Viral Respiratory Tract Infections in Allogeneic Hematopoietic Stem Cell Transplantation Recipients in the Era of Molecular Testing

Lower Respiratory Infections in Children With Febrile Neutropenic Leukemia: A Case in a Jordanian Hospital

The study aimed to examine the prevalence of pneumonia in pediatric children diagnosed with leukemia at King Hussein Medical Center, Royal Medical Services, Amman, Jordan. The study was conducted from January 2019 to March 2020. A total of 100 hospitalized leukemia patients with febrile neutropenic episodes were evaluated for the presence of pneumonia. Samples were collected from all patients and tested for microbial growth. Univariate analysis revealed that age (P = .033) and packed cell volume (P = .006) were statistically significant risk factors, associated with the prevalence of pneumonia in leukemia patients with febrile neutropenia episodes. Similarly, as the absolute neutrophil count counts increased with an odds ratio and a 95% confidence interval of 2.386 (0.859-6.625), the odds of pneumonia in febrile neutropenic patients were more prevalent. The study reported the prevalence of pneumonia in immunocompromised febrile neutropenic patients with leukemia, which could lead to the development of evidence-based febrile neutropenic treatment protocol development. It will assure more responsive patient management and treatment.

COVID-19 in hematopoietic stem-cell transplant recipients: A systematic review and meta-analysis of clinical characteristics and outcomes

Patients who undergo hematopoietic stem-cell transplantation (HSCT) are more susceptible to developing severe forms of COVID-19 with an increased risk of mortality. The aim of this study was to analyze, by performing a systematic review and meta-analysis, all studies that evaluated COVID-19 in HSCT adult recipients and present clinical characteristics and outcomes. Studies were eligible for inclusion if they: (I) described the clinical characteristics of COVID-19 in adult (aged 18 years old or above) HSCT recipients; (II) described outcomes of COVID-19 in this population, mainly lethality; (III) were full-text articles. We searched MedLine, Embase, SCOPUS, LILACS and Web of Science for full-text studies that evaluated COVID-19 in adult HSCT patients until 26 Apr 2023. Two independent reviewers screened the articles and extracted the data. The Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Studies Reporting Prevalence Data was used to assess quality of the included studies. Meta-analysis was performed and the pooled prevalence of severe/critical disease and of death with a 95% CI was calculated with the random-effects model. Sixteen studies were included; seven (43.7%) were multicenter. Most of the studies were from Europe (37.5%). All of them had a low risk of bias using the JBI Checklist. A total of 1186 patients were included. Allogeneic HSCT patients were the majority in most studies, with a total of 861 patients (72.5%). The symptomatic rate was 79.4%. The pooled prevalence of severe/critical COVID-19 was 24.0% (95% CI 0.13-0.36; I2  = 94%; n = 334/990). The pooled prevalence of death for the entire population was 17% (95% CI 0.13-0.22; I2  = 76%; n = 221/1117), 17% (95% CI 0.12-0.23; I2  = 67%; n = 152/822) for allogeneic-HSCT and 14% (95% CI 0.08-0.22; I4  = 65%; n = 48/293) for autologous-HSCT. In conclusion, frequently the infection of SARS-CoV-2 in HSCT was symptomatic and lethality is higher than in general population. Thus, it is essential to focus on the implementation of measures to mitigate the risk of SARS-CoV-2 infection in this population, as well as to carefully assess HSCT recipients who develop COVID-19.

Respiratory virus infections after allogeneic stem cell transplantation: Current understanding, knowledge gaps, and recent advances

Before the COVID-19 pandemic, common community-acquired seasonal respiratory viruses (CARVs) were a significant threat to the health and well-being of allogeneic hematopoietic cell transplant (allo-HCT) recipients, often resulting in severe illness and even death. The pandemic has further highlighted the significant risk that immunosuppressed patients, including allo-HCT recipients, face when infected with SARS-CoV-2. As preventive transmission measures are relaxed and CARVs circulate again among the community, including in allo-HSCT recipients, it is crucial to understand the current state of knowledge, gaps, and recent advances regarding CARV infection in allo-HCT recipients. Urgent research is needed to identify seasonal respiratory viruses as potential drivers for future pandemics.

Risk factors for lower respiratory tract disease and outcomes in allogeneic hematopoietic stem cell transplantation recipients with influenza virus infection

INTRODUCTION

Influenza virus infection (IVI) is frequent in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients, and reports from several countries indicate high morbidity and mortality from progression to lower respiratory tract disease (LRTD). However, there have been no reports on IVI clinical characteristics, treatment outcomes, and risk factor for progression to LRTD among allo-HSCT recipients in Japan.

METHODS

We retrospectively reviewed the medical charts of allo-HSCT recipients who developed IVI between 2012 and 2019.

RESULTS

Forty-eight cases of IVI following allo-HSCT were identified at our institution. The median age was 42 years, and median time from allo-HSCT to IVI was 25 months. Thirty-seven patients (77.1%) were administered neuraminidase inhibitors (NAIs) as antiviral therapy within 48 h of symptom onset (early therapy), whereas 11 (22.9%) received NAI over 48 h after onset (delayed therapy). Subsequently, 12 patients (25.0%) developed LRTD after IVI. Multivariate analysis identified older age (hazard ratio [HR], 7.65; 95% confidence interval [CI], 2.22-26.3) and bronchiolitis obliterans (HR, 5.74; 95% CI, 1.57-21.0) as independent risk factors for progression to LRTD. Moreover, land-mark analysis showed that early therapy prevented progression to LRTD (11.8% vs. 45.5%, P = 0.013). The IVI-related mortality rate was 2.1%.

CONCLUSIONS

Early NAI treatment is recommended for reducing the risk of LRTD progression due to IVI in allo-HSTC recipients, particularly for older patients and those with bronchiolitis obliterans.

Economic and clinical burden associated with respiratory viral infections after allogeneic hematopoietic cell transplant in the United States

Background

Methods

Results

Conclusion

Incidence, economic burden, and treatment of acute respiratory tract infection in hematopoietic stem cell transplantation recipients using real world data in Japan: a retrospective claims data analysis

AIMS

Acute respiratory tract infections (ARTIs) are common in hematopoietic stem cell transplantation (HSCT) recipients, however, data is limited regarding epidemiology and economic burden of ARTI in HSCT recipients in Japan. We evaluated the incidence of ARTI in HSCT recipients, associated economic burden, and ARTI-related treatments post-HSCT.

MATERIALS AND METHODS

Patients receiving HSCT between July 2017 and December 2018, and those enrolled in the JMDC Claims Database for ≥6 months before index month (month when latest medical procedure code of HSCT recorded) were included. The outcomes included demographics, ARTI incidence, healthcare resource utilization (HCRU), direct costs, and ARTI-related treatments.

RESULTS

In 330 analyzed patients, the ARTI incidence rate was 85.5% during total follow-up, consisting of post-HSCT hospitalization of mean 2.1 months and post-discharge periods of mean 17.6 months (post-HSCT hospitalization: 44.8%; post-discharge: 77.6%). For ARTI vs non-ARTI patients during post-HSCT hospitalization, length of hospitalization was significantly longer (mean [SD] months; 2.40 [1.73] vs 1.84 [1.09]; p = 0.0004), and median cost was significantly higher (JPY; 6,250,120.00 vs 4,774,570.00; p = 0.0096). The cost of outpatient visits during post-discharge periods, drug-related and non-drug-related costs of outpatient visits were generally higher for ARTI vs non-ARTI patients. In ARTI vs non-ARTI patients, utilization of any symptom relievers (decongestants, antitussives, and antipyretics), bronchodilators, immunoglobulin G, antibiotics, antivirals, and oxygen supply were numerically higher during post-HSCT hospitalization and post-discharge periods. The proportion of patients and mean prescription days for immunosuppressants during post-HSCT hospitalization were higher in ARTI vs non-ARTI patients.

LIMITATIONS

This administrative claims study lacks clinical data and contains only direct medical costs. Patients were retained if they had at least 1 month of enrollment post-HSCT.

CONCLUSIONS

In HSCT recipients, ARTI leads to substantial incremental HCRU and direct costs for management in real-world settings in Japan.

SARS-CoV-2 in saliva, viremia and seroprevalence for COVID-19 surveillance at a single hematopoietic stem cell transplantation center: a prospective cohort study

This prospective cohort study aims to analyze the surveillance of COVID-19 at a single hematopoietic stem cell transplantation (HSCT) center in Brazil, in 29 patients undergoing allogeneic HSCT and 57 healthcare workers (nurses and dentists), through viral shedding of SARS-CoV-2 in saliva and plasma and seroprevalence of anti-SARS-CoV-2 IgG. In addition, we report two cases with prolonged persistent detection of SARS-CoV-2 without seroconversion. The sample collection was performed seven times for patients and five times for healthcare workers. Only two patients tested positive for SARS-CoV-2 in their saliva and plasma samples (6.9%) without seroconversion. All healthcare workers were asymptomatic and none tested positive. Two patients (6.9%) and four nurses (8%) had positive serology. No dentists had positive viral detection or positive serology. Our results reflect a low prevalence of positive RT-PCR and seroprevalence of SARS-CoV-2 in patients and healthcare workers at a single HSCT center. Results have also corroborated how the rigorous protocols adopted in transplant centers were even more strengthened in this pandemic scenario.

Adenovirus: Epidemiology, Global Spread of Novel Types, and Approach to Treatment

Adenoviruses (AdVs) are DNA viruses that typically cause mild infections involving the upper or lower respiratory tract, gastrointestinal tract, or conjunctiva. Rare manifestations of AdV infections include hemorrhagic cystitis, hepatitis, hemorrhagic colitis, pancreatitis, nephritis, or meningoencephalitis. AdV infections are more common in young children, due to lack of humoral immunity. Epidemics of AdV infection may occur in healthy children or adults in closed or crowded settings (particularly military recruits). The vast majority of cases are self-limited. However, the clinical spectrum is broad and fatalities may occur. Dissemination is more likely in patients with impaired immunity (e.g., organ transplant recipients, human immunodeficiency virus infection). Fatality rates for untreated severe AdV pneumonia or disseminated disease may exceed 50%. More than 100 genotypes and 52 serotypes of AdV have been identified and classified into seven species designated HAdV-A through -G. Different types display different tissue tropisms that correlate with clinical manifestations of infection. The predominant types circulating at a given time differ among countries or regions, and change over time. Transmission of novel strains between countries or across continents and replacement of dominant viruses by new strains may occur. Treatment of AdV infections is controversial, as prospective, randomized therapeutic trials have not been done. Cidofovir has been the drug of choice for severe AdV infections, but not all patients require treatment. Live oral vaccines are highly efficacious in reducing the risk of respiratory AdV infection and are in routine use in the military in the United States but currently are not available to civilians.

Incidence and impact of community respiratory viral infections in post-transplant cyclophosphamide-based graft-versus-host disease prophylaxis and haploidentical stem cell transplantation

Community respiratory viral infections (CRVIs) are associated with pulmonary function impairment, alloimmune lung syndromes and inferior survival in human leucocyte antigen (HLA)-matched allogeneic haematopoietic stem cell transplant (HCT) recipients. Although the incidence of viral infections in HLA-haploidentical HCT recipients who receive post-transplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis is reportedly increased, there are insufficient data describing the incidence of CRVIs and the impact of donor source and PTCy on transplant outcomes. Analysing patients receiving their first HCT between 2012 and 2017 for acute myeloid leukaemia, acute lymphoblastic leukaemia and myelodysplastic syndromes, we describe comparative outcomes between matched sibling transplants receiving either calcineurin-based GVHD prophylaxis (SibCNI, N = 1605) or PTCy (SibCy, N = 403), and related haploidentical transplants receiving PTCy (HaploCy, N = 757). The incidence of CRVIs was higher for patients receiving PTCy, regardless of donor type. Patients in the HaploCy cohort who developed a CRVI by day +180 had both a higher risk of treatment-related mortality [hazard ratio (HR) 2⋅14, 99% confidence interval (CI) 1⋅13-4⋅07; P = 0⋅002] and inferior 2-year overall survival (HR 1⋅65, 99% CI 1⋅11-2⋅43; P = 0⋅001) compared to SibCNI with no CRVI. This finding justifies further research into long-term antiviral immune recovery, as well as development of preventive and treatment strategies to improve long-term outcomes in such patients.

Risk factors for seasonal human coronavirus lower respiratory tract infection after hematopoietic cell transplantation

We demonstrate risk factors for HCoV LRTI in allogeneic HCT recipients and significance of virologic documentation by BAL on mortality.

Hyperglycemia associated with steroid use appears to be a strong predictor of HCoV disease progression.

Data are limited regarding risk factors for lower respiratory tract infection (LRTI) caused by seasonal human coronaviruses (HCoVs) and the significance of virologic documentation by bronchoalveolar lavage (BAL) on outcomes in hematopoietic cell transplant (HCT) recipients. We retrospectively analyzed patients undergoing allogeneic HCT (4/2008-9/2018) with HCoV (OC43/NL63/HKU1/229E) detected by polymerase chain reaction during conditioning or post-HCT. Risk factors for all manifestations of LRTI and progression to LRTI among those presenting with HCoV upper respiratory tract infection (URTI) were analyzed by logistic regression and Cox proportional hazard models, respectively. Mortality rates following HCoV LRTI were compared according to virologic documentation by BAL. A total of 297 patients (61 children and 236 adults) developed HCoV infection as follows: 254 had URTI alone, 18 presented with LRTI, and 25 progressed from URTI to LRTI (median, 16 days; range, 2-62 days). Multivariable logistic regression analyses showed that male sex, higher immunodeficiency scoring index, albumin <3 g/dL, glucose >150 mg/dL, and presence of respiratory copathogens were associated with occurrence of LRTI. Hyperglycemia with steroid use was associated with progression to LRTI (P < .01) in Cox models. LRTI with HCoV detected in BAL was associated with higher mortality than LRTI without documented detection in BAL (P < .01). In conclusion, we identified factors associated with HCoV LRTI, some of which are less commonly appreciated to be risk factors for LRTI with other respiratory viruses in HCT recipients. The association of hyperglycemia with LRTI might provide an intervention opportunity to reduce the risk of LRTI.

Impact of Influenza Infection Among Adult and Pediatric Populations With Hematologic Malignancy and Hematopoietic Stem Cell Transplant: A Systematic Review and Meta-Analysis

PURPOSE

Influenza is increasingly recognized as a leading cause of morbidity and mortality in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation (HSCT). However, the impact of influenza on this population has not been previously evaluated in a systematic review. This study systematically reviewed and summarized the outcomes of influenza infection as to in-hospital influenza-related mortality, development of lower respiratory tract infection and acute respiratory distress syndrome, need for hospitalization, intensive care unit admission, and mechanical ventilation.

METHODS

We conducted a systematic search of literature using the PubMed and EMBASE databases for articles published from January 1989 through January 19, 2020, reporting laboratory-confirmed influenza in patients of any age with hematologic malignancies and HSCT. Time from transplantation was not included in the search criteria. The impact of antiviral therapy on influenza outcomes was not assessed due to heterogeneity in antiviral treatment provision across the studies. Patients with influenza-like illness, solid-tumor cancers, or nonmalignant hematologic diseases were excluded from the study. A random-effects meta-analysis was performed to estimate the prevalences and 95% CIs of each outcome of interest. A subgroup analysis was carried out to assess possible sources of heterogeneity and to evaluate the potential impact of age on the influenza infection outcomes. Heterogeneity was assessed using the I² statistic.

FINDINGS

Data from 52 studies providing data on 1787 patients were included in this analysis. During seasonal epidemics, influenza-related in-hospital mortality was 16.60% (95% CI, 7.49%-27.7%), with a significantly higher death rate in adults compared to pediatric patients (19.55% [95% CI, 10.59%-29.97%] vs 0.96% [95% CI, 0%-6.77%]; P < 0.001). Complications from influenza, such as lower respiratory tract infection, developed in 35.44% of patients with hematologic malignancies and HSCT recipients, with a statistically significant difference between adults and children (46.14% vs 19.92%; P < 0.001). However, infection resulted in a higher hospital admission rate in pediatric patients compared to adults (61.62% vs 22.48%; P < 0.001). For the 2009 H1N1 pandemic, no statistically significant differences were found between adult and pediatric patients when comparing the rates of influenza-related in-hospital mortality, lower respiratory tract infection, and hospital admission. Similarly, no significant differences were noted in any of the outcomes of interest when comparing H1N1 pandemic with seasonal epidemics.

IMPLICATIONS

Regardless of influenza season, patients, and especially adults, with underlying hematologic malignancies and HSCT recipients with influenza are at risk for severe outcomes including lower respiratory tract infection and in-hospital mortality.

Impact of hospital acquired infections on post-transplant one year mortality in pediatric bone marrow transplant patients

OBJECTIVE

Children undergoing hematopoietic stem cell transplant (HSCT) are prone to infections, especially when hospitalized for the transplant or additional medical care. These infections are perceived to increase patient's mortality risk, but data are lacking. We conducted this study to assess the burden and the impact of hospital acquired infections (HAI) on mortality risk among pediatric HSCT patients.

METHODS

This retrospective study included 169 patients that received allogeneic HSCT between January 1 2011 and July 6 2017 at Children's National Hospital, a tertiary referral center. Clinical and laboratory data were reviewed for 1 year after transplant to determine HAI and survival status. The HAI incident rates stratified by bloodstream, respiratory, and gastrointestinal infections were then compared between deceased patients and survivors.

RESULTS

Including transplant, 169 patients sustained 499 hospital admissions for total of 10,523 patient days and 112 HAI episodes, resulting in a HAI rate of 10.6 per 1,000 patient-days. Within 1-year after transplant, 38 (22%) patient died, 30 (17.5%) with nonrelapse-related causes. Unadjusted univariate analysis revealed mortality correlated with cell source (p=0.035), donor type (p = 0.002), respiratory viral infections (P = .015), and central line associated blood stream infection (CLABSIs; P < .001). Adjusted analysis revealed CLABSI and respiratory adenovirus infection independently increased mortality risk by 3-fold (hazard ratio: 3.22, 95% confidence interval:1.30-8.00) and (hazard ratio: 3.32, 95% confidence interval: 1.22-9.06), respectively.

CONCLUSIONS

In light of the high frequency of multiple factors contributing to mortality we are unable to determine the degree HAI contributed mortality. However, our findings suggest preventing CLABSIs and respiratory adenovirus infections are crucial to improve the 1-year survival among pediatric HSCT patients.

Pathogen-Specific T Cells Beyond CMV, EBV and Adenovirus

PURPOSE OF REVIEW

Infectious diseases contribute significantly to morbidity and mortality in recipients of allogeneic haematopoietic stem cell transplantation (aHSCT), particularly in the era of highly immunosuppressive transplant regimens and alternate donor transplants. Delayed cellular immune recovery is a major mechanism for the increased risk in these patients. Adoptive cell therapy with ex vivo manipulated pathogen-specific T cells (PSTs) is increasingly taking its place as a treatment strategy using donor-derived or third party-banked cells.

RECENT FINDINGS

The majority of clinical trial data in the form of early-phase studies has been in the prophylaxis or treatment of cytomegalovirus (CMV), Epstein-Barr virus (EBV) and adenovirus (AdV). Advancements in methods to select and enrich PSTs offer the opportunity to target the less common viral pathogens as well as fungi with this technology. Early clinical studies of PSTs targeting polyomaviruses (BK virus and JC virus), human herpesvirus 6 (HHV6), varicella zoster virus (VZV) and Aspergillus spp. have shown promising results in small numbers of patients. Other potential targets include herpes simplex virus (HSV), respiratory viruses and other invasive fungal species. In this review, we describe the burden of disease of this wider spectrum of pathogens, the progress in the development of manufacturing capability, early clinical results and the opportunities and challenges for implementation in the clinic.

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.

A Practical Approach to the Management of Cancer Patients During the Novel Coronavirus Disease 2019 (COVID-19) Pandemic: An International Collaborative Group

The outbreak of coronavirus disease 2019 (COVID-19) has rapidly spread globally since being identified as a public health emergency of major international concern and has now been declared a pandemic by the World Health Organization (WHO). In December 2019, an outbreak of atypical pneumonia, known as COVID-19, was identified in Wuhan, China. The newly identified zoonotic coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is characterized by rapid human-to-human transmission. Many cancer patients frequently visit the hospital for treatment and disease surveillance. They may be immunocompromised due to the underlying malignancy or anticancer therapy and are at higher risk of developing infections. Several factors increase the risk of infection, and cancer patients commonly have multiple risk factors. Cancer patients appear to have an estimated twofold increased risk of contracting SARS-CoV-2 than the general population. With the WHO declaring the novel coronavirus outbreak a pandemic, there is an urgent need to address the impact of such a pandemic on cancer patients. This include changes to resource allocation, clinical care, and the consent process during a pandemic. Currently and due to limited data, there are no international guidelines to address the management of cancer patients in any infectious pandemic. In this review, the potential challenges associated with managing cancer patients during the COVID-19 infection pandemic will be addressed, with suggestions of some practical approaches. IMPLICATIONS FOR PRACTICE: The main management strategies for treating cancer patients during the COVID-19 epidemic include clear communication and education about hand hygiene, infection control measures, high-risk exposure, and the signs and symptoms of COVID-19. Consideration of risk and benefit for active intervention in the cancer population must be individualized. Postponing elective surgery or adjuvant chemotherapy for cancer patients with low risk of progression should be considered on a case-by-case basis. Minimizing outpatient visits can help to mitigate exposure and possible further transmission. Telemedicine may be used to support patients to minimize number of visits and risk of exposure. More research is needed to better understand SARS-CoV-2 virology and epidemiology.

Increased Detection of Viruses in Children with Respiratory Tract Infection Using PCR

Respiratory viruses are a common cause of respiratory tract infection (RTI), particularly in neonates and children. Rapid and accurate diagnosis of viral infections could improve clinical outcomes and reduce the use of antibiotics and treatment sessions. Advances in diagnostic technology contribute to the accurate detection of viruses. We performed a multiplex real-time polymerase chain reaction (PCR) to investigate the viral etiology in pediatric patients and compared the detection rates with those determined using traditional antigen tests and virus cultures. Fifteen respiratory viruses were included in our investigation: respiratory syncytial virus A/B (RSV), influenza virus A (FluA) and influenza virus B (FluB), human metapneumovirus (MPV), enterovirus (EV), human parainfluenza virus (PIV) types 1-4, human rhinovirus (RV), human coronavirus OC43, NL63, and 229E, human adenovirus (ADV), and human bocavirus (Boca). In total, 474 specimens were collected and tested. Respiratory viruses were detected more frequently by PCR (357, 75.3%) than they were by traditional tests (229, 49.3%). The leading pathogens were RSV (113, 23.8%), RV (72, 15.2%), PIV3 (53, 11.2%), FluA (51, 10.8%), and ADV (48, 10.1%). For children younger than 5 years, RSV and RV were most prevalent; for children older than 5 years, FluA and ADV were the most frequently detected. Of the specimens, 25.8% (92/357) were coinfected with two or more viruses. RV, Boca, PIV2, FluB, and PIV4 had higher rates of coinfection; MPV and PIV1 had the lowest rates of coinfection (9.1% and 5.3%). To conclude, the detection power of PCR was better than that of traditional antigen tests and virus cultures when considering the detection of respiratory viruses. RSV and RV were the leading viral pathogens identified in the respiratory specimens. One-quarter of the positive specimens were coinfected with two or more viruses. In the future, further application of PCR may contribute to the rapid and accurate diagnosis of respiratory viruses and could improve patient outcomes.

Respiratory Viruses Cause Late Morbidity in Recipients of Hematopoietic Stem Cell Transplantation

Common respiratory viral infections (CRVIs) frequently complicate hematopoietic stem cell transplantation (HSCT). We conducted a retrospective, single-center, observational cohort study to determine the incidence of CRVI in patients who received an allogeneic (allo) or autologous (auto) HSCT at the Royal Adelaide Hospital between 2009 and 2017. The median follow-up was 8.9 and 4.5 years for auto- and allo-HSCT recipients, respectively. There were 149 CRVI episodes in 74 patients, with rhinovirus being the most commonly isolated virus (n = 81, 47%). The majority of CRVIs (113/149, 75.8%) occurred more than 100 days post-HSCT and 67% were diagnosed in the outpatient setting. There was evidence of lower respiratory tract infection (LRTI) in 45.6% (68/149) of CRVIs. On multivariate logistic regression analysis, coviral infections and cytomegalovirus viremia were independent risk factors for progression of CRVI to LRTI. Ten (6.7%) CRVI episodes resulted in admission to intensive care for ventilatory support and 8 (5.4%) patients died within 30 days of CRVI diagnosis. In our study, 10.4% of HSCT recipients experienced a CRVI post-transplant, primarily causing late morbidity and potentially mortality. Prevention with strict infection control practices, vaccination, and patient education is essential.

Community-Acquired Respiratory Viruses in Transplant Patients: Diversity, Impact, Unmet Clinical Needs

Patients undergoing solid-organ transplantation (SOT) or allogeneic hematopoietic cell transplantation (HCT) are at increased risk for infectious complications. Community-acquired respiratory viruses (CARVs) pose a particular challenge due to the frequent exposure pre-, peri-, and posttransplantation. Although influenza A and B viruses have a top priority regarding prevention and treatment, recent molecular diagnostic tests detecting an array of other CARVs in real time have dramatically expanded our knowledge about the epidemiology, diversity, and impact of CARV infections in the general population and in allogeneic HCT and SOT patients. These data have demonstrated that non-influenza CARVs independently contribute to morbidity and mortality of transplant patients. However, effective vaccination and antiviral treatment is only emerging for non-influenza CARVs, placing emphasis on infection control and supportive measures. Here, we review the current knowledge about CARVs in SOT and allogeneic HCT patients to better define the magnitude of this unmet clinical need and to discuss some of the lessons learned from human influenza virus, respiratory syncytial virus, parainfluenzavirus, rhinovirus, coronavirus, adenovirus, and bocavirus regarding diagnosis, prevention, and treatment.

Critical Care Management: Sepsis and Disseminated and Local Infections

Local and systemic infections are a significant cause of morbidity and mortality among immunocompromised children, including but not limited to patients with hematologic and solid malignancies, congenital or acquired immunodeficiencies, or hematopoietic cell or solid organ transplantation patients. Progression to septic shock can be rapid and profound and thus requires specific diagnostic and treatment approaches. This chapter will discuss the diagnosis and the initial hemodynamic management strategies of septic shock in immunocompromised children, including strategies to improve oxygen delivery, reduce metabolic demand, and monitor hemodynamic response to resuscitation. This chapter also discusses strategies to reverse septic shock pathobiology, including the use of both empiric and targeted anti-infective strategies and pharmacologic and cell therapy-based immunomodulation. Specific consideration is also paid to the management of high-risk subpopulations and the care of septic shock patients with resolving injury.

Managing pulmonary complications in allogeneic hematopoietic stem cell transplantation

Introduction: Progress in allogeneic hematopoietic stem cell transplantation (HSCT) procedures has been associated with improved survival in HSCT recipients. However, they have also brought to light organ-specific complications, especially pulmonary complications. In this setting, pulmonary complications are consistently associated with poor outcomes, and improved management of these complications is required. Areas covered: We review the multiple infectious and noninfectious lung complications that occur both early and late after allogeneic HSCT. This includes the description of these complications, risk factors, diagnostic approach and outcome. A literature search was performed using PubMed-indexed journals. Expert commentary: Multiple lung complications after allogeneic HSCT can be diagnosed concomitantly and require a multidisciplinary approach. A specific clinical evaluation including a precise analysis of a lung CT scan is necessary. Management of these lung complications, especially the noninfectious ones, is impaired by the lack of prospective, randomized control trials, suggesting preventive strategies should be developed.

Human Rhinovirus Infections in Hematopoietic Cell Transplant Recipients: Risk Score for Progression to Lower Respiratory Tract Infection

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Risk factors for rhinovirus lower respiratory tract infection are not well characterized.

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Several risk factors in hematopoietic cell transplant recipients were identified.

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A risk score for progression to lower respiratory tract infection was developed.

Human rhinovirus lower respiratory tract infection (LRTI) is associated with mortality after hematopoietic cell transplantation (HCT); however, risk factors for LRTI are not well characterized. We sought to develop a risk score for progression to LRTI from upper respiratory tract infection (URTI) in HCT recipients. Risk factors for LRTI within 90 days were analyzed using Cox regression among HCT recipients with rhinovirus URTI between January 2009 and March 2016. The final multivariable model included factors with a meaningful effect on the bootstrapped optimism corrected concordance statistic. Weighted score contributions based on hazard ratios were determined. Cumulative incidence curves estimated the probability of LRTI at various score cut-offs. Of 588 rhinovirus URTI events, 100 (17%) progressed to LRTI. In a final multivariable model allogeneic grafts, prior rhinovirus URTI, low lymphocyte count, low albumin, positive cytomegalovirus serostatus, recipient statin use, and steroid use ≥2 mg/kg/day were associated with progression to LRTI. A weighted risk score cut-off with the highest sensitivity and specificity was determined. Risk scores above this cut-off were associated with progression to LRTI (cumulative incidence 28% versus 11% below cut-off; P < .001). The weighted risk score for progression to rhinovirus LRTI can help identify and stratify patients for clinical management and for future clinical trials of therapeutics in HCT recipients.

Healthcare-Associated Viral Infections: Considerations for Nosocomial Transmission and Infection Control

Nosocomial and healthcare-associated viral infections are major contributors to patient morbidity and mortality, prolonged hospitalization, and increased healthcare costs in all pediatric age groups. Healthcare workers are also at risk of acquiring nosocomial viral infections, affecting their own health, as well as facilitating spread of the infection to other patients, their family, and the community. Healthcare-associated viral infections may occur in a variety of healthcare settings, including clinics, emergency centers, urgent care centers, procedure suites, operating rooms, hospital wards, nurseries, and intensive care units. In addition, non-patient care areas, such as the cafeteria, waiting areas, and playrooms may also be a source of viral infections that can spread in the healthcare setting. These infections may be device-related or transmitted via blood products or organ donation and respiratory droplets, through food including human milk, person to person, or via air ducts, fomites, and surfaces. They most commonly involve the respiratory and gastrointestinal tracts; however, all organ systems may potentially be involved. Both DNA and RNA viruses, either common or exotic, may contribute to healthcare-associated viral infections. Advances in molecular viral diagnostics have enabled rapid detection and routine surveillance for viral infections and now allow early identification of viruses. Prompt identification allows timely containment measures to minimize transmission to other patients or healthcare workers and avoids hospital, community, and global outbreaks.