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Background Indoor smoke exposure is common in developing countries and may influence nasopharyngeal (NP) pneumococcal colonization density and risk of acute respiratory illness. We compared colonization density among Andean children living in households previously enrolled in a randomized controlled trial of a home intervention package including improved stoves to reduce smoke, kitchen sinks, and water disinfection. Methods We enrolled 260 children aged Results Age and sociodemographic characteristics were similar between groups. Although no differences were observed in densities between groups, colonization density varied significantly over time in both groups, with highest densities coinciding with spring months. Time during and after virus-associated ARI was also associated with higher pneumococcal colonization density than time remote from ARIs. Conclusions A home intervention package, including improved stoves, was not associated with changes in pneumococcal densities in young Andean children. However, increasing pneumococcal density was observed with spring season and viral-associated ARIs.

Background Antiviral (AV) therapy is recommended for children < 2 years, hospitalized, or with underlying conditions (UC) and suspected influenza (flu). We sought to compare demographic and clinical characteristics by AV prescription in flu-positive children who presented to the emergency department (ED) and determine the percentage of AV prescription in these high-risk children. Methods Children < 18 years who presented with respiratory symptoms and/or fever at seven New Vaccine Surveillance Network sites were enrolled. We conducted interviews, obtained mid-turbinate nasal and/or throat swabs for molecular flu testing (results unknown to providers), and reviewed medical charts for AV prescription after presenting to the ED. These are preliminary data. Results From December 2016 to June 2018, 9,524 subjects were enrolled and tested for flu; 1,260 (13%) were flu-positive by research testing; 54% were male, median age was 41 months, and 23% were prescribed an AV. The frequency of AV prescription differed by study site (Figure 1). Among research-tested flu-positive patients, AV were prescribed to 25% of children < 2 years, 31% of children with UC, and 51% admitted to the hospital from the ED (Table 1). Of the 388 (31%) clinically-tested flu-positive patients, 52%, 66%, and 77% of the same high-risk groups were prescribed an AV, respectively. Conclusion AV prescriptions varied by study site and differences by race, ethnicity, and clinical presentation were noted. Clinical testing was associated with higher use of AV treatment in appropriate target patients. Efforts are needed to understand AV use patterns and improve prescription rates in recommended patients. Disclosures All authors: No reported disclosures.

Background Developmentally-appropriate disclosure of human immunodeficiency virus (HIV) status to children living with HIV (CLWH) is essential to achieve optimal health outcomes, but stigma and fear result in delaying disclosure into adolescence. The American Academy of Pediatrics recommends disclosure of HIV status to school-age children. The objective of this quality improvement (QI) project was to increase the proportion of CLWH > 10 years of age who are disclosed about their HIV status from 57% to 80% by 18 months. Methods The Institute for Healthcare Improvement’s Model for Improvement was utilized for this QI project. This model accelerates quality improvement by implementing Plan-Do-Study-Act (PDSA) cycles to determine whether changes lead to improvement. The target population included CLWH followed at an urban pediatric HIV clinic. The primary outcome measure was the proportion of children > 10 years of age who are disclosed about their HIV status. PDSA cycles included monthly clinic check-ins to discuss new disclosures, quarterly team meetings to discuss implementation of new changes to improve disclosure and modifying a note template to prompt providers to document disclosure status and plan for undisclosed patients. Our process measure was the proportion of undisclosed children who have a documented disclosure status/plan. Annotated run charts were used to track the data. Results Prior to our first PDSA cycle, 57% of CLWH > 10 years of age were disclosed to about their HIV status, and none of the undisclosed children had a disclosure status/plan documented in their medical record. The proportion of CLWH disclosed to about their HIV status increased to 66% since meeting with the team regularly to discuss disclosure status (figure). Four months after introduction of the modified note template, the proportion of CLWH with documentation of their disclosure status and plan increased to 54%. Conclusion Team awareness of the importance of disclosure and a modified clinic note template were associated with increases in the proportion of CLWH with age-appropriate HIV disclosure and documentation of disclosure status. Future interventions will include adapting methods of step-wise disclosure which have been proven effective in other settings. Disclosures All authors: No reported disclosures.

Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) has revolutionized the proteomics analysis of complexes, cells, and tissues. In a typical proteomic analysis, the tandem mass spectra from a LC-MS/MS experiment are assigned to a peptide by a search engine that compares the experimental MS/MS peptide data to theoretical peptide sequences in a protein database. The peptide spectra matches are then used to infer a list of identified proteins in the original sample. However, the search engines often fail to distinguish between correct and incorrect peptides assignments. In this study, we designed and implemented a novel algorithm called De-Noise to reduce the number of incorrect peptide matches and maximize the number of correct peptides at a fixed false discovery rate using a minimal number of scoring outputs from the SEQUEST search engine. The novel algorithm uses a three-step process: data cleaning, data refining through a SVM-based decision function, and a final data refining step based on proteolytic peptide patterns. Using proteomics data generated on different types of mass spectrometers, we optimized the De-Noise algorithm on the basis of the resolution and mass accuracy of the mass spectrometer employed in the LC-MS/MS experiment. Our results demonstrate De-Noise improves peptide identification compared to other methods used to process the peptide sequence matches assigned by SEQUEST. Because De-Noise uses a limited number of scoring attributes, it can be easily implemented with other search engines.

We examined nasopharyngeal pneumococcal colonization density patterns surrounding acute respiratory illnesses (ARI) in young children in Peru. Pneumococcal densities were dynamic, gradually increasing leading up to an ARI, peaking during the ARI, and decreasing after the ARI. Rhinovirus co-infection was associated with higher pneumococcal densities.

Background. Human rhinoviruses (HRVs) are frequently detected in children with acute respiratory illnesses (ARIs) but also in asymptomatic children. We compared features of ARI with HRV species (A, B, C) and determined genotypes associated with repeated HRV detections within individuals. Methods. We used clinical data and respiratory samples obtained from children Results. Among 207 ARI samples sequenced, HRV-A, HRV-B, and HRV-C were detected in 104 (50%), 20 (10%), and 83 (40%), respectively. Presence of fever, decreased appetite, and malaise were significantly higher in children with HRV-B. When codetections with other viruses were excluded (n = 155), these trends persisted, but some did not reach statistical significance. When 58 paired sequential HRV detections during asymptomatic and ARI episodes were sequenced, only 9 (16%) were identical genotypes of HRV. Conclusions. Clinical features may differ among HRV species. Repeated HRV detections in young children frequently represented acquisition of new HRV strains.

Human infection with Colletotrichum species is typically limited to ophthalmologic manifestations. We present the first reported pediatric case of subcutaneous Colletotrichum truncatum infection. This case highlights the potential importance of C. truncatum as an agent of subcutaneous or disseminated disease in immunocompromised children.

Systems biology is an approach to comprehensively study complex interactions within a biological system. Most published systems vaccinology studies have utilized whole blood or peripheral blood mononuclear cells (PBMC) to monitor the immune response after vaccination. Because human blood is comprised of multiple hematopoietic cell types, the potential for masking responses of under-represented cell populations is increased when analyzing whole blood or PBMC. To investigate the contribution of individual cell types to the immune response after vaccination, we established a rapid and efficient method to purify human T and B cells, natural killer (NK) cells, myeloid dendritic cells (mDC), monocytes, and neutrophils from fresh venous blood. Purified cells were fractionated and processed in a single day. RNA-Seq and quantitative shotgun proteomics were performed to determine expression profiles for each cell type prior to and after inactivated seasonal influenza vaccination. Our results show that transcriptomic and proteomic profiles generated from purified immune cells differ significantly from PBMC. Differential expression analysis for each immune cell type also shows unique transcriptomic and proteomic expression profiles as well as changing biological networks at early time points after vaccination. This cell type-specific information provides a more comprehensive approach to monitor vaccine responses.

Background Despite widespread use of pneumococcal conjugate vaccines (PCVs), Streptococcus pneumoniae (pneumococcus) remains an important cause of pneumonia. Prior to widespread PCV use, we found a high prevalence of nasopharyngeal (NP) colonization with pneumococcus resistant to multiple antibiotic classes among young children in the rural highlands of Peru. We sought to confirm contemporary resistance profiles among young children, their mothers, and animal contacts in the post-PCV era. Methods We enrolled eligible members of Peruvian households whose children had participated in our previous study. Mothers were questioned about antibiotic use for themselves and their children age

Adjuvants enhance immunity elicited by vaccines through mechanisms that are poorly understood. Using a systems biology approach, we investigated temporal protein expression changes in five primary human immune cell populations: neutrophils, monocytes, natural killer cells, T cells, and B cells after administration of either an Adjuvant System 03 adjuvanted or unadjuvanted split-virus H5N1 influenza vaccine. Monocytes demonstrated the strongest differential signal between vaccine groups. On day 3 post-vaccination, several antigen presentation-related pathways, including MHC class I-mediated antigen processing and presentation, were enriched in monocytes and neutrophils and expression of HLA class I proteins was increased in the Adjuvant System 03 group. We identified several protein families whose proteomic responses predicted seroprotective antibody responses (>1:40 hemagglutination inhibition titer), including inflammation and oxidative stress proteins at day 1 as well as immunoproteasome subunit (PSME1 and PSME2) and HLA class I proteins at day 3 in monocytes. While comparison between temporal proteomic and transcriptomic results showed little overlap overall, enrichment of the MHC class I antigen processing and presentation pathway in monocytes and neutrophils was confirmed by both approaches.

BACKGROUNDVaccine development for influenza A/H5N1 is an important public health priority, but H5N1 vaccines are less immunogenic than seasonal influenza vaccines. Adjuvant System 03 (AS03) markedly enhances immune responses to H5N1 vaccine antigens, but the underlying molecular mechanisms are incompletely understood.OBJECTIVE AND METHODSWe compared the safety (primary endpoint), immunogenicity (secondary), gene expression (tertiary) and cytokine responses (exploratory) between AS03-adjuvanted and unadjuvanted inactivated split-virus H5N1 influenza vaccines. In a double-blinded clinical trial, we randomized twenty adults aged 18-49 to receive two doses of either AS03-adjuvanted (n = 10) or unadjuvanted (n = 10) H5N1 vaccine 28 days apart. We used a systems biology approach to characterize and correlate changes in serum cytokines, antibody titers, and gene expression levels in six immune cell types at 1, 3, 7, and 28 days after the first vaccination.RESULTSBoth vaccines were well-tolerated. Nine of 10 subjects in the adjuvanted group and 0/10 in the unadjuvanted group exhibited seroprotection (hemagglutination inhibition antibody titer > 1:40) at day 56. Within 24 hours of AS03-adjuvanted vaccination, increased serum levels of IL-6 and IP-10 were noted. Interferon signaling and antigen processing and presentation-related gene responses were induced in dendritic cells, monocytes, and neutrophils. Upregulation of MHC class II antigen presentation-related genes was seen in neutrophils. Three days after AS03-adjuvanted vaccine, upregulation of genes involved in cell cycle and division was detected in NK cells and correlated with serum levels of IP-10. Early upregulation of interferon signaling-related genes was also found to predict seroprotection 56 days after first vaccination.CONCLUSIONSUsing this cell-based systems approach, novel mechanisms of action for AS03-adjuvanted pandemic influenza vaccination were observed.TRIAL REGISTRATIONClinicalTrials.gov NCT01573312.

Background The burden, clinical features, and molecular epidemiology of norovirus infection in young children in southern Africa are not well defined. Methods Using data from a health facility-based surveillance study of children