by ESGFOR Study Group.

BACKGROUND: Acute myocarditis is an inflammatory disease of the heart mostly diagnosed in young people, which can present as sudden death. The etiology includes infectious agents (mostly viruses), systemic diseases and toxins. We aim to characterize infants and children with myocarditis at post-mortem presenting as sudden deaths. METHODS: Retrospective evaluation of 813 post-mortems in infants and children dying suddenly and unexpectedly between 2009-2019. Data retrieved included histological features, microbiology and clinical history. RESULTS: 23 of 813 post-mortems reviewed corresponded to acute myocarditis and 1 to dilated cardiomyopathy related to remote Parvovirus infection. PCR identified enterovirus (7), parvovirus (7 cases, 2 also with HHV6 and 1 case with EVB), Influenza A (1), Parainfluenza type 3 (1). Two cases corresponded to hypersensitivity myocarditis, 1 was Group A Streptococcus and 5 idiopathic myocarditis. Enterovirus was frequent in infants (7/10), and in newborns was associated with meningoencephalitis or congenital myocarditis. More than 50% were less than 2 years of age and all remained clinically unsuspected. CONCLUSION: Myocarditis represents almost 3% of all sudden pediatric deaths. Enterovirus and parvovirus were the most common viruses. This retrospective analysis showed that patients experienced viral symptoms but remained unsuspected, highlighting the need for more clinical awareness of myocarditis.

Viral Infections in Burns.

Background: Viral infections after burns are less common than bacterial infections but usually occur in the more severely burned patients and have been associated with poor outcomes. Methods: Retrospective reviews and case series were examined to provide an overview of the management of viral infections in the burn patient. Results: The most common viral pathogens in these patients are the herpesviruses, which include herpes simplex, varicella zoster, cytomegalovirus, and human herpesvirus 6. Established viral infections that may complicate patient management include human immunodeficiency virus, hepatitis B and C, and, more recently, the novel coronavirus SARS-CoV-2. Herpesvirus infections can occur as primary or nosocomial pathogens but clinical manifestations most commonly are re-activation of latent viral infection. Because of the paucity of data in the burn population, much of the evidence for specific treatments is extrapolated from patients with severe immunosuppression or critical illness. Antiviral therapy is employed for the burn patient with herpesvirus infections. This is an area of active study, and further research is needed to better understand the risks, clinical manifestations, and attributable morbidity and mortality of viral infections. Conclusions: Major burn injury results in immunosuppression and viral infection in a small number of patients. Recognition and antiviral therapy are employed, but additional studies are necessary to improve outcomes in these patients.

Gene expression profile in cases of infectious death in infancy.

BACKGROUND: Genetic predispositions in cases suffering sudden unexpected infant death have been a research focus worldwide during the past decade. Despite large efforts, there is still uncertainty concerning the molecular pathogenesis of these deaths. With genetic technology in constant development, the possibility of an alternative approach into this research field has become available, like mRNA expression studies. METHODS: In this study, we investigated mRNA gene expression in 14 cases who died suddenly and unexpectedly from infection without a history of severe illness prior to death. The control group included eight accidents, two cases of natural death, one undetermined, one case of medical malpractice, and two homicides. The study included tissue from liver, heart, and brain using Illumina whole-genome gene expression assay. RESULTS: From the array, 19 genes showed altered expression in the infectious deaths compared to controls. Tissue from the heart showed 15 genes with altered mRNA expression compared to the control group. CONCLUSIONS: Downregulation of KCNE5 in heart tissue from cases of infectious death was of particular interest. Variants of KCNE5 are associated with Brugada syndrome and sudden death and could be responsible for the fatal outcome in the group of infectious death. IMPACT: KCNE5 is downregulated in tissue from the heart in cases of infectious death in infancy. This study provides knowledge about the gene expression profile in cases of infectious death. Variants of a gene known to give increased risk of cardiac arrhythmia is downregulated in cases of infectious death in infancy. The results could give us better knowledge as to why some infants do not survive an infection. This study provides a candidate gene for future studies.

Incidence of co-infections and superinfections in hospitalized patients with COVID-19: a retrospective cohort study.

OBJECTIVES: To describe the burden, epidemiology and outcomes of co-infections and superinfections occurring in hospitalized patients with coronavirus disease 2019 (COVID-19). METHODS: We performed an observational cohort study of all consecutive patients admitted for ≥48 hours to the Hospital Clinic of Barcelona for COVID-19 (28 February to 22 April 2020) who were discharged or dead. We describe demographic, epidemiologic, laboratory and microbiologic results, as well as outcome data retrieved from electronic health records. RESULTS: Of a total of 989 consecutive patients with COVID-19, 72 (7.2%) had 88 other microbiologically confirmed infections: 74 were bacterial, seven fungal and seven viral. Community-acquired co-infection at COVID-19 diagnosis was uncommon (31/989, 3.1%) and mainly caused by Streptococcus pneumoniae and Staphylococcus aureus. A total of 51 hospital-acquired bacterial superinfections, mostly caused by Pseudomonas aeruginosa and Escherichia coli, were diagnosed in 43 patients (4.7%), with a mean (SD) time from hospital admission to superinfection diagnosis of 10.6 (6.6) days. Overall mortality was 9.8% (97/989). Patients with community-acquired co-infections and hospital-acquired superinfections had worse outcomes. CONCLUSIONS: Co-infection at COVID-19 diagnosis is uncommon. Few patients developed superinfections during hospitalization. These findings are different compared to those of other viral pandemics. As it relates to hospitalized patients with COVID-19, such findings could prove essential in defining the role of empiric antimicrobial therapy or stewardship strategies.

Impact of HLA class I allele-level mismatch on viral infection within 100 days after cord blood transplantation.

Viral infection is more frequently reported in cord blood transplantation (CBT) than in transplantation of other stem cell sources, but its precise mechanism related to antiviral host defenses has not been elucidated yet. To evaluate the effect of human leukocyte antigen (HLA) class I allele-level incompatibility on viral infection in CBT, we conducted a single-center retrospective study. Total 94 patients were included, and viral infections were detected in 32 patients (34%) within 100 days after CBT. HLA-C mismatches in graft-versus-host direction showed a significantly higher incidence of viral infection (hazard ratio (HR), 3.67; p = 0.01), while mismatches in HLA-A, -B, or -DRB1 were not significant. Overall HLA class I mismatch was also a significant risk factor and the predictor of post-CBT viral infection (≥ 3 mismatches, HR 2.38, p = 0.02), probably due to the insufficient cytotoxic T cell recognition and dendritic cell priming. Patients with viral infection had significantly worse overall survival (52.7% vs. 72.1%; p = 0.02), and higher non-relapse mortality (29.3% vs. 9.8%; p = 0.01) at 5 years. Our findings suggest that appropriate graft selection as well as prophylaxis and early intervention for viral infection in such high-risk patients with ≥ 3 HLA class I allele-level mismatches, including HLA-C, may improve CBT outcomes.

Pathogenic load and frailty in older adults: Singapore longitudinal ageing study.

Human evidence for the role of continuous antigenic stimulation from persistent latent infections in frailty is limited. We conducted a nested case-control study (99 deceased and 43 survivors) of participants aged 55 and above in a longitudinal ageing cohort followed up from 2003 to 2017. Using blood samples and baseline data collected in 2003-2004, we examined the association of pathogenic load (PL) count of seropositivity to 10 microbes (viruses, bacteria and mycoplasma) with cumulated deficit-frailty index (CD-FI) and the physical frailty (PF) phenotype, and mortality. Controlling for age, sex, education, smoking and alcohol histories, high PL (7-9) versus low PL (3-6) was associated with an estimated increase of 0.035 points in the CD-FI (Cohen's D=0.035 / 0.086, or 0.41). High PL was associated with 8.5 times odds of being physically frail (p=0.001), 2.8 times odds of being weak (p=0.010), 3.4 times odds of being slow (p=0.024), and mortality hazard ratio of 1.53 (p=0.046). There were no significant associations for specific pathogens, except marginal associations for Epstein-Barr virus and Chikungunya. Conclusion: A high pathogenic load of latent infections was associated with increased risks of frailty and mortality.

Systemic lupus erythematosus and infections.

Systemic lupus erythematosus (SLE) is an inflammatory and multi-systemic autoimmune disorder, characterized by an uncontrolled auto-reactivity of B and T lymphocytes, leading to the production of autoantibodies against self-directed antigens and tissue damage. The life expectancy in patients with SLE has improved tremendously in the last two decades, but the mortality rates still remain three times greater compared to those of the general population. Despite increased awareness and improved management, infections remain a major source of morbidity, mortality, hospitalization, and death in patients with SLE. The infections in SLE patients widely range from opportunistic to common bacterial and viral infections with typical or atypical presentations. Moreover, SLE patients exhibit an increased susceptibility to hospital-acquired infections. Factors associated with increased risk of infections include high disease activity, specific immune dysregulation, drug-induced immune deficiency, and organ failure with irreversible damage. Furthermore, immunosuppressive agents may make patients more susceptible to opportunistic infections. A big challenge faced by physicians in these patients is to distinguish between infections and flares of SLE, as infections may mimic them, leading to predicament in diagnosis and appropriate management. Immunosuppression used to treat severe flares of lupus can have catastrophic complications in patients with active infections. There is an urgent need for biomarkers to make an accurate differential diagnosis in this situation. In spite of increased understanding of SLE, many questions remain unanswered. Further research is needed to determine specific immune dysregulation underlying the increased susceptibility to specific infections, predictors of infection in SLE such as genetic markers, and biomarkers that discriminate between disease activity and active infections. Also, measures must be evaluated appropriately to prevent infections, and their complications in SLE.

SARS-CoV-2-related pneumonia cases in pneumonia picture in Russia in March-May 2020: Secondary bacterial pneumonia and viral co-infections.

BACKGROUND: We are communicating the results of investigating statistics on SARS-CoV-2-related pneumonias in Russia: percentage, mortality, cases with other viral agents, cases accompanied by secondary bacterial pneumonias, age breakdown, clinical course and outcome. METHODS: We studied two sampling sets (Set 1 and Set 2). Set 1 consisted of results of testing 3382 assays of out-patients and hospital patients (5-88 years old) with community-acquired and hospital-acquired pneumonia of yet undetermined aetiology. Set 2 contained results of 1204 assays of hospital patients (12-94 years old) with pneumonia and COVID-19 already diagnosed by molecular biological techniques in test laboratories. The results were collected in twelve Russian cities/provinces in time range 2 March - 5 May 2020. Assays were analysed for 10 bacterial, 15 viral, 2 fungal and 2 parasitic aetiological agents. RESULTS: In Set 1, 4.35% of total pneumonia cases were related to SARS-CoV-2, with substantially larger proportion (18.75%) of deaths of pneumonia with COVID-19 diagnosed. However, studying Set 2, we revealed that 52.82% patients in it were also positive for different typical and atypical aetiological agents usually causing pneumonia. 433 COVID-19 patients (35.96%) were tested positive for various bacterial aetiological agents, with Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae infections accounting for the majority of secondary pneumonia cases. CONCLUSIONS: SARS-CoV-2, a low-pathogenic virus itself, becomes exceptionally dangerous if secondary bacterial pneumonia attacks a COVID-19 patient as a complication. An essential part of the severest complications and mortality associated with COVID-19 in Russia in March-May 2020, may be attributed to secondary bacterial pneumonia and to a much less extent viral co-infections. The problem of hospital-acquired bacterial infection is exceptionally urgent in treating SARS-CoV-2 patients. The risk of secondary bacterial pneumonia and its further complications, should be given very serious attention in combating SARS-CoV-2.

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

BACKGROUND: Community-acquired respiratory viruses (CARV) cause upper and lower respiratory tract infections (URTI/LRTI) and may be life-threatening for recipients of an allogeneic stem cell transplantation (allo-SCT). METHODS: In a prospective study encompassing 4 winter-seasons, we collected throat gargles (TG) at random time points from allo-SCT recipients (patients) and controls and followed them up for at least 3 weeks including repetitive sampling and documentation of symptoms. A Multiplex-PCR system to identify 20 CARV and Mycoplasma pneumoniae was used to detect CARV. RESULTS: One hundred ninety-four patients with 426 TG and 273 controls with 549 TG were included. There were more patients with a positive test result (25% vs 11% in the controls), and the patients had a higher number of positive TG (70 = 16%) compared to controls (32 = 6%) (P < .001). Altogether, 115 viruses were detected. Multiple viruses in one TG (11/48, 34%) and prolonged shedding were only observed in patients (13/48, 27%). Patients had more RSV (18/83, 26%) and adenovirus (15/83, 21%) than controls (both viruses 2/32, 6%). Independent risk factors for the detection of CARV included age >40 years (OR 3.38, 95% CI 1.8-6.4, P < .001) and presence of URTI-symptoms (OR 3.22, 95% CI 1.9-5.5, P < .001). No controls developed a LRTI or died whereas 4/48 (8%) patients developed a LRTI (coronavirus in 2, RSV in 1 and influenza A H1N1 in 1 patient). One patient died of CARV (influenza A H1N1). CONCLUSION: Allo-SCT-recipients have more CARV-infections, exhibit a different epidemiology, have more cases of co-infection or prolonged shedding and have a higher rate of LRTI and mortality.

Intravenous immunoglobulin for presumed viral myocarditis in children and adults.

BACKGROUND: This is an update of a previous review. Case reports and case series have described dramatic responses to intravenous immunoglobulin (IVIG) in people with presumed viral myocarditis, and its administration has become commonplace. OBJECTIVES: The primary objective of this review was to compare event-free (death, requirement for a cardiac transplant, or placement of a left ventricular assist device) or overall (death) survival of adults and children with presumed viral myocarditis treated with IVIG versus those who did not receive IVIG. A secondary objective was to determine if a group of patients with presumed viral myocarditis could be identified (on the basis of age, duration of symptoms, acuity of onset of symptoms, cardiac function at presentation, virological results, or the presence or absence of histological evidence of acute myocarditis on cardiac biopsy in patients in whom a biopsy was performed) who would be the most likely to benefit from IVIG. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, DARE, CINAHL, Web of Science Core Collection, and LILACS in July 2019, and two trial registries in November 2019. We contacted authors of trials and checked reference lists of relevant papers. We applied no language restrictions. SELECTION CRITERIA: We included studies if (1) participants had a clinical diagnosis of acute myocarditis with a left ventricular ejection fraction (LVEF) ≤ 0.45, left ventricular end-diastolic diameter (LVEDD) > 2 standard deviations (SDs) above the norm, or a left ventricular shortening fraction (LVSF) > 2 SDs below the mean, with duration of cardiac symptoms < 6 months; (2) participants had no evidence of non-infectious or bacterial cardiac disease; and (3) participants were randomly assigned to receive at least 1 g/kg of IVIG versus no IVIG or placebo. We excluded studies if (1) participants had received immunosuppression before outcome assessment; or (2) onset of myocarditis was reported to have occurred < 6 months postpartum. DATA COLLECTION AND ANALYSIS: Two review authors independently screened the search results and extracted data. We assessed risk of bias with the Cochrane 'Risk of bias' tool. We conducted meta-analysis for two outcomes (overall survival and improvement in LVEF) with two adult trials. Other meta-analyses were not possible because only three relevant trials were included, and researchers analysed markedly different populations and used different outcome measures. MAIN RESULTS: In this update we added two trials to the two previously included trials. A quasi-randomised trial was previously included due to a paucity of evidence from randomised trials; however, with the addition of two new randomised trials, it was removed from this update. For two adult trials, the overall risk of bias was unclear with very low-certainty evidence for all outcomes. The first trial studied 62 adults with recent-onset dilated cardiomyopathy randomly assigned to receive IVIG or an equivalent volume of 0.1% albumin in a blinded fashion. The effect on event-free survival between groups was uncertain (risk ratio (RR) of any event 1.76, 95% confidence interval (CI) 0.48 to 6.40). The second trial studied 41 adults with acute myocarditis randomised to either high-dose IVIG (1 to 2 g/kg over two days) or no treatment. The IVIG group reported greater survival time after 60 days (no raw data, P < 0.01), but the evidence is uncertain. We pooled the reported number of deaths in both trials, with no evidence of a difference between groups (RR 0.91, 95% CI 0.23 to 3.62, I2 = 31%, very low-certainty evidence). The evidence on the effect of IVIG treatment on LVEF (pooled mean difference (MD) -0.01, 95% CI -0.06 to 0.05) after 12 months and an unknown time frame is uncertain. The results for functional capacity, assessed by peak oxygen consumption at 12 months, were uncertain (MD -0.80, 95% CI -4.57 to 2.97). The results for infusion-related side effects were also uncertain due to a very large CI (RR 20.29, 95% CI 1.25 to 329.93). Lastly, there was uncertain evidence addressing failure to attain complete recovery (RR 0.46, 95% CI 0.19 to 1.14).  Evidence for improvement in LVEDD, left ventricular shortening fraction, and hospitalisation status in adults was not reported.  In the single included paediatric trial, the overall risk of bias was low with very low-certainty evidence for all outcomes. The trial included 86 children in Egypt presenting with acute myocarditis. Children were randomly assigned to 1 g/kg IVIG daily for two consecutive days or placebo followed by echocardiography one and six months post randomisation for recording of LVEDD and LVSF. The evidence for overall survival after six months was uncertain (risk of death RR 0.48, 95% CI 0.20 to 1.15). The evidence was also uncertain for improvement in LVEDD and LVSF after six months (LVEDD MD -4.00, 95% CI -9.52 to 1.52; LVSF no raw data).  Evidence for improvement in LVEF, functional capacity, side effects, complete recovery, and hospitalisation status in children was not reported.  AUTHORS' CONCLUSIONS: Evidence from two trials of very low certainty and with unclear risk of bias provides contradictory evidence on the use of IVIG in the treatment of adults with presumed viral myocarditis. One trial reported that use of IVIG results in longer survival time after 60 days, whilst the other trial found that IVIG does not provide an appreciable benefit. The evidence of a difference in event-free or overall survival, LVEDD, or LVSF is of very low certainty in a single paediatric trial with a low risk of bias. Until higher-quality studies with low risk of bias and larger sample sizes have demonstrated benefit in a particular group of patients, the evidence for treatment with IVIG for presumed viral myocarditis is uncertain. Further studies of the pathophysiology of myocarditis would lead to improved diagnostic criteria, which would facilitate future research.

Recent Trends of Infectious Complications Following Heart Transplantation.

BACKGROUND: Heart transplantation is a life-saving procedure that has seen improvements in transplant and patient outcomes due to advances in immunosuppression and prevention of posttransplantation infectious episodes (IEps). This study systematically evaluates IEps in the modern era of heart transplantation at Stanford University Medical Center. METHODS: This is a single-center retrospective review that includes 279 consecutive adult heart transplantation recipients from January 2008 to September 2017. Baseline demographic, clinical, serological, and outcomes information were collected. Kaplan-Meier estimator was used to assess survival stratified by IEp occurrence within the first year. RESULTS: A total of 600 IEps occurred in 279 patients (2.15 IEps per patient) during a median follow-up period of 3 years. Overall survival was 83.3% (95% confidence interval [CI], 76.2-88.4) at 1 year posttransplantation for those with any IEp compared with 93.0% (95% CI, 87.2-96.4) in those without IEp (P = 0.07). Bacterial IEps were the most common (n = 375; 62.5%), followed by viral (n = 180; 30.0%), fungal (n = 40; 6.7%), and parasitic (n = 5; 0.8%). IEps by Gram-negative bacteria (n = 210) outnumbered those by Gram-positive bacteria (n = 142). Compared with prior studies from our center, there was a decreased proportion of viral (including cytomegalovirus), fungal (including Aspergillus spp. and non-Aspergillus spp. molds), and Nocardia infections. There were no IEps due to Mycobacterium tuberculosis, Pneumocystis jirovecii, or Toxoplasma gondii. CONCLUSIONS: A significant reduction in viral, fungal, and Nocardia IEps after heart transplantation was observed, most likely due to advancements in immunosuppression and preventive strategies, including pretransplant infectious diseases screening and antimicrobial prophylaxis.

Community-acquired viral respiratory infections amongst hospitalized inpatients during a COVID-19 outbreak in Singapore: co-infection and clinical outcomes.

AIMS: During the ongoing COVID-19 outbreak, co-circulation of other common respiratory viruses can potentially result in co-infections; however, reported rates of co-infections for SARS-CoV-2 vary. We sought to evaluate the prevalence and etiology of all community acquired viral respiratory infections requiring hospitalization during an ongoing COVID-19 outbreak, with a focus on co-infection rates and clinical outcomes. METHODS: Over a 10-week period, all admissions to our institution, the largest tertiary hospital in Singapore, were screened for respiratory symptoms, and COVID-19 as well as a panel of common respiratory viral pathogens were systematically tested for. Information was collated on clinical outcomes, including requirement for mechanical ventilation and in hospital mortality. RESULTS: One-fifth (19.3%, 736/3807) of hospitalized inpatients with respiratory symptoms had a PCR-proven viral respiratory infection; of which 58.5% (431/736) tested positive for SARS-CoV-2 and 42.2% (311/736) tested positive for other common respiratory viruses. The rate of co-infection with SARS-CoV-2 was 1.4% (6/431); all patients with co-infection had mild disease and stayed in communal settings. The in-hospital mortality rate and proportion of COVID-19 patients requiring invasive ventilation was low, at around 1% of patients; these rates were lower than patients with other community-acquired respiratory viruses admitted over the same period (p < 0.01). CONCLUSION: Even amidst an ongoing COVID-19 outbreak, common respiratory viruses still accounted for a substantial proportion of hospitalizations. Coinfections with SARS-CoV-2 were rare, with no observed increase in morbidity or mortality.