As the COVID-19 pandemic rages on, reports on disparities in vaccine roll out alongside COVID-19 reinfection have been emerging. We conducted a systematic review to assess the determinants and disease spectrum of COVID-19 reinfection. A comprehensive search covering relevant databases was conducted for observational studies reporting Polymerase Chain Reaction (PCR) confirmed infection and reinfection cases. A quality assessment tool developed by the National Institute of Health (NIH) for the assessment of case series was utilized. Meta-analyses were performed using RevMan 5.3 for pooled proportions of findings in first infection and reinfection with a 95% confidence interval (CI). Eighty-one studies reporting 577 cases were included from 22 countries. The mean age of patients was 46.2 ± 18.9 years and 179 (31.0%) cases of comorbidities were reported. The average time duration between first infection and reinfection was 63.6 ± 48.9 days. During first infection and reinfection, fever was the most common symptom (41.4% and 36.4%, respectively) whilst anti-viral therapy was the most common treatment regimen administered (44.5% and 43.0%, respectively). Comparable odds of symptomatic presentation and management were reported for the two infections. However, a higher Intensive Care Unit (ICU) admission rate was observed in reinfection compared to first infection (10 vs 3). Ten deaths were reported with respiratory failure being the most common cause of death (7/10 deaths). Our findings support immunization practices given increased ICU admissions and mortality in reinfections. Our cohort serves as a guide for clinicians and authorities in devising an optimal strategy for controlling the pandemic. (249 words)

Background: Cases of thrombosis with thrombocytopenia syndrome (TTS) have been reported following vaccination with AZD1222 or Ad26.COV2.S. This review aimed to explore the pathophysiology, epidemiology, diagnosis, management, and prognosis of TTS. Methods: A systematic review was conducted to identify evidence on TTS till 4^th September 2021. Case reports and series reporting patient-level data were included. Descriptive statistics were reported and compared across patients with different sexes, age groups, vaccines, types of thrombosis, and outcomes. Findings: Sixty-two studies reporting 160 cases were included from 16 countries. Patients were predominantly females with a median age of 42.50 (22) years. AZD1222 was administered to 140 patients (87·5%). TTS onset occurred in a median of 9 (4) days after vaccination. Venous thrombosis was most common (61.0%). Most patients developed cerebral venous sinus thrombosis (CVST; 66.3%). CVST was significantly more common in female vs male patients (p = 0·001) and in patients aged <45 years vs ≥45 years (p = 0·004). The mortality rate was 36.2%, and patients with suspected TTS, venous thrombosis, CVST, pulmonary embolism, or intraneural complications, patients not managed with non-heparin anticoagulants or IVIG, patients receiving platelet transfusions, and patients requiring intensive care unit admission, mechanical ventilation, or inpatient neurosurgery were more likely to expire than recover. Interpretation: These findings help to understand the pathophysiology of TTS while also recommending diagnostic and management approaches to improve prognosis in patients. Funding: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

The effect of chronic steroid therapy on postoperative outcomes after craniotomy for tumor resection remains understudied. This study aimed to fill this gap and to identify risk factors of postoperative morbidity and mortality among patients on chronic steroid use undergoing craniotomy for tumor resection. Data from the American College of Surgeons National Surgical Quality Improvement Program were used. Patients who underwent craniotomy for tumor resection between 2011 and 2019 were included. Perioperative characteristics and complications were compared among patients with and without chronic steroid therapy, defined as steroid use for at least 10 days. Multivariable regression analyses were conducted to assess the impact of steroid therapy on postoperative outcomes. Subgroup analyses involving patients on steroid therapy were conducted to explore risk factors of postoperative morbidity and mortality. Of 27,037 patients, 16.2% were on steroid therapy. On regression analyses, steroid use was significantly associated with any postoperative complication, infectious complication, urinary tract infection, septic shock, wound dehiscence, pneumonia, non-infectious, pulmonary, and thromboembolic complications, cardiac arrest, blood transfusion, unplanned reoperation, readmission, and mortality. On subgroup analysis, risk factors for postoperative morbidity and mortality among patients on steroid therapy included older age, higher American Society of Anesthesiology physical status, functional dependence, pulmonary and cardiovascular comorbidities, anemia, dirty/infected wounds, prolonged operative time, disseminated cancer, and a diagnosis of meningioma. Preoperative brain tumor patients on steroids for 10 or more days are at a relatively high risk of postoperative complications. We recommend a judicious use of steroids in brain tumor patients, both in terms of dosage and duration of treatment.