Diagnosis of Bacterial Tracheostomy-Associated Respiratory Tract Infections in Pediatric Patients.

OBJECTIVES: To identify demographic and clinical characteristics of children with fever and/or respiratory illness associated with a diagnosis of bacterial tracheostomy-associated respiratory tract infections (bTARTI). Secondary objectives included comparison of diagnostic testing, length of stay (LOS), and readmission rates between children diagnosed with bTARTI and others. METHODS: We performed a retrospective chart review of encounters over 1 year for fever and/or respiratory illness at a single academic children's hospital for children with tracheostomy dependence. Patient characteristics, features of presenting illness, and laboratory and imaging results were collected. Generalized linear mixed models were employed to study associations between patient characteristics, diagnosis of bTARTI, and impact on LOS or readmission rates. RESULTS: Among 145 children with tracheostomies identified, 79 children contributed 208 encounters. bTARTI was diagnosed in 66 (31.7%) encounters. Significant associations with bTARTI diagnosis included chest radiograph consistent with bacterial pneumonia (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.50-2.08), positive tracheal aspirate culture (OR, 1.3; 95% CI, 1.05-1.61), higher white blood cell count (16.4 vs 13.1 × 103/µ; P = .03), change in oxygen requirement (OR, 1.14; 95% CI, 1.00-1.31), telephone encounter (OR, 1.41; 95% CI, 1.09-1.81), and living at home with family (OR, 1.42; 95% CI, 1.06-1.92). LOS for admitted patients with bTARTI was 2.19 times longer (CI, 1.23-3.88). CONCLUSIONS: In our single-center study, we identified several clinical and nonclinical factors associated with a diagnosis of bTARTI. Despite widespread use, few laboratory tests were predictive of a diagnosis of bTARTI. There is need for standardization in diagnosis.

De novo protein design enables the precise induction of RSV-neutralizing antibodies.

De novo protein design has been successful in expanding the natural protein repertoire. However, most de novo proteins lack biological function, presenting a major methodological challenge. In vaccinology, the induction of precise antibody responses remains a cornerstone for next-generation vaccines. Here, we present a protein design algorithm called TopoBuilder, with which we engineered epitope-focused immunogens displaying complex structural motifs. In both mice and nonhuman primates, cocktails of three de novo-designed immunogens induced robust neutralizing responses against the respiratory syncytial virus. Furthermore, the immunogens refocused preexisting antibody responses toward defined neutralization epitopes. Overall, our design approach opens the possibility of targeting specific epitopes for the development of vaccines and therapeutic antibodies and, more generally, will be applicable to the design of de novo proteins displaying complex functional motifs.

Clinical characteristics associated with increased resource utilization of hospitalized children under 5 years with acute gastroenteritis at a tertiary hospital in the northern region of Ghana: a retrospective study.

INTRODUCTION: Acute gastroenteritis (AGE) is a leading cause of mortality in children in developing countries. Management of AGE consumes medical resources, including antibiotics and intra-venous fluids, but factors affecting resource utilization in the management of AGE are under-studied. We hope to identify clinical predictors of resource utilization in AGE. METHODS: We performed a retrospective chart review of patients 1-60 months of age admitted to a tertiary hospital in Northern Ghana between January 2013 and December 2014 with an admitting diagnosis of AGE. We collected data on patient demographics, presenting symptoms, and subsequent management. Our primary outcome was prolonged hospital length of stay, defined as >4 days. Secondary outcomes included other measures of resource utilization, such as use of antibiotics, antimalarials and intravenous fluids. Demographic and clinical characteristics were compared between groups with Pearson chi square test for categorical variables and ANOVA for continuous variables. Multivariable logistic regression modeling for each outcome included all variables found to be significant in the bivariate analysis. RESULTS: We reviewed charts for 473 patients admitted for AGE during this timeframe. 264 (56%) were male, median age was 12 months. 448 (95%) received antibiotics, 396 (84%) received antimalarials and 365 (77.2%) received intravenous fluids. 167 (35.3%) had prolonged LOS >4 days. Following multiple logistic regression analysis, clinical features associated with prolonged LOS included fever duration (OR 2.87, 95% CI 2.28-3.61 per 1-day increase), mild (OR 2.39, 95% CI 1.12-5.08) or moderate (OR 3.13, 95% CI 1.57-6.21) dehydration (compared to none) and symptom duration (OR 1.13, 95% CI 1.01-1.27 per 1-day increase). CONCLUSION: Dehydration and duration of symptoms prior to presentation predict prolonged hospital LOS in young children with AGE in Northern Ghana.

Clinical Characteristics and Health Outcomes of Neonates Reporting to the Emergency Department With Hypothermia.

OBJECTIVES: Although hypothermia has long been considered a sign of serious bacterial infection (SBI) in neonates, there is a lack of medical literature on this topic, and little is known about the prevalence of serious infection in these patients. Our primary objective was to assess the prevalence and type of serious infection in neonates with hypothermia. Our secondary objective was to describe the prevalence and type of significant pathology overall in this cohort. METHODS: We examined neonates (≤28 days old) evaluated in the emergency department and/or admitted to the hospital with hypothermia over a 3-year period. Demographics and relevant clinical data were extracted from the medical record. Fisher's exact test was used to determine differences in the prevalence of clinical and demographic characteristics in patients with and without a diagnosis of serious infection. RESULTS: Sixty-eight neonates met inclusion criteria, and 63 (93%) were admitted. Of those admitted to the hospital, 5 (7.9%) had a diagnosis of serious infection, including SBI (n = 4) and disseminated herpes simplex virus (n = 1). The types of SBI included urinary tract infection, septicemia, and meningitis. Eighty percent and 60% of neonates with hypothermia and diagnosed with serious infection had a temperature ≤34.4°C and ill appearance, respectively. Significant pathology was found in 9 (14.3%) patients and included both infectious and noninfectious diagnoses. CONCLUSIONS: Neonates presenting with hypothermia have a substantial risk for SBI or other significant pathology. This population merits further investigation; a multicenter prospective study should be conducted to better understand associations between risk factors and outcomes.

Association of Obesity and Pediatric Venous Thromboembolism.

BACKGROUND: The incidence of venous thromboembolism (VTE) is increasing among pediatric patients in the United States. Previous studies on obesity as a risk factor have produced mixed results. METHODS: We completed a retrospective chart review of patients aged 2 to 18 years with VTE identified by using International Classification of Diseases, Ninth Revision, codes and confirmed by imaging. Patients were admitted between January 2000 and September 2012. Control subjects were matched on age, gender, and the presence of a central venous catheter. Data were collected on weight, height, and risk factors, including bacteremia, ICU admission, immobilization, use of oral contraceptives, and malignancy. Underweight patients and those without documented height and weight data were excluded. Independent predictors of VTE risk were identified by using univariate and multivariate analyses. RESULTS: We identified 88 patients plus 2 matched control subjects per case. The majority of cases were nonembolic events (77%) of the lower extremity (25%) or head and neck (22%) confirmed by ultrasound (43%) or computed tomography scan (41%). A statistically significant association was found between VTE and increased BMI z score (P = .002). In multivariate analysis, BMI z score (odds ratio [OR]: 3.1; P = .007), bacteremia (OR: 4.9; P = .02), ICU stay (OR: 2.5; P = .02), and use of oral contraceptives (OR: 17.4; P < .001) were significant predictors. CONCLUSIONS: In this single-institution study, the diagnosis of VTE was significantly associated with overweight and obesity. Further study is needed to fully define this association.

Treatment Outcome of Severe Acute Malnutrition Cases at the Tamale Teaching Hospital.

Objective. This study investigated the treatment outcomes and determinant factors likely to be associated with recovery rate. Methods. A retrospective chart review (RCR) was performed on 348 patients who were enrolled in the outpatient care (OPC) during the study period. Results. Of the 348 cases, 33.6% recovered (having MUAC ≥125 mm), 49.1% defaulted, and 11.5% transferred to other OPC units to continue with treatment. There were 187 (53.7%) males and 161 (46.3%) females with severe malnutrition. The average weight gain rate was 28 g/kg/day. Controlling for other factors, patients who completed the treatment plan had 3.2 times higher probability of recovery from severe acute malnutrition (SAM) as compared to patients who defaulted (adjusted odds ratio (AOR) = 3.2, 95% CI = 1.9, 5.3, and p < 0.001). The children aged 24-59 months had 5.8 times higher probability of recovery from SAM as compared to children aged 6-11 months (AOR = 5.8, 95% CI = 2.5, 10.6, and p < 0.001). Conclusions. Cure rate was low and the default rate was quite high. Children who were diagnosed as having marasmus on admission stayed longer before recovery than their kwashiorkor counterparts. Younger children were of greater risk of nonrecovery.

Association of NPO Status and Type of Nutritional Support on Weight and Length of Stay in Infants Hospitalized With Bronchiolitis.

OBJECTIVES: We investigated the association of nil per os (NPO) status and subsequent nutritional support with patient weight and length of stay (LOS) during admission for bronchiolitis in patients <2 years old. METHODS: A retrospective chart review was performed of all patients <2 years old admitted to an academic pediatric hospital between November 2009 and June 2011 with a Current Procedural Terminology code of bronchiolitis. Data extracted from the medical record included respiratory rate, per os/NPO status, use of intravenous fluids, use of enteral tube feedings, weight, and LOS. Patients who did not have 2 weights recorded were excluded. The major outcome measures were weight change during admission and LOS. RESULTS: The study included 149 patients. The mean ± SD patient age was 3.7 ± 3.8 months, with a median age of 2 months. The median length of stay was 4 days (interquartile range: 3-6). Overall, 16% of patients were made NPO, 75% received intravenous fluids, and 9% received enteral tube feedings. The mean weight loss for all patients was 38 (289) g during the hospitalization, which was not statistically significant. No significant association was found between weight loss and LOS, per os/NPO status, or use of intravenous fluids. However, NPO status was associated with a significant increase in LOS. CONCLUSIONS: The infants admitted for bronchiolitis did not demonstrate weight loss in this study; however, an association was seen between NPO status and prolonged LOS.

Surveillance tracheal aspirate cultures do not reliably predict bacteria cultured at the time of an acute respiratory infection in children with tracheostomy tubes.

BACKGROUND: The aim of this study was to characterize the practice of routinely obtaining tracheal aspirate cultures in children with tracheostomy tubes and to analyze the appropriateness of using this information to guide antibiotic selection for treatment of subsequent lower respiratory infections. METHODS: Pediatric otolaryngologists and pulmonologists were surveyed regarding surveillance culture practices. Records of children with tracheostomy tubes from January 1, 2003, through December 31, 2007, were reviewed. Consecutive cultures were compared for similarity of bacteria and antibiotic sensitivity when a clinic culture preceded a culture from when the child was ill and received antibiotics and when a hospital culture preceded a hospital culture from a separate hospitalization. RESULTS: Seventy-nine of 146 pulmonologists and five of 33 otolaryngologists obtained routine surveillance tracheal aspirate cultures (P < .001); 97% of pulmonologists used these cultures to guide subsequent empiric therapy. There were 36 of 170 children with one or more eligible pairs of cultures. Nearly all children had a change in flora in their tracheal cultures. Limiting empiric antibiotic choices to those that would cover microbes isolated in the previous culture likely would not have been effective in covering one or more microbes isolated in the second culture in 56% of pairs with the first culture from hospitalization vs 30% with the first culture from an outpatient setting (P = .15). CONCLUSIONS: This study demonstrated that there are significant changes in bacteria or antibiotic sensitivity between consecutive tracheal cultures in children with tracheostomy tubes. Use of prior tracheal cultures from these children was of limited value for choosing empiric antibiotic therapy in treating acute lower respiratory exacerbations. Surveillance cultures, thus, are an unnecessary burden and expense of care.

Immunization of young African green monkeys with OprF epitope 8-OprI-type A- and B-flagellin fusion proteins promotes the production of protective antibodies against nonmucoid Pseudomonas aeruginosa.

There is currently no approved vaccine against Pseudomonas aeruginosa, the major cause of morbidity and mortality in cystic fibrosis (CF) patients and a major pathogen in ventilated and burn patients. In a previous study, we demonstrated the immunization of mice with OprF(311-341)-OprI-type A- and B-flagellin fusion proteins dramatically enhanced clearance of nonmucoid P. aeruginosa. The goal of the current study was to evaluate the ability of OprF(311-341)-OprI-flagellins to elicit the production of protective IgG in young (4-6 months old) African green monkeys. Intramuscular immunization of African green monkeys with 1, 3, 10, or 30mug of OprF(311-341)-OprI-flagellins generated robust antigen-specific IgG responses. In addition, immunization with OprF(311-341)-OprI-flagellins elicited high-affinity anti-flagellins, OprI, and OprF IgG that individually promoted extensive deposition of complement component C3 on P. aeruginosa and synergized to facilitate maximal C3 deposition. Passive immunization of mice with plasma from OprF(311-341)-OprI-flagellins immunized monkeys significantly reduced lung bacterial burden three days post-challenge compared to mice that received pre-immunization plasma. Based on our results, OprF(311-341)-OprI-A- and B-flagellin fusion proteins are highly effective in mice and nonhuman primates and thus merit additional development as a potential vaccine for use in humans.

Flagellin-F1-V fusion protein is an effective plague vaccine in mice and two species of nonhuman primates.

A number of studies have clearly demonstrated that flagellin is a potent adjuvant that promotes robust immune responses when it is given with a protein antigen. In view of the potential biological and practical benefits of a recombinant protein vaccine composed of a single fusion protein containing flagellin and antigen, we have evaluated the efficacy of a fusion protein composed of flagellin and two protective antigens of Yersinia pestis (F1 and V) in eliciting protection against respiratory challenge with Y. pestis. Flagellin-F1-V was produced and purified in high yield under good manufacturing practices conditions. The fusion protein retains full Toll-like receptor 5-stimulating activity in vitro. Using a prime-boost immunization protocol, we found that flagellin-F1-V elicits robust antigen-specific humoral immunity in mice and two species of nonhuman primates. Immune mice were fully protected against intranasal challenge with 150 mean tolerated doses of Y. pestis CO92. In immune mice, the bacteria were completely cleared within 3 days after challenge. Flagellin-F1-V exhibited full stability for at least 297 days at 4 degrees C and at least 168 days at 25 degrees C. At between 29 and 84 days at 37 degrees C, the protein exhibited a loss of biological activity that appeared to be associated with a substantial change in protein diameter, possibly due to oligomerization. On the basis of our results, we believe that flagellin-F1-V is an outstanding candidate for evaluation in studies with humans.

PrimaTB STAT-PAK assay, a novel, rapid lateral-flow test for tuberculosis in nonhuman primates.

Tuberculosis (TB) is the most important zoonotic bacterial disease in nonhuman primates (NHP). The current diagnostic method, the intradermal palpebral tuberculin test, has serious shortcomings. We characterized antibody responses in NHP against Mycobacterium tuberculosis to identify immunodominant antigens and develop a rapid serodiagnostic test for TB. A total of 422 NHP were evaluated, including 243 rhesus (Macaca mulatta), 46 cynomolgus (Macaca fascicularis), and 133 African green (Cercopithecus aethiops sabaeus) monkeys at five collaborative centers. Of those, 50 monkeys of the three species were experimentally inoculated with M. tuberculosis. Antibody responses were monitored every 2 to 4 weeks for up to 8 months postinfection by MultiAntigen Print ImmunoAssay with a panel of 12 recombinant antigens. All of the infected monkeys produced antibodies at various levels and with different antigen recognition patterns. ESAT-6 and MPB83 were the most frequently recognized proteins during infection. A combination of selected antigens which detected antibodies in all of the infected monkeys was designed to develop the PrimaTB STAT-PAK assay by lateral-flow technology. Serological evaluation demonstrated high diagnostic sensitivity (90%) and specificity (99%). The highest rate of TB detection was achieved when the skin test was combined with the PrimaTB STAT-PAK kit. This novel immunoassay provides a simple, rapid, and accurate test for TB in NHP.