Determination of Serum Antibody to Bordetella pertussis Adenylate Cyclase Toxin in Vaccinated and Unvaccinated Children and in Children and Adults with Pertussis

Presence of antibody to adenylate cyclase toxin (ACT) has been noted following Bordetella pertussis infection. Because ACT is not presently in any acellular pertussis vaccines, it has been considered as a possible antigen to use in B. pertussis diagnostic enzyme-linked immunosorbent assay (ELISA) studies. We determined antibody to B. pertussis ACT by ELISA and Western blot tests in serum samples obtained from unvaccinated children, from children vaccinated with several diphtheria and tetanus toxoid vaccines (DTP vaccines), from children vaccinated with vaccines containing acellular pertussis components in combination with diphtheria and tetanus toxoids (DTaP vaccines), and from children and adults with pertussis. Primary infections with either B. pertussis or Bordetella parapertussis stimulated a vigorous antibody response to ACT. In contrast, patients in whom DTP and DTaP vaccines failed had minimal ACT antibody responses. The lack of a significant ACT antibody response in children in whom the vaccine failed is of interest but would seem to preclude the use of ACT in diagnostic test

Photochemistry of 2-butenedial and 4-oxo-2-pentenal under atmospheric boundary layer conditions

Unsaturated 1,4-dicarbonyl compounds, such as 2-butenedial and 4-oxo-2-pentenal are produced in the atmospheric boundary layer from the oxidation of aromatic compounds and furans. These species are expected to undergo rapid photochemical processing, affecting atmospheric composition. In this study, the photochemistry of (E)-2-butenedial and both E and Z isomers of 4-oxo-2- pentenal was investigated under natural sunlight conditions at the large outdoor atmospheric simulation chamber EUPHORE. Photochemical loss rates, relative to j(NO2), are determined to be j((E)-2-butenedial)/j(NO2) = 0.14 (0.02), j((E)-4-oxo-2-pentenal)/j(NO2) = 0.18 (0.01), and j((Z)-4-oxo-2-pentenal)/j(NO2) = 0.20 (0.03). The major products detected for both species are a furanone (30 – 42%) and, for (E)-2-butenedial, maleic anhydride (2,5-furandione) (12 – 14%). The mechanism appears to proceed predominantly via photoisomerization to a ketene- enol species following -H abstraction. The lifetimes of the ketene-enol species in the dark from 2-butenedial and 4-oxo-2-pentenal are determined to be 465 s and 235 s, respectively. The ketene-enol can undergo ring closure to yield the corresponding furanone, or further unimolecular rearrangement which can subsequently form maleic anhydride. A minor channel (10 – 15%) also appears to form CO directly. This is presumed to be via a molecular elimination route of an initial biradical intermediate formed in photolysis, with an unsaturated carbonyl (detected here but not quantified) as co-product. -dicarbonyl and radical yields are very low, which has implications for ozone production from the photo-oxidation of unsaturated 1,4-dicarbonyls in the boundary layer. Photochemical removal is determined to be the major loss process for these species in the boundary layer with lifetimes of the order of 10 – 15 minutes, compared to > 3 hours for reaction with OH

Estimation of rate coefficients for the reactions of O3 with unsaturated organic compounds for use in automated mechanism construction

Reaction with ozone (O3) is an important removal process for unsaturated volatile organic compounds (VOCs) in the atmosphere. Rate coefficients for reactions of 3with VOCs are therefore essential parameters for chemical mechanisms used in chemistry transport models. Updated and extended structure-activity relationship (SAR) methods are presented for the reactions of O3 with mono- and polyunsaturated organic compounds. The methods are optimized using a preferred set of data including reactions of O3 with 221 unsaturated compounds. For conjugated dialkene structures, site-specific rates are defined, and for isolated polyalkenes rates are defined for each double bond to determine the branching ratios for primary ozonide formation. The information can therefore guide the representation of the O3 reactions in the next generation of explicit detailed chemical mechanisms

Association of inappropriate outpatient pediatric antibiotic prescriptions with adverse drug events and health care expenditures

Importance: Nonguideline antibiotic prescribing for the treatment of pediatric infections is common, but the consequences of inappropriate antibiotics are not well described. Objective: To evaluate the comparative safety and health care expenditures of inappropriate vs appropriate oral antibiotic prescriptions for common outpatient pediatric infections. Design, Setting, and Participants: This cohort study included children aged 6 months to 17 years diagnosed with a bacterial infection (suppurative otitis media [OM], pharyngitis, sinusitis) or viral infection (influenza, viral upper respiratory infection [URI], bronchiolitis, bronchitis, nonsuppurative OM) as an outpatient from April 1, 2016, to September 30, 2018, in the IBM MarketScan Commercial Database. Data were analyzed from August to November 2021. Exposures: Inappropriate (ie, non-guideline-recommended) vs appropriate (ie, guideline-recommended) oral antibiotic agents dispensed from an outpatient pharmacy on the date of infection. Main Outcomes and Measures: Propensity score-weighted Cox proportional hazards models were used to estimate hazards ratios (HRs) and 95% CIs for the association between inappropriate antibiotic prescriptions and adverse drug events. Two-part models were used to calculate 30-day all-cause attributable health care expenditures by infection type. National-level annual attributable expenditures were calculated by scaling attributable expenditures in the study cohort to the national employer-sponsored insurance population. Results: The cohort included 2 804 245 eligible children (52% male; median [IQR] age, 8 [4-12] years). Overall, 31% to 36% received inappropriate antibiotics for bacterial infections and 4% to 70% for viral infections. Inappropriate antibiotics were associated with increased risk of several adverse drug events, including Clostridioides difficile infection and severe allergic reaction among children treated with a nonrecommended antibiotic agent for a bacterial infection (among patients with suppurative OM, C. difficile infection: HR, 6.23; 95% CI, 2.24-17.32; allergic reaction: HR, 4.14; 95% CI, 2.48-6.92). Thirty-day attributable health care expenditures were generally higher among children who received inappropriate antibiotics, ranging from $21 to$56 for bacterial infections and from -$96 to$97 for viral infections. National annual attributable expenditure estimates were highest for suppurative OM ($25.3 million), pharyngitis ($21.3 million), and viral URI ($19.1 million). Conclusions and Relevance: In this cohort study of children with common infections treated in an outpatient setting, inappropriate antibiotic prescriptions were common and associated with increased risks of adverse drug events and higher attributable health care expenditures. These findings highlight the individual- and national-level consequences of inappropriate antibiotic prescribing and further support implementation of outpatient antibiotic stewardship programs

Experiences from the Missouri Antimicrobial Stewardship Collaborative: A mixed methods study

We performed a mixed-methods study to evaluate antimicrobial stewardship program (ASP) uptake and to assess variability of program implementation in Missouri hospitals. Despite increasing uptake of ASPs in Missouri, there is wide variability in both the scope and sophistication of these programs

AtChem (version 1), an open-source box model for the Master Chemical Mechanism

AtChem is an open-source zero-dimensional box model for atmospheric chemistry. Any general set of chemical reactions can be used with AtChem, but the model was designed specifically for use with the Master Chemical Mechanism (MCM, http://mcm.york.ac.uk/, last access: 16 January 2020). AtChem was initially developed within the EUROCHAMP project as a web application (AtChem-online, https://atchem.leeds.ac.uk/webapp/, last access: 16 January 2020) for modelling environmental chamber experiments; it was recently upgraded and further developed into a stand-alone offline version (AtChem2), which allows the user to run complex and long simulations, such as those needed for modelling of intensive field campaigns, as well as to perform batch model runs for sensitivity studies. AtChem is installed, set up and configured using semi-automated scripts and simple text configuration files, making it easy to use even for inexperienced users. A key feature of AtChem is that it can easily be constrained to observational data which may have different timescales, thus retaining all the information contained in the observations. Implementation of a continuous integration workflow, coupled with a comprehensive suite of tests and version control software, makes the AtChem code base robust, reliable and traceable. The AtChem2 code and documentation are available at https://github.com/AtChem/ (last access: 16 January 2020) under the open-source MIT License