The effectiveness of vaccination for preventing hospitalisation with COVID-19 in regional Queensland: a data linkage study.

OBJECTIVE: To estimate the effectiveness of vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for protecting people in a largely coronavirus disease 2019 (COVID-19)-naïve regional population from hospitalisation with symptomatic COVID-19. DESIGN: Retrospective cohort study; analysis of positive SARS-CoV-2 polymerase chain reaction (PCR) test results linked with Central Queensland hospitals admissions data and Australian Immunisation Register data. SETTING, PARTICIPANTS: Adult residents of Central Queensland, 1 January - 31 March 2022. MAIN OUTCOME MEASURES: Vaccine effectiveness (1 - relative risk of hospitalisation for vaccinated and unvaccinated people) with respect to protecting against hospitalisation with symptomatic COVID-19 after primary vaccination course only (two doses of an approved SARS-CoV-2 vaccine) and after a booster vaccine dose. RESULTS: Positive SARS-CoV-2 test results were recorded during 1 January - 31 March 2022 for 9682 adults, 7244 of whom had been vaccinated (75%); 5929 people were aged 40 years or younger (62%), 5180 were women (52%). Forty-seven people were admitted to hospital with COVID-19 (0.48%), four required intensive care (0.04%); there were no in-hospital deaths. Vaccine effectiveness was 69.9% (95% confidence interval [CI], 44.3-83.8%) for people who had received only a primary vaccination course and 81.8% (95% CI, 39.5-94.5%) for people who had also received a booster. Of the 665 Aboriginal and Torres Strait Islander adults with positive SARS-CoV-2 test results, 401 had been vaccinated (60%). Six Indigenous people were hospitalised with symptomatic COVID-19 (0.9%); vaccine effectiveness was 69.4% (95% CI, -56.5% to 95.8%) for Indigenous people who had received a primary vaccination course only or the primary course and a booster. CONCLUSION: The hospitalisation rate for Central Queensland people with PCR-confirmed Omicron variant SARS-CoV-2 infections during the first quarter of 2022 was low, indicating the protection afforded by vaccination and the value of booster vaccine doses.

Incidence and Outcome of Aneurysmal Subarachnoid Hemorrhage: The Swiss Study on Subarachnoid Hemorrhage (Swiss SOS).

BACKGROUND AND PURPOSE: The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level. METHODS: All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded. RESULTS: We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0-2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3-5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year. CONCLUSIONS: The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03245866.

Predictors of In-Hospital Death After Aneurysmal Subarachnoid Hemorrhage: Analysis of a Nationwide Database (Swiss SOS [Swiss Study on Aneurysmal Subarachnoid Hemorrhage]).

BACKGROUND AND PURPOSE: To identify predictors of in-hospital mortality in patients with aneurysmal subarachnoid hemorrhage and to estimate their impact. METHODS: Retrospective analysis of prospective data from a nationwide multicenter registry on all aneurysmal subarachnoid hemorrhage cases admitted to a tertiary neurosurgical department in Switzerland (Swiss SOS [Swiss Study on Aneurysmal Subarachnoid Hemorrhage]; 2009-2015). Both clinical and radiological independent predictors of in-hospital mortality were identified, and their effect size was determined by calculating adjusted odds ratios (aORs) using multivariate logistic regression. Survival was displayed using Kaplan-Meier curves. RESULTS: Data of n=1866 aneurysmal subarachnoid hemorrhage patients in the Swiss SOS database were available. In-hospital mortality was 20% (n=373). In n=197 patients (10.6%), active treatment was discontinued after hospital admission (no aneurysm occlusion attempted), and this cohort was excluded from analysis of the main statistical model. In the remaining n=1669 patients, the rate of in-hospital mortality was 13.9% (n=232). Strong independent predictors of in-hospital mortality were rebleeding (aOR, 7.69; 95% confidence interval, 3.00-19.71; P<0.001), cerebral infarction attributable to delayed cerebral ischemia (aOR, 3.66; 95% confidence interval, 1.94-6.89; P<0.001), intraventricular hemorrhage (aOR, 2.65; 95% confidence interval, 1.38-5.09; P=0.003), and new infarction post-treatment (aOR, 2.57; 95% confidence interval, 1.43-4.62; P=0.002). CONCLUSIONS: Several-and among them modifiable-factors seem to be associated with in-hospital mortality after aneurysmal subarachnoid hemorrhage. Our data suggest that strategies aiming to reduce the risk of rebleeding are most promising in patients where active treatment is initially pursued. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT03245866.

Improving the aesthetic outcome with burr hole cover placement in chronic subdural hematoma evacuation-a retrospective pilot study.

BACKGROUND: The aesthetic outcome after burr hole trepanation for the evacuation of chronic subdural hematomas (cSDH) is often unsatisfactory, as the bony skull defects may cause visible skin depressions. The purpose of this study was to evaluate the efficacy of burr hole cover placement to improve the aesthetic outcome. METHODS: We reviewed consecutive patients treated by burr hole trepanation for cSDH with or without placement of burr hole covers by a single surgeon between October 2016 and May 2018. The clinical data, including complications, were derived from the institution's prospective patient registry. The primary endpoint was the aesthetic outcome, as perceived by patients on the aesthetic numeric analog (ANA) scale, assessed by means of a standardized telephone interview. Secondary endpoints were skin depression rates and wound pain, as well as complications. RESULTS: From n = 33, outcome evaluation was possible in n = 28 patients (n = 24 male; mean age of 70.4 ± 16.1 years) with uni- (n = 20) or bilateral cSDH (n = 8). A total of 14 burr hole covers were placed in 11 patients and compared to 50 burr holes that were not covered. Patient satisfaction with the aesthetic outcome was significantly better for covered burr holes (mean ANA 9.3 ± 0.74 vs. 7.9 ± 1.0; p < 0.001). Skin depressions occurred over 7% (n = 1/14) of covered and over 92% (n = 46/50) of uncovered burr holes (p < 0.001). There was no difference in wound pain (p = 0.903) between covered and uncovered sites. No surgical site infection, cSDH recurrence, or material failure was encountered in patients who had received a burr hole plate. CONCLUSIONS: In this retrospective series, placement of burr hole covers was associated with improved aesthetic outcome, likely due to reduction of skin depressions. A randomized controlled trial is developed to investigate whether adding burr hole covers results in superior aesthetic outcomes, without increasing the risk for complications.

The usefulness of radiological grading scales to predict pain intensity, functional impairment, and health-related quality of life after surgery for lumbar degenerative disc disease.

PURPOSE: The goal of this study is to determine the relationship of radiological grading scales of lumbar degenerative disc disease (DDD) with postoperative pain intensity, functional impairment, and health-related quality of life (HRQoL). METHODS: Response to surgical treatment at 6 weeks (W6) on the visual analogue scale (VAS) for back and leg pain, Oswestry-Disability (ODI) and Roland-Morris Disability Index (RMDI), Timed Up and Go (TUG) test, EuroQol (EQ) 5D, and Short-Form Health-Survey (SF-12) physical component summary (PCS) was compared between patients with different Modic (MOD) and Pfirrmann (PFI) grades. Longitudinal outcomes at day 3 (D3), W6, 6 months (M6), and 1 year (Y1) were compared. RESULTS: The study included 338 patients (mean age, 58.6 years), of which n = 202 (59.8%) had MOD 1-3 and n = 217 (64.2%) PFI 4-5 changes. Patients with MOD 1-3 were as likely as patients without MOD changes to be treatment-responders at W6 in terms of VAS leg pain, ODI, RMDI, TUG, EQ5D, and SF-12 PCS. Similarly, patients with PFI 4-5 were as likely as patients with PFI 1-3 changes to be treatment-responders at W6. Longitudinal outcomes were similar at D3, W6, M6, and Y1 between patients with and without MOD changes. Patients with PFI 4-5 fared similar to those with PFI 1-3 except for inferior HRQoL on the SF-12 PCS metric at Y1. CONCLUSIONS: There was no distinct relationship between commonly used radiological grading scales of lumbar DDD with clinical outcome. Therefore, no prognosis should be made on the grounds of preoperative PFI and MOD classifications for patients undergoing spine surgery for lumbar DDD.

Validation of the National Institutes of Health Stroke Scale-8 to Detect Large Vessel Occlusion in Ischemic Stroke.

BACKGROUND: Patients with acute ischemic stroke and large vessel occlusion (LVO) may benefit from prehospital identification and transfer to a center offering endovascular therapy. AIMS: We aimed to assess the accuracy of an existing 8-item stroke scale (National Institutes of Health Stroke Scale-8 [NIHSS-8]) for identification of patients with acute stroke with LVO. METHODS: We retrospectively calculated NIHSS-8 scores in a population of consecutive patients with presumed acute stroke assessed by emergency medical services (EMS). LVO was identified on admission computed tomography angiography. Accuracy to identify LVO was calculated using receiver operating characteristics analysis. We used weighted Cohen's kappa statistics to assess inter-rater reliability for the NIHSS-8 score between the EMS and the hospital stroke team on a prospectively evaluated subgroup. RESULTS: Of the 551 included patients, 381 had a confirmed ischemic stroke and 136 patients had an LVO. NIHSS scores were significantly higher in patients with LVO (median 18; interquartile range 14-22). The NIHSS-8 score reliably predicted the presence of LVO (area under the receiver operating characteristic curve .82). The optimum NIHSS-8 cutoff of 8 or more had a sensitivity of .81, specificity of .75, and Youden index of .56 for prediction of LVO. The EMS and the stroke team reached substantial agreement (κ = .69). CONCLUSIONS: Accuracy of the NIHSS-8 to identify LVO in a population of patients with suspected acute stroke is comparable to existing prehospital stroke scales. The scale can be performed by EMS with reasonable reliability. Further validation in the field is needed to assess accuracy of the scale to identify patients with LVO eligible for endovascular treatment in a prehospital setting.

Pre- and postoperative correlation of patient-reported outcome measures with standardized Timed Up and Go (TUG) test results in lumbar degenerative disc disease.

BACKGROUND: The Timed Up and Go (TUG) test is a reliable tool for evaluating objective functional impairment (OFI) in patients with degenerative disc disease before a surgical intervention. The aim of this study is to assess the validity of the TUG test to measure change in function postoperatively. METHODS: In a prospective two-center study, OFI was assessed by the TUG test in patients scheduled for lumbar spine surgery, as well as 3 days (D3) and 6 weeks (W6) postoperatively. At each time point, the TUG test results were correlated with established subjective measures of pain intensity (visual analogue scale (VAS) for back and leg pain), functional impairment (Oswestry Disability Index (ODI)) and health-related quality of life (HRQoL; Short Form-12 (SF12)). RESULTS: The patient cohort comprised 136 patients with a mean age of 57.7 years; 76 were males, 54 had a microdiscectomy for lumbar disc herniation, 58 a decompression for a lumbar spinal stenosis, 24 had a surgical fusion procedure. The mean OFI t-score was 125.1 before surgery, and as patients improved on the subjective measures in the postoperative interval, the OFI t-score likewise decreased to 118.8 (D3) and 103.4 (W6). The Pearson correlation coefficient (PCC) between the OFI t-score and VAS leg pain was 0.187 preoperatively (p = 0.029) and 0.252 at W6 (p = 0.003). The PCC between OFI t-score and the ODI was 0.324 preoperatively (p < 0.001) and 0.413 at W6 (p < 0.001). The PCC between OFI t-score and physical HRQoL (SF12) was -0.091 preoperatively (p = 0.293) and -0.330 at W6 (p < 0.001). CONCLUSIONS: The TUG test is sensitive to change, and reflects the postoperative functional outcome even more exact than preoperatively, as indicated by better correlation coefficients of the OFI t-score with subjective measures of pain intensity, functional impairment and HRQoL.

Dynamic transpedicular stabilisation and decompression in single-level degenerative anterolisthesis and stenosis.

BACKGROUND: Different treatment options exist for symptomatic single-level degenerative anterolisthesis and stenosis. While simple micro-decompression has been advocated lately, most authors recommend posterior decompression with fusion. In recent years, decompression and dynamic transpedicular stabilisation has been introduced for this indication. The aim of this study was to evaluate the safety and efficacy of decompression and dynamic transpedicular stabilisation with the Dynesys® system in single-level degenerative anterolisthesis and stenosis. METHODS: Thirty consecutive patients with symptomatic single-level degenerative anterolisthesis and stenosis without scoliosis underwent decompression and single-level Dynesys stabilisation at the level of degenerative anterolisthesis. Patients were followed prospectively for 24 months with radiographs, Oswestry Disability Index scores, visual analogue scale (VAS) for back and leg pain, and estimated pain-free walking distance. RESULTS: At the 2-year follow-up, back pain was reduced from 6.5 preoperatively to 2.5, leg pain from 5.4 to 0.6. The pain-free walking distance was estimated at 500 m preoperatively and at over 2 km after 2 years, while the ODI decreased from 54 % to 18 %. Screw loosening was found in 2/30 cases. Symptomatic adjacent segment disease was found in 3/30 patients between 12 and 24 months postoperatively. CONCLUSIONS: Single-level Dynesys stabilisation combined with single- or multi-level decompression seems to be a safe and efficient treatment option in single-level degenerative anterolisthesis and stenosis over an observation period of 2 years, avoiding iliac crest or local bone grafting required by fusion procedures. However, it does not seem to avoid adjacent segment disease.

Incidental durotomy in lumbar spine surgery--a three-nation survey to evaluate its management.

BACKGROUND: Although it is generally accepted that incidental durotomies (ID) should be primarily repaired, the current literature shows no consensus regarding the peri- and postoperative management in case of ID during lumbar spine surgery. Because ID is a rather frequent complication and may be associated with significant disability, we were interested to analyze the current handling of ID in three European countries. METHODS: In March 2014, members of the Swiss, German, and Austrian neurosurgical and spine societies were asked to complete an online questionnaire regarding the management of ID during and after lumbar spine surgery. Two, respectively 4 weeks after the first invitation, reminder requests were sent to all invitees, who had not already responded at that time. RESULTS: There were 175 responses from 397 requests (44.1 %). Responders were predominantly neurosurgeons (89.7 %; 10.3 % were orthopedic surgeons), of which 45.7, 40.0, and 17.8 % work in a non-university hospital, university hospital, and private clinic, respectively. As for the perioperative management of ID, 19.4 % of the responders suggest only bed rest, while, depending on the extent of the ID, 84.0 % suggest additional actions, TachoSil/Spongostan with fibrin glue or a similar product and single suture repair being the most mentioned. Concerning epidural wound drainage in case of ID, 37.2 % desist from placing an epidural wound drainage with or without aspiration, 30.9 % place it sometimes, and 33.7 % place it regularly, but only without aspiration. Most responders prescribe bed rest for 24 (34.9 %) or 48 h (28.0 %), with much fewer prescribing bed rest for 72 h (6.3 %) and none more than 72 h, and 14.9 % of participants never prescribe bed rest. The vast majority of physicians (82.9 %, n = 145) always inform their patients after the operation in case of ID. CONCLUSIONS: There is substantial heterogeneity in the management of incidental durotomies. The majority of spine surgeons today aim at complete/sufficient primary repair of the ID with varying recommendations concerning postoperative bed rest. Still, there is a trend towards early mobilization if the incidental durotomy has been closed completely/sufficiently with no participant favoring bed rest for more than 72 h.

Early surgical education of residents is safe for microscopic lumbar disc surgery.

INTRODUCTION: It is a well-established dogma that many surgeons do not reach a quintessential level of their technical operative skills until successful completion of their training program. The aim of this study was to test the hypothesis that early introduction of supervised residents to non-complex spinal surgical procedures within a structured and supervised educational program does not harm the patient in terms of higher complication rates or worse pain- and health-related quality of life (HrQOL) outcomes. METHODS: A prospective study on 102 patients undergoing surgery for lumbar disc herniation (LDH) was performed. The procedures were dichotomized into two groups according to the surgeon's level of experience: teaching cases (neurosurgical residents in the 1st to 4th year of training) and non-teaching cases (experienced board-certified faculty neurosurgeons). Pain levels (VAS) and the HrQOL using the 12-item short-form health survey (SF-12) were measured at baseline, at 4 weeks and as a survey at 1 year postoperatively. In addition, data concerning the operation and the postoperative course including common complications were assessed. RESULTS: Intraoperative blood loss, length of surgery, as well as intra- and postoperative complications were similar between the study groups. Patients in both groups achieved equal results in terms of pain reduction after 4 weeks [mean VAS change -3.8 (teaching cases) vs. -3.1 (non-teaching cases), p = 0.25] and 1 year postoperatively [mean change in VAS -3.5 (teaching cases) vs. -3.37 (non-teaching cases), p = 0.84]. Teaching cases were 100 % (odds ratio of 1.00) as likely as non-teaching cases to achieve a favorable HrQOL response to surgery (p = 0.99). CONCLUSIONS: Early introduction of resident surgeons to lumbar microdiscectomy can be conducted safely within a structured and supervised educational program as it neither harms the patient nor leads to worse 1-year results. Surgical resident education may thus be implemented safely in times of rigorous working laws. However, a structured education program in which the senior surgeon gives advice, guidance and communicates cautions during each resident surgery is of paramount importance to provide high-quality patient care.

Incidence and relative survival of chordomas: the standardized mortality ratio and the impact of chordomas on a population.

BACKGROUND: Chordomas are rare bone tumors arising from remnants of the embryonic notochord. METHODS: Data for this study were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute (1973-2009) to calculate the incidence, relative survival (RS), and standardized mortality ratio (SMR) of patients diagnosed with intracranial and extracranial chordomas and to assess the effects of age and sex on this disease. RESULTS: The overall incidence of extracranial and intracranial chordomas was 8.4 per 10 million population. The median overall survival of patients with chordoma patients was 7.7 years. The median survival was 7.7 years for male patients and 7.8 years for female patients. Younger patients (aged <40 years) survived longer compared with older patients (10-year RS, 68% vs 43%). The estimated age-standardized 5-year, 10-year, and 20-year RS rates was 72%, 48%, and 31%, respectively. The SMR in the overall cohort was 4.6 (95% confidence interval, 4.22-5.0) or 21.0 (95% confidence interval, 16.6-27.2) in young adult patients and 3.0 (95% confidence interval, 2.6-3.4) in elderly patients. CONCLUSIONS: The elderly had a more aggressive form of this disease; and, other than the incidence, sex did not influence outcome in this disease. The study of chordomas presents a good case for the contribution that the SMR can have on measuring the impact of a disease on a population of patients. Although the younger population has better survival rates, the impact (SMR) in the younger age groups is much higher than in older populations.

Computed tomography scan radiation and brain cancer incidence.

BACKGROUND: Computed tomography (CT) scans make substantial contributions to low-dose ionizing radiation exposures, raising concerns about excess cancers caused by diagnostic radiation. METHODS: Deidentified medicare records for all Australians aged 0-19 years between 1985-2005 were linked to national death and cancer registrations to 2012. The National Cancer Institute CT program was used to estimate radiation doses to the brain from CT exposures in 1985-2005, Poisson regression was used to model the dependence of brain cancer incidence on brain radiation dose, which lagged by 2 years to minimize reverse causation bias. RESULTS: Of 10 524 842 young Australians, 611 544 were CT-exposed before the age of 20 years, with a mean cumulative brain dose of 44 milligrays (mGy) at an average follow-up of 13.5 years after the 2-year lag period. 4472 were diagnosed with brain cancer, of whom only 237 had been CT-exposed. Brain cancer incidence increased with radiation dose to the brain, with an excess relative risk of 0.8 (95% CI 0.57-1.06) per 100 mGy. Approximately 6391 (95% CI 5255, 8155) persons would need to be exposed to cause 1 extra brain cancer. CONCLUSIONS: For brain tumors that follow CT exposures in childhood by more than 2 years, we estimate that 40% (95% CI 29%-50%) are attributable to CT Radiation and not due to reverse causation. However, because of relatively low rates of CT exposure in Australia, only 3.7% (95% CI 2.3%-5.4%) of all brain cancers are attributable to CT scans. The population-attributable fraction will be greater in countries with higher rates of pediatric scanning.

COveRs to impRove EsthetiC ouTcome after Surgery for Chronic subdural hemAtoma by buRr hole trepanation-Results of a Swiss Single-Blinded, Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Burr hole trepanation to evacuate chronic subdural hematoma (cSDH) results in bony skull defects that can lead to skin depressions. We intend to study the effect of burr hole covers to prevent skin depressions and improve the esthetic result. METHODS: In a randomized trial, we enrolled adult patients with symptomatic cSDH. Patients received burr hole trepanation with (intervention) vs without burr hole covers (control) in a 1:1 ratio. Patients requiring evacuation of bilateral cSDHs served as their internal control. Primary outcome was satisfaction with the esthetic result of the scar, measured from 0 (dissatisfied) to 10 (very satisfied) on the Esthetic Numeric Analog (ANA) scale at 90 days. Secondary outcomes included ANA scale, rates of skin depression, complications, as well as neurological, disability, and health-related quality of life outcomes until 12 months. RESULTS: We included 78 patients (55 with unilateral and 23 with bilateral cSDH; median age 78 years, 83% male) between 03/2019 and 05/2021, 50 trepanations for the intervention and 51 for the control group. In an intention-to-treat analysis, the ANA scale scores were 9.0 (intervention) and 8.5 (control arm) at 90 days (P = .498). At 12 months, the ANA scale scores were 9.0 and 8.0 for the intervention and control groups, respectively (P = .183). Skin depressions over the frontal burr hole were noted by 35% (intervention) and 63% (control) of patients at 90 days (P = .009) and by 35% and 79% (P < .001) at 12 months, respectively. There were no differences in complications, neurological, disability, and health-related quality of life outcomes. CONCLUSION: Satisfaction with the esthetic result of the scar was inherently high. This study does not show evidence for improvement on the ANA scale by applying a burr hole cover. The application of burr hole covers resulted in less skin depressions and did not negatively affect complication rates or outcomes.

SMS reminders increase on-time vaccination in Aboriginal and Torres Strait Islander infants.

Abstract: Timely immunisation is important to protect children from communicable diseases. However, immunisation uptake in Aboriginal and Torres Strait Islander children under the age of two years is often lower than in non-Indigenous children. This contributes to the gap in health outcomes between Aboriginal and Torres Strait Islander children and non-Indigenous children. We have tested the effectiveness of short message service (SMS) reminders in improving timeliness of childhood immunisation in Aboriginal and Torres Strait Islander infants in regional Queensland, Australia. Reminders were sent to parents of Aboriginal and Torres Strait Islander children, at five immunisation age milestones: six weeks, four months, six months, 12 months, and 18 months. There was a significant improvement in the proportion of children vaccinated on-time (within 30 days of the due date), compared to an earlier age cohort, at all milestones except 12 months. The absolute risk difference (ARD) of on-time vaccination between the two cohorts ranged between 4.7% (95% confidence interval [95% CI]: 1.1-8.2%, at six weeks) and 12.9% (95% CI: 7.4-18.5%, at six months). The likelihood of on-time vaccination (rate ratio, RR) in the intervention group compared to the control group ranged from 1.05 (95% CI: 1.01-1.10, at six weeks) to 1.31 (95% CI: 1.14-1.50, at 18 months). SMS reminders were associated with an improvement in immunisation timeliness in Aboriginal and Torres Strait Islander infants at all age milestones measured except 12 months.

Several confirmed and probable zoonotic cases of toxigenic Corynebacterium ulcerans, Queensland, Australia.

Background: Toxigenic Corynebacterium ulcerans is an emerging zoonosis globally, causing both cutaneous and respiratory diphtheria-like illness. In Queensland, human infection with toxigenic C. ulcerans is rare, with only three cases reported before October 2015. This case series describes five subsequent cases of toxigenic C. ulcerans in Queensland with links to companion animals. Methods: All data were collected as part of routine public health response, and strains were whole genome sequenced for further characterisation. Household contacts were screened, treated with appropriate antibiotics, and received a diphtheria toxoid-containing vaccine if more than five years had elapsed since their last dose. Findings: No epidemiological or genomic links could be established between any of the five patients, including between the two cases notified from the same locality within eight days of each other. The C. ulcerans strains from Cases Two, Four and Five were closely related to the strains isolated from their respective pets by whole genome sequencing. Domestic dogs were identified as the most likely mode of transmission for Cases One and Three; however, this was unable to be laboratory confirmed, since Case One's dog was treated with antibiotics before it could be tested, and Case Three's dog was euthanised and cremated prior to case notification. Interpretation: These are the first reported Australian cases of this emerging zoonosis with links to companion animals. These cases demonstrate the likely transmission route between companion animals and humans, with no evidence of human-to-human transmission. The existing requirement in the Queensland Health Public Health Management Guidelines, of restrictions on cases and some contacts while awaiting swab results, is currently under review.

Relative survival of childhood and adult medulloblastomas and primitive neuroectodermal tumors (PNETs).

BACKGROUND: Medulloblastomas are 1 of the most common brain tumors in children but can affect individuals of all ages. For this report, the author investigated the impact of medulloblastomas/primitive neuroectodermal tumors (PNETs) on the US population with a focus on age differences. METHODS: Data from the Surveillance, Epidemiology, and End Results (SEER) database were used to describe cumulative relative survival (CRS) using crude, period, and longitudinal period approaches for patients diagnosed with all medulloblastoma subtypes and PNETs. CRS estimates were obtained using SEER expected mortality data and the Ederer II method for expected survival estimation. These data were applied to the construction of rational follow-up scheduling protocols. RESULTS: The 5-year period CRS for all patients who were followed between 2001 and 2006 was 69%. Adults had a worse overall prognosis, but this difference in excess hazard rates appeared only after 4 years of follow-up. Furthermore, the 5-year and 10-year CRS has improved a minimum of 11% in children, adolescents, and adults over the past 25 years. CONCLUSIONS: The survival difference between children, adolescents, and adults with medulloblastomas and PNETs depended on the length of follow-up, which was described in this report as an age-by-follow-up interaction and observed as a "fork" on Kaplan-Meier curves. Differences in survival between children and adults emerged only 4 years after diagnosis, and adults fared worse. There has been significant improvement in survival from medulloblastomas/PNETs since the late 1970s and early 1980s.

The cure fraction of glioblastoma multiforme.

BACKGROUND AND PURPOSE: This study presents a statistical model to explore the presence of a population-based cure fraction in populations with a GBM. PATIENTS AND METHODS: Data for this study was obtained from the Surveillance, Epidemiology and End-Results (SEER) database. Relative survival measures were modelled using non-mixture cure fraction models. RESULTS: The extraction and subsequent period modeling of the dataset resulted in a final total of 11,189 patients and a total of 10,289 years of patient follow-up (between 2001 and 2006). The cure fraction of young adults is expected to be 12% (95% CI 7-16), which is estimated to occur at a minimum time of 10 years post diagnosis. INTERPRETATION: The data, using population-based cure fraction models, indicate that a possibility for cure appears to be present in the young adult population, and occurs at 10 years after diagnosis. Because of the biological and statistical features of this patient population, it is appropriate to study GBM populations using cure fraction models.

The barriers and enablers to downloading the COVIDSafe app - a topic modelling analysis.

OBJECTIVE: We report a survey in regional Queensland to understand the reasons for suboptimal uptake of the COVIDSafe app. METHODS: A short five-minute electronic survey disseminated to healthcare professionals, mining groups and school communities in the Central Queensland region. Free text responses and their topics were modelled using natural language processing and a latent Dirichlet model. RESULTS: We received a total of 723 responses; of these, 69% had downloaded the app and 31% had not. The respondents' reasons for not downloading the app were grouped under four topics: lack of perceived risk of COVID-19/lack of perceived need and privacy issues; phone-related issues; tracking and misuse of data; and trust, security and credibility. Among the 472 people who downloaded the app and provided text amenable to text mining, the two topics most commonly listed were: to assist with contact tracing; and to return to normal. CONCLUSIONS: This survey of a regional population found that lack of perceived need, concerns around privacy and technical difficulties were the major barriers to users downloading the application. Implications for public health: Health promotion campaigns aimed at increasing the uptake of the COVIDSafe app should focus on promoting how the app will assist with contact tracing to help return to 'normal'. Additionally, health promotors should address the app's impacts on privacy, people's lack of perceived need for the app and technical barriers.

A Discrete-Event, Simulated Social Agent-Based Network Transmission (DESSABNeT) model for communicable diseases: Method and validation using SARS-CoV-2 data in three large Australian cities.

IMPORTANCE: During pandemics Agent Based Models (ABMs) can model complex, fine-grained behavioural interactions occurring in social networks, that contribute to disease transmission by novel viruses such as SARS-CoV-2. OBJECTIVE: We present a new agent-based model (ABM) called the Discrete-Event, Simulated Social Agent based Network Transmission model (DESSABNeT) and demonstrate its ability to model the spread of COVID-19 in large cities like Sydney, Melbourne and Gold Coast. Our aim was to validate the model with its disease dynamics and underlying social network. DESIGN: DESSABNeT relies on disease transmission within simulated social networks. It employs an epidemiological SEIRD+M (Susceptible, exposed, infected, recovered, died and managed) structure. One hundred simulations were run for each city, with simulated social restrictions closely modelling real restrictions imposed in each location. MAIN OUTCOME(S) AND MEASURE(S): The mean predicted daily incidence of COVID-19 cases were compared to real case incidence data for each city. Reff and health service utilisation outputs were compared to the literature, or for the Gold Coast with daily incidence of hospitalisation. RESULTS: DESSABNeT modelled multiple physical distancing restrictions and predicted epidemiological outcomes of Sydney, Melbourne and the Gold Coast, validating this model for future simulation work. CONCLUSIONS AND RELEVANCE: DESSABNeT is a valid platform to model the spread of COVID-19 in large cities in Australia and potentially internationally. The platform is suitable to model different combinations of social restrictions, or to model contact tracing, predict, and plan for, the impact on hospital and ICU admissions, and deaths; and also the rollout of COVID-19 vaccines and optimal social restrictions during vaccination.

CT scans in childhood predict subsequent brain cancer: Finite mixture modelling can help separate reverse causation scans from those that may be causal.

BACKGROUND: Excess brain cancers observed after computed tomography (CT) scans could be caused by ionizing radiation. However, as scans are often used to investigate symptoms of brain cancer, excess cancers could also be due to reverse causation bias. We used finite mixture models (FMM) to differentiate CT exposures that are plausibly causal from those due to reverse causation. METHODS: Persons with at least one CT scan exposure and a subsequent diagnosis of brain cancer were selected from a cohort of 11 million young Australians. We fitted FMMs and used the posterior probability to inform the choice of exclusion periods. We validated our findings using a separate clinical dataset describing the time between first symptoms and brain cancer diagnosis (pre-diagnostic symptomatic interval; PSI). RESULTS: The cohort included 1028 persons with a diagnosed brain tumor and exposed to a total of 1,450 CT scans. The best-fitting model was a generalized linear mixture model using the exponential distribution with three latent classes and two covariates (age at exposure and year of exposure). The 99th percentile classifier cutoff was 18.9 months. The sample-size weighted mean of the 99th percentile of the PSI, derived from clinical data, was 15.6 months. CONCLUSIONS: To minimize reverse causation bias in studies of CT scan and brain cancer, the optimal exclusion period is one to two years (depending on the choice of classifier). This information will inform the interpretation of current and future studies.