Epidemiological changes of invasive fungal disease in children with cancer: Prospective study of the National Child Program of Antineoplastic Drugs network, Chile.

BACKGROUND: Invasive fungal diseases (IFD) are high morbidity and mortality infections in children with cancer suffering episodes of high-risk febrile neutropenia (HRFN). IFD epidemiology has changed in the last two decades, with an increasing incidence in recent years due to the growing number of immunocompromised children at risk for IFD. The aim of this study was to evaluate the incidence of IFD in children with cancer in the period 2016-2020 compared to 2004-2006 in six hospitals in Chile. METHODS: Prospective, multicentre study, carried out between 2016 and 2020 in six hospitals in Chile. The defined cohort corresponds to a dynamic group of HRFN episodes in patients <18 years old with cancer, who at the fourth day of evolution still presented fever and neutropenia (persistent HRFN). Each episode was followed until resolution of FN. The incidence of IFD was calculated between 2016 and 2020 and compared with data obtained in the period 2004-2006. The incidence rate was estimated. RESULTS: A total of 777 episodes of HRFN were analysed; 257 (33.1%) were considered as persistent-HRFN occurring in 174 patients. The median age was 7 years (IQR: 3-12 years) and 52.3% (N = 91) were male. Fifty-three episodes of IFD were detected: 21 proven, 14 probable and 18 possible. Possible IFD were excluded, leaving 239 episodes of persistent-HRFN with an IFD incidence of 14.6% (95% CI 10.5-19.9) and an incidence rate of 13.6 IFD cases per 1000 days of neutropenia (95% CI 9.5-20.0). Compared to 2004-2006 cohort (incidence: 8.5% (95% CI 5.2-13.5)), a significant increase in incidence of 6.1% (95% CI 0.2-12.1, p = .047) was detected in cohorts between 2016 and 2020. CONCLUSION: We observed a significant increase in IFD in 2016-2020, compared to 2004-2006 period.

[Microorganisms isolated from blood cultures and resistance profile in children with cancer and high-risk febrile neutropenia. Red PINDA, Chile, 2016-2021]. / Microorganismos aislados de hemocultivos y su perfil de resistencia en niños con cáncer y neutropenia febril de alto riesgo. Red PINDA, Chile, 2016-2021.

Bacteremia is a major cause of morbidity and mortality in patients with cancer and episodes of high-risk febrile neutropenia (HRFN). OBJECTIVE: To identify the frequency of microorganisms isolated from blood cultures (BC) and their antimicrobial resistance (R) profile in children with HRFN, compared with the same data from previous studies of the same group. METHOD: Prospective, multicenter, epidemiological surveillance study of microorganisms isolated from BC in patients under 18 years of age, from 7 PINDA network hospitals, between 2016 and 2021. RESULTS: 284 episodes of HRFN with positive BC were analyzed out of 1091 enrolled episodes (26%). Median age 7.2 years [3.0-12.3]. The main isolates were gram-negative bacilli (GNB) 49.2%, gram-positive cocci (GPC) 43.8%, and fungi 3.6%. The most frequently isolated microorganisms were viridans group Streptococci (VGS) (25.8%), Escherichia coli (19.8%), Pseudomonas spp. (11.2%), Klebsiella spp. (10.9%), and coagulase negative Staphylococci (CoNS) (10.9%). There was an increase in R to third-generation cephalosporins (p = 0.011) in GNB and to oxacillin in CoNS (p = 0.00), as well as a decrease in R to amikacin in non-fermenting GNB (p = 0.02) and to penicillin in VGS (p = 0.04). CONCLUSION: VGS is the main agent isolated in BC from pediatric patients with cancer and episodes of HRFN, followed by E. coli, Pseudomonas spp., and Klebsiella spp. Having epidemiological surveillance of microorganisms isolated from BC and their antimicrobial R profile is essential to favor the rational use of antimicrobials.

Transdisciplinary research before, during and after COVID-19 vaccination in Chile: a virtuoso collaboration with future perspectives.

The COVID-19 pandemic presented numerous challenges that required immediate attention to mitigate its devastating consequences on a local and global scale. In March 2020, the Chilean government, along with health and science authorities, implemented a strategy aimed at generating relevant evidence to inform effective public health decisions. One of the key strengths of this strategy was the active involvement of the scientific community, employing transdisciplinary approaches to address critical questions and support political decision-making. The strategy promoted collaborations between the government, public and private institutions, and transdisciplinary academic groups throughout each phase of the pandemic. By focusing on pressing problems and questions, this approach formed the foundation of this report which reflects the collaborative effort throughout the pandemic of individuals from the Instituto de Sistemas Complejos de Ingeniería (ISCI), the Faculty of Medicine of the University of Chile, government authorities and industry. Early in the pandemic, it became crucial to gather evidence on how to minimize the impact of infection and disease while awaiting the availability of vaccines. This included studying the dynamics of SARS-CoV-2 infection in children, assessing the impact of quarantines on people's mobility, implementing strategies for widespread SARS-CoV-2 polymerase chain reaction (PCR) testing, and exploring pool testing for large populations. The urgent need to reduce disease severity and transmission posed a significant challenge, as it was essential to prevent overwhelming healthcare systems. Studies were conducted to predict ICU bed requirements at the local level using mathematical models. Additionally, novel approaches, such as using cellphone mobility-based technology to actively identify infected individuals, and to optimize population sampling, were explored following the first wave of the pandemic. Chile took early action in addressing vaccination through a high-level scientific board, before vaccines became available. Studies conducted during this period included population-based immunologic evaluations of different vaccines, which helped build confidence in the population and supported the need for booster doses and potential vaccination of children. These studies and collaborations, which will be discussed here, have provided valuable insights and will inform future approaches in a post-pandemic world. Importantly, highly conservative estimates indicate that 3,000 lives and more than 300 million USD were saved by this academic-public-private collaborative effort.

Efficacy and safety of withholding antimicrobial therapy in children with cancer, fever, and neutropenia, with a demonstrated viral respiratory infection: a randomized clinical trial.

OBJECTIVES: To validate the efficacy and safety of withholding antimicrobial therapy in a new cohort of children with cancer and febrile neutropenia (FN) having a demonstrated viral respiratory tract infection. METHODS: Prospective, multicenter, noninferiority, randomized study, approved by the ethical committee, in children presenting with FN at seven hospitals in Chile, evaluated at admission for diagnosis of bacterial and viral pathogens. Children who were positive for a respiratory virus, negative for a bacterial pathogen, and had a favourable evolution after 48-72 hours of antimicrobial therapy were randomized to either maintain or withhold antimicrobial therapy. The primary endpoint was the percentage of episodes with an uneventful resolution, whereas the secondary endpoints were days of fever, days of hospitalization, requirement of antimicrobial treatment readministration, sepsis, paediatric intensive care unit admission, and death. RESULTS: A total of 301 of 939 children with FN episodes recruited between March 2021 and December 2023 had a respiratory virus as a unique identified microorganism, of which 139 had a favourable evolution at 48-72 hours and were randomized, 70 to maintain and 69 to withdraw antimicrobial therapy. The median days of antimicrobial therapy was 5 (IQR 3-6) versus 3 (IQR 3-6) days (p < 0.001), with similar frequency of uneventful resolution 66/70 (94%) and 66/69 (96%); relative risk, 1.01; (95% CI, 0.93 to 1.09), absolute risk difference 0.01; (95% CI, -0.05 to 0.08) and similar number of days of fever and days of hospitalization. No cases of sepsis, paediatric intensive care unit admission, or death were reported. DISCUSSION: We validated the strategy of withdrawal antimicrobial therapy in children with FN and viral respiratory tract infection based on clinical and microbiological/molecular diagnostic criteria. This will enable advances in antimicrobial stewardship strategies with a possible future impact on antimicrobial resistance.

Usefulness of Peripheral Blood Cultures in Children With Cancer and Episodes of Fever and Neutropenia.

BACKGROUND: The collection of blood cultures (BC) is key for guiding antimicrobial therapy in children with febrile neutropenia (FN), more than 90% have central venous catheters (CVC). There is no consensus on the need for peripheral BC over central BC in this population. The aim of this study was to determine the contribution of peripheral BC over central BC in the diagnosis of bloodstream infections in children with FN. METHODS: Descriptive, retrospective study, episodes of FN recorded prospectively in 6 hospitals in Santiago, Chile, from 2016 to 2021. Central and peripheral BC were drawn upon admission. All episodes with at least one (+) BC were allocated to one of these groups: consistent (+) BC, inconsistent (+) BC, only CVC (+) BC and only peripheral (+) BC. The volume of the samples was recorded. RESULTS: The analysis included 241 episodes of FN with at least one (+) BC. The median age was 7.2 years, 51% were female, 84% had hematological cancer and 98% had episodes of high-risk FN. Of a total of 241 episodes, 135 (56%) had consistent (+) BC, 13 (5%) had inconsistent (+) BC, 35 (15%) had only CVC (+) BC and 58 (24%) had only peripheral (+) BC. There were no significant differences in the volume of the samples between central and peripheral BC. CONCLUSIONS: The proportion of bloodstream infections detected only through peripheral BC was 24%, higher than previously reported, not due to sample volume. We recommend obtaining peripheral as well CVC BC in children with FN.

Epidemiology of Meningococcal Disease in Four South American Countries and Rationale of Vaccination in Adolescents from the Region: Position Paper of the Latin American Society of Pediatric Infectious Diseases (SLIPE).

Surveillance of meningococcal disease (MD) is crucial after the implementation of vaccination strategies to monitor their impact on disease burden. Adolescent vaccination could provide direct and indirect protection. Argentina, Brazil, and Chile have introduced meningococcal conjugate vaccines (MCV) into their National Immunization Programs (NIP), while Uruguay has not. Here, we analyze the epidemiology of MD and vaccination experience from these four South American countries to identify needs and plans to improve the current vaccination programs. METHODOLOGY: Descriptive study of MD incidence rates, serogroup distribution, case fatality rates (CFR), and MCV uptakes during the period 2010-2021 in Argentina, Brazil, Chile, and Uruguay. Data were extracted from national surveillance programs, reference laboratories, NIPs, and Pubmed. RESULTS: MD overall incidence from 2010 to 2021 have a decreasing trend in Argentina (0.37 [IQR = 0.20-0.61]), Brazil (0.59 [IQR = 0.54-1.22]), and Chile (0.45 [IQR = 0.40-0.77]), while a significant increase in Uruguay (0.47 [IQR = 0.33-0.69]) was found from 2016 to 2019. During the COVID-19 pandemic, all countries sharply reduced their MD incidence. The highest incidence rates were observed among infants, followed by children 1-4 years of age. No second peak was evident in adolescents. A reduction in serogroup C, W, and Y cases has occurred in Argentina, Brazil, and Chile after introduction of MCV, serogroup B becoming predominant in all four countries. Median CFR was 9.0%, 21%, 19.9%, and 17.9% in Argentina, Brazil, Chile, and Uruguay, respectively. Median uptake of MCV for Argentina and Brazil were 66.6% and 91.0% for priming in infants; 54.7% and 84.5% for booster in toddlers; and 47.5% and 53% for adolescents; while for Chile, 95.6% for toddlers. CONCLUSIONS: Experience after the implementation of MCV programs in South America was successful, reducing the burden of MD due to the vaccine serogroups. High vaccine uptake and the inclusion of adolescents will be crucial in the post-pandemic period to maintain the protection of the population. The increase in the proportion of serogroup B cases emphasizes the importance of continuous surveillance to guide future vaccination strategies.

Efficacy, Safety, and Pain Level of Subcutaneous Catheter Use for Administration of Granulocyte Colony-Stimulating Factor (G-CSF) in Children With Cancer: A Randomized Pilot Study.

Background: The aim of this study was to explore the efficacy, safety, and pain level of granulocyte colony-stimulating factor (G-CSF) administration via a subcutaneous catheter compared with direct injection in children with cancer. Method: This was a pilot randomized controlled trial of standard G-CSF administration versus subcutaneous catheter administration. Children 2-15 years of age who were beginning G-CSF after their first chemotherapy cycle and anticipated to receive G-CSF following the next three cycles of chemotherapy were eligible. Efficacy, safety, and pain were as outcomes of the study. Results: Twenty-nine children with cancer (median age 12 years) were enrolled in the study (16 children in the subcutaneous catheter group and 13 children in the direct injection group). During Cycle 2, the median number of days to reach absolute neutrophil count (ANC) ≥ 500/mm3 was greater among those in the subcutaneous catheter group (12 vs. 10; p = .02). In Cycle 3, however, the subcutaneous catheter group received fewer doses of G-CSF (8 vs. 12; p = .004). No complications related to subcutaneous catheter use were observed. No differences in the visual analog scale pain score were observed between groups in Cycles 1 to 3; however, in Cycle 4, children in the subcutaneous catheter group had lower median pain scores than those in the direct subcutaneous injection group (Mdn = 0, [IQR] = 0-2 vs. Mdn = 1, IQR = 0-6; p < 0.01). Conclusion: Results demonstrated administering G-CSF via a subcutaneous catheter enables ANC to recover with no pain or complications associated with its use. Thus, oncology teams may consider this administration method to be used in children with cancer.

Clinical Outcome in Children With Cancer With Two or More Microorganisms Isolated From Blood Cultures During Episodes of Fever and Neutropenia.

BACKGROUND: Bacterial bloodstream infections are a major cause of morbidity and mortality in children with cancer and episodes of fever and neutropenia (FN). The aim of this study was to evaluate the clinical outcome in children with cancer with 2 or more microorganisms isolated from blood cultures during their episodes of FN. METHODS: Between 2016 and 2021, children presenting with high-risk FN, admitted to any of the 6 participating hospitals in Santiago, Chile, were included in this study if they have positive blood cultures. We compared the clinical outcome of children with 2 or more microorganisms versus those with single agent isolation. RESULTS: A total of 1074 episodes of high-risk FN were enrolled in the study period, of which 27% (298) had positive blood cultures and 3% (32) had 2 or more microorganisms isolated from blood cultures. The most frequent identified agents were Viridans group streptococci and Escherichia coli in 20%, followed by Coagulase negative staphylococci in 14%. Children with 2 or more microorganisms presented more days of fever (7 vs. 4 days, P = 0.02), needed longer courses of antimicrobial therapy (16 vs. 14 days, P = 0.04) and had higher mortality at day 30 (13% vs. 1%, P = 0.003). CONCLUSIONS: Children with cancer and FN with 2 or more microorganisms isolated from blood cultures had a worse clinical outcome than children with single agent isolation.

Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Prevalence in Blood in a Large School Community Subject to a Coronavirus Disease 2019 Outbreak: A Cross-sectional Study.

BACKGROUND: A severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak affecting 52 people from a large school community in Santiago, Chile, was identified (12 March) 9 days after the first case in the country. We assessed the magnitude of the outbreak and the role students and staff played using self-administered antibody detection tests and a self-administered survey. METHODS: The school was closed on 13 March, and the entire community was placed under quarantine. We implemented a home-delivery, self-administered, immunoglobin (Ig) G/IgM antibody test and survey to a classroom-stratified sample of students and all staff from 4-19 May. We aimed to determine the overall seroprevalence rates by age group, reported symptoms, and contact exposure, and to explore the dynamics of transmission. RESULTS: The antibody positivity rates were 9.9% (95% confidence interval [CI], 8.2-11.8) for 1009 students and 16.6% (95% CI, 12.1-21.9) for 235 staff. Among students, positivity was associated with a younger age (P = .01), a lower grade level (P = .05), prior real-time polymerase chain reaction (RT-PCR) positivity (P = .03), and a history of contact with a confirmed case (P < .001). Among staff, positivity was higher in teachers (P = .01) and in those previously RT-PCR positive (P < .001). Excluding RT-PCR-positive individuals, antibody positivity was associated with fever in adults and children (P = .02 and P = .002, respectively), abdominal pain in children (P = .001), and chest pain in adults (P = .02). Within antibody-positive individuals, 40% of students and 18% of staff reported no symptoms (P = .01). CONCLUSIONS: Teachers were more affected during the outbreak and younger children were at a higher risk for infection, likely because index case(s) were teachers and/or parents from the preschool. Self-administered antibody testing, supervised remotely, proved to be a suitable and rapid tool. Our study provides useful information for school reopenings.

Impact of a structured educational programme for caregivers of children with cancer on parental knowledge of the disease and paediatric clinical outcomes during the first year of treatment.

OBJECTIVE: To assess the impact of a structured educational programme for caregivers of children with cancer on their level of knowledge about the disease and patient's clinical outcome. METHODS: This prospective, non-randomised, experimental study included caregivers of recently diagnosed children at two hospitals in Chile. Caregivers whose children were treated at the first centre were the structured education programme group (EPG), while the second hospital provided the standard care (SCG). We evaluated caregivers' level of knowledge on days 1, 10 and 90 as well as the children's clinical outcomes over 1 year of treatment. RESULTS: A total of 102 caregivers were enrolled between 2014 and 2015. Only the EPG showed a significant increase in knowledge between days 1 and 90. The rate of central venous catheter infections was significantly lower in the EPG versus SCG (7% versus 26%; p = .01). The risk ratio was 0.35 (95% CI = 0.13-0.94), and a log-rank test showed a statistically significant difference between the two groups (p = .018). There were also fewer Emergency Department visits in the EPG for fever episodes. CONCLUSION: Providing a structured education to caregivers increased their level of knowledge and improved the clinical outcome of their children during the first year of treatment.

Usefulness of serum galactomannan in initiating and modifying antifungal therapy in children with cancer and persistent high-risk febrile neutropenia.

BACKGROUND: Invasive fungal disease is a major cause of morbidity and mortality in children with cancer and high-risk febrile neutropenia (HRFN). Repeated serum galactomannan (sGM) measurements have been described as an effective tool to guide therapy in adults under suspicion of invasive aspergillosis. However, the utility of this approach has not been reported in paediatric population. OBJECTIVES: To evaluate the usefulness of sGM measurements in initiating and modifying antifungal therapy (AFT) in children with cancer and persistent HRFN. PATIENTS/METHODS: Nested case-control study in children with cancer and persistent HRFN episodes, between July 2013 and January 2019. Patients were classified as cases and controls depending on if they received AFT or not, respectively. Through odds ratio analysis, we assessed the role of sGM positivity in the AFT initiation decision. Then, we analysed the group of patients that initiated AFT, and compared those who had AFT modifications and those who did not, analysing different sGM kinetics thresholds. RESULTS: A total of 191 episodes from children with persistent HRFN were enrolled, of which 107 received AFT and 84 did not. The median age was 7 years (IQR 4-12), 52% were male and 89% had a haematologic malignancy as underlying disease. Positive sGM was not associated with AFT initiation (OR 0.99, 95% CI 0.43-2.33, P = .99). A difference threshold in sGM Δ ≥ 0.3 sGM was significantly associated with AFT modification (OR 5.07, 95% CI 1.02- 25.70, P = .04). CONCLUSIONS: Our results suggest the utility of serial sGM sampling during AFT in children with persistent HRFN.

Efficacy of pre-emptive versus empirical antifungal therapy in children with cancer and high-risk febrile neutropenia: a randomized clinical trial.

Objectives: To compare the efficacy of pre-emptive versus empirical antifungal therapy in children with cancer, fever and neutropenia. Methods: This was a prospective, multicentre, randomized clinical trial. Children presenting with persistent high-risk febrile neutropenia at five hospitals in Santiago, Chile, were randomized to empirical or pre-emptive antifungal therapy. The pre-emptive group received antifungal therapy only if the persistent high-risk febrile neutropenia was accompanied by clinical, laboratory, imaging or microbiological pre-defined criteria. The primary endpoint was overall mortality at day 30 of follow-up. Secondary endpoints included invasive fungal disease (IFD)-related mortality, number of days of fever, days of hospitalization and use of antifungal drugs, percentage of children developing IFD, requiring modification of initial treatment strategy and need for ICU. The trial was registered with Registro Brasileiro de Ensaios Clínicos (ReBEC) under trial number RBR-3m9d74. Results: A total of 149 children were randomized, 73 to empirical therapy and 76 to pre-emptive therapy. Thirty-two out of 76 (42%) children in the pre-emptive group received antifungal therapy. The median duration of antifungal therapy was 11 days in the empirical arm and 6 days in the pre-emptive arm (P < 0.001), with similar overall mortality (8% in the empirical arm and 5% in the pre-emptive arm, P = 0.47). IFD-related mortality was the same in both groups (3%, P = 0.97), as were the percentage of children with IFD (12%, P = 0.92) and the number of days of fever (9, P = 0.76). The number of days of hospitalization was 19 in the empirical arm and 17 in the pre-emptive arm (P = 0.15) and the need for ICU was 25% in the empirical arm and 20% in the pre-emptive arm (P = 0.47). Conclusions: Pre-emptive antifungal therapy was as effective as empirical antifungal therapy in children with cancer, fever and neutropenia, significantly reducing the use of antifungal drugs.

[Microorganisms isolated from blood cultures in children with cancer and high-risk febrile neutropenia from five hospitals in Santiago, Chile, 2012-2015]. / Microorganismos aislados de hemocultivos en niños con cáncer y neutropenia febril de alto riesgo en cinco hospitales de Santiago, Chile, período 2012-2015.

BACKGROUND: Microorganisms isolated from blood cultures (BC) in patients with febrile neutropenia (NF) vary over time, requiring systematic monitoring to guide appropriate empirical therapy. AIM: To identify microorganisms isolated from BC and their antimicrobial resistance profile in children with cancer and high risk NF. METHOD: Prospective, multicenter study. The analysis included episodes of high-risk FN with positive BC in children under 18 years of age treated in five hospitals in Santiago, Chile, 2012-2015. RESULTS: A total of 206 microorganisms were analyzed in 185 episodes of high-risk FN. The main isolates were Gram negative bacilli (46.6%) and Gram positive cocci (45.1%) and the most frequent microorganisms were Escherichia coli (22.8%), coagulase negative Staphylococcus (18.0%) and Klebsiella spp. (16.5%). Escherichia coli and Klebsiella spp showed 4.2% and 67.6% resistance to third generation cephalosporins (cefotaxime/ceftriaxone), 10.6% and 40.6% resistance to fluoroquinolones (ciprofloxacin) and 2.1% and 26.5% to amikacin, respectively. Coagulase negative Staphylococcus and Staphylococcus aureus had 86.4% and 22.2% resistance to oxacillin, Streptococcus viridans group had 71% resistance to penicillin. DISCUSSION: This study updates the etiology and resistance profile of microorganisms isolated in BC from children with cancer and high risk FN, an essential tool for the adequate management of these patients.

Aproximación diagnóstica de patología otológica mediante imágenes, en médicos APS, de la I y II Región de Chile / Diagnostic approach of othologic patology using images, in primary health physicians from the first and second region of Chile

Introducción: La otoscopía corresponde a la herramienta principal que muchos médicos deben utilizar durante la evaluación de patologías otorrinolaringológicas, cuya enseñanza se realiza durante la formación del médico general en un tiempo acotado. Objetivo: En este trabajo se pretende evaluar el diagnóstico correcto de imágenes características de otoscopía por médicos de APS. Material y método: Se realizó un estudio no experimental, descriptivo, cuantitativo y de corte transversal donde se aplicó un test a médicos no especialistas de APS de la I y II región de Chile. Resultados: Se encuestó a un total de 89 médicos. El porcentaje total de respuestas correctas correspondió a 24,8%. La imagen más reconocida corresponde a la perforación timpánica. Sólo 20,2% reconoció la imagen correspondiente a un tímpano normal. Conclusión: Estos resultados se pueden atribuir a la falta de conocimientos y entrenamiento adquirido por los médicos generales, por lo que se debe trabajar en un mejor entrenamiento en otoscopía en el pregrado.

Introduction: Otoscopy is the main tool used by general practitioners for the assesment of ENT patologies, wich is taught during a short period in medicine schools. Aim: The intention of this study is to evaluate the accurate diagnosis of characteristic otoscopy images by primary health physicians. Material and method: A non-experimental, descriptive, quantitative and cross-cut study was carried out; A survey was applied to general practitioners who were working on primary health care of I and II region of Chile. Results: A total of 89 physicians were surveyd. The total percentage of correct answers was 24.8%. The most recognized image was timpanic perforation. Just a 20.2% recognized the image corresponding to a normal timpanic membrane. Conclusion: This results can be attributed to the lack of knowledge and training acquired by the general practitioners, So we must work on a better training in otoscopy in the undergraduate.

Intravenous palivizumab in respiratory syncytial virus infection after hematopoietic stem cell transplant in children.

Respiratory syncytial virus (RSV) infection can cause lower respiratory tract disease and mortality in pediatric hematopoietic stem cell transplant (HSCT) recipients. We report two children who underwent HSCT and developed RSV infection simultaneously at the Bone Marrow Transplant Unit. The treatment with intravenous palivizumab was provided and sequential viral loads were measured in nasopharyngeal (NP) and whole blood samples. To our knowledge, this is the first report where RSV loads were measured in parallel (NP and blood), before and after palivizumab, in correlation with a favorable clinical outcome in both cases.

Respiratory Viral Infections and Coinfections in Children With Cancer, Fever and Neutropenia: Clinical Outcome of Infections Caused by Different Respiratory Viruses.

BACKGROUND: Respiratory viral infections in episodes of fever and neutropenia (FN) in children with cancer are not well characterized. We compared the clinical outcome of infections caused by different respiratory viruses (RVs) and by RV coinfection in this population. METHODS: Children with cancer and FN at 3 hospitals in Chile were prospectively evaluated by clinical examination, blood cultures and detection of 17 RVs using multiplex polymerase chain reaction (nasopharyngeal samples). Clinical characterization and outcome variables were determined and compared by the type of RV detected. RESULTS: A total of 1044 episodes of FN in 525 children were included. At least 1 RV was detected in 46%. In 350 of 1044 (34%) episodes, we detected only RVs, of which 284 (81%) were classified as a single-RV infection and 66 (19%) as a viral coinfection. Respiratory symptoms were present at admission in 65% of the episodes with any detected RV. Median age was 6 years (interquartile range, 3-10), and 51% were women. The most common RVs detected were rhinovirus, respiratory syncytial virus, parainfluenza, influenza, adenovirus and human metapneumovirus. Episodes caused by different types of RVs had no differences in the clinical outcome (days of hospitalization, days of fever, O2 requirement, admission to the intensive care unit and death) and when comparing single and viral coinfection. CONCLUSIONS: To our knowledge, this is the largest report comparing clinical outcome in FN episodes caused by different RVs in children with cancer. A positive polymerase chain reaction for RV at admission was significantly associated with the presence of respiratory symptoms. Our data showed a favorable outcome in all episodes with RV detection, including single and viral coinfections.

Frequency and clinical outcome of respiratory viral infections and mixed viral-bacterial infections in children with cancer, fever and neutropenia.

BACKGROUND: The role of respiratory viral infections (RVIs) as a cause of overall fever and neutropenia (FN) episodes in children with cancer has been less characterized than bacterial infections. We conducted a study aimed to determine the frequency of RVI in children with low compared with high risk for invasive bacterial infection (IBI) FN episodes and compare the clinical outcome of RVI and mixed RV-bacterial infections. METHODS: Prospective, multicenter study in children with cancer and FN admitted to pediatric hospitals in Chile between May 2009 and January 2011. Children were evaluated by clinical examination and laboratory tests, including bacterial cultures and their risk for IBI. Nasopharyngeal sample was obtained for the detection of 17 respiratory viruses using polymerase chain reaction-DNA microarray platform. RESULTS: A total of 331 episodes of FN in 193 children were enrolled of whom 55% were male, with the median age of 7 years and 61% had a hematological malignancy. A viral and/or bacterial pathogen was detected in 67% (224/331) episodes. Overall, RVIs were associated with 57% of FN of which one-third were mixed RV-bacterial infections. Bacterial infection was detected in 29% (97/331). Children classified at admission as high risk for IBI had a similar overall proportion of RVI compared with low-risk group. Respiratory syncytial virus (31%) and rhinovirus (23%) were the most frequently detected respiratory viruses, followed by parainfluenza (12%) and influenza A (11%). Children detected with any respiratory virus had fewer days of hospitalization and a significantly lower probability of hypotension and admission to pediatric intensive care unit irrespective of their risk classification status at admission when compared with children with mixed RV-bacterial or bacterial infections (P < 0.05). All children with a sole RVI had favorable outcome. CONCLUSIONS: RVIs were the most frequently detected agents irrespective of their initial risk assessment for IBI. The clinical outcome of mixed RVI was similar to sole RVI episodes as well as for bacterial infections compared with mixed viral-bacterial infections. Systematic and early detection of RVI in children with cancer and FN might help to optimize their management by reducing hospitalization and antimicrobial use.

Diagnosis of bacteremia in febrile neutropenic episodes in children with cancer: microbiologic and molecular approach.

BACKGROUND: Bacterial isolation using conventional microbiologic techniques rarely surpasses 25% in children with clinical and laboratory findings indicative of an invasive bacterial infection. The aim of this study was to determine the role of real-time polymerase chain reaction (RT-PCR) from whole blood samples compared with automated blood cultures (BC) in detection of relevant microorganisms causing bacteremia in episodes of high-risk febrile neutropenia (HRFN) in children with cancer. METHODS: Children presenting with HRFN at 6 hospitals in Santiago, Chile, were invited to participate. Blood samples were obtained at admission for BC, and at admission and 24 hours for RT-PCR targeting DNA of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa causing bacteremia in children with HRFN. RESULTS: A total of 177 HRFN episodes were evaluated from May 2009 to August 2010, of which 29 (16.3%) had positive BC, 9 (5%) positive for 1 of the 3 selected bacterial species: 5 for E. coli, 3 for S. aureus, and 1 for P. aeruginosa. RT-PCR detected 39 bacteria in 36 episodes (20%): 14 E. coli, 20 S. aureus, and 5 P. aeruginosa. The sensitivity, specificity, and positive and negative predictive values of RT-PCR compared with BC were 56%, 80%, 13%, and 97%. The final clinical diagnosis was compatible with an invasive bacterial infection in 30/36 (83%) RT-PCR-positive episodes. CONCLUSIONS: In our series, RT-PCR significantly improved detection of the most relevant bacteria associated with HRFN episodes. Large number of patients and close clinical monitoring, in addition to improved RT-PCR techniques will be required to fully recommend RT-PCR-based diagnosis for the routine workup of children with cancer, fever, and neutropenia.