Surface reconstruction of a blast plate using stereo vision

Includes bibliographical references.This thesis presents method for reconstructing and measuring the profile of a blast metal plate. Among the many methods in computer vision, stereo vision using two cameras is chosen as the range finding method in this thesis. This is because it is a non-contact method and hence eliminates the need to calibrate moving parts. A stereo-rig consists of two calibrated cameras and hence gives two view geometry. Stereoscopic reconstruction relies on epipolar geometry to constrain the relationship between the views. The 3-D point is then estimated using triangulation of the corresponding points from the two views. The blast plates that are reconstructed have highly reflective surfaces. This causes a problem due to specular reflection. This thesis further studies the reflective properties of the metal plate surface. Different methods of scanning the plate using the stereo-rig are investigated. The reconstructions obtained from these methods are analyzed for accuracy and consistency. Since low cost cameras are used in constructing the stereo-rig, the point cloud data obtained is further investigated for consistency by aligning different instances of the reconstruction. This is done using the Iterative Closest Programme (ICP) algorithm which tries to align two sets of data iteratively

Unpacking the dynamics of double stigma : how the HIV-TB co-epidemic alters TB stigma and its management among healthcare workers

Background HIV and tuberculosis (TB) are intricably interlinked in South Africa. The social aspects of this co-epidemic remain relatively unexplored. More specifically, no research has quantitatively explored the double stigma associated with HIV and TB in this context, and more specifically the impact of the co-epidemic on [1] the stigmatisation of TB and [2] the TB stigma mangement strategy of covering (i.e. the use of TB as a cover for having HIV). The current study aims to address this research gap by disentangling the complex mechanisms related to HIV-TB stigma. Methods Using Structural Equation Modelling (SEM), data of 882 health care workers (HCWs) in the Free State province, South Africa, are analysed to investigate the link between the stigmatization of HIV and TB and the stigma management by those affected. The current study focuses on health care workers (HCWs), as both TB and HIV have a severe impact on this professional group. Results The results demonstrate that the perceived link between the epidemics is significantly associated with double HIV-TB stigmatization. Furthermore, the link between the illnesses and the double stigma are driving the stigmatization of TB. Finally, the link between HIV and TB as well as the stigmatization of both diseases by colleagues are associated with an increased use of covering as a stigma management strategy. Conclusions This is the first quantitative study disentagling the mediating role of double stigma in the context of the co-epidemic as well as the impact of the co-epidemic on the social connotations of TB. The results stress the need for an integrated approach in the fight against HIV and TB recognizing the intertwined nature of the co-epidemic, not only in medical-clinical terms, but also in its social consequences

Tuberculosis infection control practices in a high-burden metro in South Africa : a perpetual bane for efficient primary health care service delivery

Background: Tuberculosis (TB) prevention, including infection control, is a key element in the strategy to end the global TB epidemic. While effective infection control requires all health system components to function well, this is an area that has not received sufficient attention in South Africa despite the availability of policy and guidelines. Aim: To describe the state of implementation of TB infection control measures in a high-burden metro in South Africa. Setting: The research was undertaken in a high TB-and HIV-burdened metropolitan area of South Africa. More specifically, the study sites were primary health care facilities (PHC), that among other services also diagnosed TB. Methods: A cross-sectional survey, focusing on the World Health Organization levels of infection control, which included structured interviews with nurses providing TB diagnosis and treatment services as well as observations, at all 41 PHC facilities in a high TB-burdened and HIV-burdened metro of South Africa. Results: Tuberculosis infection control was poorly implemented, with few facilities scoring 80% and above on compliance with infection control measures. Facility controls: 26 facilities (63.4%) had an infection control committee and 12 (29.3%) had a written infection control plan. Administrative controls: 26 facilities (63.4%) reported separating coughing and non-coughing patients, while observations revealed that only 11 facilities (26.8%) had separate waiting areas for (presumptive) TB patients. Environmental controls: most facilities used open windows for ventilation (n = 30; 73.2%); however, on the day of the visit, only 12 facilities (30.3%) had open windows in consulting rooms. Personal protective equipment: 9 facilities (22%) did not have any disposable respirators in stock and only 9 respondents (22%) had undergone fit testing. The most frequently reported barrier to implementing good TB infection control practices was lack of equipment (n = 22; 40%) such as masks and disposable respirators, as well as the structure or layout of the PHC facilities. The main recommendation to improve TB infection control was education for patients and health care workers (n = 18; 33.3%). Conclusion: All levels of the health care system should be engaged to address TB prevention and infection control in PHC facilities. Improved infection control will address the nosocomial spread of TB in health facilities and keep health care workers and patients safe from infection

Patient- and delivery-level factors related to acceptance of HIV counseling and testing services among tuberculosis patients in South Africa: a qualitative study with community health workers and program managers

<p>Abstract</p> <p>Background</p> <p>South Africa has a high tuberculosis (TB)-human immunodeficiency virus (HIV) coinfection rate of 73%, yet only 46% of TB patients are tested for HIV. To date, relatively little work has focused on understanding why TB patients may not accept effective services or participate in programs that are readily available in healthcare delivery systems. The objective of the study was to explore barriers to and facilitators of participation in HIV counseling and testing (HCT) among TB patients in the Free State Province, from the perspective of community health workers and program managers who offer services to patients on a daily basis. These two provider groups are positioned to alter the delivery of HCT services in order to improve patient participation and, ultimately, health outcomes.</p> <p>Methods</p> <p>Group discussions and semistructured interviews were conducted with 40 lay counselors, 57 directly observed therapy (DOT) supporters, and 13 TB and HIV/acquired immune deficiency syndrome (AIDS) program managers in the Free State Province between September 2007 and March 2008. Sessions were audio-recorded, transcribed, and thematically analyzed.</p> <p>Results</p> <p>The themes emerging from the focus group discussions and interviews included four main suggested barrier factors: (1) fears of HIV/AIDS, TB-HIV coinfection, death, and stigma; (2) perceived lack of confidentiality of HIV test results; (3) staff shortages and high workload; and (4) poor infrastructure to encourage, monitor, and deliver HCT. The four main facilitating factors emerging from the group and individual interviews were (1) encouragement and motivation by health workers, (2) alleviation of health worker shortages, (3) improved HCT training of professional and lay health workers, and (4) community outreach activities.</p> <p>Conclusions</p> <p>Our findings provide insight into the relatively low acceptance rate of HCT services among TB patients from the perspective of two healthcare workforce groups that play an integral role in the delivery of effective health services and programs. Community health workers and program managers emphasized several patient- and delivery-level factors influencing acceptance of HCT services.</p

State and non-state mental health service collaboration in a South African district : a mixed methods study

A

Reducing HIV- and TB-Stigma among healthcare co-workers in South Africa: Results of a cluster randomised trial.

RATIONALE: The HIV and TB co-epidemic has a severe impact on the South African healthcare workforce and health system. HIV- and TB- stigma directed from healthcare workers (HCWs) towards colleagues not only has a negative impact on the mental health and well-being of the HCWs, but has been identified as a barrier to their own health-seeking behaviour. It also increases the strain on the health system due to absenteeism. OBJECTIVE: This cluster-randomised trial tested an intervention to reduce HIV- and TB-stigma among HCWs. The intervention, based on the theory of Diffusion of Innovations consisted of training healthcare workers as change agents in a Social and Behavioural Change Communication workshop to help them change stigmatising attitudes in the workplace. This was supported by a social marketing campaign. METHODS: Eight hospitals in the Free State province were randomised into intervention and control group in a stratified study design. 652 respondents randomly drawn from the hospitals were surveyed on aspects of HIV and TB stigma once in 2016 and again in 2018. Since the study only used four hospitals per intervention arm, cluster-based summaries were compared when analysing the intervention effect, using the nonparametric Mann-Whitney test. To explore how the intervention worked, 24 qualitative focus groups were conducted following the intervention. RESULTS: The quantitative test did not show a significant intervention effect on stigma between intervention and control groups. Qualitative evidence reported new awareness and changed behaviour related to HIV- and TB-stigma among individual HCWs, but a combination of factors including strong social hierarchies in the workplace and the down-scaling of the original version of the intervention seemed to reduce the impact. Conclusion The findings did not indicate a significant intervention effect, but show the potential of using HCWs as change agents to reduce HIV and TB stigma in their local communities

Tuberculosis patients' reasons for, and suggestions to address non-uptake of HIV testing: a cross-sectional study in the Free State Province, South Africa

<p>Abstract</p> <p>Background</p> <p>South Africa endorses the global policy shift from primarily client-initiated voluntary counselling and testing (VCT) to routine/provider-initiated testing and counselling (PITC). The reason for this policy shift has been to facilitate uptake of HIV testing amongst at-risk populations in high-prevalence settings. Despite ostensible implementation of routine/PITC, uptake amongst tuberculosis (TB) patients in this country remains a challenge. This study presents the reasons that non-tested TB patients offered for their refusal of HIV testing and reflects on all TB patients' suggestions as to how this situation may be alleviated.</p> <p>Methods</p> <p>In February-March 2008, a cross-sectional survey was conducted amongst 600 TB patients across 61 primary health care facilities in four sub-districts in the Free State. Patient selection was done proportionally to the numbers registered at each facility in 2007. Data were subjected to bivariate tests and content analysis of open-ended questions.</p> <p>Results</p> <p>Almost one-third (32.5%) of the respondents reported that they had not undertaken HIV testing, with the most often offered explanation being that they were '<it>undecided</it>' (37.0%). Other self-reported reasons for non-uptake included: fear (e.g. of testing HIV-positive, 19.0%); perception of being at low risk of HIV infection (13.4%); desire first to deal with TB 'on its own' (12.5%); and because HIV testing had not been offered to them (12.0%). Many patients expressed the need for support and motivation not only from health care workers (33.3%), but also from their significant others (56.6%). Patients further expressed a need for (increased) dissemination of TB-HIV information by health care workers (46.1%).</p> <p>Conclusions</p> <p>Patients did not undergo HIV testing for various patient-/individual-related reasons. Non-uptake of HIV testing was also due to health system limitations such as the non-offer of HIV testing. Other measures may be necessary to supplement routine/provider-initiation of HIV testing. From the TB patient's perspective, there is a need for (improved) dissemination of information on the TB-HIV link. Patients also require (repeated) motivation and support to undergo HIV testing, the onus for which rests not only on the public health authority and health care workers, but also on other people in the patients' social support networks.</p

Factors Associated with Limited Vaccine Literacy: Lessons Learnt from COVID-19

Compared to many other developed countries, South Africa has a lower uptake of COVID-19 vaccinations. Although not widely researched, there is evidence that vaccine literacy (VL) is positively associated with vaccination uptake. Therefore, this study aimed to assess levels of VL among the adult population in South Africa, as well as to identify factors associated with limited VL. A cross-sectional, anonymous online survey was conducted during September 2021. The survey, which included the standardized Health Literacy about Vaccination in adulthood (HLVa) Scale, was widely advertised, yielding a total of 10,466 respondents. The average scores for the two HLVa sub-scales were relatively high: functional (M = 2.841, SD 0.799) and interactive-critical (M = 3.331, SD 0.559) VL. A proposed ‘limited’ VL score (score value ≤ 2.50) was observed in 40% of respondents for functional literacy and 8.2% of respondents for interactive-critical literacy. The main factors associated with limited VL included lower levels of education, lower socio-economic status, not being vaccinated against COVID-19, self-identifying as Black/African or Colored (i.e., people of mixed ethnic descent), having poorer health, and being a woman. The significant association between VL and vaccination uptake provides an impetus for policy makers such as the South African Department of Health to promote VL in the attempt to increase COVID-19 vaccination uptake

Post-Traumatic Stress and Coping Strategies of South African Nurses during the Second Wave of the COVID-19 Pandemic

Prior to the 2019 novel coronavirus (COVID-19) outbreak, the South African healthcare system was already under severe strain due to amongst others, a lack of human resources, poor governance and management, and an unequal distribution of resources among provinces and between the public and private healthcare sectors. At the center of these challenges are nurses, the backbone of the healthcare system, and the first point of call for most patients in the country. This research investigated post-traumatic stress and coping strategies of nurses during the second wave of COVID-19 in the country. A structured self-administered questionnaire captured the biographic characteristics, perceived risk factors for COVID-19, and views on infection control of 286 nurses Data were subjected to descriptive and binomial logistic regression analyses. More than four in every 10 nurses screened positive for higher levels of post-traumatic disorder (PTSD). Self-reported risk for contracting COVID-19 mainly centered on being a health worker and patients’ non-adherence to infection prevention guidelines. Unpreparedness to manage COVID-19 patients, poorer health, and avoidant coping were associated with PTSD. Nurses voiced a need for emotional support and empathy from managers. Emotional, psychological, and debriefing intervention sessions that focus on positive coping strategies to actively address stress are recommended

Community-based directly observed treatment for TB patients to improve HIV services: a cross-sectional study in a South African province

Abstract Background There is uncertainty about how directly observed treatment (DOT) support for tuberculosis (TB) can be delivered most effectively and how DOT support can simultaneously be used to strengthen human immunodeficiency virus (HIV) prevention and control among TB patients. This study describes how DOT support by community health workers (CHWs) was used in four municipalities in the Free State province – a high TB/HIV burden, poorly-resourced setting – to provide HIV outreach, referrals, and health education for TB patients. Methods The study was part of a larger cross-sectional study of HIV counselling and testing (HCT) among 1101 randomly-selected TB patients registered at 40 primary health care (PHC) facilities (clinics and community health centres) across small town/rural and large town/urban settings. Univariate analysis of percentages, chi-square tests and t-tests for difference in means were used to describe differences between the types of TB treatment support and patient characteristics, as well as the types of – and patient satisfaction with – HIV information and referrals received from various types of treatment supporters including home-based DOT supporters, clinic-based DOT supporters or support from family/friends/employers. Multivariate logistic regression was used to predict the likelihood of not having receiving home-based DOT and of never having received HIV counselling. The independent variables include poverty-related health and socio-economic risk factors for poor outcomes. Statistical significance is shown using a 95% confidence interval and a 0.05 p-value. Results Despite the fact that DOT support for all TB patients was the goal of South African health policy at the time (2012), most TB patients were not receiving formal DOT support. Only 155 (14.1%) were receiving home-based DOT, while 114 (10.4%) received clinic-based DOT. TB patients receiving home-based DOT reported higher rates of HIV counselling than other patients. Conclusions Public health providers should train DOT supporters to provide HIV prevention and target DOT to those at greatest risk of HIV, particularly those at greatest socio-economic risk