COVID-19 was protective against reinfection during a second outbreak of This study was not included in the 2021 systematic review study above. Patients were nursing/care home staff (n5106, no further demographics presented) and residents (n5103, median age 84 years old, about two-thirds female) from two London nursing/ care homes. Previous infection was confirmed with either RT-PCR or antibody tests. The primary outcome was infection with COVID-19 during the second outbreak, determined by a positive RT-PCR test. Patients with an initial COVID-19 infection had a significantly lower incidence of infection compared with those without antibodies (1.1% vs 30.1%; relative risk [RR] 0.04; 95% CI, 0.01-0.27).A 2022 surveillance study (n5550,168) examined the protection of prior COVID-19 infection against reinfection. 4 Patients were 20 years old and older and 56% female. Patients included in this study were identified as either having tested positive or negative for COVID-19 between March 6 and August 31, 2020. Patients who died within 90 days of their initial positive test were excluded. Patients with initial positive COVID-19 tests (n541,647) composed the positive test group and were followed for recurrence of a positive test from 91 days after initial result through December 31, 2020. Patients with a negative test and no subsequent positive test within the study period (n5508,521) composed the testnegative comparison group. The primary outcome was either a positive COVID-19 test by PCR or antigen tests, date of death, or until December 31, 2020. Patients with no previous infection had a significantly higher risk of a positive test compared with individuals with a history of infection (1.4% vs 6.3%; RR 4.4, 95% CI,. This corresponded to a protective effect of 77.3% (95% CI, 75.4%-79.0%) from repeat infection. Study limitations included differences in risk behaviors between cohort groups, and use of antigen testing without confirmation with PCR testing.

Study design Systematic review. Objectives The objectives were to systematically review the literature since the most recent systematic reviews for both adult and pediatric spinal cord injuries without radiologic abnormality (SCIWORA) in order to provide an update on the condition’s epidemiology and characteristics and investigate the relationship between SCIWORA and concurrent concussion. Methods A review was conducted according to the 2020 guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The databases PubMed and OvidSP were searched on February 27, 2022. Inclusion criteria were individuals of any age, diagnosis of SCIWORA with or without abnormalities on MRI, and articles published from 2013 to 2014 (adults only) and 2014–present (all ages). Exclusion criteria were any spinal fracture or dislocation, studies that were narrative reviews, letters, book chapters, or editorials. Risk of bias was assessed using tools from the Clinical Advances Through Research and Information Translation Group at McMaster University and the Joanna Briggs Institute. Collected data were synthesized using Microsoft Excel. Results Since the most recent systematic reviews, a total of 61 studies were identified, resulting in 2788 patients with SCIWORA. 69.55% of patients were pediatric, 30.45% adult. The most prevalent reported mechanism of injury was sports-related (39.56%) followed by fall-related (30.01%) and vehicle-related (27.23%). The vast majority of injuries occurred at the level of the cervical spine (82.59%). Of the 61 included studies, only 5 reported cases of concurrent concussion and/or TBI. Discussion Since the most recent previous systematic reviews, there has been a 64% increase in reported cases of SCIWORA, likely as the result of advances in imaging technology and better awareness of SCIWORA. Still, SCIWORA remains a diagnosis most prevalent in children and young adults, the most common cause being sports-related injury. With the pathogenesis of SCIWORA sharing a predisposition to concussion, the significant lack of reporting of SCIWORA with concurrent concussion suggests that there have been missed diagnoses of either SCIWORA with concurrent concussion or vice versa, leading to longer recovery times, unrecognized and/or untreated underlying pathology, and possibly additional unnecessary morbidity. When the diagnosis of either SCIWORA or concussion is suspected, the other should additionally be considered in order to minimize the possible extended recovery time and related comorbidities. Limitations included the prevalence of lower quality studies such as case reports/series, insufficient reporting of study characteristics, and variability among neurologic impairment scales used and how SCIWORA was defined.