Prospective detection of respiratory pathogens in symptomatic children with cancer

Clinical Outcomes of Respiratory Syncytial Virus Infection Among Pediatric Immunocompromised Hosts

BACKGROUND

Pediatric immunocompromised patients are at an increased risk of severe respiratory syncytial virus (RSV) infection. Here, we aimed to describe the clinical course and outcomes of RSV infection in immunocompromised children.

METHODS

This single-center study at St. Jude Children's Research Hospital involved immunocompromised children ≤21 years old with a positive RSV clinical test from 2007 to 2019. Demographic and clinical characteristics, laboratory values, treatment delays for underlying conditions, and outcomes were gathered from electronic medical records. Multivariate models identified risk factors predictive of severe RSV-lower respiratory tract infection (LRTI).

RESULTS

A total of 391 patients, predominantly children over 2 years old (median age: 5), were included in the study. Acute lymphoblastic leukemia (ALL) was the most prevalent underlying disease. Most patients (85.7%) exhibited upper respiratory tract infections, while approximately 6% progressed to LRTIs. Over half of the patients (58.8%) required hospitalization, and one-third experienced modifications or delays in their underlying disease treatment due to RSV infection. Severe RSV infections were observed in 15.9% of patients. All-cause mortality was 2.6%, with 0.7% of deaths attributed to RSV.

CONCLUSIONS

One-third of patients experienced a delay in treatment for their underlying disease due to RSV infection, a phenomenon not well understood but potentially significant. Many immunocompromised children with RSV require hospitalization, including those over 2 years old. RSV imposes a significant burden on immunocompromised children of all ages, affecting their cancer treatment plans both directly and indirectly.

Common viral respiratory infections in children with cancer during the COVID-19 pandemic: a multicenter study from Türkiye

BACKGROUND

Microbiologic confirmation of respiratory tract infections gained importance during the coronavirus disease 2019 (COVID-19) pandemic. This study retrospectively evaluated seasonal distribution, clinical presentation, and complications of respiratory viral infections (RVIs) other than COVID-19 in children with cancer during and after the pandemic lockdown.

METHODS

Two hundred and sixty-five inpatient and outpatient RVI episodes in 219 pediatric cancer patients confirmed by multiplex reverse transcriptase polymerase chain reaction (RT-PCR) panels from 13 centers were enrolled.

RESULTS

Eighty-six (32.5%) of the total 265 episodes occurred in 16 months corresponding to the lockdowns in Türkiye, and the remaining 67.5% in 10 months thereafter. Human rhinovirus/enterovirus (hRE) (48.3%) was the most common agent detected during and after lockdown. Parainfluenza virus (PIV) (23.0%), influenza virus (9.8%), and respiratory syncytial virus (RSV) (9.1%) were the other common agents. The 28.7% of episodes were lower respiratory tract infections (LRTIs), and complications and mortality were higher than upper respiratory tract infections (URTIs) (25.0% vs 5.3%). Bacteremia was identified in 11.5% of culture-drawn episodes. Treatment delay in one-third and death within four weeks after RVI in 4.9% of episodes were observed.

CONCLUSION

During the pandemic, fewer episodes of RVIs occurred during the lockdown period. Respiratory viruses may cause complications, delays in treatment, and even death in children with cancer. Therefore, increased awareness of RVIs and rapid detection of respiratory viruses will benefit the prevention and, in some cases, abrupt supportive and some antiviral treatment of RVI in children with cancer.

Approach to hematopoietic cell transplant candidates with respiratory viral detection

The management of respiratory viruses prior to hematopoietic cell transplant (HCT) can be controversial and requires special consideration of host factors, transplant parameters, and the specific respiratory virus (RV). In the setting of adenovirus (ADV), human metapneumovirus (HMPV), influenza, parainfluenza virus (PIV), and respiratory syncytial virus (RSV) detection prior to hematopoietic cell transplant (HCT), clinical practice guidelines recommend transplant delay when possible; however, there is much more ambiguity when other respiratory viruses, such as seasonal coronaviruses (CoVs), human rhinovirus (HRV), and SARS-CoV-2, are detected. Our aims for this review include detailing clinical practical guidelines and reviewing current literature on pre-transplant respiratory viral infections (RVIs), including antiviral therapies and prevention strategies, when available. We will center our discussion on three representative clinical scenarios, with the goal of providing practical guidance to clinicians.

Etiology and Factors Affecting Severe Complications and Mortality of Febrile Neutropenia in Children with Acute Leukemia

Objective

Febrile neutropenia (FN) is an important complication that causes high rates of morbidity and mortality in patients with malignancies. We aimed to investigate the etiology, epidemiological distribution and its change over the years, clinical courses, and outcomes of FN in children with acute leukemia.

Materials and Methods

We retrospectively analyzed the demographic data, clinical characteristics, laboratory results, severe complications, and mortality rates of pediatric patients with FN between January 2010 and December 2020.

Results

In 153 patients, a total of 450 FN episodes (FNEs) occurred. Eighty-four (54.9%) of these patients were male, the median age of the patients was 6.5 (range: 3-12.2) years, and 127 patients (83%) were diagnosed with acute lymphoblastic leukemia. Fever with a focus was found in approximately half of the patients, and an etiology was identified for 38.7% of the patients. The most common fever focus was bloodstream infection (n=74, 16.5%). Etiologically, a bacterial infection was identified in 22.7% (n=102), a viral infection in 13.3% (n=60), and a fungal infection in 5.8% (n=26) of the episodes. Twenty-six (23.2%) of a total of 112 bacteria were multidrug resistant (MDR) The rate of severe complications was 7.8% (n=35) and the mortality rate was 2% (n=9). In logistic regression analysis, refractory/relapsed malignancies and high C-reactive protein (CRP) at first admission were found to be the most important independent risk factors for mortality. Prolonged neutropenia after chemotherapy, diagnosis of acute myeloid leukemia, identification of fever focus or etiological agents, invasive fungal infections, polymicrobial infections, and need for intravenous immunoglobulin treatment increased the frequency of severe complications.

Conclusion

We found that there was no significant change in the epidemiological distribution or frequency of resistant bacteria in our center in the last 10 years compared to previous years. Prolonged duration of fever, relapsed/refractory malignancies, presence of fever focus, and high CRP level were significant risk factors for poor clinical course and outcome.

Viral infections in pediatric brain tumor patients treated with targeted therapies

BACKGROUND

Brain tumors are the most common solid malignancies and the leading cause of cancer-related mortality in children. While numerous studies report on viral infections in children with hematologic malignancies and solid organ transplantation, epidemiologic data on the incidence and outcome of viral infections in pediatric patients with brain tumors treated with targeted therapies are still lacking.

OBJECTIVES/STUDY DESIGN

We retrospectively reviewed all children with brain tumors receiving targeted therapies in a primary or recurrent setting at the Medical University of Vienna from 2006 to 2021. Demographic variables, quantitative and qualitative parameters of possible infections, and treatment outcomes were recorded.

RESULTS

In our cohort (n = 117), 36% of the patients developed at least one PCR-proven viral infection. Respiratory and gastrointestinal tract infections were most common, with 31% and 25%, respectively. Central nervous system (CNS) infections occurred in approximately 10%, with an almost equal distribution of varicella-zoster virus, John Cunningham virus (JCV), and enterovirus. Two patients tested PCR-positive for SARS-CoV-2 infection, with one virus-related death caused by a SARS-CoV-2-related acute respiratory distress syndrome. Patients receiving bevacizumab or mTOR inhibitors seem to have a greater susceptibility to viral infections.

CONCLUSION

Pediatric patients with brain tumors receiving targeted therapies have a higher risk of viral infections when compared to children receiving conventional chemotherapy or the general population, and life-threatening infections can occur. Fast detection and upfront treatment are paramount to prevent life-threatening infections in immunocompromised children suffering from brain tumors receiving targeted therapies.

Lung microbiome in children with hematological malignancies and lower respiratory tract infections

Background

Respiratory infectious complications remain a major cause of morbidity and mortality in children with hematological malignancies. Knowledge regarding the lung microbiome in aforementioned children is limited.

Methods

A prospective cohort was conducted, enrolling 16 children with hematological malignancies complicated with moderate-to-severe lower respiratory tract infections (LRTIs) versus 21 LRTI children with age, gender, weight, and infection severity matched, with no underlying malignancies, to evaluate the lung microbiome from bronchoalveolar lavage fluid samples in different groups.

Results

The lung microbiome from children with hematological malignancies and LRTIs showed obviously decreased α and β diversity; increased microbial function in infectious disease:bacteria/parasite; drug resistance:antimicrobial and human pathogenesis than the control group; a significantly reduced proportion of Firmicutes, Bacteroidota, Actinobacteriota; increased Proteobacteria at the phylum level; and distinctly elevated Parabacteroides, Klebsiella, Grimontia, Escherichia_Shigella, unclassified_Enterobacteriaceae at the genus level than the control group. Furthermore, it was revealed that α diversity (Shannon), β diversity (Bray-Curtis dissimilarity), Proteobacteria at the phylum level, and unclassified_Enterobacteriaceae and Escherichia_Shigella at the genus level were significantly negatively associated with hospitalization course whereas Firmicutes at the phylum level was established positively correlated with the hospitalization course.

Conclusions

Children with hematological malignancies and LRTIs showed obviously decreased α and β diversity, significantly increased function in infectious disease pathogenesis, antimicrobial drug resistance, and unfavorable environment tolerance. Moreover, α diversity (Shannon), β diversity (Bray-Curtis dissimilarity), and Proteobacteria may be used as negative correlated predictors for hospitalization course in these children whereas Firmicutes may be utilized as a positive correlated predictor.

Admissions due to vaccine preventable diseases in a large paediatric intensive care unit in Greece over a 10-year period

AIM

Childhood immunisation is an important preventive measure. However, care givers may delay routine immunisations or seek exemptions from state vaccine mandates. Vaccine refusal creates barriers on vaccine coverage and leads to morbidity and mortality.

METHODS

Our study reviews morbidity and mortality from vaccine preventable diseases (VPDs) in a large paediatric intensive care unit in Greece over a 10-year period.

RESULTS

During the study period, 73 cases of VPDs were recorded, corresponding to 3.5% of total paediatric intensive care unit admissions. Influenza was the most prevalent VPD, followed by pneumococcal disease, measles, pertussis and meningococcal disease. Most patients (83.3%) were unvaccinated for the admission's VPD. Outcome was unfavourable for 31.9% of the patients (17 children died, 6 developed chronic impairment).

CONCLUSION

Absent or incomplete vaccination may result in serious morbidity and mortality from preventable diseases. Strengthening vaccination strategies are needed to improve individual protection as well as herd immunity.

Mycoplasma pneumoniae Infections and Primary Immune Deficiencies

Mycoplasma pneumoniae (M. pneumoniae) is one of the leading causes of community-acquired pneumonia in children and is also implicated in a variety of reactive extrapulmonary diseases. Recurrent and/or severe respiratory infections are one of the most frequent manifestations of several types of primary immunodeficiency. Here, we reviewed the medical literature to assess the potential relevance of M. pneumoniae in the infections observed in children affected with combined, humoral, and innate primary immune deficiencies. M. pneumoniae does not result to be epidemiologically prevalent as a cause of pneumonia in children affected by primary immunodeficiencies, but this infection can have a persistent or severe course in this category of patients. Indeed, the active search of M. pneumoniae could be useful and appropriate especially in children with humoral immune deficiencies. Indeed, most cases of M. pneumoniae infection in primary immunodeficiencies are described in patients affected by a/hypo-gammaglobulinemia.

Viral Respiratory Infections in Hematological Patients

Viral infections of the respiratory system represent one of the most important complications in hematological patients in terms of both the severity of the clinical picture and its related impact on the duration of hospitalization, and of mortality. The most implicated viruses are those that commonly cause community-based respiratory diseases: respiratory syncytial virus, Influenza virus and rhinovirus. However, in some cases the clinical picture may be triggered by first infection with or reactivation of pathogens normally not responsible for clinically relevant diseases in immunocompetent subjects. This issue is currently being taken into greater consideration within the scientific community. However, the strong heterogeneity in the epidemiology and clinical expression of these infections and the lack of adequate therapeutic options imply that there is currently no uniform consensus on the best management of these patients. The main purpose of this review is to highlight which viruses are currently most implicated in the onset of these infections, what is their incidence in so heterogeneous and fragile patients and the factors that lead to disease's onset and evolution. Possible or available clinical management options, diagnostic and therapeutic tools, and preventive and prophylaxis measures are also discussed.

Pulmonary Infectious Complications in Children with Hematologic Malignancies and Chemotherapy-Induced Neutropenia

Infections frequently complicate the treatment course in children with hematologic malignancies undergoing chemotherapy. Febrile neutropenia (FN) remains a major cause of hospital admissions in this population, and respiratory tract is often proven to be the site of infection even without respiratory signs and symptoms. Clinical presentation may be subtle due to impaired inflammatory response. Common respiratory viruses and bacteria are widely identified in these patients, while fungi and, less commonly, bacteria are the causative agents in more severe cases. A detailed history, thorough clinical and basic laboratory examination along with a chest radiograph are the first steps in the evaluation of a child presenting signs of a pulmonary infection. After stratifying patient’s risk, prompt initiation of the appropriate empirical antimicrobial treatment is crucial and efficient for the majority of the patients. High-risk children should be treated with an intravenous antipseudomonal beta lactam agent, unless there is suspicion of multi-drug resistance when an antibiotic combination should be used. In unresponsive cases, more invasive procedures, including bronchoalveolar lavage (BAL), computed tomography (CT)-guided fine-needle aspiration or open lung biopsy (OLB), are recommended. Overall mortality rate can reach 20% with higher rates seen in cases unresponsive to initial therapy and those under mechanical ventilation.

Detection of Respiratory Viruses in the Clinical Outcome of Children With Fever and Neutropenia

BACKGROUND

Several evidence-based guidelines for the management of children with febrile neutropenia (FN) have been published, with special focus in bacterial and fungal infections. However, the role of acute respiratory infections caused by respiratory viruses (RV) has not been clearly established. The aim of this study was to evaluate the epidemiology, clinical presentation and outcome of acute respiratory infections in children with FN.

METHODS

Patients, <18 years of age admitted to the Pediatric Oncology-Hematology Unit after developing FN between November 2010 and December 2013, were prospectively included in the study. Children were evaluated by clinical examination and laboratory tests. Nasopharyngeal sample was obtained for detection of RV.

RESULTS

There was a total of 112 episodes of FN in 73 children admitted to the hospital during a 32-month period. According to disease severity, 33% of the episodes were considered moderate or severe. Rhinovirus was the most frequently detected RV (66.6%; 24/36), followed by parainfluenza. On regard to clinical outcome, RV-infected children developed fewer episodes of moderate or severe FN compared with non-RV infected children (16.7% vs. 33.3%; P = 0.08).

CONCLUSIONS

A great proportion of children with FN admitted to a tertiary hospital had a RV isolation. The rate of this RV isolation was significantly higher when a rapid molecular test was used compared with conventional microbiologic methods. Rhinovirus was the most frequently isolated, although its role as an active agent of acute infection was not clear. Children with FN and a RV isolate had a lower rate of severe disease.

HMPV in Immunocompromised Patients: Frequency and Severity in Pediatric Oncology Patients

Cancer is the first cause of death by disease in childhood globally. The most frequent types of cancers in children and adolescents are leukemias, followed by brain and central nervous system tumors and lymphomas. The recovery rate of cancer in children is around 80% in developed countries and up to 30% in developing countries. Some of the main causes of complications in children and adolescents with cancer are respiratory viral infections, mainly in bone marrow-transplanted patients. Respiratory viruses have been detected in the bronchoalveolar lavage or nasal wash specimens from cancer patients with or without respiratory illness symptoms. Human metapneumovirus (HMPV) is within the ten most common viruses that are encountered in samples from pediatric patients with underlying oncology conditions. In most of cases, HMPV is found as the only viral agent, but co-infection with other viruses or with bacterial agents has also been reported. The discrepancies between the most prevalent viral agents may be due to the different populations studied or the range of viral agents tested. Some of the cases of infection with HMPV in cancer patients have been fatal, especially in those who have received a hematopoietic stem cell transplant. This review seeks to show a general view of the participation of HMPV in respiratory illness as a complication of cancer in childhood and adolescence.

Possible role of highly activated mucosal NK cells against viral respiratory infections in children undergoing haematopoietic stem cell transplantation

Infection is the leading cause of non-relapse-related mortality after allogeneic haematopoietic stem cell transplantation (HSCT). Altered functions of immune cells in nasal secretions may influence post HSCT susceptibility to viral respiratory infections. In this prospective study, we determined T and NK cell numbers together with NK activation status in nasopharyngeal aspirates (NPA) in HSCT recipients and healthy controls using multiparametric flow cytometry. We also determined by polymerase chain reaction (PCR) the presence of 16 respiratory viruses. Samples were collected pre-HSCT, at day 0, +10, +20 and +30 after HSCT. Peripheral blood (PB) was also analyzed to determine T and NK cell numbers. A total of 27 pediatric HSCT recipients were enrolled and 16 of them had at least one viral detection (60%). Rhinovirus was the most frequent pathogen (84% of positive NPAs). NPAs of patients contained fewer T and NK cells compared to healthy controls (p = 0.0132 and p = 0.120, respectively). Viral PCR + patients showed higher NK cell number in their NPAs. The activating receptors repertoire expressed by NK cells was also higher in NPA samples, especially NKp44 and NKp46. Our study supports NK cells relevance for the immune defense against respiratory viruses in HSCT recipients.

Are Community Acquired Respiratory Viral Infections an Underestimated Burden in Hematology Patients?

Despite a plethora of studies demonstrating significant morbidity and mortality due to community-acquired respiratory viral (CRV) infections in intensively treated hematology patients, and despite the availability of evidence-based guidelines for the diagnosis and management of respiratory viral infections in this setting, there is no uniform inclusion of respiratory viral infection management in the clinical hematology routine. Nevertheless, timely diagnosis and systematic management of CRV infections in intensively treated hematology patients has a demonstrated potential to significantly improve outcome. We have briefly summarized the recently published data on CRV infection epidemiology, as well as guidelines on the diagnosis and management of CRV infections in patients intensively treated for hematological malignancies. We have also assessed available treatment options, as well as mentioned novel agents currently in development.

Long-term morbidity of respiratory viral infections during chemotherapy in children with leukaemia

BACKGROUND

Respiratory viruses are a common cause of infection in immunosuppressed children undergoing cancer therapy. Pulmonary sequelae have been documented following respiratory viral infections (RVIs) in hematopoietic stem cell transplant (HSCT) recipients; however potential late effects in children undergoing nonmyeloablative chemotherapy have not been investigated.

AIM

To evaluate the long-term pulmonary morbidity of respiratory viral infections during chemotherapy in children with acute lymphoblastic leukemia (ALL).

METHODS

Childhood ALL survivors, aged 7 to 18 years, greater than 6 months posttreatment were recruited. Exclusion criteria included HSCT or proven bacterial/fungal respiratory infection during treatment. Subjects were classified into "viral" or "control" groups according to retrospective medical records that documented the presence of laboratory-proven RVIs during chemotherapy. Symptom questionnaires (Liverpool, ISAAC) and lung function testing (spirometry, plethysmography, diffusing capacity, forced oscillation technique to ATS/ERS standards) were then performed cross-sectionally at the time of recruitment.

RESULTS

Fifty-four patients (31 viral, 23 control) were recruited: median (range) age 11.2 (7.2-18.1) years, and at 4.9 (0.5-13) years posttherapy. Abnormalities were detected in 17 (31%) individuals (8 viral, 9 control), with the most common being DLCO impairment (3 viral, 4 control) and reduced respiratory reactance at 5 Hz (5 viral, 6 control). Children with RVIs during chemotherapy reported more current respiratory symptoms, particularly wheeze (odds ratio [OR], 3.0; 95% confidence interval [CI]: 0.9-10.0; P = .09) and cough (OR, 2.7; 95% CI: 0.8-9.5; P = .11). No differences in lung function tests were observed between the two groups.

CONCLUSIONS

Our study found children with RVIs during chemotherapy developed more long-term respiratory symptoms than controls; however, differences did not reach statistical significance. No differences in static lung function were found between the two groups. Overall, pulmonary abnormalities and/or significant ongoing respiratory symptoms were detected in nearly a third of ALL survivors treated without HSCT. Larger, prospective studies are warranted to evaluate the etiology and clinical significance of these findings.

The impact analysis of a multiplex PCR respiratory panel for hospitalized pediatric respiratory infections in Japan

Background

Rapid molecular diagnosis of infections has contributed to timely treatments and antimicrobial stewardship. However, the benefit and cost-effectiveness vary in each country or community because they have different standard practices and health care systems. In Japan, rapid antigen tests (RATs) have been frequently used for pediatric respiratory infections. We investigated the impact and cost-effectiveness of a multiplex PCR (mPCR) respiratory panel for pediatric respiratory infections in a Japanese community hospital.

Methods

We replaced RATs with an mPCR respiratory panel (FilmArray®) for admitted pediatric respiratory infections on March 26, 2018. We compared the days of antimicrobial therapy (DOT) and length of stay (LOS) during the mPCR period (March 2018 to April 2019) with those of the RAT period (March 2012 to March 2018).

Results

During the RAT and mPCR periods, 1132 and 149 patients were analyzed. The DOT/case was 12.82 vs 8.56 (p < 0.001), and the LOS was 8.18 vs 6.83 days (p = 0.032) in the RAT and mPCR groups, respectively. The total costs during admissions were ∖258,824 ($2331.7) and ∖243,841 ($2196.8)/case, respectively. Pathogen detection rates were 30.2% vs 87.2% (p < 0.001).

Conclusion

Compared to conventional RATs, the mPCR test contributed to a reduction in the DOT and LOS in a Japanese community hospital for admission-requiring pediatric respiratory infections. However, a proper stewardship program is essential to further reduce the unnecessary usage of antimicrobials.

A 3-Year Retrospective Study of the Epidemiology of Acute Respiratory Viral Infections in Pediatric Patients With Cancer Undergoing Chemotherapy

BACKGROUND

Acute viral respiratory infections are common causes of febrile episodes in children. There are still limited data about distribution of acute viral respiratory infections in children with cancer.

OBJECTIVE

The first aim of this study was to evaluate the viral etiology and seasonality of acute viral respiratory infection in pediatric patients with cancer in a 3-year study. Our second aim was to evaluate the impact of viral infections on delaying the patients' chemotherapy or radiotherapy.

MATERIALS AND METHODS

This cross-sectional study was conducted from January 2014 to July 2017. Nasopharyngeal aspirates were analyzed in patients younger than 21 years with acute respiratory infections. Patients were treated in the Pediatric Hematology and Oncology Department of Dr. Behçet Uz Children's Hospital with real-time multiplex polymerase chain reaction. Data were analyzed to determine the frequency and seasonality of infections. The χ or the Fisher exact tests were used.

RESULTS

A total of 219 samples of nasopharyngeal aspirates and blood were analyzed. The mean patient age was 76.8±59.3 months, with 46.3% female and 53.7% male children in a total of 108 patients. Of this total, 55% (60/108 cases) had multiple acute respiratory infections. Acute lymphoblastic leukemia (48.1%) was the most prevalent disease. The 3 most prevalent viruses were human rhinovirus (HRV) (33.1%), parainfluenza (PI) (18.7%), and coronavirus (CoV) (14.8%). In terms of the seasonal distribution of viruses, PI was most common in winter 2014, HRV in spring 2014, HRV in fall 2014, PI in winter 2015 and summer 2015, CoV in spring 2015, HRV in fall 2015, both influenza and HRV in winter 2016, both human metapneumovirus and bocavirus in spring 2016, HRV in summer 2016, both HRV and PI in fall 2016, both respiratory syncytial virus and influenza in winter 2017, HRV in spring 2017, and both HRV and adenovirus in summer 2017. The mean duration of neutropenia for patients with viral respiratory infection was 17.1±13.8 (range: 2 to 90) days. The mean duration of symptoms of viral respiratory infection was 6.8±4.2 (range: 2 to 31) days. A delay in chemotherapy treatment owing to viral respiratory infection was detected in 73 (33.3%) patients. The mean duration of delay in chemotherapy treatment was 9.6±5.4 (range: 3 to 31) days.

CONCLUSIONS

In conclusion, we report our 3-year experience about the frequency and seasonality of respiratory viruses in children with cancer.

A prospective study on the epidemiology and clinical significance of viral respiratory infections among pediatric oncology patients

Respiratory infections in oncology are both common and potentially severe. However, there is still a gap in the literature, regarding the epidemiology of viral respiratory infections in children with cancer. We prospectively enrolled 224 patients, from September 2012 to August 2015. The cohort included children with hematologic or solid malignancies receiving chemotherapy, or undergoing hemopoietic stem cell transplantation, outpatients/inpatients exhibiting signs/symptoms of febrile/afebrile upper/lower respiratory infection. Viral infection was diagnosed by detection of ≥1 viruses from a sample at time of enrollment, using the CLART^® PneumoVir kit (GENOMICA, Spain). Α detailed questionnaire including demographics and medical history was also completed. Samples were processed in batches, results were communicated as soon as they became available. Children recruited in whom no virus was detected composed the no virus detected group. Viral prevalence was 38.4% in children presenting with respiratory illness. A single virus was found in 30.4%, with RSV being the most frequent. Viral coinfections were detected in 8%. Children with viral infection were more likely to be febrile upon enrollment and to present with lower respiratory signs/symptoms. They had longer duration of illness and they were more likely to receive antibiotics/antifungals. Only 22% of children with influenza received oseltamivir. Mortality was low (2.7%), however, pediatric intensive care unit (PICU) admission and death were correlated with virus detection. In our study mortality was low and PICU admission was related to virus identification. Further research is needed to clarify whether antibiotics in virus-proven infection are of value and underline the importance of oseltamivir's timely administration in influenza.

Human bocaviruses and paediatric infections

Human bocavirus 1 (HBoV1), belonging to the Parvoviridae family, was discovered in 2005, in nasopharyngeal samples from children with respiratory tract infections. Three additional bocaviruses, HBoV2-4, were discovered in 2009-10. These viruses have mainly been found in faecal samples and their role in human diseases is still uncertain. HBoV1 causes a wide spectrum of respiratory diseases in children, including common cold, acute otitis media, pneumonia, bronchiolitis, and asthma exacerbations. HBoV1 DNA can persist in airway secretions for months after an acute infection. Consequently, acute HBoV1 infection cannot be diagnosed with standard DNA PCR; quantitative PCR and serology are better diagnostic approaches. Because of their high clinical specificity, diagnostic developments such as HBoV1 mRNA and antigen detection have shown promising results. This Review summarises the knowledge on human bocaviruses, with a special focus on HBoV1.

Respiratory Viral Infections in Children and Adolescents with Hematological Malignancies

Background

Despite the introduction of a polymerase chain reaction (PCR) test for the diagnosis of respiratory viral infection (RVI), guidance on the application of this test and the management of RVI in immunocompromised children is lacking. This study evaluated the clinical characteristics of RVI and established strategies for the PCR test in children and adolescents with hematological malignancies.

Methods

This study included children and adolescents with underlying hematological malignancies and respiratory symptoms, in whom a multiplex PCR test was performed. Patients in whom RVI was identified and not identified were categorized into Groups I and II, respectively. Group I was sub-divided into patients with upper and lower respiratory infections. The medical records of the enrolled patients were retrospectively reviewed.

Results

A total of 93 respiratory illnesses were included. Group I included 46 (49.5%) cases of RVI, including 31 (67.4%) upper and 15 (32.6%) lower respiratory infections. Rhinovirus (37.0%) was the most common viral pathogen. Significantly more patients in Group I had community-acquired respiratory illnesses (p=0.003) and complained of rhinorrhea (p<0.001) and sputum (p=0.008) than those in Group II. In Group I, significantly more patients with lower respiratory infections had uncontrolled underlying malignancies (p=0.038) and received re-induction or palliative chemotherapy (p=0.006) than those with upper respiratory infections.

Conclusions

A multiplex PCR test should be considered for RVI diagnosis in immunocompromised children and adolescents with respiratory symptoms, especially in those with rhinorrhea or sputum prominent over a cough. The early application of the PCR test in patients with uncontrolled underlying malignancies may improve outcomes.

Characteristics and Outcomes of Coronavirus Infection in Children: The Role of Viral Factors and an Immunocompromised State

BACKGROUND

Immunocompromised children might be predisposed to serious infections from human coronaviruses (HCoVs), including strains OC43, NL63, HKU1, and 229E; however, the virologic and clinical features of HCoV infection in immunocompromised children have not been compared to those in nonimmunocompromised children.

METHODS

We retrospectively analyzed a cohort of children who presented to Seattle Children's Hospital and in whom HCoV was detected by a multiplex respiratory polymerase chain reaction assay of a nasal sample between October 2012 and March 2016. Lower respiratory tract disease (LRTD) was defined as possible or definite infiltrate seen in chest imaging, need for oxygen, or abnormal lung examination in conjunction with a physician diagnosis of LRTD. We used logistic regression modeling to evaluate risk factors for LRTD and LRTD that necessitated oxygen use (severe LRTD), including an immunocompromised state, in children with HCoV infection.

RESULTS

The median ages of 85 immunocompromised and 1152 nonimmunocompromised children with HCoV infection were 6.3 and 1.6 years, respectively. The prevalence of LRTD and of severe LRTD did not differ greatly between the immunocompromised and nonimmunocompromised patients (22% vs 26% [LRTD] and 15% vs 11% [severe LRTD], respectively); however, in a multivariable model, an immunocompromised state was associated with an increased likelihood of severe LRTD (adjusted odds ratio, 2.5 [95% confidence interval, 1.2-4.9]; P = .01). Younger age, having an underlying pulmonary disorder, and the presence of respiratory syncytial virus were also associated with LRTD or severe LRTD in multivariable models. The risks of LRTD or severe LRTD did not differ among the children with different HCoV strains.

CONCLUSIONS

The presence of a copathogen and host factors, including an immunocompromised state, were associated with increased risk for severe LRTD. Recognizing risk factors for severe respiratory illness might assist in risk stratification.

Burden of human metapneumovirus infections in patients with cancer: Risk factors and outcomes

BACKGROUND

Human metapneumovirus (hMPV) causes upper and lower respiratory tract infections (URIs and LRIs, respectively) in healthy and immunocompromised patients; however, its clinical burden in patients with cancer remains unknown.

METHODS

In a retrospective study of all laboratory‐confirmed hMPV infections treated at the authors’ institution between April 2012 and May 2015, clinical characteristics, risk factors for progression to an LRI, treatment, and outcomes in patients with cancer were determined.

RESULTS

In total, 181 hMPV infections were identified in 90 patients (50%) with hematologic malignancies (HMs), in 57 (31%) hematopoietic cell transplantation (HCT) recipients, and in 34 patients (19%) with solid tumors. Most patients (92%) had a community‐acquired infection and presented with URIs (67%), and 43% developed LRIs (59 presented with LRIs and 19 progressed from a URI to an LRI). On multivariable analysis, an underlying HM (adjusted odds ratio [aOR], 3.11; 95% confidence interval [CI], 1.12‐8.64; P = .029), nosocomial infection (aOR, 26.9; 95% CI, 2.79‐259.75; P = .004), and hypoxia (oxygen saturation [SpO2], ≤ 92%) at presentation (aOR, 9.61; 95% CI, 1.98‐46.57; P = .005) were identified as independent factors associated with LRI. All‐cause mortality at 30 days from hMPV diagnosis was low (4%), and patients with LRIs had a 10% mortality rate at day 30 from diagnosis; whereas patients with URIs had a 0% mortality rate.

CONCLUSIONS

hMPV infections in patients with cancer may cause significant morbidity, especially for those with underlying HM who may develop an LRI. Despite high morbidity and the lack of directed antiviral therapy for hMPV infections, mortality at day 30 from this infection remained low in this studied population. Cancer 2017;123:2329–2337. © 2017 American Cancer Society.

Human metapneumovirus infections in patients with cancer may cause significant morbidity, especially in those with underlying hematologic malignancies who may develop a lower respiratory infection. Despite high morbidity and the lack of directed antiviral therapy for human metapneumovirus infections, mortality from this infection at day 30 and day 90 remains low in the studied population.

Human metapneumovirus infections in hematopoietic cell transplant recipients and hematologic malignancy patients: A systematic review

Over the past decade, reported incidence of human metapneumovirus (hMPV) has increased owing to the use of molecular assays for diagnosis of respiratory viral infections in cancer patients. The seasonality of these infections, differences in sampling strategies across institutions, and small sample size of published studies make it difficult to appreciate the true incidence and impact of hMPV infections. In this systematic review, we summarized the published data on hMPV infections in hematopoietic cell transplant recipients and patients with hematologic malignancy, focusing on incidence, hMPV-associated lower respiratory tract infection (LRTI), mortality, prevention, and management with ribavirin and/or intravenous immunoglobulins. Although the incidence of hMPV infections and hMPV-associated LRTI in this patient population is similar to respiratory syncytial virus or parainfluenza virus and despite lack of directed antiviral therapy, the mortality rate remains low unless patients develop LRTI. In the absence of vaccine to prevent hMPV, infection control measures are recommended to reduce its burden in cancer patients.

Parainfluenza virus infections in hematopoietic cell transplant recipients and hematologic malignancy patients: A systematic review

Parainfluenza viral infections are increasingly recognized as common causes of morbidity and mortality in cancer patients, particularly in hematopoietic cell transplant (HCT) recipients and hematologic malignancy (HM) patients because of their immunocompromised status and susceptibility to lower respiratory tract infections. Advances in diagnostic methods, including polymerase chain reaction, have led to increased identification and awareness of these infections. Lack of consensus on clinically significant endpoints and the small number of patients affected in each cancer institution every year make it difficult to assess the efficacy of new or available antiviral drugs. In this systematic review, we summarized data from all published studies on parainfluenza virus infections in HM patients and HCT recipients, focusing on incidence, risk factors, long-term outcomes, mortality, prevention, and management with available or new investigational agents. Vaccines against these viruses are lacking; thus, infection control measures remain the mainstay for preventing nosocomial spread. A multi-institutional collaborative effort is recommended to standardize and validate clinical endpoints for PIV infections, which will be essential for determining efficacy of future vaccine and antiviral therapies.

Respiratory viruses and their impact in healthcare

PURPOSE OF REVIEW

As viral respiratory infections are responsible for significant morbidity and mortality, and are associated with numerous challenges for infection control, we provide an overview of the most recent publications on healthcare-associated respiratory infections.

RECENT FINDINGS

Populations most susceptible to respiratory viruses include neonates, immunocompromised and elderly populations. Newer polymerase chain reaction-based assays are more sensitive and are able to detect multiple respiratory viruses. The significance of virus detection among asymptomatic individuals, however, remains unclear. There is more evidence of airborne transmission of influenza, but currently N95 masks are recommended only for aerosol generating procedures. Transocular transmission of influenza has been demonstrated in the experimental setting, but further research is needed of transocular transmission of other respiratory viruses. Mandatory vaccination of healthcare workers against influenza has been shown to reduce influenza rates and patient mortality.

SUMMARY

Infection control measures can be supplemented with use of polymerase chain reaction testing to determine causes, but the cornerstone of prevention relies on enforcing appropriate isolation measures for patients: hand hygiene; appropriate use of personal protective equipment by healthcare workers; illness screening of visitors; and influenza vaccination of healthcare workers, patients and families.

Human rhinovirus C infections in pediatric hematology and oncology patients

Children with cancer and HSCT recipients are at high risk for common viral infections. We sought to define the viral etiology of ARI and identify risk factors. Nasal wash samples were collected from pediatric hematology-oncology patients and HSCT recipients with ARI during the 2003-2005 winter seasons. Real-time RT-PCR was performed to detect Flu A, influenza B, RSV, PIV 1-3, human MPV, and HRV. HRV specimens were sequenced and genotyped. Seventy-eight samples from 62 children were included. Viruses were detected in 31 of 78 samples (40%). HRV were detected most frequently, in 16 (52%) including five HRVC; followed by seven (22%) RSV, five (16%) Flu A, four (13%) MPV, and two (6%) PIV2. There was a trend toward higher risk of viral infection for children in day care. Only 8% of the study children had received influenza vaccine. HRV, including the recently discovered HRVC, are an important cause of infection in pediatric oncology and HSCT patients. Molecular testing is superior to conventional methods and should be standard of care, as HRV are not detected by conventional methods.

The role of multiplex PCR in respiratory tract infections in children

BACKGROUND

Infants, toddlers, and children of primary-school age without any special risk factors generally have three to ten febrile respiratory infections per year. Most such infections are of viral origin and self-limiting, but viral infection is often hard to distinguish from bacterial infection. The use of a multiplex polymerase chain reaction (PCR) to detect viruses in respiratory secretions is potentially beneficial, as it might help physicians avoid giving antibiotics unnecessarily.

METHOD

This article is based on a selective review of the literature and on the findings of the authors' own investigations.

RESULTS

Multiplex PCR is a highly sensitive, highly specific test for the detection of viral nucleic acids in respiratory secretions. If PCR reveals the presence of RNA derived from respiratory syncytial virus, human metapneumovirus, parainfluenza virus, or influenza virus, then an acute infection caused by the corresponding pathogen is probably present, and further treatment can be given accordingly. On the other hand, the nucleic acids of adeno-, boca-, rhino- or coronaviruses can be found in relatively trivial infections as well as in asymptomatic persons, probably reflecting either a prior infection or a current subclinical one. For children in particular, upper respiratory infections are so common in the winter months that acute and prior infections with these pathogens cannot be distinguished by multiplex PCR. The use of multiplex PCR in children has not been shown to shorten hospital stays or to lessen antibiotic consumption or overall cost.

CONCLUSION

The detectability of viral nucleic acids is an important contribution to the diagnostic assessment of children with severe respiratory infection. For these highly sensitive diagnostic tests to be used optimally, primary viral infections must be distinguished from bacterial superinfections.

Acute respiratory viral infections in pediatric cancer patients undergoing chemotherapy

OBJECTIVE

to estimate the prevalence of infection by respiratory viruses in pediatric patients with cancer and acute respiratory infection (ARI) and/or fever.

METHODS

cross-sectional study, from January 2011 to December 2012. The secretions of nasopharyngeal aspirates were analyzed in children younger than 21 years with acute respiratory infections. Patients were treated at the Grupo em Defesa da Criança Com Câncer (Grendacc) and University Hospital (HU), Jundiaí, SP. The rapid test was used for detection of influenza virus (Kit Biotrin, Inc. Ireland), and real-time multiplex polymerase chain reaction (FTD, Respiratory pathogens, multiplex Fast Trade Kit, Malta) for detection of influenza virus (H1N1, B), rhinovirus, parainfluenza virus, adenovirus, respiratory syncytial virus, human parechovirus, bocavirus, metapneumovirus, and human coronavirus. The prevalence of viral infection was estimated and association tests were used (χ(2) or Fisher's exact test).

RESULTS

104 samples of nasopharyngeal aspirate and blood were analyzed. The median age was 12 ± 5.2 years, 51% males, 68% whites, 32% had repeated ARIs, 32% prior antibiotic use, 19.8% cough, and 8% contact with ARIs. A total of 94.3% were in good general status. Acute lymphocytic leukemia (42.3%) was the most prevalent neoplasia. Respiratory viruses were detected in 50 samples: rhinoviruses (23.1%), respiratory syncytial virus AB (8.7%), and coronavirus (6.8%). Co-detection occurred in 19% of cases with 2 viruses and in 3% of those with 3 viruses, and was more frequent between rhinovirus and coronavirus 43. Fever in neutropenic patients was observed in 13%, of which four (30.7) were positive for viruses. There were no deaths.

CONCLUSIONS

the prevalence of respiratory viruses was relevant in the infectious episode, with no increase in morbidity and mortality. Viral co-detection was frequent in patients with cancer and ARIs.

Prospective evaluation for respiratory pathogens in children with sickle cell disease and acute respiratory illness

BACKGROUND

Human rhinovirus (HRV), human coronavirus (hCoV), human bocavirus (hBoV), and human metapneumovirus (hMPV) infections in children with sickle cell disease have not been well studied.

PROCEDURE

Nasopharyngeal wash specimens were prospectively collected from 60 children with sickle cell disease and acute respiratory illness, over a 1-year period. Samples were tested with multiplexed-PCR, using an automated system for nine respiratory viruses, Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Bordetella pertussis. Clinical characteristics and distribution of respiratory viruses in patients with and without acute chest syndrome (ACS) were evaluated.

RESULTS

A respiratory virus was detected in 47 (78%) patients. Nine (15%) patients had ACS; a respiratory virus was detected in all of them. The demographic characteristics of patients with and without ACS were similar. HRV was the most common virus, detected in 29 of 47 (62%) patients. Logistic regression showed no association between ACS and detection of HRV, hCoV, hBoV, hMPV, and other respiratory pathogens. Co-infection with at least one additional respiratory virus was seen in 14 (30%) infected patients, and was not significantly higher in patients with ACS (P = 0.10). Co-infections with more than two respiratory viruses were seen in seven patients, all in patients without ACS. Bacterial pathogens were not detected.

CONCLUSION

HRV was the most common virus detected in children with sickle cell disease and acute respiratory illness, and was not associated with increased morbidity. Larger prospective studies with asymptomatic controls are needed to study the association of these emerging respiratory viruses with ACS in children with sickle cell disease.

Infection in cancer and transplantation

The range of opportunist pathogens in cancer and transplant patients continues to increase. New treatment modalities and forms of immunosuppression following transplantation have improved survival from the underlying disease but can lead to prolonged immunosuppression and increased risk of infection. NICE guidelines for the management of neutropenic sepsis are now available but have aroused some controversy, particularly over the recommendation for quinolone prophylaxis in high-risk patient groups.

In addition to neutropenia, long-term defects in cell-mediated immunity are exposing patients to risk of chronic, viral, protozoal and fungal infection. Advances in diagnostic techniques have the potential to improve management and limit unnecessary empirical treatment, allowing a move towards a diagnosis-driven strategy. However, interpreting the clinical validity and utility of some of these assays can be difficult, particularly for low-prevalence infection where the positive predictive value of any diagnostic test is likely to be low and prompt empirical antibacterial therapy is still indicated in neutropenic patients.