The drinking water crises of Flint and Havelock North: a failure of public health risk management.

Between 2014 and 2016, there were two severe community water system (CWS) failures in Flint, Michigan (MI), USA and Havelock North, Hawkes Bay, New Zealand. These events had profound implications for public health in their respective countries. While the nature of both crises was different, certain aspects of the failings were strikingly similar. These included: failure of authorities to protect the integrity of their source water, 'wait-and-see approach' to address problems if and when they occurred, negligent approach to regulatory oversight and responsibility, substandard facilities and lack of knowledge and training of staff, failure of consultants and advisory services engaged by suppliers, and failure of government agencies to enforce regulations. The lessons from both incidents must be learned, or similar tragic events are likely to reoccur. The six principles identified in the Government Inquiry into the Havelock North outbreak are an essential first step. The next step is to implement them throughout the drinking water sector.

Prevalence of ICU Delirium in Postoperative Pediatric Cardiac Surgery Patients.

OBJECTIVES: The objective of this study was to determine the prevalence of ICU delirium in children less than 18 years old that underwent cardiac surgery within the last 30 days. The secondary aim of the study was to identify risk factors associated with ICU delirium in postoperative pediatric cardiac surgical patients. DESIGN: A 1-day, multicenter point-prevalence study of delirium in pediatric postoperative cardiac surgery patients. SETTING: Twenty-seven pediatric cardiac and general critical care units caring for postoperative pediatric cardiac surgery patients in North America. PATIENTS: All children less than 18 years old hospitalized in the cardiac critical care units at 06:00 on a randomly selected, study day. INTERVENTIONS: Eligible children were screened for delirium using the Cornell Assessment of Pediatric Delirium by the study team in collaboration with the bedside nurse. MEASUREMENT AND MAIN RESULTS: Overall, 181 patients were enrolled and 40% (n = 73) screened positive for delirium. There were no statistically significant differences in patient demographic information, severity of defect or surgical procedure, past medical history, or postoperative day between patients screening positive or negative for delirium. Our bivariate analysis found those patients screening positive had a longer duration of mechanical ventilation (12.8 vs 5.1 d; p = 0.02); required more vasoactive support (55% vs 26%; p = 0.0009); and had a higher number of invasive catheters (4 vs 3 catheters; p = 0.001). Delirium-positive patients received more total opioid exposure (1.80 vs 0.36 mg/kg/d of morphine equivalents; p < 0.001), did not have an ambulation or physical therapy schedule (p = 0.02), had not been out of bed in the previous 24 hours (p < 0.0002), and parents were not at the bedside at time of data collection (p = 0.008). In the mixed-effects logistic regression analysis of modifiable risk factors, the following variables were associated with a positive delirium screen: 1) pain score, per point increase (odds ratio, 1.3; 1.06-1.60); 2) total opioid exposure, per mg/kg/d increase (odds ratio, 1.35; 1.06-1.73); 3) SBS less than 0 (odds ratio, 4.01; 1.21-13.27); 4) pain medication or sedative administered in the previous 4 hours (odds ratio, 3.49; 1.32-9.28); 5) no progressive physical therapy or ambulation schedule in their medical record (odds ratio, 4.40; 1.41-13.68); and 6) parents not at bedside at time of data collection (odds ratio, 2.31; 1.01-5.31). CONCLUSIONS: We found delirium to be a common problem after cardiac surgery with several important modifiable risk factors.

Building Capacity for Evidence-Based Practice Together.

Social workers are increasingly called to implement evidence-based practices and systematically evaluate efficacy. As healthcare reform magnifies these mandates for a growing population of service users, social work educators are positioned to play important roles in helping organizations build capacity for this work. This article presents two examples of faculty members successfully filling this role; one developed a teaching model for evidence-based practice that synchronized classroom and field continuing education, and the other linked curricular goals with an agency's need for program evaluation. The success of these initiatives identifies opportunities for educators to meet growing needs in health services.

Conservative Management of Dental Caries Using Silver Nitrate and Atraumatic Restorative Treatment in Remote Rural Setting.

Managing dental caries remains a challenge to clinicians­more so when treating caries in remote, underserved areas of the world. The purpose of this article is to report preliminary results of an effort to reduce to practice the best features of silver nitrate (SN) anti-caries effect and atraumatic restorative treatment (ART) for lesion preparation and restoration. The modifications made to two approaches have practical applications to school-based outreach programs hoping to respond to the dire need for preventive and conservative restorative methods in parts of the world where access to the dental office is unobtainable.

Streptococcus mutans Displays Altered Stress Responses While Enhancing Biofilm Formation by Lactobacillus casei in Mixed-Species Consortium.

Like Streptococcus mutans, lactobacilli are commonly isolated from carious sites, although their exact role in caries development remains unclear. This study used mixed-species models to analyze biofilm formation by major groups of oral lactobacilli, including L. casei, L. fermentum, L. rhamnosus, L. salivarius ssp. salivarius, and L. gasseri. The results showed that lactobacilli did not form good biofilms when grown alone, although differences existed between different species. When grown together with S. mutans, biofilm formation by L. gasseri and L. rhamnosus was increased by 2-log (P < 0.001), while biofilms by L. fermentum reduced by >1-log (P < 0.001). L. casei enhanced biofilm formation by ~2-log when grown with S. mutans wild-type, but no such effects were observed with S. mutans deficient of glucosyltransferase GtfB and adhesin P1. Both S. mutans and L. casei in dual-species enhanced resistance to acid killing with increases of survival rate by >1-log (P < 0.001), but drastically reduced the survival rates following exposure to hydrogen peroxide (P < 0.001), as compared to the respective mono-species cultures. When analyzed by RNA-seq, more than 134 genes were identified in S. mutans in dual-species with L. casei as either up- or down-regulated when compared to those grown alone. The up-regulated genes include those for superoxide dismutase, NADH oxidase, and members of the mutanobactin biosynthesis cluster. Among the down-regulated genes were those for GtfB and alternative sigma factor SigX. These results further suggest that interactions between S. mutans and oral lactobacilli are species-specific and may have significant impact on cariogenic potential of the community.

Expanding the biotechnology potential of lactobacilli through comparative genomics of 213 strains and associated genera.

Lactobacilli are a diverse group of species that occupy diverse nutrient-rich niches associated with humans, animals, plants and food. They are used widely in biotechnology and food preservation, and are being explored as therapeutics. Exploiting lactobacilli has been complicated by metabolic diversity, unclear species identity and uncertain relationships between them and other commercially important lactic acid bacteria. The capacity for biotransformations catalysed by lactobacilli is an untapped biotechnology resource. Here we report the genome sequences of 213 Lactobacillus strains and associated genera, and their encoded genetic catalogue for modifying carbohydrates and proteins. In addition, we describe broad and diverse presence of novel CRISPR-Cas immune systems in lactobacilli that may be exploited for genome editing. We rationalize the phylogenomic distribution of host interaction factors and bacteriocins that affect their natural and industrial environments, and mechanisms to withstand stress during technological processes. We present a robust phylogenomic framework of existing species and for classifying new species.

Characterizing Diversity of Lactobacilli Associated with Severe Early Childhood Caries: A Study Protocol.

Lactobacilli have been consistently associated with dental caries for decades; however, knowledge of this group of bacteria in the etiology of the disease is limited to quantitative elucidation. Nowadays, explicit identification of oral Lactobacillus species is possible, despite their taxonomic complexity. Here we describe a combined approach involving both cultivation and genetic methods to ascertain and characterize the diversity and abundance of the Lactobacillus population in the oral cavities of children with severe early childhood caries (S-ECC). Eighty 3- to 6-year-old children (40 S-ECC and 40 caries free) who were seeking dental care at the Pediatric Dental Clinic of Bellevue Hospital in New York City were invited to participate in this study. Clinical data on socio-demographic information and oral health behavior were obtained from the primary caregiver. The data included a detailed dental examination, children's medical history, and a questionnaire survey. Combined non-stimulated saliva and supra-gingival plaque samples were collected from each child and cultivated on selective media for quantitative measures of lactobacilli levels. The procedure for Lactobacillus species screening will include the random selection of 50 colonies per plate, extraction of DNA from each colony, and genotyping by arbitrarily primed polymerase chain reaction (AP-PCR). Each unique Lactobacillus AP-PCR genotype will be selected for taxonomic assessment by 16S rRNA gene sequencing analysis. Lactobacillus species will be identified by comparing the 16S rRNA sequences with the Ribosomal Database and the Human Oral Microbiome Database. Meanwhile, the same set of clinical samples will be independently subjected to genomic DNA isolation, 16S rRNA amplification with Lactobacillus genus-specific primers, sequencing, and taxonomic identification, both at genus and species levels with a customized pipeline. The distribution and phylogenetic differences of these Lactobacillus species will be compared between children with or without S-ECC. One of the main objectives of this study is to establish a study protocol for the identification and characterization of lactobacilli in the oral cavity. Future caries risk assessments can include lactobacilli counts (quantitative) and the presence/absence of specific cariogenic genetic signatures of a Lactobacillus species (qualitative) associated with S-ECC.

Comparative genomics of oral isolates of Streptococcus mutans by in silico genome subtraction does not reveal accessory DNA associated with severe early childhood caries.

Comparative genomics is a popular method for the identification of microbial virulence determinants, especially since the sequencing of a large number of whole bacterial genomes from pathogenic and non-pathogenic strains has become relatively inexpensive. The bioinformatics pipelines for comparative genomics usually include gene prediction and annotation and can require significant computer power. To circumvent this, we developed a rapid method for genome-scale in silico subtractive hybridization, based on blastn and independent of feature identification and annotation. Whole genome comparisons by in silico genome subtraction were performed to identify genetic loci specific to Streptococcus mutans strains associated with severe early childhood caries (S-ECC), compared to strains isolated from caries-free (CF) children. The genome similarity of the 20 S. mutans strains included in this study, calculated by Simrank k-mer sharing, ranged from 79.5% to 90.9%, confirming this is a genetically heterogeneous group of strains. We identified strain-specific genetic elements in 19 strains, with sizes ranging from 200 to 39 kb. These elements contained protein-coding regions with functions mostly associated with mobile DNA. We did not, however, identify any genetic loci consistently associated with dental caries, i.e., shared by all the S-ECC strains and absent in the CF strains. Conversely, we did not identify any genetic loci specific with the healthy group. Comparison of previously published genomes from pathogenic and carriage strains of Neisseria meningitidis with our in silico genome subtraction yielded the same set of genes specific to the pathogenic strains, thus validating our method. Our results suggest that S. mutans strains derived from caries active or caries free dentitions cannot be differentiated based on the presence or absence of specific genetic elements. Our in silico genome subtraction method is available as the Microbial Genome Comparison (MGC) tool, with a user-friendly JAVA graphical interface.

Phylogenetic analysis of glucosyltransferases and implications for the coevolution of mutans streptococci with their mammalian hosts.

Glucosyltransferases (Gtfs) catalyze the synthesis of glucans from sucrose and are produced by several species of lactic-acid bacteria. The oral bacterium Streptococcus mutans produces large amounts of glucans through the action of three Gtfs. GtfD produces water-soluble glucan (WSG), GtfB synthesizes water-insoluble glucans (WIG) and GtfC produces mainly WIG but also WSG. These enzymes, especially those synthesizing WIG, are of particular interest because of their role in the formation of dental plaque, an environment where S. mutans can thrive and produce lactic acid, promoting the formation of dental caries. We sequenced the gtfB, gtfC and gtfD genes from several mutans streptococcal strains isolated from the oral cavity of humans and searched for their homologues in strains isolated from chimpanzees and macaque monkeys. The sequence data were analyzed in conjunction with the available Gtf sequences from other bacteria in the genera Streptococcus, Lactobacillus and Leuconostoc to gain insights into the evolutionary history of this family of enzymes, with a particular emphasis on S. mutans Gtfs. Our analyses indicate that streptococcal Gtfs arose from a common ancestral progenitor gene, and that they expanded to form two clades according to the type of glucan they synthesize. We also show that the clade of streptococcal Gtfs synthesizing WIG appeared shortly after the divergence of viviparous, dentate mammals, which potentially contributed to the formation of dental plaque and the establishment of several streptococci in the oral cavity. The two S. mutans Gtfs capable of WIG synthesis, GtfB and GtfC, are likely the product of a gene duplication event. We dated this event to coincide with the divergence of the genomes of ancestral early primates. Thus, the acquisition and diversification of S. mutans Gtfs predates modern humans and is unrelated to the increase in dietary sucrose consumption.

Assessing the image quality of pelvic MR images acquired with a flat couch for radiotherapy treatment planning.

OBJECTIVES: To improve the integration of MRI with radiotherapy treatment planning, our department fabricated a flat couch top for our MR scanner. Setting up using this couch top meant that the patients were physically higher up in the scanner and, posteriorly, a gap was introduced between the patient and radiofrequency coil. METHODS: Phantom measurements were performed to assess the quantitative impact on image quality. A phantom was set up with and without the flat couch insert in place, and measurements of image uniformity and signal to noise were made. To assess clinical impact, six patients with pelvic cancer were recruited and scanned on both couch types. The image quality of pairs of scans was assessed by two consultant radiologists. RESULTS: The use of the flat couch insert led to a drop in image signal to noise of approximately 14%. Uniformity in the anteroposterior direction was affected the most, with little change in right-to-left and feet-to-head directions. All six patients were successfully scanned on the flat couch, although one patient had to be positioned with their arms by their sides. The image quality scores showed no statistically significant change between scans with and without the flat couch in place. CONCLUSION: Although the quantitative performance of the coil is affected by the integration of a flat couch top, there is no discernible deterioration of diagnostic image quality, as assessed by two consultant radiologists. Although the flat couch insert moved patients higher in the bore of the scanner, all patients in the study were successfully scanned.

Distribution of putative virulence genes in Streptococcus mutans strains does not correlate with caries experience.

Streptococcus mutans, a member of the human oral flora, is a widely recognized etiological agent of dental caries. The cariogenic potential of S. mutans is related to its ability to metabolize a wide variety of sugars, form a robust biofilm, produce copious amounts of lactic acid, and thrive in the acid environment that it generates. The remarkable genetic variability present within the species is reflected at the phenotypic level, notably in the differences in the cariogenic potential between strains. However, the genetic basis of these differences is yet to be elucidated. In this study, we surveyed by PCR and DNA hybridization the distribution of putative virulence genes, genomic islands, and insertion sequences across a collection of 33 strains isolated from either children with severe early childhood caries (S-ECC) or those who were caries free (CF). We found this genetically diverse group of isolates to be remarkably homogeneous with regard to the distribution of the putative virulence genes and genetic elements analyzed. Our findings point to the role of other factors in the pathogenesis of S-ECC, such as uncharacterized virulence genes, differences in gene expression and/or enzymatic activity, cooperation between S. mutans strains or with other members of the oral biota, and host factors.

Screening for hepatitis B in East Arnhem Land: a high prevalence of chronic infection despite incomplete screening.

Infection with hepatitis B virus (HBV) is common in Aboriginal Australians, but current seroprevalences in Northern Territory communities are unknown. We performed an audit of HBV serology on a convenience sample of 112 adults at an East Arnhem Land Health Service. Complete HBV serology was only available in 26 (23%) patients. Evidence of HBV exposure (core antibody-positive) was found in 43 of 68 (63%) patients tested, and current HBV infection (surface antigen-positive) was found in nine of 76 (12%). HBV is an incompletely defined, under-resourced and substantial public health problem in Aboriginal Australians.

Evidence-based clinical recommendations for the use of pit-and-fissure sealants: a report of the American Dental Association Council on Scientific Affairs.

This article presents evidence-based clinical recommendations for use of pit-and-fissure sealants developed by an expert panel convened by the American Dental Association (ADA) Council on Scientific Affairs. The panel addressed the following clinical questions. Under what circumstances should sealants be placed to prevent caries? Does placing sealants over early (noncavitated) lesions prevent progression of the lesion? Are there conditions that favor the placement of resin-based versus glass ionomer cement sealants in terms of retention or caries prevention? Are there any techniques that could improve sealants' retention and effectiveness in caries prevention? Staff of the ADA Division of Science conducted a MEDLINE search to identify systematic reviews and clinical studies published after the identified systematic reviews.

A peptide antagonist of the TLR4-MD2 interaction.

Toll-like receptors are an integral part of innate immunity in the central nervous system (CNS); they orchestrate a robust defense in response to both exogenous and endogenous danger signals. Recently, toll-like receptor 4 (TLR4) has emerged as a therapeutic target for the treatment of CNS-related diseases such as sepsis and chronic pain. We herein report a chemical biology approach by using a rationally designed peptide inhibitor to disrupt the TLR4-MD2 association, thereby blocking TLR4 signaling.

The static accuracy and calibration of inertial measurement units for 3D orientation.

Inertial measurement units (IMUs) are integrated electronic devices that contain accelerometers, magnetometers and gyroscopes. Wearable motion capture systems based on IMUs have been advertised as alternatives to optical motion capture. In this paper, the accuracy of five different IMUs of the same type in measuring 3D orientation in static situations, as well as the calibration of the accelerometers and magnetometers within the IMUs, has been investigated. The maximum absolute static orientation error was 5.2 degrees , higher than the 1 degrees claimed by the vendor. If the IMUs are re-calibrated at the time of measurement with the re-calibration procedure described in this paper, it is possible to obtain an error of less than 1 degrees , in agreement with the vendor's specifications (XSens Technologies B.V. 2005. Motion tracker technical documentation Mtx-B. Version 1.03. Available from: www.xsens.com). The new calibration appears to be valid for at least 22 days providing the sensor is not exposed to high impacts. However, if several sensors are 'daisy chained' together changes to the magnetometer bias can cause heading errors of up to 15 degrees . The results demonstrate the non-linear relationship between the vendor's orthogonality claim of < 0.1 degrees and the accuracy of 3D orientation obtained from factory calibrated IMUs in static situations. The authors hypothesise that the high magnetic dip (64 degrees ) in our laboratory may have exacerbated the errors reported. For biomechanical research, small relative movements of a body segment from a calibrated position are likely to be more accurate than large scale global motion that may have an error of up to 9.8 degrees .

Genetic classification of severe early childhood caries by use of subtracted DNA fragments from Streptococcus mutans.

Streptococcus mutans is one of several members of the oral indigenous biota linked with severe early childhood caries (S-ECC). Because most humans harbor S. mutans, but not all manifest disease, it has been proposed that the strains of S. mutans associated with S-ECC are genetically distinct from those found in caries-free (CF) children. The objective of this study was to identify common DNA fragments from S. mutans present in S-ECC but not in CF children. Using suppressive subtractive hybridization, we found a number of DNA fragments (biomarkers) present in 88 to 95% of the S-ECC S. mutans strains but not in CF S. mutans strains. We then applied machine learning techniques including support vector machines and neural networks to identify the biomarkers with the most predictive power for disease status, achieving a 92% accurate classification of the strains as either S-ECC or CF associated. The presence of these gene fragments in 90 to 100% of the 26 S-ECC isolates tested suggested their possible functional role in the pathogenesis of S. mutans associated with dental caries.

Dynamic accuracy of inertial measurement units during simple pendulum motion.

A motion measurement system based on inertial measurement units (IMUs) has been suggested as an alternative to contemporary video motion capture. This paper reports an investigation into the accuracy of IMUs in estimating 3D orientation during simple pendulum motion. The IMU vendor's (XSens Technologies) accuracy claim of 3 degrees root mean squared (RMS) error is tested. IMUs are integrated electronic devices that contain accelerometers, magnetometers and gyroscopes. The motion of a pendulum swing was measured using both IMUs and video motion capture as a reference. The IMU raw data were processed by the Kalman filter algorithm supplied by the vendor and a custom fusion algorithm developed by the authors. The IMU measurement of pendulum motion using the vendor's Kalman filter algorithm did not compare well with the video motion capture with a RMS error of between 8.5 degrees and 11.7 degrees depending on the length and type of pendulum swing. The maximum orientation error was greater than 30 degrees , occurring approximately eight seconds into the motion. The custom fusion algorithm estimation of orientation compared well with the video motion capture with a RMS error of between 0.8 degrees and 1.3 degrees . Future research should concentrate on developing a general purpose fusion algorithm and vendors of IMUs should provide details about the errors to be expected in different measurement situations, not just those in a 'best case' scenario.

Evidence-based clinical recommendations for the use of pit-and-fissure sealants: a report of the American Dental Association Council on Scientific Affairs.

BACKGROUND: This article presents evidence-based clinical recommendations for use of pit-and-fissure sealants developed by an expert panel convened by the American Dental Association Council on Scientific Affairs. The panel addressed the following clinical questions: Under what circumstances should sealants be placed to prevent caries? Does placing sealants over early (noncavitated) lesions prevent progression of the lesion? Are there conditions that favor the placement of resin-based versus. glass ionomer cement sealants in terms of retention or caries prevention? Are there any techniques that could improve sealants' retention and effectiveness in caries prevention? TYPES OF STUDIES REVIEWED: Staff of the ADA Division of Science conducted a MEDLINE search to identify systematic reviews and clinical studies published after the identified systematic reviews. At the panel's request, the ADA Division of Science staff conducted additional searches for clinical studies related to specific topics. The Centers for Disease Control and Prevention also provided unpublished systematic reviews that since have been accepted for publication. RESULTS: The expert panel developed clinical recommendations for each clinical question. The panel concluded that sealants are effective in caries prevention and that sealants can prevent the progression of early noncavitated carious lesions. CLINICAL IMPLICATIONS: These recommendations are presented as a resource to be considered in the clinical decision-making process. As part of the evidence-based approach to care, these clinical recommendations should be integrated with the practitioner's professional judgment and the patient's needs and preferences. The evidence indicates that sealants can be used effectively to prevent the initiation and progression of dental caries.

The effect of dental sealants on bacteria levels in caries lesions: a review of the evidence.

BACKGROUND: Concern about inadvertently sealing over caries often prevents dentists from providing dental sealants. The objective of the authors' review was to examine the effects of sealants on bacteria levels within caries lesions under dental sealants. METHODS: The authors searched electronic databases for comparative studies examining bacteria levels in sealed permanent teeth. To measure the effect of sealants on bacteria levels, they used the log(10) reduction in mean total viable bacteria counts (VBC) between sealed and not-sealed caries and the percentage reduction in the proportion of samples with viable bacteria. RESULTS: Six studies--three randomized controlled trials, two controlled trials and one before-and-after study-were included in the analysis. Although studies varied considerably, there were no findings of significant increases in bacteria under sealants. Sealing caries was associated with a 100-fold reduction in mean total VBC (four studies, 138 samples). Sealants reduced the probability of viable bacteria by about 50.0 percent (four studies, 117 samples). CONCLUSIONS: The authors found that sealants reduced bacteria in carious lesions, but that in some studies, low levels of bacteria persisted. These findings do not support reported concerns about poorer outcomes associated with inadvertently sealing caries. CLINICAL IMPLICATIONS: Practitioners should not be reluctant to provide sealants-an intervention proven to be highly effective in preventing caries-because of concerns about inadvertently sealing over caries.