Virus Infection In Pediatric Patients Research Articles

Cytomegalovirus and Epstein-Barr virus infections in pediatric patients of choledochal cyst

Association of viral infection with obstructive jaundice is well-known however frequency of cholangiotropic virus infection in pediatric choledochal cyst is not known. IgG and IgM antibodies against Cytomegalo virus (CMV) and Epstein Barr virus (EBV) in 48 children with choledochal cysts and 26 controls were analysed using ELISA. We found significantly higher anti-CMV IgG and IgM in patients (95.8% and 77.1%, respectively) compared to controls (73.1% and 42.3%) and a notable prevalence of anti-EBV antibodies among both groups (83.3% versus 65.4% IgG and 77.1% versus 46.1 for IgM in patients and controls respectively). Moreover, 79.2% of patients were positive for both anti-CMV and anti-EBV IgG, and 62.5% for both IgMs. This pilot study suggests that infection with CMV, EBV, or both is frequently seen in pediatric patients with CDC. Molecular screening and follow-up in a larger cohort is therefore required for further validation.

Cytomegalovirus and Epstein-Barr virus infections in pediatric patients of choledochal cyst

Cytomegalovirus and Epstein-Barr virus infections in pediatric patients of choledochal cyst

Outcomes of Pediatric SARS-CoV-2 Omicron Infection vs Influenza and Respiratory Syncytial Virus Infections

This cohort study compares outcomes of SARS-CoV-2 Omicron infection with those of influenza or respiratory syncytial virus infection in pediatric patients attending the emergency department.

Analysis of respiratory virus detection in hospitalized children with acute respiratory infection during the COVID-19 pandemic

ObjectiveIt is now understood that the Coronavirus disease 2019 (COVID-19) pandemic and its associated containment measures have influenced the epidemiology of other respiratory viruses. This study aimed to characterize respiratory virus infections in pediatric patients hospitalized for acute respiratory infections (ARIs) in East China both prior to and during the COVID-19 pandemic.MethodsWe collected nasal secretions from 9782 pediatric ARI patients admitted to Shaoxing Maternal and Child Health Care Hospital between January 2018 and December 2022. We analyzed and compared changes in viral detection rates, epidemiological features, and clinical characteristics.ResultsA total of 1633 strains from 7 common respiratory viruses were identified, with an overall positive rate of 16.35% (n = 821/5021) in 2018–2019 and 17.06% (n = 812/4761) in 2020–2022. Compared to 2018–2019, the positive rate for RSV significantly increased in 2020–2022, while detection rates for ADV, PIV-2, PIV-3, and flu-B showed reductions (P < 0.05). The RSV-positive rate experienced a more significant increase in winter compared to other seasons both before and during COVID-19 (P < 0.05), whereas PIV-3 predominantly circulated in spring and summer before COVID-19.ConclusionDuring the COVID-19 pandemic, marked variations in age distribution and seasonality of respiratory virus infections were observed among hospitalized children with ARIs in East China. Non-pharmaceutical interventions (NPIs) implemented during the pandemic yielded a limited impact on common respiratory viruses.

Direct-Acting Antivirals for Pediatric Chronic Hepatitis C Virus Infection

&#x0D; Clinical evidence showed that treatment with glecaprevir-pibrentasvir for children and adolescents with chronic hepatitis C virus infection was efficacious with an overall sustained virologic response 12 weeks after treatment near 100%.&#x0D; Glecaprevir-pibrentasvir treatment was well-tolerated as there were no serious adverse events or adverse events leading to treatment discontinuation. Most adverse events were mild.&#x0D; We did not find any studies that evaluated the cost-effectiveness of glecaprevir-pibrentasvir for the treatment of chronic hepatitis C virus infection in pediatric patients.&#x0D; We did not find any peer-reviewed studies that evaluated the clinical effectiveness of sofosbuvir-velpatasvir for the treatment of chronic hepatitis C virus infection in pediatric patients. Unpublished data in a conference abstract and clinical trial registry suggest effectiveness of sofosbuvir-velpatasvir, but the findings should be interpreted with cautions.&#x0D; We did not find any studies that evaluated the cost-effectiveness of sofosbuvir-velpatasvir for the treatment of chronic hepatitis C virus infection in pediatric patients.&#x0D;

EE415 Burden of the Disease in Mexico of Respiratory Syncytial Virus Infection in Pediatric Patients Under 2 Years of Age with Risk Factors

To perform a burden of the disease study that quantifies direct and indirect medical costs in pediatric patients under 2 years of age diagnosed with a Respiratory Syncytial Virus infection (RSV) and risk factors from the perspective of Mexico’s public health institutions.

Salivary Biomarkers to Differentiate between Streptococcus pneumoniae and Influenza A Virus-Related Pneumonia in Children.

Community-acquired pneumonia (CAP) is common among children and can be fatal in certain conditions. In children, CAP can be caused by viral or bacterial infections. Identification of pathogens can help select appropriate therapeutic strategies. Salivary analysis may be a potential diagnostic tool because it is noninvasive, patient-friendly, and easy to perform in children. A prospective study was conducted in children with pneumonia admitted to a hospital. Salivary samples from patients with definite Streptococcus pneumoniae and influenza A strains were used for gel-free (isobaric tag for relative and absolute quantitation (iTRAQ)) proteomics. No statistically significant difference was detected in salivary CRP levels between Streptococcus pneumoniae and influenza A pneumonia in children. Several potential salivary biomarkers were identified using gel-free iTRAQ proteomics to differentiate pneumonia from Streptococcus pneumoniae or influenza A virus infections in pediatric patients. ELISA validated that Streptococcus pneumoniae group has a higher abundance of salivary alpha 1-antichymotrypsin than those in the influenza A group. Whether these salivary biomarkers can be used to distinguish other bacteria from viral pneumonia requires further verification.

Influenza and Respiratory Syncytial Virus Infections in Pediatric Patients during the COVID-19 Pandemic: A Single-Center Experience.

The overlap of coronavirus disease 2019 (COVID-19) with other common respiratory pathogens may complicate the course of the disease and prognosis. The aim of the study was to evaluate the rates, characteristics, and outcomes of pediatric patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respiratory syncytial virus (RSV), influenza A/B infections, and their coinfections. A single-center prospective cross-sectional study was performed at the pediatric emergency department in Vilnius from 1 October 2021 to 30 April 2022. In total, 5127 children were screened for SARS-CoV-2, RSV, and influenza A/B. SARS-CoV-2 PCR tests were positive for 21.0% of children (1074/5127). The coinfection rate of respiratory viruses (RSV, influenza A) in patients with COVID-19 was 7.2% (77/1074). Among the 4053 SARS-CoV-2 negative patients, RSV was diagnosed in 405 (10.0%) patients and influenza A/B in 827 (20.4%) patients. Patients with COVID-19 and coinfection did not have a more severe clinical course than those with RSV or influenza infection alone. RSV and SARS-CoV-2 primarily affected younger patients (up to 2 years), while the influenza was more common in older children (4-10 years). Patients infected with RSV were more severely ill, reflected by higher hospitalization proportion and need for respiratory support.

Changes in endemic patterns of respiratory syncytial virus infection in pediatric patients under the pressure of nonpharmaceutical interventions for COVID-19 in Beijing, China.

A series of nonpharmaceutical interventions (NPIs) was launched in Beijing, China, on January 24, 2020, to control coronavirus disease 2019. To reveal the roles of NPIs on the respiratory syncytial virus (RSV), respiratory specimens collected from children with acute respiratory tract infection between July 2017 and Dec 2021 in Beijing were screened by capillary electrophoresis-based multiplex PCR(CEMP) assay. Specimens positive for RSV were subjected to a polymerase chain reaction(PCR) and genotyped by G gene sequencing and phylogenetic analysis using iqtree v1.6.12. The parallel and fixed (paraFix) mutations were analyzed with the R package sitePath. Clinical data were compared using SPSS 22.0 software. Before NPIs launched, each RSV endemic season started from October/November to February/March of the next year in Beijing. After that, the RSV positive rate abruptly dropped from 31.93% in January to 4.39% in February 2020; then, a dormant state with RSV positive rates ≤1% from March to September, a nearly dormant state in October (2.85%) and November (2.98%) and a delayed endemic season in 2020, and abnormal RSV positive rates remaining at approximately 10% in summer until September 2021 were detected. Finally, an endemic RSV season returned in October 2021. There was a game between Subtypes A and B, and RSV-A replaced RSV-B in July 2021 to become the dominant subtype. Six RSV-A and eightRSV-B paraFix mutations were identified on G. The percentage of severe pneumonia patients decreased to 40.51% after NPIs launched.NPIs launched in Beijing seriously interfered with the endemic season of RSV.

Epstein-Barr Virus Prevalence at Diagnosis and Seroconversion during Follow-Up in Pediatric Inflammatory Bowel Disease.

Primary Epstein–Barr virus infection in pediatric patients with inflammatory bowel disease during immunomodulation with thiopurines has been associated with increased risk for malignancies or hemophagocytic lymphohistiocytosis. We determined Epstein–Barr virus (EBV) seroprevalence at inflammatory bowel disease (IBD) diagnosis and seroconversion during follow-up in a large single center cohort of children with IBD. EBV serology results and patient characteristics were retrospectively retrieved from the hospital documentation system. EBV seronegative patients at IBD diagnosis were prospectively retested. We report on IBD patients with symptomatic active EBV infection and a complicated disease course, and those diagnosed with malignancy with respect to EBV status and drug exposure. Of 402 patients, 194 (48%) had available EBV serology results at time of IBD diagnosis at a median of 12 years (IQR 9–14 years). Thereof, 102 (53%) were EBV-positive. Of 92 EBV-negative patients, 66 were retested and 17% showed a seroconversion at a mean follow-up time of 4.3 years (SD 3 years). Three children treated with azathioprine experienced acute clinically relevant EBV infection 2, 2.5, and 4 years after IBD diagnosis, two developed signs of hemophagocytic lymphohistiocytosis. Three cases of malignancy occurred in the cohort, though none seemed to be triggered by EBV. In conclusion, almost 50% of pediatric IBD patients were EBV-naïve following diagnosis and may be at increased risk to develop severe EBV infection during immunosuppressive therapy, potentially associated with complications such as hemophagocytic lymphohistiocytosis or malignancy.

BK Virus Infections in Pediatric Patients with Hematopoietic Stem Cell Transplantation

Aim: BK virus (BKV)-associated hemorrhagic cystitis (HC) is a common complication in patients after hematopoietic stem cell transplantation (HSCT). The aim of this study was to investigate the incidence of BKV infection in pediatric patients receiving HSCT.&#x0D; Material and Methods: Total of 51 patients aged between 16 months and 16 years old and followed up between October 2015 and September 2017 were included in the study. The patients were monitored by quantitative real-time polymerase chain reaction (Anatolia Geneworks, Turkey) test for the detection of BKV DNA in urine and blood.&#x0D; Results: Of patients, 46 received allogeneic HSCT and 5 autologous HSCT. BKV DNA positivity was detected in urine and/or blood of total 27 (52.9%) patients in whom 26 (56.5%) of 46 patients with allogeneic transplantation, and 1 (20.0%) of 5 patients with autologous transplantation. BKV viral load in urine &gt;107 copies/ml required for preemptive treatment was detected in 12 (26.1%) of 46 patients received allogeneic HSCT. The development of HC was prevented in 9 (75.0%) of the 12 patients given preemptive treatment, while 3 (25.0%) cases developed HC and cured by treatment. BKV viruria was detected &gt;109 copies/ml in two weeks before the onset of HC and was accepted as a prognostic indicator for predictive diagnosis of HC. BKV viremia was found &gt;104 copies/ml in 1 patient within two weeks before the onset of cystitis.&#x0D; Conclusion: Screening for BKV infection, especially BKV viruria in HSCT patients, is recommended for the predictive diagnosis of HC in patients at high risk.

A GeXP-Based Assay for Simultaneous Detection of Multiple Viruses in Hospitalized Children with Community Acquired Pneumonia.

The GeXP-based assay has recently been developed for simultaneous detection of multiple pathogens. So far, the application of the GeXP assay to test larger clinical samples has hardly been reported. Community-acquired pneumonia (CAP) is the leading cause of death in children worldwide and a substantial proportion of childhood CAP is caused by viruses. Rapid and accurate diagnosis of virus infection is important for the clinical management of CAP. In this study, we explored the GeXP assay for simultaneous detection of 20 types/subtypes of viruses in hospitalized children with CAP. A total of 1699 nasopharyngeal swabs were prospectively collected and viral nucleic acid was extracted and assayed. Using viral genomic DNA or RNA as template, we showed that at the concentration of 104 copies of DNA or RNA of each virus/μl, all 20 target viruses were simultaneously identified by the GeXP assay. Fifteen control microorganisms, in contrast, failed to be amplified by the assay. About 65% of cases tested in this study had viral infection, with patients aged <3 years having a 70% positive rate, significantly higher than that in patients aged > 3 years (40%). The most frequently detected virus was RSV followed by PIV3, HRV, ADV and HBoV. Seasonal distribution analysis revealed that RSV was the most predominant in autumn and winter, while in spring and summer PIV3 and RSV were the most frequently identified with similar positive percentages. One hundred twenty randomly-chosen samples tested by the GeXP assay were re-evaluated by mono-RT-PCR, the results showed 97.5% diagnosis agreement between these 2 methods. Our findings suggest that the GeXP assay could be a valuable diagnostic tool for virus infection in pediatric patients with CAP.

Immune Response to Dengue Virus Infection in Pediatric Patients in New Delhi, India--Association of Viremia, Inflammatory Mediators and Monocytes with Disease Severity.

Dengue virus, a mosquito-borne flavivirus, is a causative agent for dengue infection, which manifests with symptoms ranging from mild fever to fatal dengue shock syndrome. The presence of four serotypes, against which immune cross-protection is short-lived and serotype cross-reactive antibodies that might enhance infection, pose a challenge to further investigate the role of virus and immune response in pathogenesis. We evaluated the viral and immunological factors that correlate with severe dengue disease in a cohort of pediatric dengue patients in New Delhi. Severe dengue disease was observed in both primary and secondary infections. Viral load had no association with disease severity but high viral load correlated with prolonged thrombocytopenia and delayed recovery. Severe dengue cases had low Th1 cytokines and a concurrent increase in the inflammatory mediators such as IL-6, IL-8 and IL-10. A transient increase in CD14+CD16+ intermediate monocytes was observed early in infection. Sorting of monocytes from dengue patient peripheral blood mononuclear cells revealed that it is the CD14+ cells, but not the CD16+ or the T or B cells, that were infected with dengue virus and were major producers of IL-10. Using the Boruta algorithm, reduced interferon-α levels and enhanced aforementioned pro-inflammatory cytokines were identified as some of the distinctive markers of severe dengue. Furthermore, the reduction in the levels of IL-8 and IL-10 were identified as the most significant markers of recovery from severe disease. Our results provide further insights into the immune response of children to primary and secondary dengue infection and help us to understand the complex interplay between the intrinsic factors in dengue pathogenesis.

Effects of mTOR and calcineurin inhibitors combined therapy in Epstein–Barr virus positive and negative Burkitt lymphoma cells

Post-transplant lymphoproliferative disorder is a severe complication in solid organ transplant recipients, which is highly associated with Epstein–Barr virus infection in pediatric patients and occasionally presents as Burkitt- or Burkitt-like lymphoma. The mammalian target of rapamycin (mTOR) pathway has been described as a possible antitumor target whose inhibition may influence lymphoma development and proliferation after pediatric transplantation. We treated Epstein–Barr virus positive (Raji and Daudi) and negative (Ramos) human Burkitt lymphoma derived cells with mTOR inhibitor everolimus alone and in combination with clinically relevant immunosuppressive calcineurin inhibitors (tacrolimus or cyclosporin A). Cell proliferation, toxicity, and mitochondrial metabolic activity were analyzed. The effect on mTOR Complex 1 downstream targets p70 S6 kinase, eukaryotic initiation factor 4G, and S6 ribosomal protein activation was also investigated. We observed that treatment with everolimus alone significantly decreased Burkitt lymphoma cell proliferation and mitochondrial metabolic activity. Everolimus in combination with cyclosporin A had a stronger suppressive effect in Epstein–Barr virus negative but not in Epstein–Barr virus positive cells. In contrast, tacrolimus completely abolished the everolimus-mediated suppressive effects. Moreover, we showed a significant decrease in activation of mTOR Complex 1 downstream targets after treatment with everolimus that was attenuated when combined with tacrolimus, but not with cyclosporin A. For the first time we showed the competitive effect between everolimus and tacrolimus when used as combination therapy on Burkitt lymphoma derived cells. Thus, according to our in vitro data, the combination of calcineurin inhibitor cyclosporin A with everolimus is preferred to the combination of tacrolimus and everolimus.

Immunophenotype Expressions and Cytokine Profiles of Influenza A H1N1 Virus Infection in Pediatric Patients in 2009

Background. A novel swine-origin influenza A H1N1 virus (S-OIV) caused human infection and acute respiratory illness in 2009, resulting in an influenza pandemic. Objectives. This study characterized the immune responses of S-OIV infection in pediatric patients at risk of pulmonary complications. Methods. All enrolled pediatric patients were confirmed virologically for S-OIV infection in 2009-2010, prospectively. Changes in cellular immunophenotypes were analyzed using flow cytometry. Plasma cytokine levels associated with S-OIV infection by pulmonary and without pulmonary complications were measured using cytokine cytometric bead assay kits. Results. A total of 85 patients with a mean age of 10.3 years were recruited. The level of C-reactive protein (CRP) was high in patients exhibiting pulmonary complications. The percentage of cellular immunophenotypes did not change between patients with and without pulmonary complications. The absolute numbers of peripheral blood mononuclear cells (PBMC), CD3, CD8, and CD16CD56 decreased with acute S-OIV pulmonary complications. Acute influenza infection with pulmonary complications was associated with high plasma concentrations of IL-1β, IL-6, IL-12, and IFN-γ. Conclusion. Immunophenotype studies have reported variability in immune response to the severity of S-OIV infections. Acute phase cytokine profiles of the 2009 S-OIV infection might have contributed to the pathogenesis of the pulmonary complications.

Analysis of Fatal Cases of Pandemic Influenza A (H1N1) Virus Infections in Pediatric Patients with Leukemia

Background: Pandemic influenza A/H1N1/2009 virus usually causes mild illness in healthy children. Chronic medical conditions are recognized as increasing the risk for complications of influenza virus infection. Although most studies including children with acute leukemia and H1N1 virus have reported no deaths, some anectodal reports with low patient numbers have reported mortality rates as high as 28.5%. Here, we report patients with leukemia and H1N1 virus and review the literature. Methods: Medical records of all children with leukemia and H1N1 virus in our institution were reviewed for demographic, clinical, and laboratory data. We also carried out a systematic review of the English-language literature. Among the 24 articles found, only patients with leukemia and pandemic H1N1 infections were reviewed by two independent reviewers. Results: Eight of 98 children who received chemotherapy for leukemia were diagnosed with pandemic H1N1 infection. One developed pneumonia and acute respiratory distress syndrome (ARDS) and died. Another one developed hemophagocytic lymphohistiocytosis (HLH) and died due to secondary infection during the 6th week of treatment for HLH. In our study, 2 of 8 patients had a fatal course (25%), compared with an overall mortality of 2.5% in the studies retrieved from PubMed (6/232). Conclusion: Pandemic H1N1 influenza virus caused mortality in patients with ARDS or HLH; an unexpected finding for pandemic H1N1 (2009) influenza virus. Thus, for children with leukemia and infected with H1N1 virus, short- and long-term complications should be kept in mind during evaluation.

Treatment of Herpes Simplex Virus Infections in Pediatric Patients: Current Status and Future Needs

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are members of the Herpesviridae family and are characterized by their ability to establish latency after primary infection and subsequently reactivate. HSV infections in the neonatal and pediatric populations range from uncomplicated mucocutaneous diseases to severe, life-threatening infections involving the central nervous system (CNS). The antiviral agent acyclovir has significantly improved treatment outcomes of HSV infections, including the frequency of mucocutaneous recurrences and mortality associated with CNS and disseminated infections.

Scant Attention to Pediatric Hepatitis C Means Most Children Are Left Behind

THE GREAT UNKNOWN IN PEDIATric hepatitis C infection is what course the disease will take as patients mature from childhood to adolescence and into adulthood. Some will spontaneously clear the infection, while others eventually may develop liver cancer. But researchers find it difficult, if not impossible, to arrive at any conclusions about disease progression because so few children infected with hepatitis C virus (HCV) are identified early in their lives. The Institute of Medicine made the case in a January report for stepped-up surveillance of hepatitis B and C infection, but a recent study highlights the particular inadequacies in diagnosing and treating children and teens infected with hepatitis C. “There’s a frightening lack of awareness among both the public and clinicians about hepatitis C virus infection in pediatric patients,” said lead author Aymin Delgado-Borrego, MD, MPH, a pediatric gastroenterologist at the University of Miami Miller School of Medicine. She presented the findings in early May during the Digestive Disease Week conference. Delgado-Borrego and her colleagues focused on undiagnosed pediatric hepatitis C infection in Florida because the state is among only a few that require reporting of acute and chronic cases. They used data from the 3rd National Health and Nutrition Examination Survey and the US Census Bureau to estimate that about 0.3% of US children and teens aged 6 to 19 years are infected with HCV. About 75% have chronic infections. Applying the national 0.3% prevalence rate, the researchers calculated that Florida would have 12 155 cases of pediatric hepatitis C infection. But a state database contained 1755 unique

Cost Analysis of Multiplex PCR Testing for Diagnosing Respiratory Virus Infections

We performed a cost analysis study using decision tree modeling to determine whether the use of multiplex PCR testing for respiratory viruses (xTAG RVP test) is a more or less costly strategy than the status quo testing methods used for the diagnosis of respiratory virus infections in pediatric patients. The decision tree model was constructed by using four testing strategies for respiratory virus detection, viz., direct fluorescent-antibody staining (DFA) alone, DFA plus shell vial culture (SVC), the xTAG RVP test alone, or DFA plus the xTAG RVP test. A review of the charts of 661 pediatric patients was used to determine the length of hospital stay, the number of days in isolation, antibiotic usage, and all other medical procedures performed. The cost of hospitalization by diagnostic status was determined on the basis of the average cost per patient and the number of patients in each arm of the decision tree. The cost per case was the highest for DFA plus SVC at $3,914 (in Canadian dollars), and the lowest was for the xTAG RVP test alone at $3,623, while the costs of DFA alone ($3,911) and DFA plus RVP ($3,849) were intermediate. When all four diagnostic strategies were compared, the least costly strategy was the xTAG RVP test alone when the prevalence of infection was 11% or higher and DFA alone when the prevalence was under 11%. These data indicate a savings of $291 per case investigated if the strategy of using the xTAG RVP test alone was used to replace the status quo test of DFA plus SVC, resulting in a savings of $529,620 per year in direct costs for the four Hamilton, Ontario, Canada, hospitals on the basis of the testing of specimens from 1,820 pediatric inpatients. We conclude that the use of the xTAG RVP test is the least costly strategy for the diagnosis of respiratory virus infections in children and would generate a significant savings for hospitals.

Risk Factors for Severe Respiratory Syncytial Virus Disease in Children With Cancer: The Importance of Lymphopenia and Young Age

We sought to determine the epidemiologic features of respiratory syncytial virus infection in immunocompromised pediatric patients and to identify the risk factors for severe disease. We designed a retrospective study examining the experience with respiratory syncytial virus infection in pediatric patients with underlying malignancies and hematopoietic stem cell transplant recipients seen between 1997 and 2005. Clinical and laboratory data were extracted from patient records, and independent predictors of disease severity were investigated. Fifty-eight patients met the study criteria. Twenty-three patients (40%) had underlying diagnoses of acute lymphoblastic leukemia, 11 (19%) had solid tumors, and 24 (41%) were hematopoietic stem cell transplant recipients, had acute myeloid leukemia, or had severe combined immunodeficiency syndrome. Seventeen patients (29%) were < 2 years of age. Overall, 16 patients (28%) developed lower respiratory tract infections. The frequency of lower respiratory tract infections was highest in patients with hematopoietic stem cell transplants, acute myeloid leukemia, or severe combined immunodeficiency syndrome (42%). Independent predictors of lower respiratory tract infections were profound lymphopenia, with absolute lymphocyte counts of < 100 cells per mm3, and age of < or = 2 years. Of all patients with lower respiratory tract infections, 31% died as a result of respiratory syncytial virus infection. The overall mortality rate was low (5 of 58 patients; 8.6%). All deaths occurred in patients with lower respiratory tract infections who were before or after hematopoietic stem cell transplants or were < 2 years of age and receiving treatment for acute myeloid leukemia. Neutropenia was not a predictor of respiratory syncytial virus lower respiratory tract infection or death. This study identified profound lymphopenia and young age as independent predictors of respiratory syncytial virus-related lower respiratory tract infections in immunocompromised children. No association between neutropenia and respiratory syncytial virus-related morbidity or death was found. These findings can guide interventions for respiratory syncytial virus infection in high risk hosts.