The effect of transportation and lairage on faecal shedding and carcass contamination with Escherichia coli O157 and O26 in very young calves in New Zealand.

The effect of transportation and lairage on the faecal shedding and post-slaughter contamination of carcasses with Escherichia coli O157 and O26 in young calves (4-7-day-old) was assessed in a cohort study at a regional calf-processing plant in the North Island of New Zealand, following 60 calves as cohorts from six dairy farms to slaughter. Multiple samples from each animal at pre-slaughter (recto-anal mucosal swab) and carcass at post-slaughter (sponge swab) were collected and screened using real-time PCR and culture isolation methods for the presence of E. coli O157 and O26 (Shiga toxin-producing E. coli (STEC) and non-STEC). Genotype analysis of E. coli O157 and O26 isolates provided little evidence of faecal-oral transmission of infection between calves during transportation and lairage. Increased cross-contamination of hides and carcasses with E. coli O157 and O26 between co-transported calves was confirmed at pre-hide removal and post-evisceration stages but not at pre-boning (at the end of dressing prior to chilling), indicating that good hygiene practices and application of an approved intervention effectively controlled carcass contamination. This study was the first of its kind to assess the impact of transportation and lairage on the faecal carriage and post-harvest contamination of carcasses with E. coli O157 and O26 in very young calves.

Nationwide prevalence and risk factors for faecal carriage of Escherichia coli O157 and O26 in very young calves and adult cattle at slaughter in New Zealand.

Nationwide prevalence and risk factors for faecal carriage of Escherichia coli O157 and O26 in cattle were assessed in a 2-year cross-sectional study at four large slaughter plants in New Zealand. Recto-anal mucosal swab samples from a total of 695 young (aged 4-7 days) calves and 895 adult cattle were collected post-slaughter and screened with real-time polymerase chain reaction (PCR) for the presence of E. coli O157 and O26 [Shiga toxin-producing E. coli (STEC) and non-STEC]. Co-infection with either serogroup of E. coli (O157 or O26) was identified as a risk factor in both calves and adult cattle for being tested real-time PCR-positive for E. coli O157 or O26. As confirmed by culture isolation and molecular analysis, the overall prevalence of STEC (STEC O157 and STEC O26 combined) was significantly higher in calves [6·0% (42/695), 95% confidence interval (CI) 4·4-8·1] than in adult cattle [1·8% (16/895), 95% CI 1·1-3·0] (P < 0·001). This study is the first of its kind in New Zealand to assess the relative importance of cattle as a reservoir of STEC O157 and O26 at a national level. Epidemiological data collected will be used in the development of a risk management strategy for STEC in New Zealand.

MRI guides diagnostic approach for ischaemic stroke.

BACKGROUND AND AIM: Identification of ischaemic stroke subtype currently relies on clinical evaluation supported by various diagnostic studies. The authors sought to determine whether specific diffusion-weighted MRI (DWI) patterns could reliably guide the subsequent work-up for patients presenting with acute ischaemic stroke symptoms. METHODS: 273 consecutive patients with acute ischaemic stroke symptoms were enrolled in this prospective, observational, single-centre NIH-sponsored study. Electrocardiogram, non-contrast head CT, brain MRI, head and neck magnetic resonance angiography (MRA) and transoesophageal echocardiography were performed in this prespecified order. Stroke neurologists determined TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification on admission and on discharge. Initial TOAST stroke subtypes were compared with the final TOAST subtype. If the final subtype differed from the initial assessment, the diagnostic test deemed the principal determinant of change was recorded. These principal determinants of change were compared between a CT-based and an MRI-based classification schema. RESULTS: Among patients with a thromboembolic DWI pattern, transoesophageal echocardiography was the principal determinant of diagnostic change in 8.8% versus 0% for the small vessel group and 1.7% for the other group (p<0.01). Among patients with the combination of a thromboembolic pattern on MRI and a negative cervical MRA, transoesophageal echocardiography led to a change in diagnosis in 12.1%. There was no significant difference between groups using a CT-based scheme. CONCLUSIONS: DWI patterns appear to predict stroke aetiologies better than conventional methods. The study data suggest an MRI-based diagnostic algorithm that can potentially obviate the need for echocardiography in one-third of stroke patients and may limit the number of secondary extracranial vascular imaging studies to approximately 10%.

Acute gastrointestinal illness in New Zealand: a community study.

We report the results of the New Zealand Acute Gastrointestinal Illness (AGI) Community Study, a representative cross-sectional community telephone survey of 3655 participants conducted over a 12-month period. Respondents were asked questions about vomiting and diarrhoea in the previous 4 weeks. At least one episode of diarrhoea and/or vomiting was reported by 8·6% of respondents, an incidence of 1·11 episodes/person per year. Prevalence was highest in children aged <5 years and lowest in those aged >64 years. The mean duration of illness was 2·5 days and most common symptoms were diarrhoea (82·5%), stomach cramps (75·7%), nausea (56·9%) and vomiting (49·0%). Extrapolation of the adjusted estimates indicates there are about 4·66 million episodes of AGI per year in New Zealand, nearly 1 million visits to the general medical practitioner, in excess of 300,000 courses of antibiotics being dispensed and more than 4·5 million days of paid work lost due to AGI. This represents a significant burden of disease.

Investigation of non-linear acoustic losses at the open end of a tube.

At high acoustic level, non-linear losses at the end of a tube are usually interpreted as the consequence of a jet formation at the tube end resulting in annular vortices dissipating part of the acoustic energy. Previous work has shown that two different regimes may occur. The present work, using particle image velocimetry visualization, lattice Boltzmann method simulation in 2D, and an analytical model, shows that the two different regimes correspond to situations for which the annular vortices remain attached to the tube (low acoustic particle velocity) or detached (high acoustic particle velocity).

Source attributed case-control study of campylobacteriosis in New Zealand.

BACKGROUND: Following an initial reduction in human campylobacteriosis in New Zealand after the implementation of poultry food chain-focused interventions during 2006-2008, further decline has been relatively small. We report a year-long study of notified campylobacteriosis cases, incorporating a case control study combined with a source attribution study. The purpose was to generate up-to-date evidence on the relative contributions of different sources of campylobacteriosis in New Zealand. METHODS: The study approach included: • A case-control study of notified cases (aged six months or more) sampled in a major urban centre (Auckland, every second case) and a mixed urban/rural area (Manawatu/Whanganui, every case), between 12 March 2018 and 11 March 2019. • Source attribution of human campylobacteriosis cases sampled from these two regions over the study period by modelling of multilocus sequence typing data of Campylobacter jejuni and C. coli isolates from faecal samples of notified human cases and relevant sources (poultry, cattle, sheep). RESULTS: Most cases (84%) were infected with strains attributed to a poultry source, while 14% were attributed to a cattle source. Approximately 90% of urban campylobacteriosis cases were attributed to poultry sources, compared to almost 75% of rural cases. Poultry consumption per se was not identified as a significant risk factor. However specific risk factors related to poultry meat preparation and consumption did result in statistically significantly elevated odds ratios. CONCLUSIONS: The overall findings combining source attribution and analysis of specific risk factors indicate that poultry meat remains a dominant pathway for exposure and infection.

The disease pyramid for acute gastrointestinal illness in New Zealand.

The disease pyramid of under-ascertainment for surveillance of acute gastrointestinal illness (AGI) in New Zealand has been estimated using 2005-2007 data on notifiable diseases, a community telephone survey, and a survey of diagnostic laboratories. For each notified case of AGI there were an estimated 222 cases in the community, about 49 of which visited a general practitioner. Faecal samples were requested from about 15 of these cases, and 13 samples were provided. Of the faecal samples, pathogens were detected in about three cases. These ratios are similar to those reported in other developed countries, and provide baseline measurements of the AGI burden in the New Zealand community.

Molecular and spatial epidemiology of human campylobacteriosis: source association and genotype-related risk factors.

The epidemiology of human campylobacteriosis is complex but in recent years understanding of this disease has advanced considerably. Despite being a major public health concern in many countries, the presence of multiple hosts, genotypes and transmission pathways has made it difficult to identify and quantify the determinants of human infection and disease. This has delayed the development of successful intervention programmes for this disease in many countries including New Zealand, a country with a comparatively high, yet until recently poorly understood, rate of notified disease. This study investigated the epidemiology of Campylobacter jejuni at the genotype-level over a 3-year period between 2005 and 2008 using multilocus sequence typing. By combining epidemiological surveillance and population genetics, a dominant, internationally rare strain of C. jejuni (ST474) was identified, and most human cases (65.7%) were found to be caused by only seven different genotypes. Source association of genotypes was used to identify risk factors at the genotype-level through multivariable logistic regression and a spatial model. Poultry-associated cases were more likely to be found in urban areas compared to rural areas. In particular young children in rural areas had a higher risk of infection with ruminant strains than their urban counterparts. These findings provide important information for the implementation of pathway-specific control strategies.

Breastfeeding by Women Living With Human Immunodeficiency Virus in a Resource-Rich Setting: A Case Series of Maternal and Infant Management and Outcomes.

The reduction in human immunodeficiency virus (HIV) transmission through breastmilk with maternal combination antiretroviral therapy (cART) has led many pregnant women living with HIV and healthcare providers to question exclusive formula feeding in resource-rich settings. Here, we describe cART prophylaxis in 3 breastfed infants whose mothers had sustained virologic suppression; all 3 of these infants remained uninfected.

Cognitive aid for neonatal resuscitation: a prospective single-blinded randomized controlled trial.

BACKGROUND: Retention of skills and knowledge after neonatal resuscitation courses (NRP) is known to be problematic. The use of cognitive aids is mandatory in industries such as aviation, to avoid dependence on memory when decision-making in critical situations. We aimed to prospectively investigate the effect of a cognitive aid on the performance of simulated neonatal resuscitation. METHODS: Thirty-two anaesthesia residents were recruited. The intervention group had a poster detailing the NRP algorithm and the control group did not. Video recordings of each of the performances were analysed using a previously validated checklist by a peer, an expert anaesthetist, and an expert neonatologist. RESULTS: The median (IQR) checklist score in the control group [18.2 (15.0-20.5)] was not significantly different from that in the intervention group [20.3 (18.3-21.3)] (P=0.08). When evaluated by the neonatologist, none of the subjects correctly performed all life-saving interventions necessary to pass the checklist. A minority of the intervention group used the cognitive aid frequently. CONCLUSIONS: Retention of skills after NRP training is poor. The infrequent use of the cognitive aid may be the reason that it did not improve performance. Further research is required to investigate whether cognitive aids can be useful if their use is incorporated into the NRP training.

Single-Shot Readout Performance of Two Heterojunction-Bipolar-Transistor Amplification Circuits at Millikelvin Temperatures.

High-fidelity single-shot readout of spin qubits requires distinguishing states much faster than the T1 time of the spin state. One approach to improving readout fidelity and bandwidth (BW) is cryogenic amplification, where the signal from the qubit is amplified before noise sources are introduced and room-temperature amplifiers can operate at lower gain and higher BW. We compare the performance of two cryogenic amplification circuits: a current-biased heterojunction bipolar transistor circuit (CB-HBT), and an AC-coupled HBT circuit (AC-HBT). Both circuits are mounted on the mixing-chamber stage of a dilution refrigerator and are connected to silicon metal oxide semiconductor (Si-MOS) quantum dot devices on a printed circuit board (PCB). The power dissipated by the CB-HBT ranges from 0.1 to 1 µW whereas the power of the AC-HBT ranges from 1 to 20 µW. Referred to the input, the noise spectral density is low for both circuits, in the 15 to 30 fA/[Formula: see text] range. The charge sensitivity for the CB-HBT and AC-HBT is 330 µe/[Formula: see text] and 400 µe/[Formula: see text], respectively. For the single-shot readout performed, less than 10 µs is required for both circuits to achieve bit error rates below 10-3, which is a putative threshold for quantum error correction.

Folic acid use in pregnancy and embryo selection.

OBJECTIVE: Folic acid supplement use is recommended in pregnancy to reduce the risk of neural tube defect but concerns have been raised that increasing folic acid intake may select for embryos with genotypes that increase disease risk in the offspring. Our aim was to test for this effect. DESIGN: Observational prospective cohort study. SETTING: Aberdeen Maternity Hospital. POPULATION OR SAMPLE: Women born before the introduction of folic acid advice (1970-80) and carrying singleton pregnancies (n = 1234) and their offspring (n = 1083) born after (2001-03). METHODS: We measured the genotype (MTHFR C677T and A1298C, MTR A2756G, MTRR A66G and TCN G776C) of mothers and their offspring, maternal supplement intake, intake of folate and vitamin B12 from natural foods and maternal blood folate and B12 status at 19 weeks of gestation. MAIN OUTCOME MEASURES: B vitamin related genotype of the offspring. RESULTS: There were no significant differences in any of the five genotype frequencies between mothers and their babies. There was no deviation from Hardy-Weinberg equilibrium in either generation and no change in the frequency of doubly homozygous MTHFR variants (677 TT/1298 CC). The genotype of the offspring was not related to maternal periconceptual supplement use, folate intake from foods or plasma and red cell folate measured at 19 weeks of gestation. CONCLUSIONS: We found no evidence to support the concern that folic acid fortification or supplement use in pregnancy results in selection of deleterious genotypes.

Nasal continuous positive airway pressure from high flow cannula versus Infant Flow for Preterm infants.

OBJECTIVE: To compare the feasibility of continuous positive airway pressure (CPAP) support generated by high flow nasal cannula with conventional CPAP for prevention of reintubation among preterm infants with a birth weight of

Inhibitors of fibrinolysis in amniotic fluid.

Amniotic fluid inhibited the fibrinolytic, amidolytic and esterolytic activity of urokinase. Kinetic studies with AGLMe demonstrated non-competitive inhibition. A major part of the inhibitory activity could be separated from alpha 1-antitrypsin by ion-exchange chromatography on DEAE-Sephadex A-50. Plasminogen activator prepared from porcine heart was not inhibited by amniotic fluid. Amniotic fluid also inhibited the caseinolytic and amidolytic activities of plasmin.

The inhibition by plasma of urokinase and tissue activator-induced fibrinolysis in pregnancy and the puerperium.

The activity of urokinase and tissue activator on fibrin plates was inhibited by plasma from women in the third trimester of pregnancy to a greater extent than by non-pregnant plasma. Pregnancy also inhibited the amidolytic activity of urokinase. The high molecular weight fractions of pregnancy plasma gel filtered on Sephadex G-200 showed comparable inhibitory activity against urokinase as fractions for non-pregnant plasma; in contrast with non-pregnant plasma, the lower molecular weight fractions of pregnancy plasma were markedly inhibitory against urokinase. Plasma exposed to lysine-Sepharose to remove plasminogen and then fractionated on Sephadex G-100 provided a pattern of three areas of inhibition against tissue activator similar to that seen in non-pregnant plasma. The urokinase-inhibitory activity of lower molecular weight fractions of plasma separated on Sephadex G-200 fell within 1 hr of delivery and fell further over the following 18 to 30 hr.

Prothrombotic genotypes are not associated with pre-eclampsia and gestational hypertension: results from a large population-based study and systematic review.

DNA samples collected as part of a large population-based case-control study were genotyped to examine the associations of five prothrombotic gene polymorphisms with pre-eclampsia (PE) and gestational hypertension (GH). The polymorphisms studied were: G1691A in Factor V (Factor V Leiden; FVL), prothrombin G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T, plasminogen activator inhibitor-1 4G/5G and the platelet collagen receptor alpha2beta1 C807T. A group of 404 women who developed PE were retrospectively compared with 303 women with GH and 164 control women. The frequency of genotypes did not differ significantly between cases of PE or GH and controls for any of the five polymorphisms studied. We conclude that these prothrombotic genotypes are not associated with the development of PE or GH in our population. The systematic review supports our conclusion, for all but cases of severe disease. which appear to be associated with FVL and, to a lesser extent, MTHFR C677T. There is little value in antenatal screening for prothrombotic polymorphisms to predict the development of pre-eclampsia or gestational hypertension.

Rosette inhibition levels during early human gestation.

The inhibitory effect of antilymphocyte globulin on spontaneous rosette formation by peripheral blood T cells between 10 and 21 weeks gestation was examined. No evidence was obtained from either a cross-sectional or a longitudinal study that increased rosette inhibition levels occur during early human pregnancy. Comparable values were found in oestrogen-treated women. The results are consistent with the view that the intrinsic reactivity of human T lymphocytes is unimpaired during gestation and oestrogen treatment.

Laboratory examination for Cryptosporidium spp in Scotland.

AIMS: To ascertain the present practices of Scottish microbiological laboratories for examining faecal samples for Cryptosporidium spp and to compare these with practices elsewhere. METHOD: A questionnaire was circulated to all 35 Scottish NHS bacteriological laboratories, where human stool samples are subjected to routine microbiological examination, to determine current laboratory testing methods and selection criteria used to examine faecal specimens for Cryptosporidium spp. RESULTS: All laboratories responded, of which the first began testing in 1984 and the last in 1990. At 15 sites all diagnostic stool samples submitted are routinely examined for Cryptosporidium spp. Elsewhere, selection criteria, principally based on age, specific request, and foreign travel, are used. The age distribution of Scottish cases differed significantly from that of the PHLS study of 16 laboratories (p < 0.001), probably as a result of the selection criteria used. The phenol-auramine staining procedure is used by 19 laboratories, with modified Ziehl-Neelsen staining used by 14 laboratories; eight used a second, confirmatory method. CONCLUSIONS: Currently applied selection criteria for examination of stools for Cryptosporidium in Scotland do not accord with published epidemiological data. Specimen selection based on age of patient and stool consistency may lead to cases of public health importance being missed. Nationally agreed criteria for testing of human samples based on epidemiological evidence are required.

The fibrinolytic system in pre-eclampsia.

Plasma fibrinolytic activity and plasma inhibitory activity against urokinase and tissue activator were measured in primigravidae with moderate or severe pre-eclampsia and in gestation-matched primigravidae with uncomplicated pregnancy. The mean levels of fibrinolytic activity and inhibitory activity against urokinase and tissue activator did not differ significantly between the pre-eclampsia and uncomplicated pregnancy groups. The pattern of inhibitory fractions of plasminogen-depleted plasma from pre-eclamptic and uncomplicated primigravidae after gel filtration on sephadex G-100 was similar.

Underlying causes of recurrent pneumonia in children.

OBJECTIVES: To determine the relative frequency of underlying factors for recurrent pneumonia and the proportion of patients in whom the underlying illness diagnosis was known prior to pneumonia recurrence. METHODS: Retrospective medical record review for a 10-year period from January 1987 through December 1997 at The Hospital for Sick Children in Toronto, Ontario, a tertiary care pediatric hospital. Recurrent pneumonia was defined as at least 2 pneumonia episodes in a 1-year period or at least 3 during a lifetime. RESULTS: Of 2952 children hospitalized with pneumonia, 238 (8%) met criteria for recurrent pneumonia. An underlying illness diagnosis was identified in 220 (92%). Of these, the underlying illness was diagnosed prior to pneumonia in 178 (81%), with the first episode in 25 (11%), and during recurrence in 17 (8%). Underlying illnesses included oropharyngeal incoordination with aspiration syndrome (114 cases [48%]), immune disorder (24 [10%]), congenital cardiac defects (22 [9%]), asthma (19 [8%]), pulmonary anomalies (18 [8%]), gastroesophageal reflux (13[5%]), and sickle cell anemia (10 [4%]). Clinical clues to diagnosis were recurrent infections at other locations and failure to thrive in the cases of an immune disorder, recurrences involving the same location in those with underlying pulmonary pathology, the association of respiratory symptoms with feeding in those with gastroesophageal reflux, or recurrent wheezing in asthmatic children. CONCLUSIONS: Recurrent pneumonia occurs in fewer than one tenth of all children hospitalized with pneumonia. Most of them have a known predisposing factor. The most common cause was oropharyngeal incoordination.