Background: The Rapid Assessment of Avoidable Blindness (RAAB) survey methodology is a cost-effective tool for assessing the burden of blindness and cataract surgical services in a population. This study analyses the 2015 Rwanda National RAAB data to ascertain whether there are gender differences in access to cataract surgical services and also assess whether there is an association between measured distances travelled to access cataract surgical services and the cataract surgical coverage (CSC) in the country. Methods: Secondary data non automated analysis was performed on the 2015 Rwanda RAAB data, which had a sample of 5,275 persons who underwent ophthalmic examinations as per RAAB protocols to elicit the prevalence and causes of blindness and answered a standard questionnaire on barriers to cataract surgery. Cataract blindness prevalence and cataract surgical coverage were estimated for males and females and assessed for significant differences. Distances from clustered patients' locations to the nearest eye surgical facility ere calculated using Google Maps and analyses performed to identify if a relationship exists between distances travelled and the CSC for the area. Results: The prevalence of bilateral cataract blindness for males was 0.4% (n=8; 95% CI=0.1-0.7) and females 0.5% (n=17; 95% CI=0.3-0.8) and the CSC for males and females were 69.2% and 68.5% respectively. The difference in CSC was not statistically significant. Females aged ≥70 years reported more barriers to cataract surgical services compared to men. At a VA <3/60 in the better eye, 1km increase in the distance to the nearest eye surgicalcentre was associated with a reduction in the CSC for the area of 4.8% (Linear regression: F (1,95) = 16.06, p = 0.0001, R-Squared = 0.1446, Adjusted R-Squared = 0.1356). Conclusions: Older women (≥70 years) were the most vulnerable to untreated cataract blindness in Rwanda and therefore special programs need to target them for cataract surgical services. Distance to surgical facilities with ophthalmologists is related to the cataract surgical coverage even in a small country like Rwanda.

Background Tuberculosis remains a prevalent and deadly global disease. Diagnostic delays are partly due to reduced diagnostic performance of tuberculosis tests in HIV-positive people. The use of reliable pointof-care and near-patient diagnostic tests (e.g. urine lipoarabinomannan and point-of-care ultrasound) are increasingly being used and would benefit patients presenting to emergency centres by rapidly diagnosing HIV-associated tuberculosis. Methods Two studies were done: i) A systematic (Cochrane) review was done to determine the diagnostic accuracy of abdominal ultrasound for detecting abdominal tuberculosis or disseminated tuberculosis with abdominal involvement in HIV-positive individuals, and ii) A cross-sectional diagnostic study to derive a multi-parameter clinical decision tree, incorporating clinical information, point-of-care ultrasound features, chest x-ray and urine lateral flow lipoarabinomannan. The cross-sectional study was performed at the emergency centre of Khayelitsha Hospital, a South African district-level hospital in a high HIV-prevalence community, and resulted in three different publications. Consecutive HIV-positive adults presenting with ≥1 WHO tuberculosis symptoms were enrolled over a 16-month period (June 2016 to October 2017). Demographic and clinical information was recorded on a standardized data collection form. Point-of-care ultrasound was performed according to a standardized protocol. Urine lipoarabinomannan assays were done at point-of-care by emergency physicians and repeated in the laboratory. Chest x-rays were reviewed by a single radiologist using a standardized assessment form. The reference standard was a positive tuberculosis culture or Xpert MTB/RIF test on sputum, or appropriate extra-pulmonary samples. We compared diagnostic accuracy and reproducibility of urine lipoarabinomannan between point-ofcare readers and laboratory readers. We determined the diagnostic accuracy of individual point-ofcare ultrasound features, performed an external validation of the focused assessment with sonography for HIV/TB (FASH) protocol, and determined independent point-of-care ultrasound predictors of HIV-associated tuberculosis. We derived the decision tree model from multivariable logistic regression models. Results Abdominal ultrasound had a pooled sensitivity of 63% (95%CI 43-79; 5 studies, 368 participants; very low-certainty evidence) and a pooled specificity of 68% (95%CI 42-87; 5 studies, 511 participants; very low-certainty evidence) for bacteriologically confirmed tuberculosis. We screened 556 patients in the cross-sectional study of whom 414 (74.5%) were enrolled. The prevalence of microbiologically confirmed tuberculosis was 41.5% (n=172). Point-of-care and laboratory-performed urine lipoarabinomannan had similar sensitivity (41.8% vs 42.0%, P=1.0) and specificity (90.5% vs 87.5%, P=0.23). Moderate agreement was found between point-of-care and laboratory testing (k=0.62), but there was strong agreement between point-of-care readers (k=0.95) and between laboratory readers (k=0.94). Sensitivity and specificity of ≥1 individual point-of-care ultrasound feature were 73% (95%CI 65-79) and 54% (95%CI 47-60), and of the FASH protocol 71% (95%CI 64-78) and 57% (95%CI 50-63). Independent point-of-care ultrasound predictors identified were intra-abdominal lymphadenopathy of any size (aDOR 3.7; 95%CI 2.0-6.7), ascites (aDOR 3.0; 95%CI 1.5-5.7), and pericardial effusion of any size (aDOR 1.9; 95%CI 1.2-3.0). Two or more independent point-of-care ultrasound predictors had 33% (95%CI 27–41) sensitivity and 91% (95%CI 86-94) specificity. The best performing model included WHO screening symptoms ≥2, antiretroviral therapy use, urinary lipoarabinomannan, independently predictive point-of-care ultrasound features (ascites, any size pericardial effusion, any size intra-abdominal lymphadenopathy), and chest x-ray (c-statistic 0.82; 95%CI 0.78–0.86). Adding CD4 cell count did not improve the performance of the model. Classification And Regression Tree (CART) analysis positioned urinary lipoarabinomannan as the optimal screening test after WHO symptoms (75% true positive rate, representing 17% of participants). Conclusion An evidence-based algorithm for the rapid diagnosis of tuberculosis in HIV-positive patients presenting to an emergency centre was developed. Urinary lipoarabinomannan can be reliably performed at the point-of-care since there was no diagnostic accuracy advantage in laboratory-performed versus pointof-care–performed tests. The role of ultrasound in diagnosing HIV-associated tuberculosis had limitations. The low sensitivity of ultrasound (63% in the systematic review; 73% in the cross-sectional study) and the moderate discrimination (specificity 91%) of the presence of ≥2 independent point-ofcare ultrasound predictors indicate that point-of-care ultrasound results should be interpreted in combination with other diagnostic information. The derived decision tree can facilitate the immediate initiation of anti-tuberculosis treatment in about a quarter of patients among whom 75% would have a definitive diagnosis of tuberculosis regardless of CD4 cell count. The 30% false negative rate indicates that the algorithm should not be used to exclude tuberculosis. The performance of the decision tree needs to be further evaluated in settings with a different prevalence of HIV-associated tuberculosis.

The Human Immunodeficiency Virus (HIV) epidemic still poses a problem with approximately 2 million new infections reported worldwide in 2014. New strategies are required to alleviate this burden. Our laboratory has previously shown that crude saliva and purified mucins from cervical plug mucin, saliva and breast milk inhibit HIV-1 infection in vitro. This project investigates purified mucins sourced from pig and horse mucus, as an alternative and abundant source of material for anti-HIV-1 research. Pig gastric and cervico-vaginal mucus was collected and stirred overnight in 6M guanidine hydrochloride with 10mM Na₂HPO4, 10mM EDTA, 1mM PMSF and 5mM NEM. Gastric and cervicovaginal mucus was purified by density gradient ultracentrifugations in CsCl at 105 000g for 48 hours, twice, and mucin rich fractions were separated by size exclusion column chromatography. Mucin-rich materials eluting in the void volume (V₀) were reduced with 10mM dithithreitol (DTT) or subjected to proteolysis with trypsin. Pig saliva was collected in 0.2M NaCl:0.02% sodium azide and horse saliva (due to its viscous nature) was collected and stirred overnight in 6M guanidine hydrochloride with 10mM Na₂HPO4, 10mM EDTA, 1mM PMSF and 5mM NEM. Pig and horse saliva samples underwent size exclusion column chromatography, where the V₀ fractions of both were purified with one density gradient ultracentrifugation and then dialysed and freeze dried, after which aliquots were treated with either DTT or trypsin. At every stage of purification, lyophilized aliquots of all mucin sources were tested on a luciferase based replication defective HIV neutralization assay on a CD4 expressing HeLa cell line. Luciferase expression quantified as relative light units by a luminometer was used to calculate percentage neutralization. Log dose response curves were constructed to extrapolate the half maximal inhibitory concentrations (IC₅₀) on GraphPad Prism. Samples were tested on an MTT cell toxicity assay. Pig gastric and cervicovaginal mucins were added to a simulated vaginal fluid to make gels (at a concentration of 30mg of mucin per ml of buffer). These gels were tested on the neutralization, MTT assays and the pig gastric mucin gel then underwent particle tracking and nanoparticle diffusion assays at varying pH. Pig gastric and cervicovaginal mucin showed good inhibition and low toxicity, with pig gastric mucin V₀ having the best IC₅₀ (1.668μg/ml). Pig and horse saliva showed inhibition but low cell viability. Pig gastric and cervicovaginal mucin gels exhibited good IC₅₀'s but pig gastric mucin had the best neutralization and lowest toxicity (PGM in Gel Solution 4 IC₅₀: 20.23μg/ml). HIV particle tracking and nanoparticle diffusion assays showed that the pig gastric mucin gel inhibited HIV-1 at low pH and existed as a soft gel. This project shows the efficacy of pig gastric mucin to possibly being a component of an anti-HIV-1 vaginal microbicide.

Scaffold based delivery of RNA interference (RNAi) molecules such as free small interfering RNA (siRNA) and microRNA has recently begun to be employed towards treatment of diseases such as cancer, bone regeneration, muscular dystrophy and cardiovascular disease. Effective translation from bench side to clinical use of RNAi has been limited in part because upon systemic delivery the RNAi molecules are degraded by RNases and flushed by excretory organs causing an inefficient duration of gene silencing effect at target tissues. These challenges can potentially be minimised by delivering RNAi molecules via non-viral nanoparticle carriers encapsulated in biocompatible, biodegradable and injectable scaffolds such as hydrogels. Various scaffolds have been shown to aid in sustained localised delivery of RNAi molecules and improve gene silencing. This research focused on optimising and establishing such an RNAi hydrogel-siRNA-nanoparticle (hydrogel-nanocomplex) system for targeted and sustained gene knockdown both in vitro and in vivo using dendrimer and lipid based nanoparticles in combination with synthetic polyethylene glycol (PEG) and natural fibrin hydrogel scaffolds. Four siRNA nanocarriers were investigated for siRNA delivery, that is, fourth generation dendrimer nanoparticles poly(amidoamine) (D) and its modified version (MD) with PEG and a lipid 1, 2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) molecule, commercial lipid based Lipofectamine® RNAiMax and Invivofectamine® 3.0 nanoparticles. D and MD achieved better RNase protection compared to lipid nanocomplexes though Invivofectamine® 3.0 nanocomplexes protected a small percentage of siRNA over 10 days. The MD nanoparticle displayed improved siRNA release and transfection efficacy compared to D but efficacy of the dendrimers was lower than the lipid particles. Four hydrogels that have not been investigated for RNAi were assessed for sustainability. Namely, hydrolytically and proteolytically degradable PEG-acrylate (PEGAC), proteolytically degradable PEG - vinyl sulfone (PEG-VS) hydrogels, unmodified fibrin and PEGylated fibrin hydrogel. The nanocomplex release rate in vitro from the various hydrogels showed minimal release from PEGylated hydrogels, burst release from unmodified fibrin and sustained release from PEGylated fibrin. Invivofectamine® 3.0 nanocomplexes retained efficacy optimally after release from PEGylated fibrin hence this hydrogel was utilised for downstream analysis. For in vivo sustained delivery to be effective, determination of hydrogel persistence in vivo was required. After injection in the mouse tibialis anterior (TA) muscle PEG-AC and PEGylated fibrin gels degraded within 2 days. The efficacy of the various nanocomplexes was assayed in a 3D assay that more closely resembled delivery in soft tissue. PEGylated fibrin containing nanocomplexes with cell death siRNA sequences was polymerised around a preformed PEGylated fibrin cell containing droplet. Invivofectamine® 3.0 nanocomplex consistently achieved the highest gene knockdown effect with no evidence of cytotoxicity whilst Lipofectamine® RNAiMax was ineffective. MD showed signs of cytotoxicity when delivered in a sustained fashion. Thus Invivofectamine® 3.0 nanocomplexes in PEGylated fibrin hydrogel were found to be the optimal gel-nanocomplex system to proceed to in vivo assessment. BALB/c GFP transgenic injected in their TA muscle with Invivofectamine® 3.0 nanocomplexes made with siRNA targeting GFP or myostatin (siGFP/siMSTN) in the presence or absence of PEGylated fibrin gel were analysed 7 days post treatment for siRNA retention and GFP and Mstn gene knockdown. Increased retention of siRNA after encapsulation in PEGylated fibrin was observed at 7 days. A non-significant reduction in GFP protein was seen for limbs injected with siGFP- fibrin after 7 days. A substantial and significant reduction in Mstn mRNA levels was elicited by delivery of siMstn–fibrin. Furthermore, only siMstn-fibrin resulted in significant increase in muscle mass. In this study, dendrimer based nanoparticles were found to effectively protect siRNA against RNases however lipid based nanocomplexes were the most efficacious at gene knockdown. The combination of Invivofectamine® 3.0 and PEGylated fibrin was shown to be the most effective in 3D assays and as an injectable controlled release scaffold into soft tissue suggesting that this approach has therapeutic potential.

Background: Blunt and penetrating traumatic thoracic aortic injuries constitute surgical emergencies that are attended with high mortality rates. Most patients do not survive long enough, post injury, to reach a hospital. On-site mortality rates may approach approximately 85%. Two main treatment options for blunt thoracic aortic injuries (BTAI) are open surgery and thoracic endovascular repair (TEVAR). Penetrating thoracic aortic injuries (PTAI) have a higher mortality than blunt trauma, with patients often only reaching the hospital in extremis. Most will require early intervention. Currently TEVAR is rapidly evolving as the standard of care for thoracic aortic injuries (TAI) at many centres, primarily due to the emerging evidence of lower mortality and morbidity trends in comparison to open surgery (1–4). Methods: From December 2006 to December 2016, 34 patients (30 blunt trauma, 4 penetrating trauma) with traumatic aortic injuries (grades I-IV) were treated with thoracic aortic stent-grafts in the Groote Schuur Hospital Vascular Unit, Cape Town. We assessed the technical and clinical outcomes following TEVAR in these patients. Results: The 30- day mortality rate was 5.8%, corresponding to 2 deaths both associated with the index trauma-related fatal strokes. The overall mortality rate was 11.8% (4/34): three deaths were due to major strokes and one death was related to pulmonary complications. Conclusion: TEVAR after TAI is associated with significantly lower procedural and postoperative mortality. The 30 day and overall mortality after TEVAR in our unit is comparable to international standards. Even though there is a paucity of literature on PTAI, TEVAR has low peri-procedural adverse events and is safe in selected patients.

Background: In resource-poor settings with limited surgical services, it is essential to identify and prioritise children with severe and very severe obstructive sleep apnoea syndrome (OSAS) to expedite surgery. McGill's Oximetry Score (MOS) has been validated against polysomnography for OSAS and is affordable and easy to use. Aims: The aim of this study was to assess the correlation of tonsillar size and clinical symptoms with MOS grade 3 or 4, to identify who requires overnight oximetry and who to prioritise for adenotonsillectomy. Methods: Children with suspected OSAS were recruited from the otolaryngology clinic at the Red Cross War Memorial Children‟s Hospital. Demographics, symptom screening scores (SSS), patient characteristics, overnight oximetry (OO), echocardiography and MOS scores (graded 1- 4) were recorded. Multivariate modified-Poisson regression models were used to examine correlations of patient characteristics „with grade 3 or 4 MOS. Results: One-hundred-and-three children were analysed, 38% were female, and median (IQR) age was 3.8 (2.5-5.3) years. Increased tonsil size was associated with a 60% increased risk of grade 3 or 4 MOS, risk ratio (RR) 1.59, 95% CI 1.10-2.29 (p=0.014). Children with witnessed apnoeic events during sleep had 1.3 times increased risk of MOS Grade 3 or 4, RR 1.31, 95% CI (p=0.033). A significant correlation was shown with grade 3 or 4 MOS, RR 1.15, 95% CI 1.03-1.27 (p=0.010) by combining tonsillar size with the following symptoms: apnoeic events; struggling to breathe during sleep and; needing to stimulate the child to breathe. Conclusion: Identifying children with suspected OSAS who require overnight oximetry can be performed using a simple 3-question screening tool: witnessed apnoeic events, struggling to breathe and the need to shake them awake to breathe. This is more precise with an additional clinical finding of grade 3 or 4 tonsils. These children should have surgery expedited. Any child with a MOS 3 or 4 score on OO needs to have expedited surgery.

Background: There are few surgical options available to manage complex talar pathology that result in predictably acceptable functional and patient satisfaction scores. Recently, the total talar replacement has gained popularity as a viable option. This study presents the clinical outcomes of the first case series of total talar replacements in South Africa. Methodology: A retrospective review of prospectively collected data of eight consecutive patients who underwent a total talus replacement between July 2014 and August 2018 was performed. The American Orthopaedic Foot and Ankle Hindfoot Score (AOFAS) was used to assess clinical functional outcome and the Short Form36 satisfaction index (SF-36) was used to assess patient satisfaction. Patient demographics as well as data on pathology, range of motion, gait analysis and radiological outcomes were included. Results: The average age was 46 years (range, 23 to 71). Pathologies included trauma, avascular necrosis and tumours. Average followup time was 23 months (range, 12 to 49). The mean AOFAS score was 79.25 (range, 69 to 88) and the mean SF36 was 83.25. (range, 60 to 93). No complications or revision surgeries have been performed to date. Seven patients demonstrated a mildly abnormal gait pattern with one in the moderate category. One patient showed radiological changes of minor tibial wear, however this was the patient with the longest followup time (49 months) and he remained symptom free. Conclusion: Total talar replacements are a viable surgical option in appropriately selected patients with end stage talar pathology in the short to medium term, without compromising future salvage options.

Background: The surgical management of scapula body, neck and glenoid fractures remains a challenge. This study focusses on templating an available anatomical pre-contoured plating system using 3D printed scapulae to assess the ability of these plates to address the aforementioned fractures and to determine consensus on classifying scapula body, neck and glenoid fractures. Methods: We used a cohort of twenty-two 3D printed fractured scapulae prototypes and an available anatomical pre-contoured plating system to determine anatomical congruency and fit. Nine investigators templated the scapula fractures using four pre-contoured plates and the investigators classified the twenty-two fractured scapulae using the Ideberg and AO/OTA classification system. Results: Eleven out of twenty-two fractures were found to be fixable using the plates under study. The long lateral plate addressed 83.3% of fractures involving the lateral border, while the glenoid plate was unable to adequately address any glenoid fractures. We observed good to excellent (p ≤ 0.001) inter-observer reliability for three of the four plates. The inter-observer reliability was moderate (ICC = 0.74) for the AO/OTA classification and good (ICC = 0.88) for the Ideberg classification. Conclusion: We believe that the anatomical pre-contoured plating system does not address all the fracture patterns encountered in clinical practice and further development in plate design is required. Good to moderate interobserver reliability were observed using the Ideberg fracture classification for intra-articular fractures and the AO/OTA classification for extraarticular fractures involving the body.

Background Radiologically measured psoas muscle area has been associated with poorer surgical outcomes. Our hypothesis is that patients with gastric cancer and lower psoas muscle area have poorer short-term surgical outcomes. Methods Individuals with gastric cancer were assessed and total psoas muscle area (TPA) in mm2 was measured at the level of the third lumbar vertebra on staging CT, using Phillips IntelloSpace PACS Enterprise version 4.4.553.50. The psoas muscle area was normalised for height (TPA mm2 /m2 ), creating the psoas muscle index (PMI). All individuals proceeding to surgery were compared in terms of PMI with correlation to short-term complications (Accordion), length of stay and mortality. In addition, PMI and tumour staging was evaluated. Results One hundred and seventy-seven individuals (115 males, 62 females, mean age of 60.8 ± 0.9) were evaluated of which sixty-eight underwent surgery (56 resections, 12 palliative bypasses). The surgical complication rate was 40% (27/68), major complications being Accordion 3 or higher at a rate of 16% (11/68) and mortality rate of 10% (7/68). The average length of stay was 10 ± 0.7 days. There was no statistically significant difference in PMI for males or females in respect to all complications, major complications, length of stay or mortality. PMI and tumour staging did not correlate. Males with gastric outlet obstruction had a statistically significant lower PMI (p <0.03) Conclusions Although low psoas muscle area has been shown to correlate with poorer surgical outcomes, we did not show this is our population undergoing surgery for gastric cancer.

Purpose: Elimination of trachoma-related blindness requires addressing not only issues of trichiasis surgery availability and accessibility, but also quality. To improve surgeon performance, programmes undertake surgeon audits to identify surgeons needing re-training, reasons for poor outcomes, and actions to optimise surgical outcomes. This study aims to determine the frequency and associated factors of audits conducted in selected countries and factors associated with failed audits. Methods: A multicentric study was conducted as a secondary data analysis of surgeon audit results for eight African countries. Stata® was used to generate results for chi-square tests for association, odds ratio and 95% confidence intervals between independent samples for categorical variables and one-way ANOVA tests for continuous variables. Results: The study included 561 trichiasis surgeons and 193 (34.4%) had an audit. Dedicated eye care workers were more likely to have an audit (p<0.001) compared to general health workers. Among audited surgeons, 29 (15%) failed and were recommended for re-training. Surgeons using posterior lamellar tarsal rotation (PLTR) surgery (59.8%) and those trained more recently (mean 4.2 years) were more likely to pass the audit. Conclusion: Although surgeon audits are considered a routine part of programme activities in trachoma endemic countries, too few audits are being undertaken. Further research is needed to learn why surgeons practicing PLTR surgery and those trained more recently are more likely to pass their audit. To improve surgical outcomes, programmes must not only focus on surgical volume but carry out surgeon audits and use the audits to make programme decisions.