A multicenter study to define the epidemiology and outcomes of Clostridioides difficile infection in pediatric hematopoietic cell and solid organ transplant recipients

Hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients are at increased risk for Clostridioides difficile infection (CDI). We conducted a multicenter retrospective study to describe the incidence of CDI in children transplanted between January 2010 and June 2013. Nested case-control substudies, matched 1:1 by transplant type, institution, patient age, and time of year (quartile) of transplant, identified CDI risk factors. Cohorts included 1496 HCT and 1090 SOT recipients. Among HCT recipients, 355 CDI episodes were diagnosed in 265 recipients (18.2%). Nested case-control study identified prior history of CDI (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.5-4.7), proton pump inhibitors (PPIs; OR 2.1, 95% CI 1.3-3.4), and exposure to third- (OR 2.4, 95% CI 1.4-4.2) or fourth-generation (OR 2.1, 95% CI 1.2-3.7) cephalosporins as risk factors. Notably, fluoroquinolone exposure appeared protective (OR 0.6, 95% CI 0.3-0.9). Ninety-two episodes of CDI were diagnosed among 79 SOT recipients (7.3%), and exposure to PPIs (OR 2.4, 95% CI 1.1-5.4) and third-generation cephalosporin therapy (OR 3.9, 95% CI 1.4-10.5) were identified as risk factors. Strategies to decrease PPI use and changes in the class of prophylactic antibiotics may impact CDI incidence and warrant further study.

Respiratory syncytial virus and influenza hospitalizations in Alaska native adults

BACKGROUND

Alaska Native (AN) infants from Yukon Kuskokwim Delta (YKD) have the highest U.S. infant hospitalization rate for respiratory syncytial virus (RSV). RSV can cause significant morbidity and mortality in adult populations, although the RSV burden in AN adults is unknown. Here we investigate RSV, influenza, and human metapneumovirus (hMPV) in hospitalized rural AN adults.

METHODS

YKD AN adults, hospitalized with acute respiratory illness between November 2016 and October 2018 were enrolled prospectively. Nasopharyngeal (NP) swabs were tested for RSV, influenza and hMPV using polymerase chain reaction. Hospitalization rates were calculated.

RESULTS

Of 251 patients who had an NP swab, RSV was detected in 8 (3.2 %), influenza in 31 (12.4 %), and hMPV in no patients. Weighted annual rates of lower respiratory tract infection (LRTI), RSV and influenza hospitalization were 192.0 (95 % CI: 176.5-208.4), 9.1 (6.0-13.3), and 42.2 (35.1-50.2) per 10,000. The most common discharge diagnosis was pneumonia (57.0 %), followed by chronic obstructive pulmonary disease (51.4 %). Ninety-eight percent (246/251) had a medical co-morbidity and 49.8 % (125/251) lived in a house with a smoker. Overall, 6.4 % (16/251) required mechanical ventilation, and 3.6 % (9/251) died during hospitalization. Only 35.7 % (66/185) of patients admitted during influenza season had received the annual influenza vaccine.

DISCUSSION

We examined adult LRTI, influenza, and RSV hospitalization rates in an AN population with high infant RSV hospitalization rates. While we confirmed a high rate of hospitalization from LRTIs and influenza, we did not find a high rate due to RSV or hMPV. Improving influenza vaccination rates, and addressing co-morbidities could reduce respiratory hospitalizations.

Cytokine Profiles and Severity of Influenza Infection in Transplant Recipients

Influenza is responsible for significant morbidity after transplantation. We evaluated T-helper 1/T-helper 2 (Th2) cytokines and interleukin (IL) 10 levels during influenza infection in the posttransplant setting. Serum samples from 277 transplant recipients were analyzed at influenza diagnosis and 28 days later for interferon gamma (IFN-γ), IL-4, IL-13, and IL-10. IL-13 levels were associated with protection against pneumonia and intensive care unit (ICU) admission, whereas the IFN-γ/IL-13 ratio and IL-10 levels were associated with an increased risk of pneumonia and ICU admission. This association was independent of viral load. A skewing of immune responses toward Th2 in transplant patients appears to confer protection from severe influenza infection, independent of viral load.

Evaluating addition of self-collected throat swabs to nasal swabs for respiratory virus detection

BACKGROUND

Early and accurate detection of respiratory viruses (RV) is important for patient management. We have previously shown that self-collected nasal swabs (NS) are feasible and as sensitive as clinician-collected nasal washes for detection of RV, but the additive benefit of self-collected throat swabs is unknown.

OBJECTIVES

To evaluate the added yield of self-collected nasal to throat swabs for detection of RV by PCR in patients with upper respiratory tract infection (URTI) symptoms.

STUDY DESIGN

Patients with URTI symptoms self-collected paired polyurethane foam NS and nylon flocked throat swabs and completed a symptom survey. Swabs were tested for 12 RV by real-time reverse transcription (RT)-PCR. Descriptive, McNemar's, and Wilcoxon signed rank statistical tests were used.

RESULTS

115 paired nasal and throat swabs were collected from 63 individuals, with 71/115 (62%) positive for a RV by at least one specimen, including 51 positive by both, 17 positive by NS only, and 3 positive by throat swab only. The sensitivity of NS was 96% (95%CI: 88-99) versus 76% (95% CI: 65-85) in throat swabs, p<0.001. The median PCR cycle threshold (Ct) in 51 concordant samples was lower (indicating higher viral concentration) in NS (25.1) versus throat swabs (32.0). The three samples positive only by throat swab had high Ct values (33.8, 36.2, and 38.8, all rhinovirus).

CONCLUSION

Self-collection of NS was significantly more sensitive than self collection of throat swabs for detection of RV by RT-PCR. The addition of throat sampling does not appear to increase the diagnostic load in the self-testing setting.

An integrated device for the rapid and sensitive detection of the influenza hemagglutinin

Influenza is a viral respiratory tract infection responsible for up to 5 million cases of severe infection and nearly 600 000 deaths worldwide each year. While treatments for influenza exist, diagnostics for the virus at the point of care are limited in their sensitivity and ability to differentiate between subtypes. We have developed an integrated two-dimensional paper network (2DPN) for the detection of the influenza virus by the surface glycoprotein, hemagglutinin. The hemagglutinin assay was developed using proteins computationally designed to bind with high affinity to the highly-conserved sialic acid binding site. The integrated 2DPN uses a novel geometry that allows automated introduction of an enzymatic amplification reagent directly to the detection zone. This assay was integrated into a prototype device and demonstrated successful detection of clinically relevant virus concentrations spiked into 70 μL of virus-free pediatric nasal swab samples. Using this novel geometry, we found improved assay performance on the device (compared to a manually-operated dipstick method), with a sensitivity of 4.45 × 102 TCID50 per mL on device.

Cytomegalovirus in Pediatric Hematopoietic Stem Cell Transplantation: A Case-Based Panel Discussion of Current Challenges

Cytomegalovirus (CMV) remains a significant contributor to morbidity and death after pediatric solid and stem cell transplantation. Decisions regarding prevention and treatment often lack pediatric-specific data to drive decision making. We present here a case-based discussion around some of these specific topics and focus on approaches to CMV prevention, post-CMV secondary prophylaxis options, and identification and treatment of resistant CMV infection, including emerging antiviral agents and the use of cytotoxic CMV-specific T-cells, in the setting of pediatric hematopoietic stem cell transplantation.

751. Acute Respiratory Illness Hospitalizations Among Young Children: Multi-Center Viral Surveillance Network, United States, 2015–2016

Background

Viral infections are a significant cause of severe acute respiratory illnesses (ARI) in young children. Understanding the current epidemiology of these viruses is important for informing treatment and prevention measures. We describe the New Vaccine Surveillance Network (NVSN) and report preliminary results from 2015 to 2016.

Methods

Prospective active surveillance for hospitalized ARI was conducted from November 1, 2015 to June 30, 2016 among children <5 years of age at seven pediatric hospital sites (figure) using a broad case definition based on admission diagnoses. Parent interviews and medical chart reviews were performed, and mid-turbinate nasal and throat flocked swabs and/or tracheal aspirates were tested for adenovirus, human metapneumovirus (HMPV), influenza, parainfluenza viruses (PIV) 1–3, respiratory syncytial virus (RSV), and rhinovirus/enterovirus using molecular diagnostic assays at each site. Asymptomatic controls <5 years of age were also enrolled.

Results

Among 2,974 hospitalized children with ARI whose specimens were tested for viruses, 2,228 (75%) were <2 years old, with 745 (25%) 0–2 months, and 309 (10%) 3–5 months old. The majority were male (58%; n = 1,732) and 63% (n = 1,093) had no documented comorbid conditions. The median length of stay was 2 days; 1,683 (57%) received supplemental oxygen, 435 (15%) were admitted to intensive care, 95 (3%) required mechanical ventilation, and 1 (<1%) died. Viruses were detected in 2,242 (75%) children with ARI, with >1 virus detected in 234 (8%). RSV was detected in 1,039 (35%) children with ARI, HMPV in 245 (8%), influenza in 104 (4%), and PIV-1, PIV-2, and PIV-3 in 49 (2%), 2 (<1%), and 78 (3%), respectively. Rhinovirus/enterovirus was detected in 849 (29%) and adenovirus in 118 (4%) children with ARI, but were also detected in 18% (n = 227) and 5% (n = 60), respectively, of the 1,243 controls tested; the other viruses were more rarely detected in controls.

Conclusion

During the 2015–2016 season, viral detections were common in young children hospitalized for ARI at seven US sites. NVSN combines clinical data with current molecular laboratory techniques to describe respiratory virus epidemiology in cases of hospitalized pediatric ARI in order to inform current and future prevention, treatment, and healthcare utilization measures.

Disclosures

N. Halasa, Sanofi Pasteur: Investigator, Research support. GSK: Consultant, Consulting fee. Moderna: Consultant, Consulting fee. J. Englund, Gilead: Consultant and Investigator, Consulting fee and Research support. Novavax: Investigator, Research support. GlaxoSmithKline: Investigator, Research support. Alios: Investigator, Research support. MedImmune: Investigator, Research support. J. V. Williams, Quidel: Board Member, Consulting fee. GlaxoSmithKline: Consultant, Consulting fee.

750. Respiratory Virus Infections and Airflow Obstruction After Allogeneic Hematopoietic Cell Transplantation

Background

Respiratory viruses are readily detectable in hematopoietic cell transplant (HCT) recipients in the molecular diagnostic era. The association of respiratory virus infections with acute and chronic airflow obstruction (AFO) is poorly defined.

Methods

HCT recipients were prospectively followed with weekly handheld spirometry and symptom questionnaires through 1 year after HCT. Weekly multiplex PCR testing for 11 respiratory viruses was performed through day 100 post-HCT and every 3 months and with respiratory symptoms thereafter. Standard pulmonary function testing occurred at recommended intervals. Cox proportional hazard models were used to correlate longitudinal symptomatic respiratory tract viral infections with AFO phenotypes, defined as 2- or 4-week decline (↓) of 1 second forced expiratory volume (FEV1) &gt;10% by handheld spirometry; late AFO (FEV1/forced vital capacity [FVC] &lt; lower limit normal predicted and FEV1 decline &gt;10% from baseline at 3 years; or bronchiolitis obliterans syndrome (BOS; FEV1 &lt;75%, FEV1/FVC &lt; 0.7, and FEV1 ↓ &gt;10% from baseline) by 3 years after HCT; late AFO and BOS were assessed by standard pulmonary function testing.

Results

Overall, 7,091 PCR tests were performed in 471 patients; 70% of patients had ≥1 respiratory virus detected. Among 437 patients who survived &gt;4 weeks, decline of FEV-1 for 2 or 4 weeks, late AFO or BOS occurred in 11.9%, 7.1%, 15.6%, and 3.9%, respectively. In adjusted Cox models, human metapneumovirus (HMPV), influenza virus A/B, and parainfluenza virus 1–4 (PIV) upper tract infections (URI) were associated with 2 and 4 weeks FEV-1 decline (Figure 1). Late AFO and BOS were only significantly associated with RSV- or HMPV-related URI (Figure 2). Lower respiratory disease (LRD) due to HMPV (adjusted HR 11.1, P = 0.02) was associated with a 2- and 4-week FEV-1 decline.

Conclusion

Development of AFO after HCT is common. Respiratory viruses are significantly associated with both short-term airflow decline and long-term airflow obstruction. Interventional strategies that target multiple viruses are warranted.

Disclosures

M. Boeckh, Gilead Sciences: Consultant, Grant Investigator and Investigator, Clinical trial support, Consulting fee and Research grant. Asun Biopharma: Consultant, Grant Investigator and Investigator, Clinical trial support, Consulting fee and Research grant. Humabs: Consultant, Consulting fee. Aviragen: Consultant and Grant Investigator, Consulting fee and Research grant. Chimerix Inc.: Consultant, Grant Investigator and Investigator, Clinical trial support, Consulting fee and Research grant. Ablynx: Consultant and Investigator, Clinical trial support and Consulting fee. GSK: Investigator, Clinical trial support. A. Waghmare, Ablynx: Investigator, Research support. Vicol: Investigator, Research support. J. Chien, Gilead Sciences, Inc.: Employee and Shareholder, Salary and stocks. J. Englund, Gilead: Consultant and Investigator, Consulting fee and Research support. Novavax: Investigator, Research support. GlaxoSmithKline: Investigator, Research support. Alios: Investigator, Research support. MedImmune: Investigator, Research support.

1106. Infectious Etiologies of Acute Gastroenteritis in Children during the First 100 Days Post-Allogeneic Hematopoietic Cell Transplant

Background

Acute gastroenteritis (AGE) is a frequent sequela in children undergoing hematopoietic cell transplant (HCT). Although rotavirus and norovirus have been implicated as important causes of AGE, the frequency of other pathogens is unknown. Little data exist on longitudinal prevalence of infectious AGE in HCT.

Methods

From February 2015 to May 2016, subjects <18 years undergoing allogeneic HCT were enrolled at four CDC-NVSN sites: Oakland, Kansas City, Seattle, and Nashville. Stool samples were collected at enrollment, weekly until discharge or day 100 (whichever occurred earliest), during re-admissions within the first 100 days, and day 100. AGE was defined as unexplained ≥3 episodes diarrhea and/or ≥1 episode vomiting/24 hours. Specimens were tested using Luminex xTAG Gastrointestinal Pathogen Panel (Austin, TX) and real-time PCR for adenovirus, astrovirus, norovirus, and sapovirus.

Results

Thirty-one patients were enrolled at four sites (Seattle: 13, Kansas City: 8, Oakland: 6, Nashville: (4) with median age 5 (IQR 3–10) years. Two hundred sixteen samples were obtained with median 7 samples/subject. During the first 100 days, 29 (94%) subjects met the AGE definition. Thirty-six single pathogen detections occurred in 16 (52%) subjects. Clostridium difficile was the most frequent pathogen (Figure 1), with 14 detections in nine patients, all ≥3 years; 50% of detections were asymptomatic. Seven (50%) detections occurred at HCT onset and none received targeted C. difficile therapy. Sapovirus was detected nine times in four patients, with seven (78%) detections associated with AGE symptoms. Rotavirus was detected nine times, during five symptomatic episodes, in three patients. Adenovirus was detected four times in three patients and all were symptomatic.

Conclusion

We longitudinally characterized the etiology of infectious AGE in children undergoing HCT. Despite the majority of patients meeting the definition for AGE, only half had a pathogen detected, suggesting that differentiating infectious vs. noninfectious AGE (e.g., medication induced) in this population is difficult. Although all subjects with adenovirus and most with sapovirus were symptomatic, asymptomatic C. difficile detection was common. Interestingly, norovirus was not detected. Further investigation of AGE is warranted in this population.

Disclosures

All authors: No reported disclosures.

1553. Infectious Complications Following Hematopoietic Cell Transplantation in Patients With Primary Immunodeficiency Diseases

Background

Hematopoietic cell transplantation (HCT) has significantly improved long-term survival for children with primary immunodeficiency diseases (PID). Little is known about specific risk factors for infections after transplant in PID patients and differences from others undergoing HCT. Factors impacting success of HCT in PID include age at HCT, underlying genetic defect, type of donor and conditioning regimen, and importantly, the presence of pre-existing infection. We describe the epidemiology and risk factors for bacterial, viral and fungal infections in patients undergoing HCT for PID.

Methods

After IRB approval, medical records of patients undergoing HCT at Seattle Children’s Hospital for PID between 1998 and 2017 were reviewed. Donor and stem cell source, conditioning regimen, development of graft vs. host disease (GVHD), chimerism and mortality were considered, in addition to details of pre-HCT infections. Timing, character and treatment details of each incident infection during 12 months post-HCT were collected. Standardized antimicrobial prophylactic regimens were administered. Primary outcomes included mortality and infection-free survival. Kaplan–Meier curves were used to examine infection-free survival, by diagnosis and by HCT era.

Results

Sixty-nine patients with PID underwent HCT during the study period. Mean age at HCT was 6.2 years and varied by underlying PID. Altogether, 24 children (34.8%) had severe combined immune deficiency (SCID), 14 (20.3%) had chronic granulomatous disease (CGD), nine (13%) had combined immune deficiency (CID), and six (8.7%) had hyper IgM syndrome. Fifty-six patients received HLA-matched grafts. Umbilical cord blood was utilized in 10% of patients. Acute GVHD grades II–IV developed in 46 (67%) patients. Bacterial infections were the most common infection post-HCT, followed by respiratory and herpes group viral infections. Overall mortality at 1 year was 19%, of which at least 50% was infection related.

Conclusion

Infection occurs frequently and contributes to morbidity and mortality in patients undergoing HCT for PID. Understanding the timing of infections and contributing risk factors could help develop preemptive and monitoring strategies to improve outcomes in this patient population.

Disclosures

All authors: No reported disclosures.

117. Effect of Nasopharyngeal Pneumococcal Carriage on RSV and hMPV Illness Severity in Infants in Nepal

Background

Pneumococcal pneumonia after a preceding respiratory viral illness is associated with morbidity and mortality in infants. Our study sought to determine how pneumococcal carriage impacted illness severity due to respiratory syncytial virus (RSV) or human metapneumovirus (hMPV) in infants 0–6 months in a low resource setting in South Asia without pneumococcal vaccination. Previous studies in this population found an overall 79.4% prevalence of pneumococcal carriage in ages 1–36 months with higher rates of carriage among healthy controls when compared with those with respiratory illness.

Methods

Infants were enrolled at the time of birth in a maternal influenza immunization trial conducted in rural Nepal from 2011 to 2014. Weekly household-based active surveillance was performed from birth to 6 months to assess for infant respiratory illness, defined as fever, cough, difficulty breathing, wheeze, or otorrhea. Mid-nasal swabs were collected and tested by PCR for RSV, hMPV, and streptococcus pneumoniae with inclusion of first illness episode in the surveillance period. Disease severity was defined using the World Health Organization Integrated Management of Childhood Illness criteria.

Results

Altogether, 247 (73.5%) of 336 infants with RSV and 154 (83.7%) of 184 infants with hMPV had S. pneumoniae detected. Mean age at RSV illness with concurrent pneumococcal carriage was 97.0 days (91.3–102.6) versus 72.8 days (63.3–82.4) for infants without carriage (P < 0.001). Mean age at hMPV illness with concurrent pneumococcal carriage was 101.3 days (93.9–108.7) versus 77.2 days (56.5–98.0) for infants without carriage (P = 0.01). Frequency of reported lower respiratory tract infection did not differ with or without carriage (RSV: 64.4% vs. 65.2% respectively; P = 0.89, hMPV: 52.6% vs. 50.0% P = 0.79). S. pneumoniae PCR cycle threshold value did not differ by duration or severity of RSV or hMPV illness episode.

Conclusion

High rates of pneumococcal carriage were observed with RSV and hMPV illness episodes in a birth cohort of infants in rural Nepal. The majority of infants with RSV or hMPV illness had pneumococcus detected at the time of first observed illness. However, no increase in RSV or hMPV illness severity or duration was seen with pneumococcal carriage.

Disclosures

H. Y. Chu, sanofi pasteur: Grant Investigator, Grant recipient. Novavax: Grant Investigator, Grant to co-investigator’s institution.

721. Clinical Respiratory Syndromes and Association with Influenza Clinical Diagnostic Testing and Antiviral Treatment among Children Hospitalized with Acute Respiratory Illness, 2015–2016

Background

We investigated clinical influenza testing and treatment in children hospitalized with acute respiratory illness (ARI) who had distinct respiratory syndromes.

Methods

Children <18 years old with ARI were enrolled at seven hospitals in the New Vaccine Surveillance Network (NVSN) between November 1, 2015–June 30, 2016. ICD10 admission diagnosis codes were grouped to define syndromes of bronchiolitis, asthma, pneumonia, and croup. At clinician discretion, influenza testing with a rapid influenza diagnostic test or molecular assay was performed on respiratory samples. As part of the study, each site performed influenza testing using molecular assays on mid-turbinate nasal and throat swabs from all enrolled children. Analysis was restricted to influenza season; children who received antivirals before hospitalization were excluded.

Results

Among 2,134 children with available ICD10 codes, on preliminary analysis 1,119 (52%) had influenza testing ordered by a clinician: 111 (10%) were positive, and 57 (51%) of 111 received antiviral treatment. Of the 2,134, 858 (40%) had one of the four mutually exclusive syndromes (table). Hospital clinical testing per clinician discretion was influenza positive in 16 of the 858 children (percent positivity per syndrome ranged from <1% to 38%; table). Research study testing of children not undergoing clinical influenza testing identified 11 additional positives. Antiviral treatment was highest for pneumonia patients.

Conclusion

Understanding testing and treatment practices by clinical syndrome may help to identify missed opportunities for influenza diagnosis and treatment.

Table:

Disclosures

J. Englund, Gilead: Consultant and Investigator, Consulting fee and Research support. Novavax: Investigator, Research support. GlaxoSmithKline: Investigator, Research support. Alios: Investigator, Research support. MedImmune: Investigator, Research support. N. B. Halasa, sanofi pasteur: Investigator, Research support. GSK: Consultant, Consulting fee. Moderna: Consultant, Consulting fee.

1096. Effect of Diarrheal Illness During Pregnancy on Adverse Birth Outcomes in Nepal

Background

Adverse birth outcomes, including low birthweight (LBW), small-for-gestational-age (SGA) and preterm birth, contribute to 60–80% of infant mortality worldwide. Little published data exist on the association between diarrhea during pregnancy and adverse birth outcomes. We sought to identify whether diarrhea during pregnancy was associated with adverse birth outcomes.

Methods

We used data from a community-based, prospective randomized trial of maternal influenza immunization of pregnant women and their infants conducted in rural Nepal from 2011 to 2014. Illness episodes were defined as at least three watery bowel movements per day for one or more days with 7 diarrhea-free days between episodes. Diarrheal illnesses were identified through longitudinal household-based weekly symptom surveillance. The c² test, two-sample t-test, and log-binomial regression were performed to evaluate baseline characteristics and the association between diarrhea during pregnancy and adverse birth outcomes.

Results

Of 3,682 women in the study, 527 (14.3%) experienced one or more episodes of diarrhea during pregnancy. Diarrhea incidence was not seasonal. Women with diarrhea had a median of one episode of diarrhea (interquartile range (IQR) 1–2 episodes) and two cumulative days of diarrhea (IQR 1–3 days). Of women with diarrhea, 16.1% (85) sought medical care. Mean maternal age, parity, biomass cook stove use, home latrine, water source, caste, and smoking did not differ in pregnant women with and without diarrhea. In crude and adjusted analyses, women with diarrhea during pregnancy were significantly more likely to have SGA infants (42.6% vs. 36.8%; adjusted risk ratio=1.20, 95% CI 1.06–1.36, P = 0.005). LBW and preterm birth incidence did not significantly differ between women with diarrhea during pregnancy and those without. There was no significant association between seeking medical care for diarrhea and birth outcomes.

Conclusion

Diarrheal illness during pregnancy was associated with a significantly higher risk of SGA infants in this rural South Asian population. Interventions to reduce the burden of diarrheal illness during pregnancy may have an impact on SGA births in resource-limited settings.

Disclosures

All authors: No reported disclosures.

871. Symptomatic Respiratory Syncytial Virus and Adenovirus Upper Respiratory Tract Infections Increase the Risk of Invasive Aspergillosis After Allogeneic Hematopoietic Cell Transplantation

Background

Invasive aspergillosis (IA) is a serious infectious complication following hematopoietic cell transplantation (HCT). Few studies have reported respiratory viral infections (RVIs) as a risk factor for developing IA, and data regarding specific viruses is sparse. We examined whether specific respiratory viruses were associated with increased risk of developing IA post-HCT.

Methods

In a longitudinal surveillance study of RVIs among allogeneic HCT recipients conducted 2005–2010, weekly post-HCT nasal washes were collected through day 100, then every 3 months, and whenever respiratory symptoms occurred through 1 year post-HCT. Nasal and bronchoalveolar lavage (BAL) samples were tested by multiplex PCR for respiratory syncytial virus (RSV), parainfluenza viruses (PIV)1–4, influenza A/B, human metapneumovirus, adenovirus (ADV), and human rhinoviruses, and coronaviruses. Only respiratory virus detections with symptoms were counted as RVI. Separate Cox proportional hazards models were used to examine adjusted associations between each RVI and the development of first proven/probable IA by 1-year post-HCT.

Results

Among 437 patients who survived >28 days following HCT, 39 patients developed IA by 1-year post-HCT (median 87 days, range 5–283). After adjusting for age at HCT, neutropenia, high-grade CMV viremia, and HLA status (matched related vs. others) or severe acute graft-versus-host disease (GVHD Grade 0–2 vs. 3–4), RSV and ADV upper respiratory tract infections (URTI) were associated with increased risk of developing IA (figure). Detection of any respiratory virus in the BAL was associated with IA (P < 0.001).

Conclusion

RSV and ADV URTI are significant risk factors for development of IA post-HCT; the association between PIV URTI and development of IA approached statistical significance. Viral lower respiratory tract infection was associated with IA. Our data provide a rationale to assess IA as an endpoint in preventive studies of novel agents for respiratory viruses and further emphasize the importance of effective infection prevention practices for RVIs after HCT.

Disclosures

J. Chien, Gilead Sciences, Inc.: Employee and Shareholder, Salary and stocks. A. Waghmare, Ablynx: Investigator, Research support. J. Englund, Gilead: Consultant and Investigator, Consulting fee and Research support. Novavax: Investigator, Research support. GlaxoSmithKline: Investigator, Research support. Alios: Investigator, Research support. MedImmune: Investigator, Research support. M. Boeckh, Asun Biopharma: Consultant and Investigator, Consulting fee and Research support. Gilead Sciences: Consultant and Investigator, Consulting fee and Research support. Chimerix Inc.: Consultant and Investigator, Consulting fee and Research support. Humabs: Consultant, Consulting fee. GSK: Investigator, Research support.

Who's the Target: Mother or Baby?

Maternal immunization for prevention of morbidity and mortality of pregnant women and their neonates due to infectious diseases is ongoing worldwide. The complexity of vaccine research and development in this population is challenging. Not only do vaccines for pregnant women require evidence of immunogenicity, potency, stability, and limited reactogenicity, they must also provide efficacy in decreasing morbidity for the pregnant woman, her fetus, and the neonate, demonstrate safety or lack of evidence of harm, and offer benefit or potential benefit of vaccination during pregnancy. Since the 19th century, evidence of protective effects of vaccination during pregnancy has been documented. Pandemic influenza and pertussis outbreaks in recent years have affected a paradigm shift in vaccine research and development as well as current policy regarding immunization in pregnancy. Studies of the immune system in pregnant women and neonates have shown that immune changes associated with pregnancy in women do not interfere with maternal vaccine responses, multiple factors are important in transplacental transfer of antibodies, and maternal antibodies are beneficial to neonates. In recent years, guidelines have been developed by expert panels to help design studies for maternal vaccinations and for harmonization of data collection, analysis, and adverse event reporting. Further research into maternal and neonatal immunology, transplacental antibody transfer, and epidemiology of diseases is needed, especially as new vaccines to respiratory syncytial virus, cytomegalovirus, and Group B streptococcus are developed. Maternal vaccinations have the potential to change the epidemiology of infectious diseases in reproductive health and pediatrics and may lead to new clinical applications to improve global maternal and neonatal health.

Influenza Clinical Diagnostic Testing and Antiviral Treatment among Children Hospitalized with Acute Respiratory Illness During the 2015–16 Influenza Season

Background

Although antiviral therapy is recommended for hospitalized patients with suspected or confirmed influenza, clinicians often rely on test results to determine management. Rapid influenza diagnostic tests (RIDTs) have suboptimal sensitivity; use of molecular assays may improve care. We evaluated clinical influenza testing and antiviral treatment practices in hospitalized children.

Methods

Children aged <18 years with acute respiratory illness (ARI) were enrolled through active surveillance at 7 hospitals in the New Vaccine Surveillance Network between November 2015 and June 30, 2016; analysis was restricted to the influenza season. Preliminary data were analyzed for children who had clinical influenza diagnostic testing with a rapid influenza diagnostic test or molecular assay on nasopharyngeal or nasal swabs or nasal washes. Children who had received antivirals prior to hospitalization were excluded.

Results

Of 2267 children, 1165 (51%) had clinical diagnostic testing on upper respiratory samples: 276 (24%) by RIDT alone, 780 (67%) by molecular testing alone, and 109 (9%) by both. The use of molecular testing alone varied by site, from 10% to 100% of samples tested. Of 116 (10%) children testing positive for influenza, 60 (52%) were treated; by site, treatment of children positive for influenza ranged from 25% to 83%. Antiviral treatment was given to 16/20 (80%) of those admitted ≤2 days from symptom onset vs. 44/96 (46%) children admitted >2 days after onset. Among 94 children tested by one method who were positive, >80% had samples collected in the emergency department or on day of admission, and 47 started treatment (Figure, A): 16/37 (43%) and 31/57 (54%) were treated when tested by RIDT alone and molecular testing alone, respectively. Of those positive children treated, 7/16 (44%) tested by RIDT vs. 22/31 (71%) by molecular testing started treatment on the day of testing (Figure, B).

Conclusion

Half of hospitalized children with ARI who tested positive for influenza received antiviral treatment. Although there was high variability in testing and treatment by site, in positive patients who were treated the use of molecular testing appeared to be associated with prompt antiviral therapy. Understanding clinician reasons for relatively low treatment overall will require further investigation.

Disclosures

J. Englund, Gilead: Consultant and Investigator, Research support Chimerix: Investigator, Research support Alios: Investigator, Research support Novavax: Investigator, Research support MedImmune: Investigator, Research support GlaxoSmithKline: Investigator, Research support N. B. Halasa, sanofi pasteur: Research Contractor, Research support Astra Zeneca: Research Contractor, Grant recipient

Blood Viral Load (VL) Not Clinically Meaningful in Symptomatic Congenital Cytomegalovirus (cCMV) Infection

Background

Sensorineural hearing loss (SNHL) and neurodevelopmental (ND) outcomes are favorably impacted by antiviral therapy in infants with symptomatic cCMV disease. We correlated blood VL before and during therapy with clinical findings at presentation and follow-up in this population.

Methods

Post-hoc analysis of two clinical trials conducted by the CASG from 2002 to 2013 evaluating valganciclovir therapy. 120 subjects (73 treated × 6 weeks, 47 treated × 6 months) were included. Whole blood VL was determined by real-time PCR at a central laboratory before therapy (baseline, BL) and periodically for 6 months.

Results

In subjects treated for 6 months, increases in BL VL correlated with decreased probability of better hearing outcomes at 12 months (Figure 1), but clinically meaningful VL thresholds that predict SNHL were not identified (Table 1). Subjects treated for 6 weeks had no correlation between BL VL and SNHL. No correlation was found between BL VL and Bayley ND testing at 12 and 24 months for subjects receiving either treatment duration. Subjects treated for 6 months who achieved and sustained VL suppression (&lt;2.5 log) between treatment day 14 and month 4 had better hearing outcomes at 6, 12, and 24 months (89% vs. 56%, P = 0.01; 100% vs. 63%, P = 0.0007; 94% vs. 68%, P = 0.04), but 56%–68% of subjects not achieving suppression still had improved hearing. Higher BL VL correlated with BL CNS involvement, thrombocytopenia, and transaminase elevation for subjects receiving either treatment duration, but with substantial overlap in quantity of virus detected (Figure 2). Subjects with &gt;3 symptoms of congenital CMV at presentation had higher BL VL than subjects with ≤3 symptoms (3.75 log, range 1.00–5.65, vs. 3.38 log, range 1.00–5.36; P = 0.005).

Conclusion

Blood VL at BL and during therapy has little clinically meaningful predictive value for long-term outcomes in symptomatic congenital CMV.

Disclosures

J. Englund, Gilead: Consultant and Investigator, Research support; Chimerix: Investigator, Research support; Alios: Investigator, Research support; Novavax: Investigator, Research support; MedImmune: Investigator, Research support; GlaxoSmithKline: Investigator, Research support

Meterology-driven Prediction of RSV/RHV Incidence in Rural Nepal

Background

Incidence of respiratory syncytial virus (RSV) and rhinovirus (RHV) varies throughout the year. We aim to quantify the relationship between weather variables (temperature, humidity, precipitation, and aerosol concentration) and disease incidence in order to quantify how outbreaks of RSV and RHV are related to seasonal or sub-seasonal meteorology, and if these relationships can predict viral outbreaks of RSV and RHV.

Methods

Health data were collected in a community-based, prospective randomized trial of maternal influenza immunization of pregnant women and their infants conducted in rural Nepal from 2011–2014. Adult illness episodes were defined as fever plus cough, sore throat, runny nose, and/or myalgia, with infant illness defined similarly but without fever requirement. Cases were identified through longitudinal household-based weekly surveillance. Temperature, humidity, precipitation, and fine particulate matter (PM 2.5) data come from reanalysis data products NCEP, Era-Interim, and Merra-2, which are produced by assimilating historical in-situ and satellite-based observations into a weather model.

Results

RSV exhibits a relationship with temperature after removing the seasonal cycle (r = -0.16, N = 208, P = 0.02), and RHV exhibits a strong relationship to daily temperature (r =-0.14, N =208, P = 0.05). When lagging meteorology by up to 15 weeks, correlations with disease count and weather improve (RSV: r_max = 0.45, P < 0.05; RHV: r_max = 0.15, P = 0.05). We use an SIR model forced by lagged meteorological variables to predict RSV and RHV, suggesting that disease burden can be predicted at lead times of weeks to months.

Conclusion

Meteorological variables are associated with RSV and RHV incidence in rural Nepal and can be used to drive predictive models with a lead time of several months.

Disclosures

J. Englund, Gilead: Consultant and Investigator, Research support Chimerix: Investigator, Research support Alios: Investigator, Research support Novavax: Investigator, Research support MedImmune: Investigator, Research support GlaxoSmithKline: Investigator, Research support

Recommended Curriculum for Training in Pediatric Transplant Infectious Diseases

A working group representing the American Society of Transplantation, Pediatric Infectious Diseases Society, and International Pediatric Transplant Association has developed a collaborative effort to identify and develop core knowledge in pediatric transplant infectious diseases. Guidance for patient care environments for training and core competencies is included to help facilitate training directed at improving the experience for pediatric infectious diseases trainees and practitioners in the area of pediatric transplant infectious diseases.

Transmission of Methicillin-ResistantStaphylococcus aureusto Preterm Infants Through Breast Milk

Objective:

To determine a potential source of MRSA colonization and infection among preterm infants in a neonatal intensive care unit (NICU) using molecular analysis of breast milk samples.

Design:

Case report, outbreak investigation.

Results:

Preterm triplets were delivered at 26 weeks' gestation via cesarean section when routine active surveillance for MRSA was performed for all infants in a NICU. Surveillance consisted of swabbing the throat, nose, and umbilicus (TNU) weekly. Although infants A and B initially had negative TNU swabs, repeat cultures were positive for MRSA on day of life (DOL) 10 and DOL 18, respectively. Surveillance and clinical cultures for infant C were negative. Infant A developed sepsis, and multiple blood cultures were positive for MRSA beginning on DOL 14. Infant B developed conjunctivitis and a conjunctival exudate culture was positive for MRSA on DOL 70. Both infants were fed breast milk via nasogastric tube. Cultures of breast milk samples for infants A and B dated prior to either infant's first positive surveillance culture were positive for MRSA. All MRSA isolates had identical results on antibiotic susceptibility testing. PFGE demonstrated identical banding patterns for the MRSA isolates from the blood culture of infant A, breast milk for infants A and B, and a surveillance swab from infant B. At no time did the mother develop evidence of mastitis or other local breast infection.

Conclusions:

MRSA can be passed from mother to preterm infant through contaminated breast milk, even in the absence of maternal infection. Colonization and clinical disease can result.

Intestinal decontamination of multidrug-resistant Klebsiella pneumoniae after recurrent infections in an immunocompromised host

Multidrug-resistant (MDR) Enterobacteriaceae infections are associated with increased morbidity. We describe a 20-year-old hematopoietic cell transplantation recipient with recurrent MDR Klebsiella pneumoniae infection, prolonged intestinal colonization, and subsequent intestinal decontamination. Further study should evaluate stool surveillance, molecular typing, and fecal microbiota transplantation for patients with intestinal MDR Enterobacteriaceae carriage.

Stable hematopoietic cell engraftment after low-intensity nonmyeloablative conditioning in patients with immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome

BACKGROUND

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is characterized by severe systemic autoimmunity caused by mutations in the forkhead box protein 3 (FOXP3) gene. Hematopoietic cell transplantation is currently the only viable option for long-term survival, but patients are frequently very ill and may not tolerate traditional myeloablative conditioning regimens.

OBJECTIVE

Here we present the outcome of hematopoietic cell transplantation using a low-intensity, nonmyeloablative conditioning regimen in 2 patients with IPEX syndrome and significant pretransplant risk factors.

METHODS

Two high-risk patients with IPEX syndrome received HLA-matched related bone marrow or unrelated peripheral blood stem cell grafts following conditioning with 90 mg/m(2) fludarabine and 4 Gy total body irradiation. Postgrafting immunosuppression consisted of mycophenolate mofetil and cyclosporine. Immune reconstitution and immune function was evaluated by measurement of donor chimerism, regulatory T-cell numbers, absolute lymphocyte subsets, and T-cell proliferation assays.

RESULTS

Both patients experienced minimal conditioning toxicity and successfully engrafted after hematopoietic cell transplantation. With a follow-up of 4 and 1 years, respectively, patients 1 and 2 have full immune function and normal FOXP3 protein expression.

CONCLUSION

A low-intensity, nonmyeloablative conditioning regimen can establish stable engraftment and correct the life-threatening immune deficiency and enteropathy of IPEX syndrome despite the presence of comorbidities that preclude conventional hematopoietic cell transplantation.

Impact of corticosteroid treatment and antiviral therapy on clinical outcomes in hematopoietic cell transplant patients infected with influenza virus

The impact of cytokines induced during influenza infection has been described, but the effect of corticosteroids on clinical outcomes is unclear. Although antiviral therapy has been well studied in immunocompetent subjects, few data exist on its clinical efficacy in immunocompromised populations. Data from 143 hematopoietic cell transplant recipients with documented seasonal influenza infection were reviewed to examine the impact of different corticosteroid regimens and antiviral therapy on clinical outcomes. In multivariable analyses, there was no observed difference between patients who received no, low doses (<1 mg/kg/day), or high doses (≥ 1 mg/kg/day) of corticosteroids with regard to the development of lower respiratory tract disease (LRD), hypoxemia, need for mechanical ventilation, or death. However, treatment with high-dose steroids was associated with a trend toward prolonged viral shedding (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.0-11; P = .05). In multivariable analyses, antiviral therapy initiated to treat upper respiratory tract infection (URI) was associated with fewer cases of LRD (OR, 0.04; 95% CI, 0-0.2; P < .01) and fewer hypoxemia episodes (OR, 0.3; 95% CI, 0.1-0.9; P = .03). Our results suggest that corticosteroids are not associated with adverse clinical outcomes in hematopoietic cell transplant recipients infected with influenza, although use of higher doses may delay viral clearance. Antiviral therapy initiated during the URI phase reduced the risk of LRD and hypoxemia.

Safety of oseltamivir compared with the adamantanes in children less than 12 months of age

BACKGROUND

When oseltamivir is administered in extremely high doses (500-1000 mg/kg) to young juvenile rats, central nervous system toxicity and death occurred in some animals. Mortality was not observed in older juvenile rats, suggesting a possible relationship between neurotoxicity and an immature blood-brain barrier. To assess potential neurologic adverse effects of oseltamivir use in infants, a retrospective chart review was performed in infants less than 12 months of age who received oseltamivir, amantadine, or rimantadine.

METHODS

The primary objective was to describe the frequency of neurologic adverse events among children less than 12 months of age who received oseltamivir compared with those receiving adamantanes. Medical record databases, emergency department databases, and/or pharmacy records at 15 medical centers were searched to identify patients.

RESULTS

Of the 180 infants identified as having received antiviral therapy, 115 (64%) received oseltamivir, 37 (20%) received amantadine, and 28 (16%) received rimantadine. The median dose of oseltamivir was 2.0 mg/kg/dose in 3- to 5-month-old and 2.2 mg/kg/dose in 9- to 12-month-old infants. The maximum dose administered was 7.0 mg/kg/dose. There were no statistically significant differences in the occurrence of adverse neurologic events during therapy among subjects treated with oseltamivir versus those treated with the adamantanes (P = 0.13).

CONCLUSIONS

This is the largest report to date of oseltamivir use in children less than 12 months of age. Neurologic events were not more common with use of oseltamivir compared with that of the adamantanes. Dosing of oseltamivir was variable, illustrating the need for pharmacokinetic data in this younger population.

How I treat influenza in patients with hematologic malignancies

The 2009 H1N1 influenza pandemic has heightened the interest of clinicians for options in the prevention and management of influenza virus infection in immunocompromised patients. Even before the emergence of the novel 2009 H1N1 strain, influenza disease was a serious complication in patients with hematologic malignancies receiving chemotherapy or undergoing hematopoietic cell transplantation. Here we review the clinical manifestations of seasonal and 2009 H1N1 influenza and discuss current diagnosis, antiviral treatment, and prophylaxis options. We also summarize infection control and vaccination strategies for patients, family members, and caregivers.