Structures of strong shocks in low-density helium and neon gases

Strong shocks are essential components in many high-energy-density environments such as inertial confinement fusion implosions. However, the experimental measurements of the spatial structures of such shocks are sparse. In this paper, the soft x-ray emission of a shock front in a helium gas mixture (90% helium, 10% neon) and a pure neon gas was spatially resolved using an imaging spectrometer. We observe that the shock width in the helium mixture gas is about twice as large as in the pure neon gas. Moreover, they exhibit different precursor layers, where electron temperature greatly exceeds ion temperature, extending for more than ∼350µm with the helium gas mixture but less than 30µm in the pure neon. At the shock front, calculations show that the electrons are strongly collisional with mean-free path two orders of magnitude shorter than the characteristic length of the shock. However, the helium ions can reach a kinetic regime as a consequence of their mean-free path being comparable to the scale of the shock. A radiation-hydrodynamic simulation demonstrates the impact of thermal conduction on the formation of the precursors with charge state, Z, playing a major role in heat flow and the precursor formation in both the helium mixture and the pure neon gases. Particle-in-cell simulations are also performed to study the ion kinetic effects on the formation of the observed precursors. A group of fast-streaming ions is observed leading the shock only in the helium gas mixture. Both effects explain the longer precursor layer in the helium shock.

Schistosomiasis control in adults: a call for action towards the goal of universal health coverage

Background

Schistosomiasis is a high-burden parasitic disease and endemic in tropical climates, such as Madagascar. Recently it is emerging in Europe. Chronic infections lead to disabilities including loss in work productivity. Current control strategies focus on school-aged children, thereby systematically excluding adults. The goal to eliminate the disease as a public health problem is aligned with the Sustainable Development Goals agenda, including Universal Health Coverage (UHC). We aim at assessing the distribution of schistosomiasis among adults in Madagascar, in order to promote more targeted public health initiatives against the disease.

Methods

In a cross-sectional study, 1477 blood samples were collected at three primary health-care centers in Madagascar from 03.21 to 01.22. A semi quantitative PCR assay was used to assess the presence of Schistosoma. Positivity rates with 95% Confidence Intervals (CI) were reported by gender and age groups.

Results

Our study population had a balanced gender distribution with 54.2% [CI: 51.7;56.8] of females and a median age of 37 years (IQR: 24-48). Preliminary results show an overall Schistosome positivity rate of 59.5% [CI: 57.0;62.0]. Positivity was higher in males 62.4% [CI: 58.7;66.1], than in females 57.1% [CI: 53.5;60.5]. Highest positivity was seen in the 18-34 year age group with 66.2% [CI: 62.7;69.6]. Lowest positivity of 46.2% [CI: 39.2;53.2] was observed in adults aged over 55 years.

Conclusions

Our preliminary results provide evidence of high positivity rates of schistosomiasis among adults in a highly endemic country. Differently from many studies, males seem more affected than females. The youngest age group, representing the more active workforce of a population, shows a higher positivity rate. Our data suggests that, in the logic of UHC and health as a human right, public health strategies for schistosomiasis need to be re-addressed towards a universal coverage of affected individuals.

Key messages

Awareness of Female Genital Schistosomiasis: A cross-sectional survey in rural Madagascar

Background

Infections with S. haematobium are endemic in tropical regions and emerging in some European countries. Prolonged chronic infection with S. haematobium can cause Female Genital Schistosomiasis (FGS), which can lead to serious gynecological conditions, including infertility. However, awareness of FGS is limited, as are adequate guidelines and public health strategies to manage the disease. The aim of this study is to determine the levels and quality of FGS awareness among women and healthcare workers (HCW) in the Boeny region of Madagascar, where the disease is endemic.

Methods

Data collection involved a cross-sectional survey of adult women (n = 694) and HCWs (n = 93) on topics, such as respondents’ sociodemographic background characteristics, FGS awareness, and risk perceptions. Results were analyzed using descriptive statistics including proportions and 95% confidence intervals.

Results

Of the 694 women included in the study, 11.2% (CI [9.0-13.8%]) had heard of FGS. Among these, 34.6% (CI [24.1-46.2%]) were unaware of the gynecological symptoms signature for FGS, and 41% (CI [30.0-52.7%]) were unaware of the urological symptoms of the disease. Out of the 93 HCW surveyed, 53.2% (CI [42.6-63.6%]) had heard of FGS. Among these, 42.0% (CI [28.1-56.8%]) were unaware of the gynecological symptoms, and 52.0% (CI [37.4-66.3%]) were unaware of the urological symptoms.

Conclusions

Preliminary results show overall low levels of FGS awareness among the study population. While more women reported to have never heard of FGS than HCW, the proportion of HCWs who did not know the gynecological and urological symptoms of FGS was higher. Given the occurrence of FGS in Europe and the chronic character of the disease it would be crucial to conduct similar investigations in Europe. Such findings can contribute to the design of targeted local and global FGS awareness campaigns to improve the health of women affected by this disease worldwide.

Key messages

• Awareness of FGS among the study population in Madagascar, an endemic country, is low.

• Lack of awareness can delay the identification of the disease and increase individual and community burden.

Exposure of pre-school aged children to schistosomiasis: a call for public health strategies

Background

Schistosomiasis is a disease of poverty, prevalent in tropical regions and emerging in Europe. Mass drug administration (MDA) is a common strategy to fight the disease. Pre-school aged children (PSAC) are conventionally considered not to be at high risk of infection and thus usually excluded from MDA. However, chronic infections at young ages can result in serious health consequences. Our study aims to better understand the schistosomiasis transmission routes in PSAC and risk perceptions among caretakers in the endemic context of Madagascar.

Methods

This is a cross-sectional sub-study embedded in the clinical trial freeBILy. Using a mixed methods approach, 86 women and their two-year-old children in four communities of the Amoron’ I Mania and Itasy regions of Madagascar in April 2022 were interviewed using structured questionnaires, focus group discussions and in-depth-interviews. Additionally, structured observational data were collected on the behaviours of 20 PSAC around waterbodies in the communities where notes and anonymised photos were taken.

Results

Preliminary analysis shows that knowledge of schistosomiasis, its transmission routes and effects is limited. Risky behaviours of children were reported during the observations. They joined their mothers during daily activities and spent between 3-60 mins in rivers, lakes and rice fields. The exposure time to potentially contaminated waters was sufficient to represent a risk for infection.

Conclusions

Even though our preliminary results show that PSAC are at risk of schistosomiasis infection, they are currently excluded from systematic public health interventions. The lack of risk awareness among caretakers in endemic countries calls for actions to establish tailored programs on health literacy and education. Treatment should be considered for PSAC as well as the implementation of awareness campaigns, both locally and globally given the re-occurrence of schistosomiasis in countries outside the tropics.

Key messages

• Pre-school aged children are exposed to the risk of early infection with schistosomiasis.

• Public health programs against schistosomiasis should address pre-school aged children in endemic countries and in health promotion strategies globally.

Changes in mitral regurgitation following acute myocardial infarction: early and long-term follow-up

Background

Mitral regurgitation (MR) is commonly observed following acute myocardial infarction (MI). Localised left ventricular (LV) remodelling in the region of papillary muscles together with impaired myocardial contractility promote MR. There is a paucity of long-term follow-up studies to determine whether the severity of MR observed post-MI, changes with time.

Purpose

This study retrospectively followed up patients with MR detected following acute MI (AMI) to investigate changes in MR severity with time and assess for pre-discharge predictors of MR regression or progression.

Methods

Clinical records of 1000 patients admitted with AMI between 2016 and 2017 to a single centre were retrospectively interrogated. One hundred and nine patients met the inclusion criteria of MR on pre-discharge transthoracic echocardiography (TTE) and follow-up TTE scans. Echocardiographic parameters were investigated to determine predictors of progression or regression at follow-up. Patients were divided according to those who had early follow-up TTE (within 1-year) and late follow-up TTE (beyond 1-year).

Results

Early follow-up TTE was performed in 73 patients at a median of 6 (IQR 3–9) months. Patients had a mean age of 69±13 years and were predominantly male 50/73 (68%). At baseline, relative MR severities were: 49/73 (67%) mild MR, 23/73 (32%) moderate MR and 1 (1%) severe MR. At follow-up, MR had completely resolved in 18/73 (23%) patients, while 39/73 (53%) had mild MR, 15/73 (21%) moderate MR and 1 (1%) severe MR. Compared to patients with no resolution of MR, those with completel resolution were younger (mean age 62±16 vs 72±11 years; p=0.015) but there were no other significant differences between the groups. Resolution at early follow-up did not significantly influence long-term mortality rates. Late follow-up TTE was performed in 69 patients at a median 2.4 (IQR 2–3.2) years. Pre-discharge, 49/69 (71%) patients had mild MR and 20/69 (29%) moderate MR. At follow-up, MR had completely resolved in 18/69 (26%), and amongst patients with persistent MR, proportion of severities were: 37/69 (54%) mild MR, 11/69 (16%) moderate MR and 3/69 (4%) severe MR. Patients with progression of mild MR were more likely to have lower left ventricular ejection fraction (LVEF: 47±15 vs 57±12%; p=0.010) and greater indexed left ventricular end-systolic volume (LVESVi: 37±23 vs 25±14 ml/m2; p<0.001) on pre-discharge TTE. Resolution of MR at late follow-up was associated with a reduction in long-term mortality [deaths: 2/55 (3%) vs 3/14 (21%); p=0.022] at a mean follow-up of 4.2 years from MI.

Conclusion

MR observed following AMI completely resolved in approximately one-quarter of patients at 6-month and 2-year follow-up. Progression of mild MR at long-term follow-up appears to be associated with increased mortality and is predicted by lower LVEF and greater LVESVi pre-discharge.

Funding Acknowledgement

Type of funding sources: None.

Study of enteric pathogens among children in the tropics and effects of prolonged storage of stool samples

The study was performed to compare real-time PCR after nucleic acid extraction directly from stool samples as well as from samples stored and transported on Whatman papers or flocked swabs at ambient temperature in the tropics. In addition, the possible suitability for a clear determination of likely aetiological relevance of PCR-based pathogen detections based on cycle threshold (Ct) values was assessed. From 632 Tanzanian children <5 years of age with and without gastrointestinal symptoms, 466 samples were subjected to nucleic acid extraction and real-time PCR for gastrointestinal viral, bacterial and protozoan pathogens. Equal or even higher frequencies of pathogen detections from Whatman papers or flocked swabs were achieved compared with nucleic acid extraction directly from stool samples. Comparison of the Ct values showed no significant difference according to the nucleic acid extraction strategy. Also, the Ct values did not allow a decision whether a detected pathogen was associated with gastrointestinal symptoms.

Left ventricular function and clinical heart failure after myocardial infarction revascularized with percutaneous coronary intervention - comparison between STEMI and NSTEMI in modern practice

Funding Acknowledgements

Type of funding sources: None.

Introduction

Left ventricular systolic dysfunction (LVSD) is a common consequence of myocardial infarction (MI). Data from historic series identified LVSD in up to 60% of patients post-MI. However, in modern practice, with high-sensitivity cardiac biomarkers leading to early detection of MI and widespread use of early revascularization, the prevalence of LVSD in the acute phase of MI and its impact on subsequent clinical heart failure remains unknown.

Purpose

To ascertain the prevalence of LVSD on pre-discharge echocardiography and its impact on subsequent clinical heart failure after type 1 MI treated with percutaneous coronary intervention (PCI) in a UK tertiary cardiac centre.

Methods

A retrospective electronic patient records review of consecutive patients with type 1 MI treated with PCI between January 2016 - December 2017. Patients treated conservatively or with surgical revascularization were excluded.

Results

1000 consecutive patients were identified and 948/1000 who had an inpatient echocardiogram prior to discharge were included in this analysis – 413 ST elevation MI (STEMI) and 535 non-ST elevation (NSTEMI). Median door to balloon time for STEMI was 42 minutes (IQR 28-79). Median time from symptom onset to intervention for NSTEMI was 3 days (IQR 1-6). LVSD was defined as left ventricular ejection fraction (LVEF) &lt;50% on transthoracic echocardiogram carried out during the hospital episode. LVSD was significantly more prevalent in patients with STEMI compared to NSTEMI (37.4% vs 17.3%, p &lt; 0.001). Median LVEF was significantly lower in the STEMI population (55%, IQR 45-60) compared to patients with NSTEMI (60%, IQR 54-65), p &lt; 0.001. However, rates of clinical heart failure at index presentation with MI did not vary significantly between STEMI and NSTEMI patients (6.1% vs 4.9%, p = 0.414). In stepwise multivariate regression models: age, peak troponin and previous coronary artery bypass grafting were predictors of LVEF, whereas LVEF and previous MI were predictors of clinical heart failure

Patients with LVSD on pre-discharge echocardiography had significantly higher rates of 30-day readmission with heart failure (2.9% vs 0.7%, p = 0.017), 30-day all-cause mortality (6.1% vs 2%, p = 0.001), 30-day cardiac mortality (5.7% vs 1%, p &lt; 0.001) and 2-year all-cause mortality (5.7% vs 1.6%, p = 0.001). However, at 2-years, there was no difference in hospital readmission with heart failure (0.8% vs 0.3%, p = 0.276). There were no significant differences between STEMI and NSTEMI patients for these endpoints.

Conclusions

Early revascularisation with PCI has led to a reduction in the prevalence of early LVSD post-MI compared to historical data. However, the presence of LVSD remains a powerful predictor of adverse clinical outcomes. Despite lower rates of LVSD on pre-discharge echocardiography in patients with NSTEMI compared with STEMI, the incidence of subsequent clinical heart failure is similar. This however may be underestimated due to survival bias.

Ischaemic mitral regurgitation: incidence, clinical and angiographic characteristics of 1000 patients with type 1 myocardial infarction undergoing percutaneous coronary intervention

Background

Previous studies of the incidence and severity of mitral regurgitation (MR) following acute myocardial infarction (MI) were limited by the study population (ST-elevation MI only), by diagnostic methods (lack of multiparametric quantification), or by the time-frame of study (late assessment post-MI). The true incidence of ischaemic MR (IMR) immediately following type 1 MI [non-ST-elevation (NSTEMI) and ST-elevation (STEMI)] patients in the modern era of universal early revascularisation remains unclear. Since even mild IMR confers a poor prognosis, factors which promote or protect against the development of MR require further evaluation.

Purpose

To determine the incidence, clinical and angiographic characteristics of patients with IMR following type 1 MI treated with PCI.

Methods

This was a single-centre study of 1000 consecutive, prospectively recruited patients admitted to the Queen Elizabeth Hospital Birmingham with type 1 MI who underwent PCI. Early inpatient transthoracic echocardiography (TTE) was performed by accredited echocardiographers using standard multiparametric quantification.

Results

MR was observed in 294/1000 patients (29.4%) post-MI, graded as mild (76%), moderate (21%) and severe (3%). Median time from symptom onset to PCI was 1 day (IQR 0–4) and to TTE 2 days (IQR 1–3).

Compared to patients without MR (MR-), those with MR (MR+) were older (73±12 years vs 66±13 years; p&lt;0.001), male (75% vs 64%; p&lt;0.001) and more likely to have a history of hypertension (HTN) (63% vs 55%; p=0.0117), heart failure (HF) (3.4% vs 1.1%; p=0.0140) and previous MI (28% vs 20%; p&lt;0.005). MR+ patients more frequently presented with HF (8.5% vs 4.2%; p=0.0075), lower LV ejection fraction (LVEF) (50±14% vs 55±11%; p&lt;0.001) and higher peak high sensitivity troponin T (765ng/L, IQR 170–3032 vs 400ng/L, IQR 51–1966; p&lt;0.0001).

MR+ patients were more likely to have severe disease in the left circumflex (LCx) (50% vs 33%; p&lt;0.0001) or right coronary artery (RCA) (51% vs 43%; p=0.0135). Incidence of severe disease in the left main stem and left anterior descending artery (LAD) did not significantly differ between the two groups.

Incidence of MR was equal (29%) amongst STEMI (126/431) and NSTEMI (168/569) patients. While the time to revascularisation did not affect the prevalence of MR following STEMI (linear regression analysis of door-to-balloon time in MR+ and MR- patients p=0.843), NSTEMI patients were more likely to develop MR if revascularisation was delayed (linear regression analysis of symptom onset to PCI time MR+ vs MR- p=0.061).

Conclusion

Almost 1/3 of patients with type 1 MI undergoing revascularisation have MR evident on pre-discharge TTE. Factors promoting MR include older age, male sex, HTN, HF, larger non-LAD territory infarct, and depressed LVEF. The incidence of MR following STEMIs and NSTEMIs is equal. Earlier revascularisation is unlikely to reduce MR in STEMI patients but may improve MR prevalence following NSTEMI.

Funding Acknowledgement

Type of funding source: None

Risk stratification on echocardiography and outcome in ischaemic mitral regurgitation

Background

Ischaemic mitral regurgitation (IMR) confers a poor prognosis. Transcatheter intervention may improve survival but benefit is likely to depend on severity of IMR relative to LV remodelling following myocardial infarction (MI). In theory, those with “discordant” IMR (significant regurgitant volume without severe LV dilatation or impairment), are expected to benefit most from mitral intervention. While subcategorization may help to inform treatment, there are no data on post-MI patients in this respect.

Purpose

To determine the incidence of discordant & concordant IMR categorised on echocardiography post-MI and impact on outcomes.

Methods

1000 consecutive patients admitted to our hospital with myocardial infarction who underwent coronary angioplasty were included. Early inpatient TTE was performed by accredited echocardiographers using standard multiparametric quantification.

Using TTE parameters, 4 subgroups were identified (figure) according to the degree of MR relative to LV remodelling. Thresholds were based on European guidelines (± 2SD from normal) and median value among survivors for vena contracta (VC):

– LVEF: 52% (♂), 54% (♀)

– Indexed LV end diastolic volume (LVEDVi): 74ml/m2 (♂), 61ml/m2 (♀)

– Effective regurgitant orifice area (EROA) ≥0.2cm2

– Regurgitant volume (RVol) ≥30ml

– VC ≥0.5cm

Results

MR was seen in 294/1000 patients (29.4%) with a severity of mild (76%), moderate (21%) and severe (3%). Concordant and discordant IMR were each seen in 16/294 (5%) of IMR patients post-MI.

After a mean follow up of 3.2 years, IMR patients had a 3% rate of heart failure (HF) within 1 year and 19% mortality. Non-survivors had significantly worse IMR (PISA 0.65±0.25cm vs 0.54±0.19cm; p=0.033; VC 0.63±0.25cm vs 0.49±0.18cm; p=0.014), worse LV function (LVEF 44±17% vs 51±13%; p&lt;0.001), larger LV (LVEDVi 67±23ml/m2 vs 60±22ml/m2; p=0.032) and larger indexed LA volume (LAVi) (44±22ml vs 35±15ml; p&lt;0.001). Those with concordant IMR had the worst survival (50%) although almost 1 in 5 of those with discordant MR died within the follow up period (19%). Using multivariable Cox regression, significant predictors of mortality included LVEF (p&lt;0.001; HR 0.96, 0.94–0.98) and LAVi (p&lt;0.001; HR 1.02, 1.01–1.03) but not LVEDVi.

Conclusion

1) Significant predictors of mortality in IMR include LA dilatation and decline in LVEF, but not LV dilatation.

2) Although discordant severe IMR is uncommon following MI, mortality if left untreated remains high. Attention should be paid to early selection of this cohort for intervention.

Funding Acknowledgement

Type of funding source: None

Water, sanitation, and hygiene (WASH) factors associated with growth between birth and 1 year of age in children in Soweto, South Africa: results from the Soweto Baby WASH study

Interventions to reduce undernutrition and improve child growth have incorporated improved water, sanitation, and hygiene (WASH) as part of disease transmission prevention strategies. Knowledge gaps still exist, namely, when and which WASH factors are determinants for growth faltering, and when WASH interventions are most effective at improving growth. This study drew cross-sectional data from a longitudinal cohort study and used hierarchical regression analyses to assess associations between WASH factors: water index, sanitation, hygiene index, and growth: height-for-age (HAZ), weight-for-age (WAZ), weight-for-height (WHZ) at 1, 6, and 12 months postpartum among infants a priori born healthy in Soweto, Johannesburg. Household access to sanitation facilities that were not safely managed was associated with a decrease in HAZ scores at 1 month (β = -2.24) and 6 months (β = -0.96); a decrease in WAZ at 1 month (β = -1.21), 6 months (β = -1.57), and 12 months (β = -1.92); and finally, with WHZ scores at 12 months (β = -1.94). Counterintuitively, poorer scores on the hygiene index were associated with an increase at 1 month for both HAZ (β = 0.53) and WAZ (β = 0.44). Provision of safely managed sanitation at household and community levels may be required before improvements in growth-related outcomes are obtained.

Intersectoral (in)activity: towards an understanding of public sector department links between water, sanitation and hygiene (WASH) and childhood undernutrition in South Africa

Associations between different forms of malnutrition and environmental conditions, including water, sanitation and hygiene (WASH), contribute to poor child health, nutritional status and physical growth. The primary responsibility for the provision of water and sanitation, as a basic service and human right, lies with the State, as such, a number of stakeholders are involved. Despite relatively high levels of WASH infrastructure coverage in South Africa, enteric infections and stunting remain high for a middle-income country. The aim of this study is to elucidate the landscape of WASH in South Africa in relation to nutritional status of children under the age of 5 years in the South African, Gauteng and City of Johannesburg contexts. The authors detailed the national and provincial public sector departments and through purposive sampling proceeded to map the various departments and associated policies that are responsible for the provision of WASH facilities, as well the nutritional status of children. Of the six policies identified for review, three mentioned WASH, nutrition and children; however, none explicitly linked WASH to nutritional status in children. An in-depth review and analysis of these three crucial policy documents was conducted. Finally, a set of expert interviews were conducted and a consensus development conference convened, with experts at the intersection between WASH and nutritional status. The authors found that the public sector would benefit from better integration of the concept of WASH into their policy, planning and implementation frameworks. The WASH sector should emphasize the role in which WASH plans consider the impact of WASH on the nutritional status of children. The various public sector departments involved in WASH service provision, and other WASH stakeholders, including community-based organizations, non-governmental organizations and intergovernmental organizations, should be involved in the decision-making of the nutrition sector.

[Procedure-specific postoperative gastrointestinal hemorrhage]

Gastrointestinal bleeding (GIB) can occur as a complicating issue in the postoperative course after visceral surgery. It can be of varying clinical extent ranging from mild anemia to fatal hemorrhagic shock. Symptomatic manifestations of a GIB are hematemesis, melena and hematochezia. The GIB are fundamentally differentiated into upper and lower GIB. While upper GIB is defined as the occurrence of endoluminal hemorrhage above the ligament of Treitz, correspondingly the definition of lower GIB is intraluminal bleeding distal to the duodenojejunal flexure. Knowledge of their procedure-related incidence during the postoperative course enables a better assessment of the necessary intervention.

Restoration of a Mandibular Incisor With a Computer-aided Design/Computer-aided Manufacturing Fabricated Anterior Onlay

The use of computer-aided design/computer-aided manufacturing (CAD/CAM) dentistry has triggered novel approaches to restoring teeth in ways that increase efficiency, improve esthetics, and conserve tooth structure. Endodontically treated mandibular incisors offer a challenging restorative opportunity due to the small amount of natural tooth structure and the required amount of reduction needed for restorative material. The case presented demonstrates how to leverage chairside CAD/CAM technology to restore a discolored and fractured endodontically treated mandibular incisor without the use of a post and core and completing the restoration in a single visit.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Chlamydiae in febrile children with respiratory tract symptoms and age-matched controls, Ghana

Members of the Chlamydiales order are obligate intracellular pathogens causing acute and chronic infectious diseases. Chlamydiaceae are established agents of community- and zoonotically acquired respiratory tract infections, and emerging pathogens among the Chlamydia-related bacteria have been implicated in airway infections. The role of both in airway infections in Africa is underexplored. We performed a case -control study on the prevalence of Chlamydiaceae and Chlamydia-related emerging pathogens in children with febrile respiratory tract infections in West Africa, Ghana. Using a pan-Chlamydiales broad-range real-time PCR, we detected chlamydial DNA in 11 (1.9%) of 572 hospitalized febrile children with respiratory tract symptoms and in 24 (4.3%) of 560 asymptomatic age-matched controls (p 0.03). Chlamydiaceae were found to be common among both symptomatic and healthy Ghanaian children, with Chlamydia pneumoniae being the most prevalent species. Parachlamydiaceae were detected in two children without symptoms but not in the symptomatic group. We identified neither Chlamydia psittaci nor Simkania negevensis but a member of a new chlamydial family that shared 90.2% sequence identity with the 16S rRNA gene of the zoonotic pathogen Chlamydia pecorum. In addition, we found a new Chlamydia-related species that belonged to a novel family sharing 91.3% 16S rRNA sequence identity with Candidatus Syngnamydia venezia. The prevalence and spectrum of chlamydial species differed from previous results obtained from children of other geographic regions and our study indicates that both, Chlamydiaceae and Chlamydia-related bacteria, are not clearly linked to clinical symptoms in Ghanaian children.

A Remote Assay for Measuring Canine Platelet Activation and the Inhibitory Effects of Antiplatelet Agents

BACKGROUND

Antiplatelet medications are increasingly used in dogs. Remote analysis of platelet activity is challenging, limiting assessment of antiplatelet drug efficacy.

HYPOTHESIS/OBJECTIVES

To evaluate a method used in humans for stimulation and remote analysis of canine platelet activity.

ANIMALS

Forty-five dogs of various ages without a coagulopathy or thrombocytopenia. Six were receiving antiplatelet medication.

METHODS

Prospective observational study. Platelets were stimulated with combinations of arachidonic acid (AA) and epinephrine (Epi) or adenosine diphosphate (ADP) and the thromboxane A₂ -mimetic U46619 (U4). PAMFix was added to the blood samples to facilitate delayed analysis of platelet activity. Activity was assessed by flow cytometric measurement of surface P-selectin (CD62P) expression.

RESULTS

Canine platelets could be stimulated with both AA/Epi and ADP/U4. The levels of P-selectin were significantly greater than paired, unstimulated samples (P < 0.001). Inhibition of P-selectin expression occurred after this stimulation by adding antiplatelet drugs in vitro. The efficacy of antiplatelet drugs in samples from treated dogs was also measurable ex vivo using this method. Delayed analysis of platelet activity at time points up to 22 days demonstrated excellent correlation between respective mf values at each time point (r²  = 0.92, P < 0.0001).

CONCLUSIONS AND CLINICAL IMPORTANCE

This study evaluated a new method to remotely assess canine platelet activity. It shows that PAMFix can be used for this purpose. This provides opportunities to interrogate the inhibitory action of antiplatelet drugs in clinical settings.

A simple laboratory algorithm for diagnosis of melioidosis in resource-constrained areas: a study from north-central Vietnam

OBJECTIVES

Melioidosis may be endemic in many tropical developing countries, but diagnosis of the disease is currently unreliable in resource-limited areas. We aimed to validate a simple and cheap laboratory algorithm for the identification of Burkholderia pseudomallei from clinical specimens in parts of Vietnam where the disease has not previously been reported.

METHODS

In June 2015, we conducted training courses at five general hospitals in north-central provinces in order to raise awareness of the disease and to introduce a simple and cheap laboratory identification algorithm for B. pseudomallei including the three-antibiotic disc test.

RESULTS

Until the end of the year (7 months later), 94 suspected B. pseudomallei strains resistant to gentamicin and colistin but sensitive to amoxicillin/clavulanic acid were detected in clinical specimens from 70 patients. All strains were further confirmed as B. pseudomallei by using a specific TTSS1 real-time PCR assay and recA sequencing analysis. Among positive blood cultures, positive rates with B. pseudomallei ranged from 3.4% (5/147) to 10.2% (32/312) in the various clinics. A total of 82.8% (58/70) patients were bacteraemic, with a mortality of 50% (18/36) among patients with known outcome. No death occurred in nonbacteraemic patients.

CONCLUSIONS

Our results demonstrate that the introduction of a simple and easy-to-perform laboratory algorithm for the identification of B. pseudomallei from clinical samples, together with clinical awareness raising, can lead to the diagnosis of a significant number of melioidosis cases in resource-limited clinical laboratories which previously did not identify the pathogen.

Mobile phone-based interactive voice response as a tool for improving access to healthcare in remote areas in Ghana - an evaluation of user experiences

OBJECTIVES

To investigate and determine the factors that enhanced or constituted barriers to the acceptance of an mHealth system which was piloted in Asante-Akim North District of Ghana to support healthcare of children.

METHODS

Four semi-structured focus group discussions were conducted with a total of 37 mothers. Participants were selected from a study population of mothers who subscribed to a pilot mHealth system which used an interactive voice response (IVR) for its operations. Data were evaluated using qualitative content analysis methods. In addition, a short quantitative questionnaire assessed system's usability (SUS).

RESULTS

Results revealed 10 categories of factors that facilitated user acceptance of the IVR system including quality-of-care experience, health education and empowerment of women. The eight categories of factors identified as barriers to user acceptance included the lack of human interaction, lack of update and training on the electronic advices provided and lack of social integration of the system into the community. The usability (SUS median: 79.3; range: 65-97.5) of the system was rated acceptable.

CONCLUSIONS

The principles of the tested mHealth system could be of interest during infectious disease outbreaks, such as Ebola or Lassa fever, when there might be a special need for disease-specific health information within populations.

An investigation of users' attitudes, requirements and willingness to use mobile phone-based interactive voice response systems for seeking healthcare in Ghana: a qualitative study

OBJECTIVES

In implementing mobile health interventions, user requirements and willingness to use are among the most crucial concerns for success of the investigation and have only rarely been examined in sub-Saharan Africa. This study aimed to specify the requirements of caregivers of children in order to use a symptom-based interactive voice response (IVR) system for seeking healthcare. This included (i) the investigation of attitudes towards mobile phone use and user experiences and (ii) the assessment of facilitators and challenges to use the IVR system.

STUDY DESIGN

This is a population-based cross-sectional study.

METHODS

Four qualitative focus group discussions were conducted in peri-urban and rural towns in Shai Osudoku and Ga West district, as well as in Tema- and Accra Metropolitan Assembly. Participants included male and female caregivers of at least one child between 0 and 10 years of age. A qualitative content analysis was conducted for data analysis.

RESULTS

Participants showed a positive attitude towards the use of mobile phones for seeking healthcare. While no previous experience in using IVR for health information was reported, the majority of participants stated that it offers a huge advantage for improvement in health performance. Barriers to IVR use included concerns about costs, lack of familiarly with the technology, social barriers such as lack of human interaction and infrastructural challenges. The establishment of a toll-free number as well as training prior to IVR system was discussed for recommendation.

CONCLUSIONS

This study suggests that caregivers in the socio-economic environment of Ghana are interested and willing to use mobile phone-based IVR to receive health information for child healthcare. Important identified users' needs should be considered by health programme implementers and policy makers to help facilitate the development and implementation of IVR systems in the field of seeking healthcare.

Macrophage activation syndrome triggered by coeliac disease: a unique case report

BACKGROUND

Macrophage activation syndrome is described as a "clinical syndrome of hyperinflammation resulting in an uncontrolled and ineffective immune response" in the context of an autoinflammatory or rheumatic disease. Current associations of macrophage activation syndrome with autoimmune disease most notably include a host of rheumatological conditions and inflammatory bowel disease. Epidemiological studies have shown that macrophage activation syndrome is precipitated by autoimmune disease more commonly than previously thought. Diagnosing the precipitating factor is essential for effective treatment and prognosis.

CASE PRESENTATION

We report a case of a six year old girl with coeliac disease diagnosed after two episodes of secondary haemophagocytic lymphohistiocytosis. Her condition only responded to treatment once the patient was placed on a gluten free diet. Further immunological testing confirmed anti-transglutaminase and anti-endomysial antibodies, however histological biopsy was deemed inappropriate due to the severity of her condition. She has remained stable with no further episodes of macrophage activation syndrome since commencing a gluten free diet.

CONCLUSION

This case report is the first literature that links macrophage activation syndrome to coeliac disease and highlights the challenge of diagnosing coeliac disease with unusual features such as associated prolonged fever. Clinicians should have a low threshold for screening children with other autoimmune diseases for coeliac disease.

Type III and Type IV Endoleak: Toward a Complete Definition of Blood Flow in the Sac after Endoluminal AAA Repair

In this document the authors continue to refine their seminal categorization of endoleak, a major complication of endovascular aneurysm repair. In addition to type I (related to the graft device itself) and type II (retrograde flow from collateral branches) endoleak, they propose two new categories: endoleak due to fabric tears, graft disconnection, or disintegration would be classified type III, and flow through the graft presumed to be associated with graft wall “porosity” would be categorized as type IV endoleak.

Endoleak as a Complication of Endoluminal Grafting of Abdominal Aortic Aneurysms: Classification, Incidence, Diagnosis, and Management

The inability to obtain or maintain a secure seal between a vessel wall and a transluminally implanted intra-aneurysmal graft is a complication unique to the evolving technique of endovascular aneurysm exclusion. Because the term “leak” has long been associated with aneurysm rupture, the term “endoleak” is proposed as a more definitive description of this phenomenon.

Embracing both persistent blood flow into the aneurysmal sac from within or around the graft (graft related) and from patent collateral arteries (nongraft related), endoleak can be classified as primary or secondary depending on the time of occurrence (within 30 days of implantation or following apparent initial seal, respectively).

Diagnostic techniques to detect endoleak include arteriography, intraprocedural pressure monitoring, contrast-enhanced computed tomography, abdominal X ray, and duplex scanning. Management strategies for endoleak range from observation with periodic imaging surveillance to correction by additional endoluminal or surgical procedures.

Standardization of the terminology describing this important sequela to endovascular aneurysm exclusion should facilitate uniform reporting of clinical trial data vital to the evaluation of this emerging technique.

Tropheryma whipplei in children with diarrhoea in rural Ghana

Tropheryma whipplei has been hypothesized to be able to cause diarrhoea, but data from young children are scarce. In this hospital-based case-control study 534 stool samples of children aged between 2 months and 15 years from rural Ghana were analysed for the presence of T. whipplei. Overall stool prevalence of T. whipplei was high (27.5%). Although there was no difference in T. whipplei carriage overall between cases and controls, cases aged between 0 and 12 months carried T. whipplei in their stool twice as often as controls without diarrhoea. The results from this study may support the hypothesis that T. whipplei can cause diarrhoea in first-time infection.

A Demonstration Project in New York and Virginia: Retrofitting Cost-Effective Roll-over Protective Structures (CROPS) on Tractors

The NIOSH cost-effective roll-over protective structure (CROPS) demonstration project sought to determine whether three prototype roll-over protective structures (ROPS) designed to be retrofitted on Ford 8N, Ford 3000, Ford 4000, and Massey Ferguson 135 tractors could be installed in the field and whether they would be acceptable by the intended end users (farmers). There were a total of 50 CROPS. demonstrators (25 in New York and 25 in Virginia), with 45 observers attending the New York CROPS demonstrations and 36 observers attending the Virginia CROPS demonstrations, for a total of 70 participants in New York and 61 in Virginia. The oldest retrofitted tractors were 77 to 62 years old, while the newest retrofitted tractors were 40 to 37 years old. The most frequently retrofitted tractor in the CROPS demonstration project was a Ford 3000 series tractor (n = 19; 38%), followed by Ford 4000 (n = 11; 22%), Massey Ferguson 135 (n = 11; 22%), and Ford 8N (n = 9; 18%). A major issue of CROPS retrofitting was the rear wheel fenders. The effort involved in disassembling the fenders (removing the old bolts was often faster by cutting them with a torch), modifying the fender mounting brackets, and then reinstalling the fenders with the CROPS generally required the most time. In addition, various other semi-permanent equipment attachments, such as front-end loaders, required additional time and effort to fit with the CROPS. Demonstrators were asked to rank the reasons why they had not retrofitted their tractors with ROPS until they had enrolled in the CROPS demonstration program. ROPS "cost too much" was ranked as the primary reason for participants in both states (80% for New York and 88% for Virginia). The second highest ranked reasons were "ROPS wasn't available" for Virginia (80%) and "hassle to find ROPS" for New York (69%). The third highest ranked reasons were "not enough time to find ROPS" for New York (67%) and "hassle to find ROPS" for Virginia (79%). All demonstrators and observers indicated that they were glad to have participated in the CROPS project.

Group B Streptococci serotype distribution in pregnant women in Ghana: assessment of potential coverage through future vaccines

OBJECTIVE

Group B streptococcal (GBS) colonization of pregnant women can lead to subsequent infection of the new-born and potentially fatal invasive disease. Data on GBS colonization prevalence and serotype distribution from Africa are scarce, although GBS-related infections are estimated to contribute substantially to infant mortality. In recent years, GBS vaccine candidates provided promising results in phase I and II clinical trials. We aimed to assess the prevalence and serotype distribution of GBS in Ghana since this knowledge is a prerequisite for future evaluation of vaccine trials.

METHODS

This double-centre study was conducted in one rural and one urban hospital in central Ghana, West Africa. Women in late pregnancy (≥35 weeks of gestation) attending the antenatal care clinic (ANC) provided recto-vaginal swabs for GBS testing. GBS isolates were analysed for serotype and antibiotic susceptibility. GBS-positive women were treated with intrapartum antibiotic prophylaxis (IAP) according to current guidelines of the Center for Disease Control and Prevention (CDC).

RESULTS

In total, 519 women were recruited at both study sites, recto-vaginal swabs were taken from 509. The overall prevalence of GBS was 19.1% (18.1% in rural Pramso and 23.1% in urban Kumasi, restrospectively). Capsular polysaccharide serotype (CPS) Ia accounted for the most frequent serotype beyond all isolates (28.1%), followed by serotype V (27.1%) and III (21.9%). No resistance to Penicillin was found, resistances to second line antibiotics clindamycin and erythromycin were 3.1% and 1%, respectively.

DISCUSSION

Group B Streptococcus serotype distribution in Ghana is similar to that worldwide, but variations in prevalence of certain serotypes between the urban and rural study site were high. Antibiotic resistance of GBS strains was surprisingly low in this study.

Hybrid Origin of Populus * jackii Confirmed by Gas Chromatography-Mass Spectrometry Analysis of Its Bud Exudate

Bud exudate of Populus balsamifera contains an array of characteristic compounds. Bud exudate of P. deltoides contains a different array of characteristic compounds. The exudate of P. x jackii contains compounds characteristic of both P. balsamifera and P. deltoides, indicating its hybrid origin.

Evaluation of a whole blood remote platelet function test for the diagnosis of mild bleeding disorders

BACKGROUND

Mild platelet function disorders (PFDs) are complex and difficult to diagnose. The current gold standard test, light transmission aggregometry (LTA), including lumi-aggregometry, is time and labour intensive and blood samples must be processed within a limited time after venepuncture. Furthermore, many subjects with suspected PFDs do not show a platelet abnormality on LTA.

OBJECTIVE

To assess the diagnostic potential of an easy-to-use remote platelet function test (RPFT) as a diagnostic pre-test for suspected PFDs.

METHODS

A remote platelet function test was compared with lumi-aggregometry in participants recruited to the Genotyping and Phenotyping of Platelets Study (GAPP, ISRCTN 77951167). For the RPFT, whole blood was stimulated with platelet agonists, stabilized with PAMFix and returned to the central laboratory for analysis of P-selectin and CD63 by flow cytometry.

RESULTS

For the 61 study participants (42 index cases and 19 relatives) there was a good agreement between lumi-aggregometry and the RPFT, with diagnosis being concordant in 84% of cases (κ = 0.668, P < 0.0001). According to both tests, 29 participants were identified to have a deficiency in platelet function and 22 participants appeared normal. There were four participants where lumi-aggregometry revealed a defect but the RPFT did not, and six participants where the RPFT detected an abnormal platelet response that was not identified by lumi-aggregometry.

CONCLUSION

This study suggests that the RPFT could be an easy-to-use pre-test to select which participants with bleeding disorders would benefit from extensive platelet phenotyping. Further development and evaluation of the test are warranted in a wider population of patients with excessive bleeding and could provide informative screening tests for PFDs.

Selecting target populations for ROPS retrofit programs in Pennsylvania and Vermont

Agriculture has the highest injury and fatality rates when compared with other U.S. industries, and tractor overturns remain the leading cause of agricultural fatalities. Rollover protection structures (ROPS) are the only proven devices to protect a tractor operator in the event of an overturn. These devices are 99% effective when used with a seatbelt. Nearly 49% of tractors in the U.S. are not equipped with a ROPS. Interventions such as social marketing, community awareness campaigns, and financial incentives have been directed at encouraging farmers to install ROPS on their unprotected tractors. The purpose of this study was to conduct similar comparisons of ROPS protection and readiness to retrofit in different segments of the Vermont and Pennsylvania farm communities. A telephone survey was used to collect data on ROPS prevalence, farm demographic characteristics, and farmer's stage of change relative to installing ROPS on farm tractors. Our data provide new and unique information on the prevalence of ROPS-equipped tractors relative to commodity, farm size, and a variety of other demographic variables. Extrapolating from these data, the commodities studied account for roughly 162,072 tractors across the two states. Of these, 85,927 (53%) do not have ROPS. Of these unprotected tractors, 77,203 are in Pennsylvania and 8,724 are in Vermont. Our other two research questions dealt with the farmer's stage of change and possible ways to segment this population. The stage of change portion of our work demonstrates that most Pennsylvania and Vermont farmers are not contemplating ROPS retrofitting in the near future. Since no major differences were found in the stage of change, the number of unprotected tractors was examined for each of the commodity groups. In Pennsylvania, 29% of all unprotected tractors were found on cash crop farms. This trend was even more apparent on smaller farms than large farms. This led to the selection of smaller cash crop farms as the target audience for social marketing messages. In contrast, researchers in Vermont found a bimodal distribution of unprotected tractors. Of all the commodity groups surveyed in Vermont, vegetable and cash crop farmers were least likely to have even one protected tractor to use on the farm. Probably the most encouraging finding from this study is that over 85% of Pennsylvania farms and over 87% of Vermont farms surveyed had at least one tractor available that had ROPS protection. Of those farms, 25.5% of the Pennsylvania farms and 46% of the Vermont farms have ROPS on all of their tractors. Both of these findings were greater than the findings from a 2006 survey of New York State farms, which found that 75% of surveyed New York farms have ROPS on at least one tractor and 18% have ROPS on all tractors. Even with these encouraging data, the goal of 100% of tractors with ROPS is far from being met. There are still an estimated 90,000 unprotected tractors on Pennsylvania and Vermont farms, and these farm owners are currently unmotivated to install ROPS. However as demonstrated in New York State, it may be possible to use social marketing that combines persuasive messages and cost-sharing to persuade these farmers that ROPS are indeed important and accessible.

Extrapolating respiratory tract infection incidences to a rural area of Ghana using a probability model for hospital attendance

OBJECTIVE

The aim of the current study was to extrapolate incidences for respiratory tract infections (RTI) using referral data from a local hospital in Ghana weighted by the individual likelihood of a hospital visit.

METHODS

Diagnoses from children visiting a rural hospital in Ghana during August 2007 to September 2008 were recorded. A logistic regression model, based on a population study conducted within the hospital catchment area, was used to calculate the individual probability of clinic attendance and to extrapolate the number of recorded cases. Cumulative incidences for children living in the hospital catchment area were estimated.

RESULTS

Upper RTI was the most common respiratory diagnosis, with an extrapolated incidence of 17481 cases per 100000 per year, followed by pneumonia with an incidence of 2496 per 100 000 per year. All diseases analyzed were most common in the first year of life.

CONCLUSIONS

In general the study results are in line with comparable studies. Several methodological issues biasing the results in different directions were identified. For example, opportunistic infections that are more often observed in hospital attendees are likely to be overestimated. However, the applied approach presents a tool for areas where disease monitoring systems are not established.

Mechanism of generating fast electrons by an intense laser at a steep overdense interface

The acceleration and heating of electrons by an intense laser normally incident on a steep overdense plasma interface is investigated using the particle-in-cell code osiris. Energetic electrons are generated by the laser's electric field in the vacuum region within λ/4 of the surface. Only those electrons which originate within the plasma with a sufficiently large transverse momentum can escape the plasma. This mechanism relies on the standing wave structure created by the incoming and reflected wave and is therefore very different for linear and circularly polarized light.

Evaluation of mass spectrometric methods for detection of the anti-protozoal drug imidocarb

Imidocarb [N,N'-bis[3-(4,5-dihydro-1H-imidazol-2-yl)phenyl]urea, C(19)H(20)N(6)O(1), m.w. 348.41] is a symmetrical carbanilide derivative used to treat disease caused by protozoans of the Babesia genus. Imidocarb, however, is also considered capable of suppressing Babesia-specific immune responses, allowing Babesia-positive horses to pass a complement fixation test (CFT) without eliminating the infection. This scenario could enable Babesia-infected horses to pass CFT-based importation tests. It is imperative to unequivocally identify and quantify equine tissue residues of imidocarb by mass spectrometry to address this issue. As a pretext to development of sensitive tissue assays, we have investigated possibilities of mass spectrometric (MS) detection of imidocarb. Our analyses disclosed that an unequivocal mass spectral analysis of imidocarb is challenging because of its rapid fragmentation under standard gas chromatography (GC)-MS conditions. In contrast, solution chemistry of imidocarb is more stable but involves distribution into mono- and dicationic species, m/z 349 and 175, respectively, in acid owing to the compound's inherent symmetrical nature. Dicationic imidocarb was the preferred complex as viewed by either direct infusion-electrospray-MS or by liquid chromatography (LC)-MS. Dicationic imidocarb multiple reaction monitoring (MRM: m/z 175 → 162, 145, and 188) therefore offer the greatest opportunities for sensitive detection and LC-MS is more likely than GC-MS to yield a useful quantitative forensic analytical method for detecting imidocarb in horses.