Cardiovascular and health cost impacts of cuff blood pressure underestimation and overestimation of invasive aortic systolic blood pressure.

OBJECTIVE: Hypertension management is directed by cuff blood pressure (BP), but this may be inaccurate, potentially influencing cardiovascular disease (CVD) events and health costs. This study aimed to determine the impact on CVD events and related costs of the differences between cuff and invasive SBP. METHODS: Microsimulations based on Markov modelling over one year were used to determine the differences in the number of CVD events (myocardial infarction or coronary death, stroke, atrial fibrillation or heart failure) predicted by Framingham risk and total CVD health costs based on cuff SBP compared with invasive (aortic) SBP. Modelling was based on international consortium data from 1678 participants undergoing cardiac catheterization and 30 separate studies. Cuff underestimation and overestimation were defined as cuff SBP less than invasive SBP and cuff SBP greater than invasive SBP, respectively. RESULTS: The proportion of people with cuff SBP underestimation versus overestimation progressively increased as SBP increased. This reached a maximum ratio of 16 : 1 in people with hypertension grades II and III. Both the number of CVD events missed (predominantly stroke, coronary death and myocardial infarction) and associated health costs increased stepwise across levels of SBP control, as cuff SBP underestimation increased. The maximum number of CVD events potentially missed (11.8/1000 patients) and highest costs ($241 300 USD/1000 patients) were seen in people with hypertension grades II and III and with at least 15 mmHg of cuff SBP underestimation. CONCLUSION: Cuff SBP underestimation can result in potentially preventable CVD events being missed and major increases in health costs. These issues could be remedied with improved cuff SBP accuracy.

Accuracy of cuff blood pressure and systolic blood pressure amplification.

Automated cuff measured blood pressure (BP) is the global standard used for diagnosing hypertension, but there are concerns regarding the accuracy of the method. Individual variability in systolic BP (SBP) amplification from central (aorta) to peripheral (brachial) arteries could be related to the accuracy of cuff BP, but this has never been determined and was the aim of this study. Automated cuff BP and invasive brachial BP were recorded in 795 participants (74% male, aged 64 ± 11 years) receiving coronary angiography at five independent research sites (using seven different automated cuff BP devices). SBP amplification was recorded invasively by catheter and defined as brachial SBP minus aortic SBP. Compared with invasive brachial SBP, cuff SBP was significantly underestimated (130 ± 18 mmHg vs. 138 ± 22 mmHg, p < 0.001). The level of SBP amplification varied significantly among individuals (mean ± SD, 7.3 ± 9.1 mmHg) and was similar to level of difference between cuff and invasive brachial SBP (mean difference -7.6 ± 11.9 mmHg). SBP amplification explained most of the variance in accuracy of cuff SBP (R2 = 19%). The accuracy of cuff SBP was greatest among participants with the lowest SBP amplification (ptrend < 0.001). After cuff BP values were corrected for SBP amplification, there was a significant improvement in the mean difference from the intra-arterial standard (p < 0.0001) and in the accuracy of hypertension classification according to 2017 ACC/AHA guideline thresholds (p = 0.005). The level of SBP amplification is a critical factor associated with the accuracy of conventional automated cuff measured BP.

Sex Differences in Blood Pressure and Potential Implications for Cardiovascular Risk Management.

BACKGROUND: Accurate blood pressure (BP) measurement is critical for optimal cardiovascular risk management. Age-related trajectories for cuff-measured BP accelerate faster in women compared with men, but whether cuff BP represents the intraarterial (invasive) aortic BP is unknown. This study aimed to determine the sex differences between cuff BP, invasive aortic BP, and the difference between the 2 measurements. METHODS: Upper-arm cuff BP and invasive aortic BP were measured during coronary angiography in 1615 subjects from the Invasive Blood Pressure Consortium Database. This analysis comprised 22 different cuff BP devices from 28 studies. RESULTS: Subjects were 64±11 years (range 40-89) and 32% women. For the same cuff systolic BP (SBP), invasive aortic SBP was 4.4 mm Hg higher in women compared with men. Cuff and invasive aortic SBP were higher in women compared with men, but the sex difference was more pronounced from invasive aortic SBP, was the lowest in younger ages, and the highest in older ages. Cuff diastolic blood pressure overestimated invasive diastolic blood pressure in both sexes. For cuff and invasive diastolic blood pressure separately, there were sex*age interactions in which diastolic blood pressure was higher in younger men and lower in older men, compared with women. Cuff pulse pressure underestimated invasive aortic pulse pressure in excess of 10 mm Hg for both sexes in older age. CONCLUSIONS: For the same cuff SBP, invasive aortic SBP was higher in women compared with men. How this translates to cardiovascular risk prediction needs to be determined, but women may be at higher BP-related risk than estimated by cuff measurements.

Performance of the South African triage score among HIV positive individuals presenting to an emergency department.

Introduction: Over a quarter of patients presenting to South African Emergency Centres (EC) have concurrent human immunodeficiency virus (HIV), yet it is unclear how this impacts their presenting complaints, the severity of illness, and overall resource needs in the EC. The primary objective of this study was to compare the performance of the South African Triage Score (SATS) in people living with HIV (PLWH) compared to HIV-negative patients. Secondary objectives included comparing the presentation characteristics and resource utilisation of these populations. Methods: A prospective cross-sectional observational study was conducted in the Livingstone Hospital EC, Gqeberha, South Africa, to compare triage designation and clinical outcomes in PLWH and HIV-negative patients. In this six-week study, all eligible patients received point-of-care HIV testing and extensive data abstraction, including SATS designation and EC clinical course. Descriptive statistical analysis was completed, and a log-binomial model was used to examine the association between HIV status and clinical outcomes using crude (unadjPR) and adjusted prevalence ratios (adjPR). Results: During the study period, 755 adult patients who consented to a POC HIV test were enrolled, of which 193 (25.6%) were HIV positive. HIV-positive patients were significantly more likely to be admitted compared to their HIV-negative counterparts when triaged as low acuity (adjPR 1.48, 95% CI 1.14-1.92, (p=0.003)). HIV-positive patients were also significantly more likely to receive laboratory testing when triaged as low acuity (adjPR 1.31, 95% CI 1.08-1.59 (p=0.006)) and as high acuity (adjPR 1.38, 95% CI 1.08-1.59 (p=0.034)) compared to HIV negative patients of the same triage categories. Conclusion: In our study, PLWH, compared to HIV-negative patients in the same category, were more likely to be admitted and require more EC resources, thus alluding to possible under triage of HIV-positive patients under the current SATS algorithm.

Differences in intimate partner violence exposure across college, crowdsourced, and at-risk samples.

OBJECTIVE: Intimate partner violence (IPV) is a pervasive and common form of violence against women. IPV is multifaceted, with physical, sexual, and/or psychological means of perpetration, and has detrimental effects on women's mental health. IPV generally affects women; however, how IPV differentially affects different groups of women is less clear. Women who are socioeconomically vulnerable are often considered at risk for IPV, although women in college are also often the topic of IPV research due both to high rates of IPV and to ease of study recruitment. There is increasing research on the effects of IPV in a third group of women, those recruited through online platforms (i.e., crowdsourcing). How IPV differs across these three samples has yet to be examined. METHOD: In this study, we examined differences in IPV exposure across three samples of women, at risk (n = 144), college (n = 654), and crowdsourced (n = 168), using a Bayesian approach to general linear modeling. RESULTS: Results indicated that the majority of women in each sample experienced some IPV. Results further suggested that women in the crowdsourced sample had the highest exposure to IPV in general and to physical IPV, sexual IPV, and IPV-related injury in particular, whereas women in the at-risk sample had the highest rates of psychological IPV. CONCLUSION: These findings highlight the importance of sampling in studies of IPV and thus have ramifications for future research. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Undiagnosed comorbidities among individuals hospitalised with COVID-19 in South African public hospitals.

BACKGROUND: Previous studies have reported comorbid disease, including hypertension, diabetes mellitus, chronic cardiac and renal disease, malignancy, HIV, tuberculosis (TB) and obesity, to be associated with COVID­19 mortality. National demographic surveys have reported a high proportion of undiagnosed and untreated comorbid disease in South Africa (SA). OBJECTIVES: To determine the number of individuals with previously undiagnosed HIV, TB and non-communicable diseases (NCDs) among patients hospitalised with COVID­19, and the level of medical control of these chronic diseases. METHODS: We conducted a sentinel surveillance study to collect enhanced data on HIV, TB and NCDs among individuals with COVID­19 admitted to 16 secondary-level public hospitals in six of the nine provinces of SA. Trained surveillance officers approached all patients who met the surveillance case definition for inclusion in the study, and consenting patients were enrolled. The data collection instrument included questions on past medical history to determine the self-reported presence of comorbidities. The results of clinical and laboratory testing introduced as part of routine clinical care for hospitalised COVID­19 patients were collected for the study, to objectively determine the presence of hypertension, diabetes, HIV and TB and the levels of control of diabetes and HIV. RESULTS: On self-reported history, the most prevalent comorbidities were hypertension (n=1 658; 51.5%), diabetes (n=855; 26.6%) and HIV (n=603; 18.7%). The prevalence of self-reported active TB was 3.1%, and that of previous TB 5.5%. There were 1 254 patients admitted with COVID­19 (39.0%) who met the body mass index criteria for obesity. On clinical and laboratory testing, 87 patients were newly diagnosed with HIV, 29 with TB, 215 with diabetes and 40 with hypertension during their COVID­19 admission. There were 151/521 patients living with HIV (29.0%) with a viral load >1 000 copies/mL and 309/570 (54.2%) with a CD4 count <200 cells/µL. Among 901 patients classified as having diabetes, 777 (86.2%) had a glycated haemoglobin (HbA1c) level ≥6.5%. CONCLUSION: The study revealed a high prevalence of comorbid conditions among individuals with COVID­19 admitted to public hospitals in SA. In addition, a significant number of patients had previously undiagnosed hypertension, diabetes, HIV and active TB, and many and poorly controlled chronic disease, as evidenced by high HbA1c levels in patients with diabetes, and high viral loads and low CD4 levels in patients with HIV. The findings highlight the importance of strengthening health systems and care cascades for chronic disease management, which include prevention, screening for and effectively treating comorbidities, and ensuring secure and innovative supplies of medicines in primary healthcare during the COVID­19 pandemic.

Comparison between cuff-based and invasive systolic blood pressure amplification.

OBJECTIVE: Accurate measurement of central blood pressure (BP) using upper arm cuff-based methods is associated with several factors, including determining the level of systolic BP (SBP) amplification. This study aimed to determine the agreement between cuff-based and invasively measured SBP amplification. METHODS: Patients undergoing coronary angiography had invasive SBP amplification (brachial SBP - central SBP) measured simultaneously with cuff-based SBP amplification using a commercially available central BP device (device 1: Sphygmocor Xcel; n = 171, 70% men, 60 ±â€Š10 years) and a now superseded model of a central BP device (device 2: Uscom BP+; n = 52, 83% men, 62 ±â€Š10 years). RESULTS: Mean difference (±2SD, limits of agreement) between cuff-based and invasive SBP amplification was 4 mmHg (-12, +20 mmHg, P < 0.001) for device 1 and -2 mmHg (-14, +10 mmHg, P = 0.10) for device 2. Both devices systematically overestimated SBP amplification at lower levels and underestimated at higher levels of invasive SBP amplification, but with stronger bias for device 1 (r = -0.68 vs. r = -0.52; Z = 2.72; P = 0.008). Concordance of cuff-based and invasive SBP amplification across quartiles of invasive SBP amplification was low, particularly in the lowest and highest quartiles. The root mean square errors from regression between cuff-based central SBP and brachial SBP were significantly lower (indicating less variability) than from invasive regression models (P < 0.001). CONCLUSIONS: Irrespective of the difference from invasive measurements, cuff-based estimates of SBP amplification showed evidence of proportional systematic bias and had less individual variability. These observations could provide insights on how to improve the performance of cuff-based central BP.

Cupriavidus spp. and other waterborne organisms in healthcare water systems across the UK.

BACKGROUND: Cupriavidus pauculus is a rare clinical pathogen, cases of which have been linked to contaminated hospital water systems. An outbreak of three cases of C. pauculus and other waterborne organisms was reported in a Glasgow hospital in 2018. AIMS: To determine whether Cupriavidus spp. are present in hospital water systems elsewhere in Scotland and the UK, and to ascertain the optimal laboratory methodology for detection. This study also sought to establish where in the water system these organisms are detected, and whether a selective media could be developed for isolation. In addition, water samples were tested for the presence of other Gram-negative waterborne organisms. METHODS: Water samples were received from 10 UK National Health Service hospitals and from various parts of the water system. Isolates were plated on to tryptone soya agar (TSA) and Pseudomonas isolation agar, and were further identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry and 16S polymerase chain reaction. FINDINGS: Cupriavidus spp. were detected in four of 10 hospitals tested, and all five isolates were from the periphery of the water system. All hospitals had evidence of other opportunistic premise plumbing pathogens. Cupriavidus spp. were identified using TSA, with some isolates growing on Pseudomonas isolation agar; as such, they may be detected inadvertently when testing water specifically for Pseudomonas aeruginosa. CONCLUSION: Isolation of Cupriavidus spp. was not unique to the Glasgow incident, and these bacteria are present in hospital water systems elsewhere in the UK. Water testing in response to clinical cases is recommended. Consideration should also be given to water testing following bacteraemias due to other rare and unusual water-borne pathogens.

Determining the prevalence of tuberculosis in emergency departments in the Eastern Cape region of South Africa and the utility of the World Health Organization tuberculosis screening tool.

BACKGROUND: South Africa (SA) faces a significant tuberculosis (TB) burden complicated by high rates of HIV-TB co-infection. In SA, emergency departments (EDs) play an important role in screening for TB. OBJECTIVES: To determine the prevalence of TB in the ED and the effectiveness of the World Health Organization (WHO) TB screening tool. METHODS: This was a cross-sectional observational study, conducted in the ED at Livingstone Hospital, Port Elizabeth, from 4 June to 15 July 2018. All patients aged >18 years and able to consent were administered the WHO TB screening questions and underwent a point-of-care HIV test and demographic data collection. Patients were followed up for 1 year and tracked in the National Health Laboratory Service database to determine TB status using laboratory testing. RESULTS: Over the study period, 790 patients were enrolled. Overall, 121 patients (15.3%) were TB-positive, with 46 (38.0%) diagnosed after presenting to the ED and 75 (62.0%) with a previous TB history determined by self-report or confirmed laboratory testing. A greater proportion of the TB-positive patients were HIV-positive (49.6%) compared with the TB-negative population (24.8%). TB-positive individuals were more likely to present to the ED with a chief complaint of shortness of breath (SoB) (18.2%) compared with the TB-negative population (10.5%). Overall, the WHO TB screening tool had poor sensitivity (46.5%) and specificity (62.5%) for identifying TB-positive patients in the ED. A multiple logistic regression analysis, controlled for age and sex, showed HIV status (odds ratio (OR) 2.81; p<0.001) and SoB (OR 2.19; p<0.05) to be significant predictors of TB positivity. Adding positive HIV status and a presenting complaint of SoB increased sensitivity to 78.3%. CONCLUSIONS: EDs in SA face a high burden of TB. While WHO screening guidelines identify some of these patients, including routine HIV testing in the ED could significantly affect the number of TB diagnoses made.

A generalized hybrid scheme for multireference methods.

A generalization of the hybrid scheme for multireference methods as recently put forward by Saitow and Yanai [J. Chem. Phys. 152, 114 111 (2020)] is presented. The hybrid methods are constructed by defining internal and external excitation spaces and evaluating these two subsets of excitations at different levels of theory. New hybrids that use the mix of internally contracted multireference coupled-cluster, unshifted multireference coupled electron pair, and multireference perturbation methods are derived and benchmarked. A new separation of the excitation space, which combines all singles and doubles excitations to the virtual orbitals into the external space, is also presented and tested. In general, the hybrid methods improve upon their non-hybrid parent method and offer a good compromise between computational complexity and numerical accuracy.

Diverse clinical and social circumstances: developing patient-centred care for DR-TB patients in South Africa.

OBJECTIVE: To describe the medical, socio-economic and geographical profiles of patients with rifampicin-resistant TB (RR-TB) and the implications for the provision of patient-centred care. SETTING: Thirteen districts across three South African provinces. DESIGN: This descriptive study examined laboratory and healthcare facility records of 194 patients diagnosed with RR-TB in the third quarter of 2016. RESULTS: The median age was 35 years; 120/194 (62%) of patients were male. Previous TB treatment was documented in 122/194 (63%) patients and 56/194 (29%) had a record of fluoroquinolone and/or second-line injectable resistance. Of 134 (69%) HIV-positive patients, viral loads were available for 68/134 (51%) (36/68 [53%] had viral loads of >1000 copies/ml) and CD4 counts were available for 92/134 (69%) (20/92 [22%] had CD4 <50 cells/mm3). Patients presented with varying other comorbidities, including hypertension (13/194, 7%) and mental health conditions (11/194, 6%). Of 194 patients, 44 (23%) were reported to be employed. Other socio-economic challenges included substance abuse (17/194, 9%) and ill family members (17/194, 9%). Respectively 13% and 42% of patients were estimated to travel more than 20 km to reach their diagnosing and treatment-initiating healthcare facility. CONCLUSIONS: RR-TB patients had diverse medical and social challenges highlighting the need for integrated, differentiated and patient-centred healthcare to better address specific needs and underlying vulnerabilities of individual patients.

OBJECTIF: Décrire les profils médicaux, socioéconomiques et géographiques des patients atteints de TB résistante à la rifampicine (RR-TB) et les implications en matière de soins centrés sur le patient. CONTEXTE: Treize districts de trois provinces d'Afrique du Sud. MÉTHODE: Cette étude descriptive a analysé les dossiers médicaux et de laboratoire de 194 patients ayant reçu un diagnostic de RR-TB au troisième trimestre de 2016. RÉSULTATS: L'âge médian était de 35 ans ; 120/194 (62%) patients étaient des hommes. Un traitement antituberculeux antérieur était documenté chez 122/194 (63%) patients, et 56/194 (29%) avaient une résistance à la fluoroquinolone et/ou à un agent injectable de deuxième ligne documentée. Sur 134 (69%) patients infectés par le VIH, les charges virales étaient disponibles pour 68/134 (51%) patients (36/68 [53%] avaient des charges virales >1 000 copies/ml) et les taux de CD4 étaient disponibles pour 92/134 (69%) patients (20/92 [22%] avaient un taux de CD4 <50 cellules/mm3). Les patients présentaient diverses autres comorbidités, dont hypertension (13/194, 7%) et troubles psychiques (11/194, 6%). Sur les 194 patients, 44 (23%) avaient un emploi. Les autres problèmes socioéconomiques comprenaient la toxicomanie (17/194, 9%) et le fait d'avoir un membre de sa famille malade (17/194, 9%). Respectivement 13% et 42% des patients parcouraient plus de 20 km pour se rendre à leur centre de diagnostic et au centre de soins responsable de l'instauration du traitement. CONCLUSIONS: Les patients atteints de RR-TB avaient divers problèmes médicaux et sociaux. Ces résultats soulignent le besoin de soins intégrés, différenciés et centrés sur le patient afin de mieux répondre aux besoins spécifiques et aux vulnérabilités sous-jacentes de chaque patient.

Home-based virtual reality for chronic pain: protocol for an NIH-supported randomised-controlled trial.

INTRODUCTION: Chronic pain is highly prevalent and associated with a large burden of illness; there is a pressing need for safe, home-based, non-pharmacological, interventions. Virtual reality (VR) is a digital therapeutic known to be effective for acute pain, but its role in chronic pain is not yet fully elucidated. Here we present a protocol for the National Institute of Health (NIH) Back Pain Consortium (BACPAC) VR trial that evaluates the effectiveness of three forms of VR for patients with chronic lower back pain (cLBP), a highly prevalent form of chronic pain. METHODS AND ANALYSIS: The NIH BACPAC VR trial will randomise 360 patients with cLBP into one of three arms, each administered through a head-mounted display: 1) skills-based VR, a program incorporating principles of cognitive behavioural therapy, mindful meditation and physiological biofeedback therapy using embedded biometric sensors; 2) distraction-based VR, a program using 360-degree immersive videos designed to distract users from pain; and 3) sham VR, a non-immersive program using two-dimensional videos within a VR headset. Research participants will be monitored for 12 weeks using a combination of patient-reported outcomes administered via REDCap (Research Electronic Data Capture), wearable sensor data collected via Fitbit Charge 4 and electronic health record data. The primary outcome will be the NIH Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference scale. Secondary outcomes will include PROMIS Anxiety, PROMIS Sleep Disturbance, opioid prescription data and Pain Catastrophizing Scale Short Form. A subgroup analysis will explore patient level predictors for VR efficacy. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Institutional Review Board of Cedars-Sinai Health System in April 2020. The results will be disseminated in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT04409353.

Absolute risk assessment for guiding cardiovascular risk management in a chest pain clinic.

OBJECTIVES: To assess the efficacy of a pro-active, absolute cardiovascular risk-guided approach to opportunistically modifying cardiovascular risk factors in patients without coronary ischaemia attending a chest pain clinic. DESIGN: Prospective, randomised, open label, blinded endpoint study. SETTING: The rapid access chest pain clinic of Royal Hobart Hospital, a tertiary hospital. PARTICIPANTS: Patients who presented to the chest pain clinic between 1 July 2014 and 31 December 2017 who had intermediate to high absolute cardiovascular risk scores (5-year risk ≥ 8%). Patients with known cardiac disease or from groups with clinically determined high risk of cardiovascular disease were excluded. MAIN OUTCOME MEASURES: The primary endpoint was change in 5-year absolute risk score (Australian absolute risk calculator) at follow-up (at least 12 months after baseline assessment). Secondary endpoints were changes in lipid profile, blood pressure, smoking status, and body mass index, and major adverse cardiovascular events. RESULTS: The mean change in risk at follow-up was +0.4 percentage points (95% CI, -0.8 to 1.5 percentage points) for the 98 control group patients and -2.4 percentage points (95% CI, -1.5 to -3.4 percentage points) for the 91 intervention group patients; the between-group difference in change was 2.7 percentage points (95% CI, 1.2-4.1 percentage points). Mean changes in lipid profile, systolic blood pressure, and smoking status were larger for the intervention group, but not statistically different from those for the control group. CONCLUSIONS: An absolute cardiovascular risk-guided, pro-active risk factor management strategy employed opportunistically in a chest pain clinic significantly improved 5-year absolute cardiovascular risk scores. TRIAL REGISTRATION: Australia New Zealand Clinical Trial Registry, ACTRN12617000615381 (retrospective).

Identifying Isolated Systolic Hypertension From Upper-Arm Cuff Blood Pressure Compared With Invasive Measurements.

Isolated systolic hypertension (ISH) is the most common form of hypertension and is highly prevalent in older people. We recently showed differences between upper-arm cuff and invasive blood pressure (BP) become greater with increasing age, which could influence correct identification of ISH. This study sought to determine the difference between identification of ISH by cuff BP compared with invasive BP. Cuff BP and invasive aortic BP were measured in 1695 subjects (median 64 years, interquartile range [55-72], 68% male) from the INSPECT (Invasive Blood Pressure Consortium) database. Data were recorded during coronary angiography among 29 studies, using 21 different cuff BP devices. ISH was defined as ≥130/<80 mm Hg using cuff BP compared with invasive aortic BP as the reference. The prevalence of ISH was 24% (n=407) according to cuff BP but 38% (n=642) according to invasive aortic BP. There was fair agreement (Cohen κ, 0.36) and 72% concordance between cuff and invasive aortic BP for identifying ISH. Among the 28% of subjects (n=471) with misclassification of ISH status by cuff BP, 20% (n=96) of the difference was due to lower cuff systolic BP compared with invasive aortic systolic BP (mean, -16.4 mm Hg [95% CI, -18.7 to -14.1]), whereas 49% (n=231) was from higher cuff diastolic BP compared with invasive aortic diastolic BP (+14.2 mm Hg [95% CI, 11.5-16.9]). In conclusion, compared with invasive BP, cuff BP fails to identify ISH in a sizeable portion of older people and demonstrates the need to improve cuff BP measurements.

Expanding the epidemiological understanding of hepatitis C in South Africa: Perspectives from a patient cohort in a rural town.

BACKGROUND: The epidemiology of hepatitis C virus (HCV) in the general population of South Africa (SA) is incompletely understood. A high HCV prevalence in key populations is known, but data are limited in terms of a broader understanding of transmission risks in our general population. OBJECTIVES: To investigate a patient cohort with HCV infection clustering in a rural SA town, in order to identify possible HCV transmission risks, virological characteristics, phylogenetic data and treatment outcomes. METHODS: A cluster of patients with positive HCV serology, previously identified from laboratory records, were contacted by a local district hospital and offered confirmatory testing for HCV viraemia where needed. Those with confirmed HCV RNA were invited to a local hospital visit, where relevant demographic information was recorded, clinical assessment performed and a confidential questionnaire administered. HCV population-based sequencing was performed on HCV NS3/4A, NS5A and NS5B using polymerase chain reaction-specific or M13 universal primers, and sequences were aligned using BioEdit 7.2.5. Phylogenetic trees were constructed. Clinical assessments included liver fibrosis determination with FibroScan (cut-off ≥12.5 kPa = F4). Patients were offered treatment, and sustained virological response (SVR) was confirmed by undetectable HCV RNA at least 12 weeks after the end of treatment. RESULTS: Twenty-one patients, all from the same town, median (interquartile range (IQR)) age 64 (59 - 70) years, 57% female, were evaluated. Of these, 24% (n=5) were HIV co-infected, stable on antiretrovirals. The median (IQR) alanine aminotransferase level was 51 (31 - 89) U/L, with fibrosis distribution including 29% F1, 29% F2, 9% F3 and 33% F4 METAVIR fibrosis. Virologically, two genotypes were observed: 62% (n=13) genotype (GT) 1b and 38% (n=8) GT5a. No patient had ever used injecting drugs, 14% (n=3) had received blood products before 1992, and 9.5% (n=2) had undergone traditional healer-administered scarification. All (n=21) reported attendance at a single primary care clinic in the past, with most (n=20) recalling having received parenteral therapies at the clinic. Phylogenetic analysis of the HCV NS5A and NS5B regions confirmed GT1b and GT5a genotypes and formed two separate clusters within their respective genotypes, suggesting a common source for each genotype infection. Most patients received treatment with sofosbuvir/daclatasvir, 1 was treated with sofosbuvir/velpatasvir, and 1 was re-treated with sofosbuvir/velpatasvir/voxilaprevir. Per protocol SVR was 95%, with the non-SVR patient successfully re-treated. CONCLUSIONS: Data from a rural town cluster of patients suggest parenteral medical exposure as the probable common source of hepatitis C transmission risk. The cohort was of older age with a significant number having advanced fibrosis or cirrhosis, suggesting HCV acquisition in the distant past. Using a simplified care approach, treatment outcomes were very good.

Impact of Covid-19 on farming systems in Europe through the lens of resilience thinking.

Context: Resilience is the ability to deal with shocks and stresses, including the unknown and previously unimaginable, such as the Covid-19 crisis. Objective: This paper assesses (i) how different farming systems were exposed to the crisis, (ii) which resilience capacities were revealed and (iii) how resilience was enabled or constrained by the farming systems' social and institutional environment. Methods: The 11 farming systems included have been analysed since 2017. This allows a comparison of pre-Covid-19 findings and the Covid-19 crisis. Pre-Covid findings are from the SURE-Farm systematic sustainability and resilience assessment. For Covid-19 a special data collection was carried out during the early stage of lockdowns. Results and conclusions: Our case studies found limited impact of Covid-19 on the production and delivery of food and other agricultural products. This was due to either little exposure or the agile activation of robustness capacities of the farming systems in combination with an enabling institutional environment. Revealed capacities were mainly based on already existing connectedness among farmers and more broadly in value chains. Across cases, the experience of the crisis triggered reflexivity about the operation of the farming systems. Recurring topics were the need for shorter chains, more fairness towards farmers, and less dependence on migrant workers. However, actors in the farming systems and the enabling environment generally focused on the immediate issues and gave little real consideration to long-term implications and challenges. Hence, adaptive or transformative capacities were much less on display than coping capacities. The comparison with pre-Covid findings mostly showed similarities. If challenges, such as shortage of labour, already loomed before, they persisted during the crisis. Furthermore, the eminent role of resilience attributes was confirmed. In cases with high connectedness and diversity we found that these system characteristics contributed significantly to dealing with the crisis. Also the focus on coping capacities was already visible before the crisis. We are not sure yet whether the focus on short-term robustness just reflects the higher visibility and urgency of shocks compared to slow processes that undermine or threaten important system functions, or whether they betray an imbalance in resilience capacities at the expense of adaptability and transformability. Significance: Our analysis indicates that if transformations are required, e.g. to respond to concerns about transnational value chains and future pandemics from zoonosis, the transformative capacity of many farming systems needs to be actively enhanced through an enabling environment.

Excess pressure as an analogue of blood flow velocity.

INTRODUCTION: Derivation of blood flow velocity from a blood pressure waveform is a novel technique, which could have potential clinical importance. Excess pressure, calculated from the blood pressure waveform via the reservoir-excess pressure model, is purported to be an analogue of blood flow velocity but this has never been examined in detail, which was the aim of this study. METHODS: Intra-arterial blood pressure was measured sequentially at the brachial and radial arteries via fluid-filled catheter simultaneously with blood flow velocity waveforms recorded via Doppler ultrasound on the contralateral arm (n = 98, aged 61 ±â€Š10 years, 72% men). Excess pressure was derived from intra-arterial blood pressure waveforms using pressure-only reservoir-excess pressure analysis. RESULTS: Brachial and radial blood flow velocity waveform morphology were closely approximated by excess pressure derived from their respective sites of measurement (median cross-correlation coefficient r = 0.96 and r = 0.95 for brachial and radial comparisons, respectively). In frequency analyses, coherence between blood flow velocity and excess pressure was similar for brachial and radial artery comparisons (brachial and radial median coherence = 0.93 and 0.92, respectively). Brachial and radial blood flow velocity pulse heights were correlated with their respective excess pressure pulse heights (r = 0.53, P < 0.001 and r = 0.43, P < 0.001, respectively). CONCLUSION: Excess pressure is an analogue of blood flow velocity, thus affording the opportunity to derive potentially important information related to arterial blood flow using only the blood pressure waveform.

Simple, compact, high-resolution monochromatic x-ray source for characterization of x-ray calorimeter arrays.

X-ray calorimeters routinely achieve very high spectral resolution, typically a few eV full width at half maximum (FWHM). Measurements of calorimeter line shapes are usually dominated by the natural linewidth of most laboratory calibration sources. This compounds the data acquisition time necessary to statistically sample the instrumental line broadening and can add systematic uncertainty if the intrinsic line shape of the source is not well known. To address these issues, we have built a simple, compact monochromatic x-ray source using channel cut crystals. A commercial x-ray tube illuminates a pair of channel cut crystals that are aligned in a dispersive configuration to select the Kα1 line of the x-ray tube anode material. The entire device, including the x-ray tube, can be easily hand-carried by one person and may be positioned manually or using a mechanical translation stage. The output monochromatic beam provides a collimated image of the anode spot with magnification of unity in the dispersion direction (typically 100 µm-200 µm for the x-ray tubes used here) and is unfocused in the cross-dispersion direction so that the source image in the detector plane appears as a line. We measured output count rates as high as 10 count/s/pixel for the Hitomi soft x-ray spectrometer, which had 819 µm square pixels. We implemented different monochromator designs for energies of 5.4 keV (one design) and 8.0 keV (two designs), which have effective theoretical FWHM energy resolution of 0.125 eV, 0.197 eV, and 0.086 eV, respectively; these are well-suited for optimal calibration measurements of state-of-the art x-ray calorimeters. We measured an upper limit for the energy resolution of our Cr Kα1 monochromator of 0.7 eV FWHM at 5.4 keV, consistent with the theoretical prediction of 0.125 eV.

Impact of endemic HIV on emergency care service delivery in South Africa.

BACKGROUND: South Africa (SA) has the highest burden of HIV in the world. This study sought to evaluate the impact of high HIV prevalence on the burden of disease in an emergency department (ED). OBJECTIVES: To determine the burden of comorbidities in HIV-positive emergency care patients, their demographic profiles and severity of illness were compared with the general ED population in order to make recommendations for resource allocation and training in EDs in SA. METHODS: A prospective cross-sectional observational study was conducted from June 2017 to July 2018 in three EDs in Eastern Cape Province. All eligible patients (aged ≥18 years, fully conscious and clinically stable) presenting to the ED during the 6-week study period were approached and asked to give consent for a point-of-care HIV test and collection of demographic information. Simple descriptive statistics were used to analyse data. Log binomial and Poisson models were fitted to estimate prevalence ratios (PRs). RESULTS: Over the total study period, 8 000 patients presented to the ED for care across all sites and 3 537 patients were enrolled. The HIV status of 2 901 individuals (82.0%) was determined. Of those who were screened, 811 (28.0%) were identified as HIV-positive. Medical complaints were more common in HIV-positive patients (n=586, 72.3%) than in trauma patients (n=225, 27.7%). In comparison, HIV-negative patients reported fewer medical complaints (n=1 137, 54.4%) and more trauma (n=953, 45.6%) (p<0.001). HIV-positive patients were more likely to have a life-threatening emergency (n=192, 23.7%) (p=0.004), to be critically ill by triage score (p<0.001) and to be admitted to the hospital (p<0.001) than those who were HIV-negative. Despite high acuity overall, people living with HIV/AIDS were significantly less likely to be deemed critically ill according to vital signs (adjusted PR 0.94; p=0.046). CONCLUSIONS: While EDs in SA provide care to high volumes of patients with trauma-related injuries, in areas where HIV prevalence is highest, patients are more likely to present with acute medical emergencies. Providers of emergency care in SA need to be well versed in the management of HIV and associated complications.

Tuberculosis burden in stage 5 chronic kidney disease patients undergoing dialysis therapy at Livingstone Hospital, Port Elizabeth, South Africa.

BACKGROUND: Tuberculosis (TB) is currently the leading cause of death from a single infectious agent worldwide. Patients who receive dialysis are particularly vulnerable to TB infection owing to immune dysfunction. Nonetheless, there is a paucity of incidence data on dialysis patients infected with TB in high-burden countries, such as South Africa (SA). OBJECTIVES: To determine the incidence of TB in prevalent chronic kidney disease stage 5 (CKD-5D) patients on dialysis at a single centre in Eastern Cape Province, SA, and to identify the risk factors associated with TB infection. METHODS: We conducted a retrospective cohort study of all consenting CKD-5D patients between April 2010 and March 2014 at Livingstone Hospital Renal Unit, Port Elizabeth, the Eastern Cape. TB was defined as definite or probable according to World Health Organization (WHO) criteria, and the cohort was split into those who developed TB (TB+) and those who did not (TB-). RESULTS: One hundred and eleven patients were enrolled - predominantly black Africans (73%) and women (53%); the mean age (standard deviation (SD)) was 42 (9.8) years. The prevalence of HIV infection was 11%, all patients were receiving antiretroviral treatment and all had suppressed viral loads. Sixty-eight patients were on haemodialysis and 43 on peritoneal dialysis. Nineteen patients were diagnosed with 20 episodes of TB; 14 cases were pulmonary TB and 6 cases extrapulmonary TB. Of the patients with TB, 2 were HIV-infected, 7 (35%) were definite TB cases and 13 (65%) were probable cases. The calculated incidence rate was 4 505/100 000 patient years. Only informal housing (30% in TB+ v. 12% in TB-; p=0.042) and a history of hospitalisation (90% v. 76%, respectively; p=0.042) were significantly associated with a diagnosis of TB. CONCLUSIONS: Dialysis patients in the Eastern Cape region of SA are at extremely high risk of acquiring TB, with an incidence rate 4.1 times that of the local population and >5 times that of the general SA population. Only informal housing and a history of hospitalisation were identified as positive risk factors for TB in this young population with a low HIV prevalence. Isoniazid prophylaxis in this high-risk group might be of benefit, but further studies are required to inform such treatment.