Invasive Group A Streptococcus Outbreaks Associated with Home Healthcare, England, 2018-2019.

Healthcare-associated invasive group A Streptococcus (iGAS) outbreaks are common worldwide, but only England has reported outbreaks associated with home healthcare (HHC). We describe 10 outbreaks during 2018-2019 in England. A total of 96 iGAS cases (range 2-39 per outbreak) and 28 deaths (case-fatality rate 29%) occurred. Outbreak duration ranged from 3-517 days; median time between sequential cases was 20.5 days (range 1-225 days). Outbreak identification was difficult, but emm typing and whole-genome sequencing improved detection. Network analyses indicated multiple potential transmission routes. Screening of 366 HHC workers from 9 outbreaks identified group A Streptococcus carriage in just 1 worker. Outbreak control required multiple interventions, including improved infection control, equipment decontamination, and antimicrobial prophylaxis for staff. Transmission routes and effective interventions are not yet clear, and iGAS outbreaks likely are underrecognized. To improve patient safety and reduce deaths, public health agencies should be aware of HHC-associated iGAS.

Wildfire Impact on Indoor and Outdoor PAH Air Quality.

Air quality impacts from wildfires are poorly understood, particularly indoors. As frequencies increase, it is important to optimize methodologies to understand and reduce chemical exposures from wildfires. Public health recommendations use air quality estimates from outdoor stationary air monitors, discounting indoor air conditions, and do not consider chemicals in the vapor phase, known to elicit adverse effects. We investigated vapor-phase polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air before, during, and after wildfires using a community-engaged research approach. Paired passive air samplers were deployed at 15 locations across four states. Twelve unique PAHs were detected only in outdoor air during wildfires, highlighting a PAH exposure mixture for future study. Heavy-molecular-weight (HMW) outdoor PAH concentrations and average Air Quality Index (AQI) values were positively correlated (p < 0.001). Indoor PAH concentrations were higher in 77% of samples across all sampling events. Even during wildfires, 58% of sampled locations still had higher indoor PAH air concentrations. When AQI values exceeded 140 (unhealthy for sensitive groups), outdoor PAH concentrations became similar to or higher than indoors. Cancer and noncancer inhalation risk estimates from vapor-phase PAHs were higher indoors than outdoors, regardless of the wildfire impact. Consideration of indoor air quality and vapor-phase PAHs could inform public health recommendations regarding wildfires.

A Candida auris Outbreak and Its Control in an Intensive Care Setting.

BACKGROUND: Candida auris is an emerging and multidrug-resistant pathogen. Here we report the epidemiology of a hospital outbreak of C. auris colonization and infection. METHODS: After identification of a cluster of C. auris infections in the neurosciences intensive care unit (ICU) of the Oxford University Hospitals, United Kingdom, we instituted an intensive patient and environmental screening program and package of interventions. Multivariable logistic regression was used to identify predictors of C. auris colonization and infection. Isolates from patients and from the environment were analyzed by whole-genome sequencing. RESULTS: A total of 70 patients were identified as being colonized or infected with C. auris between February 2, 2015, and August 31, 2017; of these patients, 66 (94%) had been admitted to the neurosciences ICU before diagnosis. Invasive C. auris infections developed in 7 patients. When length of stay in the neurosciences ICU and patient vital signs and laboratory results were controlled for, the predictors of C. auris colonization or infection included the use of reusable skin-surface axillary temperature probes (multivariable odds ratio, 6.80; 95% confidence interval [CI], 2.96 to 15.63; P<0.001) and systemic fluconazole exposure (multivariable odds ratio, 10.34; 95% CI, 1.64 to 65.18; P=0.01). C. auris was rarely detected in the general environment. However, it was detected in isolates from reusable equipment, including multiple axillary skin-surface temperature probes. Despite a bundle of infection-control interventions, the incidence of new cases was reduced only after removal of the temperature probes. All outbreak sequences formed a single genetic cluster within the C. auris South African clade. The sequenced isolates from reusable equipment were genetically related to isolates from the patients. CONCLUSIONS: The transmission of C. auris in this hospital outbreak was found to be linked to reusable axillary temperature probes, indicating that this emerging pathogen can persist in the environment and be transmitted in health care settings. (Funded by the National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at Oxford University and others.).

A pseudo-outbreak of Rhinocladiella similis in a bronchoscopy unit of a tertiary care teaching hospital in London, United Kingdom.

Outbreaks of fungal infections due to emerging and rare species are increasingly reported in healthcare settings. We investigated a pseudo-outbreak of Rhinocladiella similis in a bronchoscopy unit of a tertiary care teaching hospital in London, UK. We aimed to determine route of healthcare-associated transmission and prevent additional infections. From July 2018 through February 2019, we detected a pseudo-outbreak of R. similis isolated from bronchoalveolar lavage (BAL) fluid samples collected from nine patients who had undergone bronchoscopy in a multispecialty teaching hospital, during a period of 8 months. Isolates were identified by MALDI-TOF mass spectrometry. Antifungal susceptibility testing was performed by EUCAST broth microdilution. To determine genetic relatedness among R. similis isolates, we undertook amplified fragment length polymorphism analysis. To determine the potential source of contamination, an epidemiological investigation was carried out. We reviewed patient records retrospectively and audited steps taken during bronchoscopy as well as the subsequent cleaning and decontamination procedures. Fungal cultures were performed on samples collected from bronchoscopes and automated endoscope washer-disinfector systems. No patient was found to have an infection due to R. similis either before or after bronchoscopy. One bronchoscope was identified to be used among all affected patients with positive fungal cultures. Physical damage was found in the index bronchoscope; however, no fungus was recovered after sampling of the affected scope or the rinse water of automated endoscope washer-disinfectors. Use of the scope was halted, and, during the following 12-month period, Rhinocladiella species were not isolated from any BAL specimen. All pseudo-outbreak isolates were identified as R. similis with high genetic relatedness (>90% similarity) on ALFP analysis. The study emphasises the emergence of a rare and uncommon black yeast R. similis, with reduced susceptibility to echinocandins, in a bronchoscope-related pseudo-outbreak with a potential water-related reservoir. Our findings highlight the importance of prolonged fungal culture and species-level identification of melanised yeasts isolated from bronchoscopy samples. Possibility of healthcare-associated transmission should be considered when R. similis is involved in clinical microbiology samples.

Serial Clustering of Late-Onset Group B Streptococcal Infections in the Neonatal Unit: A Genomic Re-evaluation of Causality.

Background: Invasive Group B streptococcus (GBS) is a major cause of serious neonatal infection. Current strategies to reduce early-onset GBS disease have no impact on late-onset disease (LOD). Although GBS LOD is viewed as a sporadic event in the community, LOD arising within the neonatal intensive care unit (ICU) raises questions about mode of acquisition. Methods: Following a cluster of 4 GBS LOD cases, enhanced surveillance for all GBS LOD was undertaken over 2 years in the neonatal ICU supported by neonatal rectal screening. GBS isolates were serotyped and genome-sequenced. Results: Twelve late -onset invasive GBS episodes were identified (incidence 0.6/1000 live births). Genomic analysis revealed that 11/12 GBS isolates (92%) were linked to at least one other LOD isolate. Isolates from the first cluster were serotype V, resistant to macrolides and lincosamides, and sequencing confirmed isolates were indistinguishable, or distinguishable by only one SNP difference, from each other. Rectal carriage was rare. Prospective surveillance identified three further clusters of LOD due to serotypes Ia (3 cases), Ib (2 cases), and III (2 cases), that would not have been identified without surveillance and genome sequencing, leading to a re-evaluation of interventions required to prevent GBS LOD. Conclusion: Acquisition routes for LOD GBS in the neonatal ICU are poorly understood; cases may not necessarily be sporadic. Within this neonatal ICU, our data suggest that a single case of LOD GBS sepsis should be considered a potential nosocomial transmission event warranting prompt investigation, heightened infection prevention vigilance and action where required.

National outbreak of Pseudomonas aeruginosa associated with an aftercare solution following piercings, July to September 2016, England.

We report a national Pseudomonas aeruginosa outbreak from a common source following piercings between July and September 2016 in England. The multi-agency outbreak investigation included active case finding, microbiological testing of environmental samples and case specimens including Variable Number Tandem Repeat (VNTR) typing and a retrospective cohort study. Overall, 162 outbreak cases (29 confirmed, 14 probable and 119 possible) and 14 non-outbreak cases were identified; all confirmed cases had ear piercings (93% cartilage). Outbreak cases were predominantly female (95%) and had a median age of 18 years (interquartile range: 13-56 years). Nineteen outbreak cases required surgery under general anaesthetic The same outbreak VNTR type (11,3,5,3,3,3,6,4,7) was isolated from bottles of an aftercare solution from a single manufacturer and in specimens from confirmed cases who attended eight different piercing studios supplied with this product. In the cohort study, use of aftercare solution was associated with becoming a case (aOR: 4.60, 95% confidence interval: 1.65-12.90). Environmental, microbiological and epidemiological investigations confirmed that contamination during production of aftercare solution was the source of this national outbreak; highlighting challenges in the regulation of a cosmetic products used in the piercing industry and that guidance on piercing aftercare may need to be reviewed.

Insidious Risk of Severe Mycobacterium chimaera Infection in Cardiac Surgery Patients.

BACKGROUND: An urgent UK investigation was launched to assess risk of invasive Mycobacterium chimaera infection in cardiothoracic surgery and a possible association with cardiopulmonary bypass heater-cooler units following alerts in Switzerland and The Netherlands. METHODS: Parallel investigations were pursued: (1) identification of cardiopulmonary bypass-associated M. chimaera infection through national laboratory and hospital admissions data linkage; (2) cohort study to assess patient risk; (3) microbiological and aerobiological investigations of heater-coolers in situ and under controlled laboratory conditions; and (4) whole-genome sequencing of clinical and environmental isolates. RESULTS: Eighteen probable cases of cardiopulmonary bypass-associated M. chimaera infection were identified; all except one occurred in adults. Patients had undergone valve replacement in 11 hospitals between 2007 and 2015, a median of 19 months prior to onset (range, 3 months to 5 years). Risk to patients increased after 2010 from <0.2 to 1.65 per 10000 person-years in 2013, a 9-fold rise for infections within 2 years of surgery (rate ratio, 9.08 [95% CI, 1.81-87.76]). Endocarditis was the most common presentation (n = 11). To date, 9 patients have died. Investigations identified aerosol release through breaches in heater-cooler tanks. Mycobacterium chimaera and other pathogens were recovered from water and air samples. Phylogenetic analysis found close clustering of strains from probable cases. CONCLUSIONS: We identified low but escalating risk of severe M. chimaera infection associated with heater-coolers with cases in a quarter of cardiothoracic centers. Our investigations strengthen etiological evidence for the role of heater-coolers in transmission and raise the possibility of an ongoing, international point-source outbreak. Active management of heater-coolers and heightened clinical awareness are imperative given the consequences of infection.

Elevational differences in trait response to UV-B radiation by long-toed salamander populations.

Amphibian species capable of optimizing trait response to environmental stressors may develop complex strategies for defending against rapid environmental change. Trait responses may differ between populations, particularly if stressor strength varies across spatial or temporal gradients. Ultraviolet-B (UV-B) radiation is one such stressor that poses a significant threat to amphibian species. We examined the ability of long-toed salamanders (Ambystoma macrodactylum) at high- and low-elevation breeding sites to cooperatively employ behavioral and physiological trait responses to mediate UV-B damage. We performed a microhabitat survey to examine differences in oviposition behavior and UV-B conditions among breeding populations at high- (n = 3; >1,500 m) and low-elevation (n = 3; <100 m) sites. We found significant differences in oviposition behavior across populations, with females at high-elevation sites selecting oviposition substrates in UV-B protected microhabitats. We also collected eggs (n = 633) from each of the breeding sites for analysis of photolyase activity, a photoreactivating enzyme that repairs UV-B damage to the DNA, using a photoproduct immunoassay. Our results revealed no significant differences in photolyase activity between long-toed salamander populations at high and low elevations. For high-elevation salamander populations, relatively low physiological repair capabilities in embryos appear to be buffered by extensive behavioral modifications to reduce UV-B exposure and standardize developmental temperatures. This study provides valuable insight into environmental stress responses via the assessment of multiple traits in allowing sensitive species to persist in rapidly changing landscapes.

Inhibition of 12/15 lipoxygenase by curcumin and an extract from Curcuma longa L.

Curcumin (diferuloylmethane) is an orange-yellow secondary metabolic compound from the rhizome of turmeric (Curcuma longa L.), a spice often found in curry powder. It is one of the major curcuminoids of turmeric. For centuries, curcumin has been used in some medicinal preparations or as a food colouring agent. A variety of enzymes that are closely associated with inflammation and cancer were found to be modulated by curcumin. This paper summarized the results of the inhibitory effect of curcumin and a Curcuma longa L. ethanolic extract on lipoxygenase from the rat lung cytosolic fraction. The positional specificity determination of arachidonic acid dioxygenation by RP- and SP-HPLC methods showed that in a purified enzyme preparation from the rat lung cytosol the specific form of lipoxygenase (LOX) is present exhibiting 12/15-LOX dual specificity (with predominant 15-LOX activity). The inhibitory activity of curcumin and Curcuma longa extract on LOX from cytosolic fraction of rat lung was expressed in the percentage of inhibition and as IC50. Lineweaver-Burk plot analysis has indicated that curcumin is the competitive inhibitor of 12/15 LOX from the rat lung cytosolic fraction.

Concurrent assessment of diffusive and advective PAH movement strongly affected by temporal and spatial changes.

Chemical movement influences exposure, remediation and interventions. Understanding chemical movement in addition to chemical concentrations at contaminated sites is critical to informed decision making. Using seepage meters and passive sampling devices we assessed both diffusive and advective flux of bioavailable polycyclic aromatic hydrocarbons (PAHs) at three time points, across two seasons, at a former creosote site in St. Helens, Oregon, United States. To our knowledge, this is the first time both diffusive and advective fluxes have been measured simultaneously at a contaminated site. Concentrations of 39 parent PAHs were determined by gas chromatography triple quadrupole mass spectrometry. Across both seasons and all sites, diffusive flux of PAHs was up to three orders of magnitude larger than advective flux. Release of PAHs from sediments and water were identified, likely from legacy contamination, as well as deposition from the air into the site from contemporary and other sources. The majority of PAH movement was comprised of three and four ring PAHs. Chemical movement on the site was found to be spatially and temporally variable. Volatilization decreased and atmospheric deposition increased from summer to fall. At the locations with higher levels of contamination, sum PAH release from sediments decreased by more than two orders of magnitude from summer to late fall. These data reflect the spatial heterogeneity and temporal variability of this site and demonstrate the importance of seasonality in assessing chemical movement at contaminated sites. Results from this study can inform future legacy site assessments to optimize remediation strategies and assess remediation effectiveness.

Chemical contaminant exposures assessed using silicone wristbands among fuel station attendants, taxi drivers and commercial motorcycle riders in Kampala, Uganda.

There are concerns over traffic-related air pollution in Uganda's capital, Kampala. Individuals in the transportation sector are hypothesized to be at greater risk for exposure to volatile organic compounds, given their proximity to vehicle exhaust. Silicone wristbands are a wearable technology that passively sample individuals' chemical exposures. We conducted a pilot cross sectional study to measure personal exposures to volatile organic compounds among 14 transportation workers who wore a wristband for five days. We analyzed for 75 volatile organic compounds; 33 chemicals (35%) were detected and quantified in at least 50% of the samples and 15 (16%) chemicals were detected and quantified across all the samples. Specific chemicals were associated with participants' occupation. The findings can guide future large studies to inform policy and practice to reduce exposure to chemicals in the environment in Kampala.

The Superfund Research Program Analytics Portal: linking environmental chemical exposure to biological phenotypes.

The OSU/PNNL Superfund Research Program (SRP) represents a longstanding collaboration to quantify Polycyclic Aromatic Hydrocarbons (PAHs) at various superfund sites in the Pacific Northwest and assess their potential impact on human health. To link the chemical measurements to biological activity, we describe the use of the zebrafish as a high-throughput developmental toxicity model that provides quantitative measurements of the exposure to chemicals. Toward this end, we have linked over 150 PAHs found at Superfund sites to the effect of these same chemicals in zebrafish, creating a rich dataset that links environmental exposure to biological response. To quantify this response, we have implemented a dose-response modelling pipeline to calculate benchmark dose parameters which enable potency comparison across over 500 chemicals and 12 of the phenotypes measured in zebrafish. We provide a rich dataset for download and analysis as well as a web portal that provides public access to this dataset via an interactive web site designed to support exploration and re-use of these data by the scientific community at http://srp.pnnl.gov .

Reversion-reporter transgenes to analyze all six base-substitution pathways in Arabidopsis.

To expand the repertoire of Arabidopsis (Arabidopsis thaliana) mutation-reporter transgenes, we constructed six mutant alleles in the same codon of the ß-glucuronidase-encoding GUS transgene. Each allele reverts to GUS+ only via a particular one of the six transition/transversion pathways. AcV5 epitope tags, fused carboxyl terminal to the inactive GUS- proteins, enabled semiquantitative immunoassays in plant protein extracts. Spontaneous G:C→T:A transversions, previously not measured using reporter transgenes, were quite frequent. This may reflect mispairing of adenine with 8-oxoguanine in DNA attacked by endogenous oxyradicals. Spontaneous G:C→A:T was modest and other reversions were relatively low, as reported previously. Frequencies of ultraviolet C-induced TT→TC and TC→TT reversions were both high. With increased transgene copy number, spontaneous G:C→T:A reversions increased but ultraviolet C-induced reversions decreased. Frequencies of some reversion events were reduced among T4 versus T3 generation plants. Based on these and other analyses of sources of experimental variation, we propose guidelines for the employment of these lines to study genotoxic stress in planta.

New pharmaceutical insights related to the pathways of PUFAs.

The fatty acyl structure represents the major lipid building block of practically all lipids and therefore is one of the most fundamental categories of these molecules. Fatty acids (FAs) differ particularly in their chain length, number of double bonds and position of the bonds in the chain. The number of double bonds in the unsaturated molecule of FA distinguishes monounsaturated FAs (MUFAs) and polyunsaturated FAs (PUFAs). In the living cell PUFAs represent the dominant substrates for the formation of biologically active compounds--octadecanoids, eicosanoids and docosanoids--classified as oxylipins or as PUFAnoids. The present review focuses only on the groups of PUFAnoids which biological activities comprise a "positive effect" for the cell. This group of omega-3 PUFAnoids consists of lipoxins, resolvins and protectins. All these biologically active lipids are formed mainly in the LOX-pathway. They are part of the cell mechanisms that contribute to the removal of inflammatory cells and restoration of tissue integrity. A new approach to an optimal anti-inflammatory model shows orientation to the dual COX/LOX-inhibition and the stimulation of the protective eicosanoids and docosanoids formation and its considerable therapeutic potential in managing of molecular mechanisms of chronic inflammatory processes.

[Identification of lipoxygenase expressing omega-6 dioxygenase activity by means of liquid chromatography]. / Identifikácia lipoxygenázy s omega-6 dioxygenázovou aktivitou kvapalinovou chromatografiou.

Lipoxygenases (LOX) represent a family of lipid peroxidising enzymes which catalyse the reaction of achiral polyunsaturated fatty acids by oxygen forming chiral peroxide products possessing high positional stereospecific purity. The four double bonds of arachidonic acid, the main substrate of animal LOX, present the position for a wide range of enzymatic modifications enabling eicosanoid creation, unique molecules with biological significance. In this study, lipoxygenase from rat lung cytoplasma was isolated and purified to 40-fold by combining hydrophobic and gel chromatography. The forming positional specific fatty acid hydroxyl-isomers were separated on a nonpolar system (RP-HPLC) and identified on a polar adsorbent (SP-HPLC). In the purified enzyme, dual positional specificity was demonstrated by the production of 12- and 15-HETE in the ratio of 1,0:1,38, which responds to the product spectrum of mammalian 15-LOX-1.

Associating Increased Chemical Exposure to Hurricane Harvey in a Longitudinal Panel Using Silicone Wristbands.

Hurricane Harvey was associated with flood-related damage to chemical plants and oil refineries, and the flooding of hazardous waste sites, including 13 Superfund sites. As clean-up efforts began, concerns were raised regarding the human health impact of possible increased chemical exposure resulting from the hurricane and subsequent flooding. Personal sampling devices in the form of silicone wristbands were deployed to a longitudinal panel of individuals (n = 99) within 45 days of the hurricane and again one year later in the Houston metropolitan area. Using gas chromatography−mass spectroscopy, each wristband was screened for 1500 chemicals and analyzed for 63 polycyclic aromatic hydrocarbons (PAHs). Chemical exposure levels found on the wristbands were generally higher post-Hurricane Harvey. In the 1500 screen, 188 chemicals were detected, 29 were detected in at least 30% of the study population, and of those, 79% (n = 23) were found in significantly higher concentrations (p < 0.05) post-Hurricane Harvey. Similarly, in PAH analysis, 51 chemicals were detected, 31 were detected in at least 30% of the study population, and 39% (n = 12) were found at statistically higher concentrations (p < 0.05) post-Hurricane Harvey. This study indicates that there were increased levels of chemical exposure after Hurricane Harvey in the Houston metropolitan area.

Preschool-Age Children's Pesticide Exposures in Child Care Centers and at Home in Northern California.

INTRODUCTION: Young children may be exposed to pesticides used in child care centers and their family homes. We examined pesticide use and environmental and behavioral factors potentially associated with child exposures in these settings. METHOD: Preschool-age children (n = 125) wore silicone wristbands to assess pesticide exposures in their child care centers and home environments. Information about environmental and behavioral exposure determinants was collected using parent surveys, child care director interviews, and observations. RESULTS: Commonly detected pesticides were bifenthrin, chlorpyrifos, cypermethrin, fipronil, and cis- and trans-permethrin. Pesticide chemical storage onsite, cracks in the walls, using doormats, observed pests, or evidence of pests were associated with child exposures. Exposures were higher in counties with higher agricultural or commercial pesticide use or when children lived in homes near agricultural fields. DISCUSSION: Young children are being exposed to harmful pesticides, and interventions are needed to lower their risk of health problems later in life.

Designing Equitable, Transparent Community-Engaged Disaster Research.

Disaster research faces significant infrastructure challenges: regional and federal coordination, access to resources, and community collaboration. Disasters can lead to chemical exposures that potentially impact human health and cause concern in affected communities. Community-engaged research, which incorporates local knowledge and voices, is well-suited for work with communities that experience impacts of environmental exposures following disasters. We present three examples of community-engaged disaster research (CEnDR) following oil spills, hurricanes, and wildfires, and their impact on long-term social, physical, and technical community infrastructure. We highlight the following CEnDR structures: researcher/community networks; convenient research tools; adaptable data collection modalities for equitable access; and return of data.

Frequency of transmission, asymptomatic shedding, and airborne spread of Streptococcus pyogenes in schoolchildren exposed to scarlet fever: a prospective, longitudinal, multicohort, molecular epidemiological, contact-tracing study in England, UK.

BACKGROUND: Despite recommendations regarding prompt treatment of cases and enhanced hygiene measures, scarlet fever outbreaks increased in England between 2014 and 2018. We aimed to assess the effects of standard interventions on transmission of Streptococcus pyogenes to classroom contacts, households, and classroom environments to inform future guidance. METHODS: We did a prospective, longitudinal, multicohort, molecular epidemiological, contact-tracing study in six settings across five schools in Greater London, UK. Schools and nurseries were eligible to participate if they had reported two cases of scarlet fever within 10 days of each other among children aged 2-8 years from the same class, with the most recent case arising in the preceding 48 h. We cultured throat swabs from children with scarlet fever, classroom contacts, and household contacts at four timepoints. We also cultured hand swabs and cough plates from all cases in years 1 and 2 of the study, and from classroom contacts in year 2. Surface swabs from toys and other fomites in classrooms were cultured in year 1, and settle plates from classrooms were collected in year 2. Any sample with S pyogenes detected was recorded as positive and underwent emm genotyping and genome sequencing to compare with the outbreak strain. FINDINGS: Six classes, comprising 12 cases of scarlet fever, 17 household contacts, and 278 classroom contacts were recruited between March 1 and May 31, 2018 (year 1), and between March 1 and May 31, 2019 (year 2). Asymptomatic throat carriage of the outbreak strains increased from 11 (10%) of 115 swabbed children in week 1, to 34 (27%) of 126 in week 2, to 26 (24%) of 108 in week 3, and then five (14%) of 35 in week 4. Compared with carriage of outbreak S pyogenes strains, colonisation with non-outbreak and non-genotyped S pyogenes strains occurred in two (2%) of 115 swabbed children in week 1, five (4%) of 126 in week 2, six (6%) of 108 in week 3, and in none of the 35 children in week 4 (median carriage for entire study 2·8% [IQR 0·0-6·6]). Genome sequencing showed clonality of outbreak isolates within each of six classes, confirming that recent transmission accounted for high carriage. When transmissibility was tested, one (9%) of 11 asymptomatic carriers of emm4 and five (36%) of 14 asymptomatic carriers of emm3.93 had a positive cough plate. The outbreak strain was identified in only one (2%) of 60 surface swabs taken from three classrooms; however, in the two classrooms with settle plates placed in elevated locations, two (17%) of 12 and six (50%) of 12 settle plates yielded the outbreak strain. INTERPRETATION: Transmission of S pyogenes in schools is intense and might occur before or despite reported treatment of cases, underlining a need for rapid case management. Despite guideline adherence, heavy shedding of S pyogenes by few classroom contacts might perpetuate outbreaks, and airborne transmission has a plausible role in its spread. These findings highlight the need for research to improve understanding and to assess effectiveness of interventions to reduce airborne transmission of S pyogenes. FUNDING: Action Medical Research, UK Research Innovation, and National Institute for Health Research.

Firefighter exposures to potential endocrine disrupting chemicals measured by military-style silicone dog tags.

Studies suggest that exposure to potential endocrine disrupting chemicals (pEDCs) may contribute to adverse health outcomes, but pEDC exposures among firefighters have not been fully characterized. Previously, we demonstrated the military-style silicone dog tag as a personal passive sampling device for assessing polycyclic aromatic hydrocarbon exposures among structural firefighters. This follow-up analysis examined the pEDC exposures based on department call volume, duty shift, and questionnaire variables. Structural firefighters (n = 56) were from one high and one low fire call volume department (Kansas City, MO metropolitan area) and wore separate dog tags while on- and off-duty (ndogtags = 110). The targeted 1530 analyte semi-quantitative screening method was conducted using gas chromatography mass spectrometry (npEDCs = 433). A total of 47 pEDCs were detected, and several less-frequently-detected pEDCs (<75%) were more commonly detected in off- compared to on-duty dog tags (conditional logistic regression). Of the 11 phthalates and fragrances detected most frequently (>75%), off-duty pEDC concentrations were strongly correlated (r = 0.31-0.82, p < 0.05), suggesting co-applications of phthalates and fragrances in consumer products. Questionnaire variables of "regular use of conventional cleaning products" and "fireplace in the home" were associated with select elevated pEDC concentrations by duty shift (paired t-test). This suggested researchers should include detailed questions about consumer product use and home environment when examining personal pEDC exposures.