Field-Collected Ticks From Benton County, Arkansas, and Prevalence of Associated Pathogens.

The recovery of a Haemaphysalis longicornis Neumann (Acari: Ixodidae) tick from a dog in Benton County, Arkansas, in 2018 triggered a significant environmental sampling effort in Hobbs State Park Conservation Area. The objective of the investigation was to assess the tick population density and diversity, as well as identify potential tick-borne pathogens that could pose a risk to public health. During a week-long sampling period in August of 2018, a total of 6,154 ticks were collected, with the majority identified as Amblyomma americanum (L), (Acari: Ixodidae) commonly known as the lone star tick. No H. longicornis ticks were found despite the initial detection of this species in the area. This discrepancy highlights the importance of continued monitoring efforts to understand the dynamics of tick populations and their movements. The investigation also focused on pathogen detection, with ticks being pooled by species, age, and sex before being processed with various bioassays. The results revealed the presence of several tick-borne pathogens, including agents associated with ehrlichiosis (n = 12), tularemia (n = 2), and Bourbon virus (BRBV) disease (n = 1), as well as nonpathogenic rickettsial and anaplasmosis organisms. These findings emphasize the importance of public health messaging to raise awareness of the risks associated with exposure to tick-borne pathogens. Prevention measures, such as wearing protective clothing, using insect repellent, and conducting regular tick checks, should be emphasized to reduce the risk of tick-borne diseases. Continued surveillance efforts and research are also essential to improve our understanding of tick-borne disease epidemiology and develop effective control strategies.

Socio-economic status and access to fluoridated water in Queensland: an ecological data linkage study.

OBJECTIVES: To investigate the relationship between access to fluoridated drinking water and area-level socio-economic status in Queensland. STUDY DESIGN: Ecological, geospatial data linkage study. SETTING: Queensland, by statistical area level 2 (SA2), 2021. MAIN OUTCOME MEASURES: Proportion of SA2s and of residents with access to fluoridated drinking water (natural or supplemented); relationship at SA2 level between access to fluoridated water and socio-economic status (Index of Relative Socio-economic Advantage and Disadvantage, IRSAD; Index of Economic Resources, IER). RESULTS: In 2021, an estimated 4 050 168 people (79.4% of the population) and 397 SA2 regions (72.7%) in Queensland had access to fluoridated water. Access was concentrated in the southeastern corner of the state. After adjusting for SA2 population, log area, and population density, the likelihood of access to fluoridated drinking water almost doubled for each 100-rank increase in IRSAD (adjusted odds ratio [aOR], 1.93; 95% confidence interval [CI], 1.59-2.36) or IER (aOR, 1.77; 95% CI, 1.50-2.11). CONCLUSIONS: The 2012 decision to devolve responsibility for water fluoridation decisions and funding from the Queensland government to local councils means that residents in lower socio-economic areas are less likely to have access to fluoridated water than those in more advantaged areas, exacerbating their already greater risk of dental disease. Queensland water fluoridation policy should be revised so that all residents can benefit from this evidence-based public health intervention for reducing the prevalence of dental caries.

Geographic patterns of dental service use in the Child Dental Benefits Schedule: 6 years of claims in the Longitudinal Study of Australian Children.

ISSUE ADDRESSED: This article explores the geographic patterns of claims within the Australian Government's Child Dental Benefits Schedule (CDBS). BACKGROUND: The CDBS is a means-tested schedule implemented in 2014 to improve access to dental services for children. Under the schedule, eligible children receive funding to subsidise dental services. METHODS: This study used data from the Longitudinal Study of Australian Children and linked data from the Medicare universal healthcare system, to examine dental service use amongst a subset of children aged 10 and 14 years. Dental service items were classified using Two-step Cluster Analysis, and appointments were analysed using multinomial logistic regression. Geographic characteristics were included as predictor variables. RESULTS: The study found that the majority of dental appointments were non-operative (70.7%, n = 5808), with diagnostic, radiographic, and preventive items being the most common. There were slightly higher proportions of operative appointments (fillings and extractions) compared with non-operative appointments in remote and very remote areas, low socio-economic areas, and Queensland and Northern Territory. Cluster analysis identified eight groups of non-operative appointments and four groups of operative appointments. New South Wales had a higher proportion of 'prophylactic IV' appointments than any other State and Territory, which included debridement and topical fluoride services. CONCLUSION: Cluster analysis identified distinct groups of non-operative and operative appointments, each with unique characteristics. The distribution of appointments varied by State/Territory and region. SO WHAT: Further research and interventions are needed to ensure equitable access to services and a shift to preventive care for disadvantaged populations of Australian children. Exploring alternative funding models that support clinically relevant claims, rather than maximising financial benefits such as time-based renumeration models should be explored.

Parental recall bias in observational studies: Child dental service use.

BACKGROUND: Parents are frequently used to recall events of exposure and disease as a proxy for their children in observational health research. AIM: To assess the validity of parental recall of children's utilisation of dental services. DESIGN: Parents in the Longitudinal Study of Australian Children (LSAC) were asked to recall their children's overall dental service use in the previous year and whether the study child had received fillings or extractions due to decay in the previous 2 years. True positives were identified through parents who correctly recalled child dental service utilisation with actual dental treatment received in a linked dataset. RESULTS: Of the 10 090 participants from the LSAC, 1290 study children had linked dental treatment data eligible for inclusion in this study. The absolute true-positive rate for parental recall of dental service use in the previous year was 82% (n = 1263). Overall true-positive percentages were lower for recall of fillings (40%) and extractions (7%) in the previous 2 years. Increasing number of recall days was associated with the rate of true-positive recall adjusted for other factors in all three models. CONCLUSION: Accuracy of parental recall for tooth fillings and extractions was low. The use of parental recall for specific dental treatment over a time span of 2 years in further research is not recommended.

Dynamic dentin: A quantitative microscopic assessment of age and spatial changes to matrix architecture, peritubular dentin, and collagens types I and III.

To investigate age and site-related changes to human dentin collagen, sound human teeth collected from donors aged 13-29 (young) and 50-74 (aged) years (n = 9/group) were cut to shallow and deep sites. Dentin collagen orientation and fibril bundling was investigated using the Picrosirius Red (PSR) stain observed under cross-polarized light microscopy (Pol), and collagen distribution was investigated using Confocal Laser Scanning Microscopy (CLSM). Collagen types III to I distribution in peritubular dentin (PTD) was revealed using Herovici stain and brightfield microscopy. Image analysis software and linear mixed modelling quantified outcomes. In situ dentin collagen was observed using Xenon Plasma Focussed Ion Beam Scanning Electron Microscopy (Xe PFIB-SEM). The PSR-Pol analysis revealed less coherently aligned and more bundled collagen fibrils in aged dentin (P = 0.005). Deep inner dentin collagen in both groups were less coherently aligned with reduced bundling. Regardless of age, CLSM showed collagen distribution remained stable; and more collagen type III was detectable in PTD located in inner dentin (Young: P = 0.006; Aged: P = 0.008). Observations following Xe PFIB-SEM cross-sectioning showed apatite-like deposits surrounding large intratubular collagen fibers, and evidence of smaller intertubular dentin collagen fibrils in situ. In conclusion, aging changes collagen network architecture, but not distribution or content.

Effect of dentine site on resin and cement adaptation tested using X-ray and electron microscopy to evaluate bond durability and adhesive interfaces.

Glass ionomer (GI) cements and self-etch (SE) or universal adhesives after etching (ER) adapt variably with dentine. Dentine characteristics vary with depth (deep/shallow), location (central/peripheral), and microscopic site (intertubular/peritubular). To directly compare adhesion to dentine, non-destructive imaging and testing are required. Here, GI, ER, and SE adapted at different dentine depths, locations, and sites were investigated using micro-CT, xenon plasma focused ion beam scanning electron microscopy (Xe PFIB-SEM), and energy dispersive X-ray spectroscopy (EDS). Extracted molars were prepared to deep or shallow slices and treated with the three adhesives. Micro-CT was used to compare changes to air volume gaps, following thermocycling, and statistically analysed using a quantile regression model and Fisher's exact test. The three adhesives performed similarly across dentine depths and locations, yet no change or overall increases and decreases in gaps at all dentine depths and locations were measured. The Xe PFIB-SEM-milled dentine-adhesive interfaces facilitated high-resolution characterization, and element profiling revealed variations across the tooth-material interfaces. Dentine depth and location had no impact on adhesive durability, although microscopic differences were observed. Here we demonstrate how micro-CT and Xe PFIB-SEM can be used to compare variable dental materials without complex multi-stage specimen preparation to minimize artefacts.

Has the Child Dental Benefits Schedule improved access to dental care for Australian children?

The Child Dental Benefits Schedule (CDBS) is an ongoing scheme administered through the Australian Government providing eligible children funding for clinical dental treatment. This study aimed to investigate the access of dental services across children's early childhood and examine whether the CDBS has improved access to dental care. The longitudinal study of Australian children is an ongoing cross-sequential cohort study with a representative sample of Australian children recruited in 2004. Birth (0-1 year) and kindergarten (4-5 years) cohorts were recruited through Medicare enrolment information at baseline and were representative of the Australian child population. Population-weighted longitudinal mixed effects Poisson models with individual identifiers as a random effect were used to assess the effect of Medicare dental schedules on reported dental attendance. Prior to the implementation of the CDBS for both cohorts, the birth cohort reported the lowest attendance rate at age 4-5. The introduction of the CDBS increased the rate of dental attendance for the low household income group by 8% (95% CI: 1%, 15%) after adjusting for confounders. The model provides evidence that dental attendance increased with age and the Indigenous population have 31% (95% CI: 4%, 55%) lower attendance rate after adjustment. The increase in reported access to dental services and favourable visiting patterns in low-income households during the operation of the CDBS provides some evidence that the schedule's primary aims to improve access to care in the child population are being met. Access to healthcare is multifaceted and the underutilisation of the schedule in the population warrants review of the schedule performance using other patient-centred indicators.

Does dentine mineral change with anatomical location, microscopic site and patient age?

OBJECTIVE: To determine the effect of patient age (young or mature), anatomical location (shallow/deep and central/peripheral) and microscopic site (intertubular/peritubular) on dentine mineral density, distribution and composition. METHODS: Extracted posterior teeth from young (aged 19-20 years, N = 4) and mature (aged 54-77 years, N = 4) subjects were prepared to shallow and deep slices. The dentine surface elemental composition was investigated in a SEM using Backscattered Electron (BSE) micrographs, Energy Dispersive X-ray Spectroscopy, and Integrated Mineral Analysis. Qualitative comparisons and quantitative measures using machine learning were used to analyse the BSE images. Quantitative outcomes were compared using quantile or linear regression models with bootstrapping to account for the multiple measures per sample. Subsequently, a Xenon Plasma Focussed Ion Beam Scanning Electron Microscopy (Xe PFIB-SEM) was used to mill large area (100 µm) cross-sections to investigate morphology through the dentine tubules using high resolution secondary electron micrographs. RESULTS: With age, dentine mineral composition remains stable, but density changes with anatomical location and microscopic site. Microscopically, accessory tubules spread into intertubular dentine (ITD) from the main tubule lumens. Within the lumens, mineral deposits form calcospherites in the young that eventually coalesce in mature tubules and branches. The mineral occlusion in mature dentine increases overall ITD density to reflect peritubular dentine (PTD) infiltrate. The ITD observed in micrographs remained consistent for age and observation plane to suggest tubule deposition affects overall dentine density. Mineral density depends on the relative distribution of PTD to ITD that varies with anatomical location. SIGNIFICANCE: Adhesive materials may interact differently within a tooth as well as in different age groups.

Water fluoridation, dental caries and parental ratings of child oral health.

OBJECTIVES: Previous studies have identified many demographic, socioeconomic, behavioural and clinical variables associated with subjective parental ratings of child oral health. This study investigated associations between children's lifetime exposure to fluoridated drinking water (LEFW) and dental caries prevalence and parental ratings. METHODS: Australia's National Child Oral Health Study 2012-2014 conducted oral epidemiological examinations for 24 664 children aged 5-14 and investigated risk factors for child oral health and disease through questionnaires. Parents also subjectively rated their child's oral health. This cross-sectional study estimated prevalence ratios for associations between LEFW and prevalence of dental caries in the primary and permanent dentitions and parental oral health ratings for 5-8 year old and 9-14 year old children. E-value sensitivity analyses helped assess whether observed effect sizes may have arisen through unmeasured confounding. RESULTS: Children aged 5-8 with 0%-10% or 11%-89% LEFW are respectively 1.5 (95% CI 1.2-1.8) and 1.5 (95% CI 1.1-2.0) times more likely than children with 90%-100% LEFW to receive a fair or poor parental oral health rating. Children aged 9-14 with 0%-10% or 11%-89% LEFW are 1.2 (95% CI 1.0-1.4) times more likely than children with 90%-100% LEFW to receive a fair or poor parental oral health rating. Children aged 5-8 with 0%-10% or 11%-89% LEFW are respectively 1.4 (1.3-1.6) and 1.3 (95% CI 1.1-1.4) times more likely than children with 90%-100% LEFW to experience caries in their primary teeth. Children aged 9-14 with 0%-10% or 11%-89% LEFW are respectively 1.4 (95% CI 1.3-1.5) and 1.1 (95% CI 1.0-1.2) times more likely than children with 90%-100% LEFW to experience caries in their permanent teeth. CONCLUSIONS: Longer lifetime exposure to fluoridated drinking water is causally associated with a lower childhood dental caries prevalence and more positive parental ratings of child oral health. The associations are stronger for younger children.

Understanding the well-being of dentistry students.

INTRODUCTION: The transactional model of stress is a framework describing the process for coping with stressful events as a relationship between the individual person and environment. This study aimed to investigate the associations between personality, learning environment and experiences of mental health for a cohort of Australian dentistry students. MATERIALS AND METHODS: Students were invited in 2017 to complete an online questionnaire including the Depression, Anxiety and Stress Scale (DASS-21), The Dundee Ready Education Environment Measure (DREEM) and Cloninger's Temperament and Character Inventory (TCIR-140). Students were followed-up one year later, and generalised estimating equations were used. RESULTS: A total of 219 (response 73.5%) students participated in the study. Two personality profiles of dentistry students were identified. Group 1 were significantly higher in the traits persistence, self-directedness, cooperativeness and reward dependence, whereas Group 2 were significantly higher in harm avoidance. Students with Group 2 personality had a 3.12 (CI:1.72-5.65) increased odds of depression compared to Group 1 students. Compared to students with positive perceptions of the learning environment, students with negative perceptions had increased odds of stress (3.48, CI: 1.85-6.53), depression (2.71, CI: 1.57- 4.65) and anxiety (2.59, CI: 1.56-4.28). CONCLUSION: Students with personalities high in levels of self-directedness, cooperativeness and persistence and low in harm avoidance, as found in Group 1, demonstrate high levels of general well-being. Positive perceptions of the dentistry learning environment were found to be an important influence on students stress. This study highlighted a number of factors important to student well-being and provides direction for further investigation of interventions aimed at enhancing student well-being.

SMS reminders to improve outpatient attendance for public dental services: A retrospective study.

Patients who miss scheduled appointments reduce clinical productivity and delay access to care for other patients. Reminders have improved attendance for healthcare appointments previously, but it is not known if short message service (SMS) implementation reduces incidence of patients unable to attend (UTA) or who fail to attend (FTA) appointments in the public dental service. This paper studied the effectiveness of SMS reminders in increasing appointment attendance at outpatient public dental services in Queensland. Data were sourced from the adult service and the children and adolescent oral health service (CAOHS) at West Moreton Hospital and Health Service, a public dental service in Queensland. A total of 63,238 appointments pre-implementation of SMS reminders and 55,028 appointments post-implementation over a period of 2 years were analysed for rates of attendance, UTA and FTA. Characteristics of UTA and FTA appointments were analysed to identify factors that hindered improvement after implementation of reminders. For the CAOHS, the attendance rate decreased 4% (95% CI: 2%, 6%) following SMS implementation. The UTA rate also increased by 20% (95% CI: 15%, 25%). Following SMS implementation in the adult service, the attendance rate increased from 73.5 (95% CI: 72.6, 74.4) to 77.7 (95% CI: 76.6-78.8) per 100 appointments. The FTA rate post-implementation was 1.08 (95% CI: 1.00, 1.16) times that from pre-intervention, and the UTA rate decreased from 21.7 (95% CI: 21.2, 22.2) to 17.1 (95% CI: 16.6, 17.7) per 100 appointments. The SMS reminders had a mixed effect on the attendance, UTA and FTA rates for the CAOHS and adult services. Reminders reduced the rates of UTA for the CAOHS service and increased the rate of attendance for the adult service. There was an increase in the FTA rate for both services.

The prevalence and burden of recurrent headache in Australian adolescents: findings from the longitudinal study of Australian children.

BACKGROUND: Headache disorders are highly prevalent worldwide, but not well investigated in adolescents. Few studies have included representative nationwide samples. This study aimed to present the prevalence and burden of recurrent headache in Australian adolescents. METHODS: The prevalence of recurrent headache, headache characteristics (severity and frequency) and burden on health-related quality of life in Australian children aged 10-17 years were presented, using nationally representative data from the Longitudinal Study of Australian children (LSAC). The LSAC, commencing in 2004, collects data every 2 years from a sample of Australian children of two different age cohorts: B 'baby' cohort, aged 0-1 years and K 'kindergarten' cohort, aged 4-5 years at the commencement of the study. Face-to-face interviews and self-complete questionnaires have been conducted with the study child and parents of the study child (carer-reported data) at each data collection wave, with seven waves of data available at the time of the current study. Wave 7 of the LSAC was conducted in 2016, with B cohort children aged 12-13 years and K cohort children aged 16-17 years. For the current study, data were accessed for four out of seven waves of available data (Wave 4-7) and presented cross-sectionally for the two cohorts of Australian children, for the included age groups (10-11 years, 12-13 years, 14-15 years and 16-17 years). All available carer-reported questionnaire data pertaining to headache prevalence, severity and frequency, general health and health-related quality of life, for the two cohorts, were included in the study, and presented for male and female adolescents. Carer-reported general health status of the study child and health-related quality of life scores, using the parent proxy-report of the Paediatric Quality of Life Inventory™ 4.0, were compared for male and female adolescents with recurrent headache and compared with a healthy group. Finally, health-related quality of life scores were compared based on headache frequency and severity. RESULTS: The LSAC study initially recruited 10,090 Australian children (B cohort n = 5107, K cohort n = 4983), and 64.1% of the initial sample responded at wave 7. Attrition rates across the included waves ranged from 26.3% to 33.8% (wave 6 and 7) for the B cohort, and 16.3% to 38.0% (wave 4-7) for the K cohort. Recurrent headache was more common in females, increasing from 6.6% in 10-11 years old females to 13.2% in 16-17 years old females. The prevalence of headache in males ranged from 4.3% to 6.4% across the age groups. Health-related quality of life scores were lower for all functional domains in adolescents with recurrent headache, for both sexes. Headache frequency, but not severity, was significantly associated with lower health-related quality of life scores, in both males and females. CONCLUSIONS: Recurrent headache was common among Australian adolescents and increased in prevalence for females, across the age groups. Frequent recurrent headache is burdensome for both male and female adolescents. This study provides information regarding the prevalence and burden of recurrent headache in the adolescent population based on findings from the Longitudinal Study of Australian Children.

Factors Affecting the Removal Time of Separated Instruments.

INTRODUCTION: Separated endodontic instruments may adversely affect the outcome of endodontic treatment. The combination of ultrasonic techniques and dental operating microscopes appears to be effective in the removal of separated instruments compared with more randomized techniques. This study evaluated the roles of root canal curvature and separated instrument length on the time needed to loosen and retrieve the instrument fragments. METHODS: The retrieval procedures of 128 separated instruments referred to a private endodontic practice for retreatment by general practitioners were evaluated in patients who were monitored for a minimum of 6 months. Preoperative cone-beam computed tomographic images were used to measure separated instrument lengths in relation to the degrees of canal curvatures. Ultrasonic instruments were used in the initial phase to remove the tooth structure and to loosen the fractured instrument. In the second phase, ultrasonic instruments, wire loops, or XP Shapers (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) were used for fragment removal. The time periods for all procedures were recorded. Statistical analysis was completed applying log-normal regression, structural equation modeling, and linear regression using Stata Version 14.2 software (StataCorp LLC, College Station, TX). RESULTS: All separated instruments were successfully retrieved. Using the protocol in this study, 89.8% of the instruments were removed using ultrasonic instruments alone with a mean time of 221 seconds. The instrument removal time was dependent on both the instrument length and the root canal curvature. Additionally, preparation times were proportionately longer with increasing separated instrument lengths when the loop device was required. CONCLUSIONS: The preparation phase appears to have an important role in the retrieval of separated instruments. Preparation times for both non-loop and loop groups demonstrate that length and curvature are independent predictors of the log-transformed time. Generally, procedure times were extended with increasing file lengths and higher degrees of canal curvature.

A comparison of 2- and 3-dimensional mandibular superimposition techniques against Björk's structural superimposition method.

INTRODUCTION: The purpose of this research was to compare mandibular growth rotation relative to the cranial base in different vertical facial patterns on the basis of multiple 2-dimensional (2D) and 3-dimensional (3D) superimposition methods. METHODS: Cone-beam computed tomography (CBCT) images taken at a mean interval of 54.8 ± 16.8 months were assessed from a sample of 70 growing patients. Three mandibular superimposition methods were compared against Björk's structural method: (1) a 2D landmark method (2D-M1), (2) a voxel-based 3D method based on a previously reported method (3D-M1), and (3) a voxel-based 3D method incorporating symphyseal structures as references (3D-M2). After superimposition, the relative change in cranial base lines as depicted in sagittal views were measured for true mandibular rotation. Agreement between methods was assessed with Lin's concordance correlation coefficient, Bland-Altman's limits of agreement, and the Bradley-Blackwood test. RESULTS: Lin's concordance correlation coefficients ranged between 0.924 for the 2D-M1 method, 0.695 for the 3D-M1 method, and 0.965 for the 3D-M2 method. Bland-Altman limits of agreement were wide for all but the 3D-M2 method. Finally, the Bradley-Blackwood test of equality of means and variances was significant in all except the 3D-M2 method. CONCLUSIONS: For time intervals between CBCT volume acquisitions >3 years, the use of the 2D-M1 and 3D-M1 methods is not recommended. There was a high concordance between the 3D-M2 method and Björk's structural method when assessing mandibular growth rotation using relative changes in cranial base lines. The high concordance was displayed across all vertical facial types and for all time differences between first and second CBCT data acquisitions.

Isolation of Borrelia miyamotoi and other Borreliae using a modified BSK medium.

Borrelia spirochetes are the causative agents of Lyme borreliosis (LB) and relapsing fever (RF). Despite the steady rise in infections and the identification of new species causing human illness over the last decade, isolation of borreliae in culture has become increasingly rare. A modified Barbour-Stoenner-Kelly (BSK) media formulation, BSK-R, was developed for isolation of the emerging RF pathogen, Borrelia miyamotoi. BSK-R is a diluted BSK-II derivative supplemented with Lebovitz's L-15, mouse and fetal calf serum. Decreasing the concentration of CMRL 1066 and other components was essential for growth of North American B. miyamotoi. Sixteen B. miyamotoi isolates, originating from Ixodes scapularis ticks, rodent and human blood collected in the eastern and upper midwestern United States, were isolated and propagated to densities > 108 spirochetes/mL. Growth of five other RF and ten different LB borreliae readily occurred in BSK-R. Additionally, primary culture recovery of 20 isolates of Borrelia hermsii, Borrelia turicatae, Borrelia burgdorferi and Borrelia mayonii was achieved in BSK-R using whole blood from infected patients. These data indicate this broadly encompassing borreliae media can aid in in vitro culture recovery of RF and LB spirochetes, including the direct isolation of new and emerging human pathogens.

Interprofessional, student-led community health clinic: expanding service provision and clinical education capacity.

Student-led interprofessional health clinics offer valuable opportunities for student learning and meeting the health care needs of the community. This case study describes the operation of a new interprofessional student-led community health service over its initial 13-month period of operation. This case study also presents an overview of the service provision, student placement opportunities and focuses on the challenges associated with the service and the impact on future planning.

The effects of exposure to microgravity and reconditioning of the lumbar multifidus and anterolateral abdominal muscles: implications for people with LBP.

BACKGROUND CONTEXT: One of the primary changes in the neuromuscular system in response to microgravity is skeletal muscle atrophy, which occurs especially in muscles that maintain posture while being upright on Earth. Reduced size of paraspinal and abdominal muscles has been documented after spaceflight. Exercises are undertaken on the International Space Station (ISS) during and following space flight to remediate these effects. Understanding the adaptations which occur in trunk muscles in response to microgravity could inform the development of specific countermeasures, which may have applications for people with conditions on Earth such as low back pain (LBP). PURPOSE: The aim of this study was to examine the changes in muscle size and function of the lumbar multifidus (MF) and anterolateral abdominal muscles (1) in response to exposure to 6 months of microgravity on the ISS and (2) in response to a 15-day reconditioning program on Earth. DESIGN: Prospective longitudinal series. PATIENT SAMPLE: Data were collected from five astronauts who undertook seven long-duration missions on the ISS. OUTCOME MEASURES: For the MF muscle, measures included cross-sectional area (CSA) and linear measures to assess voluntary isometric contractions at vertebral levels L2 to L5. For the abdominal muscles, the thickness of the transversus abdominis (TrA), obliquus internus abdominis (IO) and obliquus externus abdominis (EO) muscles at rest and on contraction were measured. METHODS: Ultrasound imaging of trunk muscles was conducted at four timepoints (preflight, postflight, mid-reconditioning, and post reconditioning). Data were analyzed using multilevel linear models to estimate the change in muscle parameters of interest across three time periods. RESULTS: Beta-coefficients (estimates of the expected change in the measure across the specified time period, adjusted for the baseline measurement) indicated that the CSA of the MF muscles decreased significantly at all lumbar vertebral levels (except L2) in response to exposure to microgravity (L3=12.6%; L4=6.1%, L5=10.3%; p<.001), and CSAs at L3-L5 vertebral levels increased in the reconditioning period (p<.001). The thickness of the TrA decreased by 34.1% (p<.017), IO decreased by 15.4% (p=.04), and the combination of anterolateral abdominal muscles decreased by 16.2% (p<.001) between pre- and postflight assessment and increased (TrA<0.008; combined p=.035) during the postreconditioning period. Results showed decreased contraction of the MF muscles at the L2 (from 12.8% to 3.4%; p=.007) and L3 (from 12.2% to 5%; p=.032) vertebral levels following exposure to microgravity which increased (L2, p=.046) after the postreconditioning period. Comparison with preflight measures indicated that there were no residual changes in muscle size and function after the postreconditioning period, apart from CSA of MF at L2, which remained 15.3% larger than preflight values (p<.001). CONCLUSIONS: In-flight exercise countermeasures mitigated, but did not completely prevent, changes in the size and function of the lumbar MF and anterolateral abdominal muscles. Many of the observed changes in size and control of the MF and abdominal muscles that occurred in response to prolonged exposure to microgravity paralleled those seen in people with LBP or exposed to prolonged bed rest on Earth. Daily individualized postflight reconditioning, which included both motor control training and weight-bearing exercises with an emphasis on retraining strength and endurance to re-establish normal postural alignment with respect to gravity, restored the decreased size and control of the MF (at the L3-L5 vertebral levels) and anterolateral abdominal muscles. Drawing parallels between changes which occur to the neuromuscular system in microgravity and which exercises best recover muscle size and function could help health professionals tailor improved interventions for terrestrial populations. Results suggested that the principles underpinning the exercises developed for astronauts following prolonged exposure to microgravity (emphasizing strength and endurance training to re-establish normal postural alignment and distribution of load with respect to gravity) can also be applied for people with chronic LBP, as the MF and anterolateral abdominal muscles were affected in similar ways in both populations. The results may also inform the development of new astronaut countermeasures targeting the MF and abdominal muscles.

Borrelia burgdorferi and Borrelia miyamotoi seroprevalence in California blood donors.

The western blacklegged tick, Ixodes pacificus, an important vector in the western United States of two zoonotic spirochetes: Borrelia burgdorferi (also called Borreliella burgdorferi), causing Lyme disease, and Borrelia miyamotoi, causing a relapsing fever-type illness. Human cases of Lyme disease are well-documented in California, with increased risk in the north coastal areas and western slopes of the Sierra Nevada range. Despite the established presence of B. miyamotoi in the human-biting I. pacificus tick in California, clinical cases with this spirochete have not been well studied. To assess exposure to B. burgdorferi and B. miyamotoi in California, and to address the hypothesis that B. miyamotoi exposure in humans is similar in geographic range to B. burgdorferi, 1,700 blood donor sera from California were tested for antibodies to both pathogens. Sampling was from high endemic and low endemic counties for Lyme disease in California. All sera were screened using the C6 ELISA. All C6 positive and equivocal samples and nine randomly chosen C6 negative samples were further analyzed for B. burgdorferi antibody using IgG western blot and a modified two ELISA test system and for B. miyamotoi antibody using the GlpQ ELISA and B. miyamotoi whole cell sonicate western blot. Of the 1,700 samples tested in series, eight tested positive for antibodies to B. burgdorferi (0.47%, Exact 95% CI: 0.20, 0.93) and two tested positive for antibodies to B. miyamotoi (0.12%, Exact 95% CI: 0.01, 0.42). There was no statistically significant difference in seroprevalence for either pathogen between high and low Lyme disease endemic counties. Our results confirm a low frequency of Lyme disease and an even lower frequency of B. miyamotoi exposure among adult blood donors in California; however, our findings reinforce public health messaging that there is risk of infection by these emerging diseases in the state.

The changing triad of plague in Uganda: invasive black rats (Rattus rattus), indigenous small mammals, and their fleas.

Rattus rattus was first reported from the West Nile Region of Uganda in 1961, an event that preceded the appearance of the first documented human plague outbreak in 1970. We investigated how invasive R. rattus and native small mammal populations, as well as their fleas, have changed in recent decades. Over an 18-month period, a total of 2,959 small mammals were captured, sampled, and examined for fleas, resulting in the identification of 20 small mammal taxa that were hosts to 5,109 fleas (nine species). Over three-fourths (75.8%) of captured mammals belonged to four taxa: R. rattus, which predominated inside huts, and Arvicanthis niloticus, Mastomys sp., and Crocidura sp., which were more common outside huts. These mammals were hosts for 85.8% of fleas collected, including the efficient plague vectors Xenopsylla cheopis and X. brasiliensis, as well as likely enzootic vectors, Dinopsyllus lypusus and Ctenophthalmus bacopus. Flea loads on small mammals were higher in certain environments in villages with a recent history of plague compared to those that lacked such a history. The significance of these results is discussed in relation to historical data, the initial spread of plague in the WNR and the continuing threat posed by the disease.