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Background. An increased incidence of thromboembolic events in hospitalised COVID‐19 patients has been demonstrated despite the use of low‐molecular‐weight heparin (LMWH). Antiplatelet therapy prior to admission and early in the disease course has been hypothesised to be protective against thrombosis.Objectives. To describe the bleeding and thrombosis outcomes in hospitalised patients with confirmed COVID‐19 receiving LMWH, with and without concomitant antiplatelet therapy. Secondary objectives were to explore predictors of bleeding and thrombosis outcomes, and dosing practices of antiplatelet therapy and LMWH. Methods. We conducted a descriptive, cross‐sectional study of bleeding and thrombosis outcomes at Tygerberg Academic Hospital, Cape Town, South Africa, during the first COVID‐19 wave, in 808 hospitalised patients with confirmed COVID‐19 receiving LMWH with and without concomitant antiplatelet therapy. Multivariate logistic regression analysis was performed if predictors were deemed statistically and clinically significant. Results. Patients receiving both LMWH and antiplatelet therapy had similar bleeding outcomes compared with patients only receiving LMWH (odds ratio (OR) 1.5; 95% confidence interval (CI) 0.6 ‐ 4.0). Patients receiving both LMWH and antiplatelet therapy had increased odds of developing thrombosis compared with patients only receiving LMWH (OR 4.8; 95% CI 2.1 ‐ 10.7).Conclusion. The bleeding risk in COVID‐19 patients receiving both LMWH and antiplatelet therapy was not significantly increased. A potentially higher risk of thrombosis in patients receiving LMWH and antiplatelet therapy was observed. However, this could reflect confounding by indication. Randomised studies are required to further evaluate the use of antiplatelet therapy to treat hospitalised patients with COVID‐19.

Background: Historically, infective endocarditis (IE) in South Africa (SA) was associated with the viridans group of streptococci affectingpatients with underlying rheumatic heart disease (RHD). A changing IE bacteriological profile raises the question of whether the profile of underlying valvular abnormality has changed.Objectives: To investigate the prevalence of underlying structural valve abnormalities and their aetiologies associated with IE in SA, and describe the typical imaging findings.Methods: The Tygerberg Endocarditis Cohort study prospectively enrolled patients with IE between November 2019 and April 2021. Patients underwent detailed transthoracic and transoesophageal echocardiography to assess their underlying cardiac and valvular structure.Results: Among 71 patients included, a predisposing endocardial abnormality was detected in 49.3%, with RHD the most common single identifiable aetiology (16.9%). The in-hospital mortality rate was similar in patients with and without a predisposing endocardial abnormality (20% v. 16.7%; p=0.72), as was the rate of embolic events (20% v. 27.2%; p=0.58). Significantly more patients with a predisposing endocardial abnormality had an indication for surgery (94.3% v. 69.4%; p10 mm was associated with an increased risk of in-hospital mortality (24% v. 5%; p=0.05).Conclusion: We observed a marked decrease in the prevalence of RHD in this cohort of patients with IE. The viridans group of streptococci was an uncommon cause of IE in patients with no predisposing endocardial abnormality detected. The presence of a predisposing endocardial abnormality was not associated with an increased risk of in-hospital mortality or embolic events. Linear vegetation length >10 mm was associated with an increased risk of in-hospital mortality in patients with left-sided IE.

Objectives: We aimed to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves in the Western Cape, the contribution of undiagnosed prior infection to differences in outcomes in a context of high seroprevalence due to prior infection, and whether protection against severe disease conferred by prior infection and/or vaccination was maintained. Methods: In this cohort study, we included public sector patients aged ≥20 years with a laboratory confirmed COVID-19 diagnosis between 14 November-11 December 2021 (wave four) and equivalent prior wave periods. We compared the risk between waves of the following outcomes using Cox regression: death, severe hospitalization or death and any hospitalization or death (all ≤14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection. Results: We included 5,144 patients from wave four and 11,609 from prior waves. Risk of all outcomes was lower in wave four compared to the Delta-driven wave three (adjusted Hazard Ratio (aHR) [95% confidence interval (CI)] for death 0.27 [0.19; 0.38]. Risk reduction was lower when adjusting for vaccination and prior diagnosed infection (aHR:0.41, 95% CI: 0.29; 0.59) and reduced further when accounting for unascertained prior infections (aHR: 0.72). Vaccine protection was maintained in wave four (aHR for outcome of death: 0.24; 95% CI: 0.10; 0.58). Conclusions: In the Omicron-driven wave, severe COVID-19 outcomes were reduced mostly due to protection conferred by prior infection and/or vaccination, but intrinsically reduced virulence may account for an approximately 25% reduced risk of severe hospitalization or death compared to Delta.

BACKGROUND. Incorrect empirical antibiotic therapy is one of the factors that contribute to poor clinical outcomes and the development of antimicrobial resistance. Knowledge of the local infectious disease burden and antibiotic resistance patterns can assist with development of strategies, updating of guidelines and subsequent improvement in initial empirical therapy. OBJECTIVES. To determine whether the empirical antibiotic choice for treatment of septic episodes at a district-level hospital was appropriate according to national guidelines, and to describe the epidemiological features of the septic episode population being studied and depict their antibiotic susceptibility profile. METHODS. This was a retrospective, descriptive study of adult inpatients with bloodstream infections at Karl Bremer Hospital, Cape Town, South Africa. Laboratory and clinical data were obtained and analysed for the period 1 July 2017 - 30 June 2018. Septic episodes were subdivided into community-acquired bloodstream infection (CABSI) and hospital-acquired bloodstream infection (HABSI) study populations, and empirical antibiotics for both groups were assessed and compared with the adult Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level Care, 2015 edition (STG and EML). RESULTS. Our study sample consisted of 184 septic episodes, isolated from 176 patients. Nearly half of the septic episodes (49.5%) were hospital acquired. Overall guideline adherence in the CABSI population was 88%, compared with 58% in the HABSI population. The reasons for guideline non-adherence in the CABSI population were lack of source-appropriate empirical antibiotics (n=7) and septic episodes where empirical antibiotics were indicated but not prescribed (n=4), while in the HABSI group the main reason was that the patients were treated by community-acquired standards (n=30; 33.0%). The in-hospital mortality rate for a septic episode in this study was 38%. Considering the typical first-line antibiotics used, 77.3% of CABSIs were found to be susceptible to co-amoxiclav (n=75) and 59.8% to ceftriaxone (n=58). With the exclusion of methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii isolates as confounders, HABSIs had a susceptibility of 86% to the piperacillin/tazobactam plus amikacin combination, 81% to ertapenem, 90% to imipenem and 93% to meropenem. CONCLUSIONS. This study demonstrates poor guideline adherence in HABSIs, emphasising the importance of distinguishing between CABSIs and HABSIs. The empirical antibiotics advised by the STG and EML were found to be appropriate in the majority of septic episodes. Future revision and improvement of prescribing practices can assist in rationalising empirical antibiotic decisions.

BACKGROUND: The hyperinflammation seen as part of a dysregulated immune response to SARS-CoV-2 in its most severe form leads to acute respiratory distress syndrome (ARDS), multiorgan failure and death. Corticosteroid therapy targets this hyperinflammation, otherwise known as a cytokine storm. It is the only therapeutic agent to date with a mortality benefit, with clear guidelines from national and international health authorities guiding its use.OBJECTIVES: To compare severity-of-illness indices, survival, length of intensive care unit (ICU) stay and potential ICU complications in patients treated with different corticosteroid regimens (high-dose hydrocortisone, high-dose methylprednisolone and lower-dose dexamethasone).METHODS: In this single-centre descriptive retrospective observational study of a cohort of patients with severe COVID-19 admitted to a COVID-dedicated ICU, we compared patients treated with the three different corticosteroid regimens.RESULTS: In 242 cases we could not demonstrate any statistically or clinically significant difference in the outcome of patients with critical COVID-19 treated with high-dose intravenous hydrocortisone (n=88) or methylprednisolone (n=46) compared with a relatively lower dose of dexamethasone (n=108). The survival rates were 38.6%, 39.1% and 33.3%, respectively (p=0.68). Patients treated with methylprednisolone tended to have a shorter length of ICU stay (median (interquartile range) 6 (4 - 10), 4 (2 - 8) and 5 (2 - 8) days; p=0.015) and fewer episodes of nosocomial sepsis (47.7%, 32.6% and 48.1%; p=0.01).CONCLUSIONS: Hydrocortisone or methylprednisolone can be given as an alternative to dexamethasone in the management of critical COVID-19, and this is a feasible alternative, especially in resource-constrained settings.

BACKGROUND: Empirical broad-spectrum antibiotics are frequently prescribed to patients with severe COVID-19, motivated by concern about bacterial coinfection. There is no evidence of benefit from such a strategy, while the dangers of inappropriate antibiotics are well described.OBJECTIVES: To investigate the frequency, profile and related outcomes of infections by bacterial pathogens in patients admitted to an intensive care unit (ICU) with severe COVID-19 pneumonia.METHODS: This was a prospective, descriptive study in a dedicated COVID-19 ICU in Cape Town, South Africa, involving all adult patients admitted to the ICU with confirmed COVID-19 pneumonia between 26 March and 31 August 2020. We collected data on patient comorbidities, laboratory results, antibiotic treatment, duration of admission and in-hospital outcome.RESULTS. We included 363 patients, who collectively had 1 199 blood cultures, 308 tracheal aspirates and 317 urine cultures performed. We found positive cultures for pathogens in 20 patients (5.5%) within the first 48 hours of ICU admission, while 73 additional patients (20.1%) had positive cultures later during their stay. The most frequently isolated pathogens at all sites were Acinetobacter baumannii (n=54), Klebsiella species (n=13) and coagulase-negative staphylococci (n=9). Length of ICU stay (p

Background Community-acquired pneumonia (CAP) is a common condition, with mortality increasing in patients who require intensive care unit (ICU) admission. A better understanding of the current aetiology of severe CAP will aid clinicians in requesting appropriate diagnostic tests and initiating appropriate empiric antimicrobials. Objectives To assess the comorbidities, aetiology and mortality associated with severe CAP in a tertiary ICU in Cape Town, South Africa. Methods We retrospectively analysed a prospective registry of all adults admitted to the medical intensive care unit at Tygerberg Hospital with severe CAP over a 1-year period. Results We identified 74 patients (mean (SD) age 40.0 (15.5) years; 44 females). The patients had a mean (SD) APACHE II score of 21.4 (7.9), and the mean ICU stay was 6.6 days. Of the 74 patients, 16 (21.6%) died in ICU. Non-survivors had a higher mean (SD) APACHE II score than survivors (28.3 (6.8) v. 19.4 (7.1); p

MEng (Mechanical Engineering), North-West University, Potchefstroom Campus The future of the South African mining industry is uncertain as a result of declining ore grades, reduced gold production and increasing operational costs. However, the industry remains a significant contributor to the country's economy. Efforts to ensure a sustained growth path for the mining industry are therefore vital for its survival, as well as the communities that depend on it. Mining companies in South Africa need to focus on reducing their operational costs to remain competitive. One such area offering potential is the production of compressed air, usually the largest consumer of electricity on a deep-level mine. Mines can reduce their operational costs by optimising compressed air production and curbing oversupply. Infrastructure, instrumentation and capital expenditure is limited. As a result, complex and expensive solutions are impractical, and the need for a simple, low-cost solution to match compressed air supply with the required demand is evident. A step-by-step methodology was developed that is easy and inexpensive to implement. The methodology focused on identifying cost-saving initiatives to reduce compressed air network inefficiencies. These inefficiencies were evaluated, and a suitable solution strategy was developed. Appropriate baselines were developed to determine the cost-saving impact after implementation. The methodology was implemented on the compressed air network of Mine A, located in the Free State province of South Africa. The method utilises setpoint control, effective compressor selection and compressed air prediction. The solution strategy was incorporated into an existing Energy Management System (EnMS), with no additional infrastructure costs. The EnMS platform was used to communicate the compressor running schedule to the control room operators, based on the demand requirements. This was shown visually by a message on a computer screen to either start or stop a specific compressor. The implemented solution strategy proved to have no negative effects on the production of the mine, while annual energy cost savings of R1,1-million was shown to be viable. This proves that the solution strategy can be sustainably implemented, and that compressed air savings can be achieved and sustained through practical and low-cost methods. Masters