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Legionnaires’ disease (LD) incidence in the USA has quadrupled since 2000. Health departments must detect LD outbreaks quickly to identify and remediate sources. We tested the performance of a system to prospectively detect simulated LD outbreaks in Allegheny County, Pennsylvania, USA. We generated three simulated LD outbreaks based on published outbreaks. After verifying no significant clusters existed in surveillance data during 2014–2016, we embedded simulated outbreak-associated cases into 2016, assigning simulated residences and report dates. We mimicked daily analyses in 2016 using the prospective space-time permutation scan statistic to detect clusters of ⩽30 and ⩽180 days using 365-day and 730-day baseline periods, respectively. We used recurrence interval (RI) thresholds of ⩾20, ⩾100 and ⩾365 days to define significant signals. We calculated sensitivity, specificity and positive and negative predictive values for daily analyses, separately for each embedded outbreak. Two large, simulated cooling tower-associated outbreaks were detected. As the RI threshold was increased, sensitivity and negative predictive value decreased, while positive predictive value and specificity increased. A small, simulated potable water-associated outbreak was not detected. Use of a RI threshold of ⩾100 days minimised time-to-detection while maximizing positive predictive value. Health departments should consider using this system to detect community-acquired LD outbreaks.
A cluster of Salmonella Paratyphi B variant L(+) tartrate(+) infections with indistinguishable pulsed-field gel electrophoresis patterns was detected in October 2015. Interviews initially identified nut butters, kale, kombucha, chia seeds and nutrition bars as common exposures. Epidemiologic, environmental and traceback investigations were conducted. Thirteen ill people infected with the outbreak strain were identified in 10 states with illness onset during 18 July–22 November 2015. Eight of 10 (80%) ill people reported eating Brand A raw sprouted nut butters. Brand A conducted a voluntary recall. Raw sprouted nut butters are a novel outbreak vehicle, though contaminated raw nuts, nut butters and sprouted seeds have all caused outbreaks previously. Firms producing raw sprouted products, including nut butters, should consider a kill step to reduce the risk of contamination. People at greater risk for foodborne illness may wish to consider avoiding raw products containing raw sprouted ingredients.
During the 2009 influenza pandemic, a rapid assessment of disease severity was a challenge as a significant proportion of cases did not seek medical care; care-seeking behaviour changed and the proportion asymptomatic was unknown. A random-digit-dialling telephone survey was undertaken during the 2011/12 winter season in England and Wales to address the feasibility of answering these questions. A proportional quota sampling strategy was employed based on gender, age group, geographical location, employment status and level of education. Households were recruited pre-season and re-contacted immediately following peak seasonal influenza activity. The pre-peak survey was undertaken in October 2011 with 1061 individuals recruited and the post-peak telephone survey in March 2012. Eight hundred and thirty-four of the 1061 (78.6%) participants were successfully re-contacted. Their demographic characteristics compared well to national census data. In total, 8.4% of participants self-reported an influenza-like illness (ILI) in the previous 2 weeks, with 3.2% conforming to the World Health Organization (WHO) ILI case definition. In total, 29.6% of the cases reported consulting their general practitioner. 54.1% of the 1061 participants agreed to be re-contacted about providing biological samples. A population-based cohort was successfully recruited and followed up. Longitudinal survey methodology provides a practical tool to assess disease severity during future pandemics.
Significant increases in excess all-cause mortality, particularly in the elderly, were observed during the winter of 2014/15 in England. With influenza A(H3N2) the dominant circulating influenza A subtype, this paper determines the contribution of influenza to this excess controlling for weather. A standardised multivariable Poisson regression model was employed with weekly all-cause deaths the dependent variable for the period 2008–2015. Adjusting for extreme temperature, a total of 26 542 (95% CI 25 301–27 804) deaths in 65+ and 1942 (95% CI 1834–2052) in 15–64-year-olds were associated with influenza from week 40, 2014 to week 20, 2015. This is compatible with the circulation of influenza A(H3N2). It is the largest estimated number of influenza-related deaths in England since prior to 2008/09. The findings highlight the potential health impact of influenza and the important role of the annual influenza vaccination programme that is required to protect the population including the elderly, who are vulnerable to a severe outcome.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
In our attempt to investigate the basic active galactic nucleus (AGN) paradigm requiring a centrally located supermassive black hole (SMBH), a close to Keplerian accretion disk and a jet perpendicular to its plane, we have searched for radio continuum in galaxies with H2O megamasers in their disks. We observed 18 such galaxies with the Very Large Baseline Array in C band (5 GHz, ~2 mas resolution) and we detected 5 galaxies at 8 σ or higher levels. For those sources for which the maser data is available, the positions of masers and those of the 5 GHz radio continuum sources coincide within the uncertainties, and the radio continuum is perpendicular to the maser disk’s orientation within the position angle uncertainties.
We present the results from the Australian Long Baseline Array (LBA) observations of the ground- and excited-state OH masers at high resolutions towards the massive star-forming region G351.417+0.645 in 2012. We obtain the most accurate spatial gradient of magnetic fields at ground state transitions and verify the reliability of magnetic field strengths measured from previous lower resolution observations. In comparison with previous LBA observations in 2001 at 6.0 GHz, we identified several matched Zeeman pairs. We found that the OH maser features have no significant change of magnetic field strengths and directions with small internal proper motions, implying quite stable physical conditions. Additionally, we found that 1665- and 6035-MHz OH maser features reveal the same trend of reversal of magnetic fields. Moreover, we also analyzed the physical conditions at different locations from the coincidence of different OH maser transitions based on current OH maser models.
Adolescence and young adulthood carry risk for suicidal thoughts and behaviours (STB). An increasing subpopulation of young people consists of college students. STB prevalence estimates among college students vary widely, precluding a validated point of reference. In addition, little is known on predictors for between-study heterogeneity in STB prevalence.
A systematic literature search identified 36 college student samples that were assessed for STB outcomes, representing a total of 634 662 students [median sample size = 2082 (IQR 353–5200); median response rate = 74% (IQR 37–89%)]. We used random-effects meta-analyses to obtain pooled STB prevalence estimates, and multivariate meta-regression models to identify predictors of between-study heterogeneity.
Pooled prevalence estimates of lifetime suicidal ideation, plans, and attempts were 22.3% [95% confidence interval (CI) 19.5–25.3%], 6.1% (95% CI 4.8–7.7%), and 3.2% (95% CI 2.2–4.5%), respectively. For 12-month prevalence, this was 10.6% (95% CI 9.1–12.3%), 3.0% (95% CI 2.1–4.0%), and 1.2% (95% CI 0.8–1.6%), respectively. Measures of heterogeneity were high for all outcomes (I2 = 93.2–99.9%), indicating substantial between-study heterogeneity not due to sampling error. Pooled estimates were generally higher for females, as compared with males (risk ratios in the range 1.12–1.67). Higher STB estimates were also found in samples with lower response rates, when using broad definitions of suicidality, and in samples from Asia.
Based on the currently available evidence, STB seem to be common among college students. Future studies should: (1) incorporate refusal conversion strategies to obtain adequate response rates, and (2) use more fine-grained measures to assess suicidal ideation.
The Infrared Astronomical Satellite (IRAS) has detected many galaxies in the infrared (IR), most of which have fairly steep 25μ to 60μ spectra. Many quasars and active galaxies exhibit a significantly flatter spectrum in the infrared. Several studies, for example, DeGrijp et al. (1985) used this characteristic to select a subsample of “warm” objects from the IRAS PSC (1985).
Six radio telescopes were operated as the first southern hemisphere VLBI array in April and May 1982. Observations were made at 2.3 and 8.4 Ghz. This array produced VLBI images of 28 southern hemisphere radio sources, high accuracy VLBI geodesy between southern hemisphere sites, and subarcsecond radio astrometry of celestial sources south of declination −45 degrees. This paper discusses only the astrophysical aspects of the experiment.
Placental transport of vitamin D and other nutrients (e.g. amino acids, fats and glucose) to the fetus is sensitive to maternal and fetal nutritional cues. We studied the effect of maternal calorific restriction on fetal vitamin D status and the placental expression of genes for nutrient transport [aromatic T-type amino acid transporter-1 (TAT-1); triglyceride hydrolase/lipoprotein uptake facilitator lipoprotein lipase (LPL)] and vitamin D homeostasis [CYP27B1; vitamin D receptor (VDR)], and their association with markers of fetal cardiovascular function and skeletal muscle growth. Pregnant sheep received 100% total metabolizable energy (ME) requirements (control), 40% total ME requirements peri-implantation [PI40, 1–31 days of gestation (dGA)] or 50% total ME requirements in late gestation (L, 104–127 dGA). Fetal, but not maternal, plasma 25-hydroxy-vitamin D (25OHD) concentration was lower in PI40 and L maternal undernutrition groups (P<0.01) compared with the control group at 0.86 gestation. PI40 group placental CYP27B1 messenger RNA (mRNA) levels were increased (P<0.05) compared with the control group. Across all groups, higher fetal plasma 25OHD concentration was associated with higher skeletal muscle myofibre and capillary density (P<0.05). In the placenta, higher VDR mRNA levels were associated with higher TAT-1 (P<0.05) and LPL (P<0.01) mRNA levels. In the PI40 maternal undernutrition group only, reduced fetal plasma 25OHD concentration may be mediated in part by altered placental CYP27B1. The association between placental mRNA levels of VDR and nutrient transport genes suggests a way in which the placenta may integrate nutritional cues in the face of maternal dietary challenges and alter fetal physiology.
Parental criminal offending is an established risk factor for offending among offspring, but little evidence is available indicating the impact of offending on early childhood functioning. We used data from a large Australian population cohort to determine associations between exposure to parental offending and a range of developmental outcomes at age 5 years.
Multi-generation data in 66 477 children and their parents from the New South Wales Child Development Study were combined using data linkage. Logistic and multinomial regressions tested associations between any and violent offending histories of parents (fathers, mothers, or both parents) obtained from official records, and multiple measures of early childhood developmental functioning (social, emotional–behavioural, cognitive, communication and physical domains) obtained from the teacher-reported 2009 Australian Early Development Census.
Parental offending conferred significantly increased risk of vulnerability on all domains, particularly the cognitive domain. Greater risk magnitudes were observed for offending by both parents and by mothers than by fathers, and for violent than for any offending. For all parental offending exposures, vulnerability on multiple domains (where medium to large effects were observed) was more likely than on a single domain (small to medium effects). Relationships remained significant and of comparable magnitude following adjustment for sociodemographic covariates.
The effect of parental offending on early childhood developmental outcomes is pervasive, with the strongest effects on functioning apparent when both parents engage in violent offending. Supporting affected families in early childhood might mitigate both early developmental vulnerability and the propensity for later delinquency among these offspring.
Toxigenic strains of Vibrio cholerae serogroups O1 and O139 have caused cholera epidemics, but other serogroups – such as O75 or O141 – can also produce cholera toxin and cause severe watery diarrhoea similar to cholera. We describe 31 years of surveillance for toxigenic non-O1, non-O139 infections in the United States and map these infections to the state where the exposure probably originated. While serogroups O75 and O141 are closely related pathogens, they differ in how and where they infect people. Oysters were the main vehicle for O75 infection. The vehicles for O141 infection include oysters, clams, and freshwater in lakes and rivers. The patients infected with serogroup O75 who had food traceback information available ate raw oysters from Florida. Patients infected with O141 ate oysters from Florida and clams from New Jersey, and those who only reported being exposed to freshwater were exposed in Arizona, Michigan, Missouri, and Texas. Improving the safety of oysters, specifically, should help prevent future illnesses from these toxigenic strains and similar pathogenic Vibrio species. Post-harvest processing of raw oysters, such as individual quick freezing, heat-cool pasteurization, and high hydrostatic pressurization, should be considered.
Childhood maltreatment and a family history of a schizophrenia spectrum disorder (SSD) are each associated with social-emotional dysfunction in childhood. Both are also strong risk factors for adult SSDs, and social-emotional dysfunction in childhood may be an antecedent of these disorders. We used data from a large Australian population cohort to determine the independent and moderating effects of maltreatment and parental SSDs on early childhood social-emotional functioning.
The New South Wales Child Development Study combines intergenerational multi-agency data using record linkage methods. Multiple measures of social-emotional functioning (social competency, prosocial/helping behaviour, anxious/fearful behaviour; aggressive behaviour, and hyperactivity/inattention) on 69 116 kindergarten children (age ~5 years) were linked with government records of child maltreatment and parental presentations to health services for SSD. Multivariable analyses investigated the association between maltreatment and social-emotional functioning, adjusting for demographic variables and parental SSD history, in the population sample and in sub-cohorts exposed and not exposed to parental SSD history. We also examined the association of parental SSD history and social-emotional functioning, adjusting for demographic variables and maltreatment.
Medium-sized associations were identified between maltreatment and poor social competency, aggressive behaviour and hyperactivity/inattention; small associations were revealed between maltreatment and poor prosocial/helping and anxious/fearful behaviours. These associations did not differ greatly when adjusted for parental SSD, and were greater in magnitude among children with no history of parental SSD. Small associations between parental SSD and poor social-emotional functioning remained after adjusting for demographic variables and maltreatment.
Childhood maltreatment and history of parental SSD are associated independently with poor early childhood social-emotional functioning, with the impact of exposure to maltreatment on social-emotional functioning in early childhood of greater magnitude than that observed for parental SSDs. The impact of maltreatment was reduced in the context of parental SSDs. The influence of parental SSDs on later outcomes of maltreated children may become more apparent during adolescence and young adulthood when overt symptoms of SSD are likely to emerge. Early intervention to strengthen childhood social-emotional functioning might mitigate the impact of maltreatment, and potentially also avert future psychopathology.
Although mental disorders are significant predictors of educational attainment throughout the entire educational career, most research on mental disorders among students has focused on the primary and secondary school years.
The World Health Organization World Mental Health Surveys were used to examine the associations of mental disorders with college entry and attrition by comparing college students (n = 1572) and non-students in the same age range (18–22 years; n = 4178), including non-students who recently left college without graduating (n = 702) based on surveys in 21 countries (four low/lower-middle income, five upper-middle-income, one lower-middle or upper-middle at the times of two different surveys, and 11 high income). Lifetime and 12-month prevalence and age-of-onset of DSM-IV anxiety, mood, behavioral and substance disorders were assessed with the Composite International Diagnostic Interview (CIDI).
One-fifth (20.3%) of college students had 12-month DSM-IV/CIDI disorders; 83.1% of these cases had pre-matriculation onsets. Disorders with pre-matriculation onsets were more important than those with post-matriculation onsets in predicting subsequent college attrition, with substance disorders and, among women, major depression the most important such disorders. Only 16.4% of students with 12-month disorders received any 12-month healthcare treatment for their mental disorders.
Mental disorders are common among college students, have onsets that mostly occur prior to college entry, in the case of pre-matriculation disorders are associated with college attrition, and are typically untreated. Detection and effective treatment of these disorders early in the college career might reduce attrition and improve educational and psychosocial functioning.
With HST and WFPC2, galaxies in the Medium Deep Survey can be reliably classified to magnitudes I814 ≲ 22.0 in the F814W band, at a mean redshift . The main result is the relatively high proportion (~40%) of objects which are in some way irregular or anomalous, and which are of relevance in understanding the origin of the familiar excess population of faint galaxies. These diverse objects include compact galaxies, apparently interacting pairs, galaxies with superluminous starforming regions and diffuse low surface brightness galaxies of various forms. The ‘irregulars’ and ‘peculiar’ galaxies contribute most of the excess counts in the I-band at our limiting magnitude, and may explain the ‘faint blue galaxy’ problem.
The committee of the Carte du Ciel in 1910 adopted the following convention : That for Ao stars between magnitudes 5·5 and 6·5 the mean photographic magnitude should equal the mean Harvard visual magnitude. As a corollary, the colour index of Ao stars would then be zero.
The zero point of the photographic magnitudes of the International Polar Sequence was fixed as nearly as possible in accordance with this definition; but it was by no means certain that the magnitudes thus adopted for the few stars of the Sequence represented the zero point defined by all the Ao stars specified.