The prevalence of adaptive immunity to COVID-19 and reinfection after recovery – a comprehensive systematic review and meta-analysis of 12 011 447 individuals

ObjectivesThis study aims to estimate the prevalence and longevity of detectable SARS-CoV-2 specific antibodies as well as memory T and B cells after recovery. In addition, the prevalence of COVID-19 reinfection, and the preventive efficacy of previous infection with SARS-CoV-2 were investigated.Methods and analysesA synthesis of existing research was conducted. The Cochrane Library for COVID-19 resources, the China Academic Journals Full Text Database, PubMed, and Scopus as well as preprint servers were searched for studies conducted between 1 January 2020 to 1 April 2021. We included studies with the relevant outcomes of interest. All included studies were assessed for methodological quality and pooled estimates of relevant outcomes were obtained in a meta-analysis using a bias adjusted synthesis method. Proportions were synthesized with the Freeman-Tukey double arcsine transformation and binary outcomes using the odds ratio (OR). Heterogeneity between included studies was assessed using the I2 and Cochran’s Q statistics and publication bias was assessed using Doi plots.ResultsFifty-four studies, from 18 countries, with a total of 12 011 447 individuals, followed up to 8 months after recovery, were included. At 6-8 months after recovery, the prevalence of detectable SARS-CoV-2 specific immunological memory remained high; IgG – 90.4% (95%CI 72.2-99.9, I2=89.0%, 5 studies), CD4+ - 91.7% (95%CI 78.2 – 97.1, one study), and memory B cells 80.6% (95%CI 65.0-90.2, one study) and the pooled prevalence of reinfection was 0.2% (95%CI 0.0 – 0.7, I2 = 98.8, 9 studies). Individuals who recovered from COVID-19 had an 81% reduction in odds of a reinfection (OR 0.19, 95% CI 0.1 - 0.3, I2 = 90.5%, 5 studies).ConclusionAround 90% of people previously infected with SARS-CoV-2 had evidence of immunological memory to SARS-CoV-2, which was sustained for at least 6-8 months after recovery, and had a low risk of reinfection.RegistrationPROSPERO: CRD42020201234

1049 Outcomes After Proximal Femoral Replacements in Metastatic Femoral Disease. A Systematic Review and Meta-Analysis

Aim The aim of the study was to assess outcomes after a proximal femoral replacement (PFR). More PFRs are being performed in accordance with the British Orthopaedic Oncology Society (BOOS) best practice guidance 2016. The population studied was patients with metastatic proximal femoral disease with actual or impending fractures. The intervention and comparator were PFR and intra-medullary nailing (IMN) respectively. The primary outcome was hospital readmission rate (all cause). Secondary outcomes were reoperation rate (all cause, infection) and dislocation rate. Method A literature search was performed in Medline, Embase, Web of Science and the Cochrane Library. The search strategy combined free and MeSH search terms related to population (e.g., “femoral neoplasms” OR “pathological femoral fracture”), intervention and comparator (e.g., “osteosynthesis” “surgery” OR “proximal femoral replacement ”). To pool the outcome data of the studies Freeman–Tukey double arcsine transformation was used. Readmission rates were generated based on complications requiring absolute hospital admission. Results After exclusions, the search provided 12 studies. The pooled rate of hospital readmission (all cause) was 0.08 (95% CI 0.04 - 0.12) (Figure 2). The pooled rate of reoperation (all cause), reoperation for infection and dislocation rate was 0.05 (95% CI 0.03 – 0.08), 0.01 (95% CI 0.00 – 0.04) and 0.02 (95% CI 0.00 – 0.05) respectively. Conclusions Following a PFR for proximal metastatic femoral disease, patients have low rates of hospital readmission and reoperation. Compared to IMN, reoperations are performed for deep infection and dislocations. The major complication with IMNs of metalwork fatigue and failure is overcome with the use of PFRs.

Predictors of Failure for Vascularized and Nonvascularized Bone Grafting of Scaphoid Nonunions: A Systematic Review

Objective This article compares predictors of failure for vascularized (VBG) and nonvascularized bone grafting (NVBG) of scaphoid nonunions. Methods We conducted a systematic literature review of outcomes after VBG and NVBG of scaphoid nonunion. Fifty-one VBG studies (N = 1,419 patients) and 81 NVBG studies (N = 3,019 patients) met the inclusion criteria. Data were collected on surgical technique, type of fixation, time from injury to surgery, fracture location, abnormal carpal posture (humpback deformity and/or dorsal intercalated segmental instability [DISI]), radiographic parameters of carpal alignment, prior failed surgery, smoking status, and avascular necrosis (AVN) as defined by punctate bleeding, magnetic resonance imaging (MRI) with contrast, MRI without contrast, X-ray, and histology. Meta-analysis of proportions was conducted with Freeman–Tukey double arcsine transformation. Multilevel mixed-effects analyses were performed with univariable and multivariable Poisson regression to identify confounders and evaluate predictors of failure. Results The pooled failure incidence effect size was comparable between VBG and NVBG (0.09 [95% confidence interval [CI] 0.05–0.13] and 0.08 [95% CI 0.06–0.11], respectively). Humpback deformity and/or DISI (incidence-rate radios [IRRs] 1.57, CI: 1.04–2.36) and lateral intrascaphoid angle (IRR 1.21, CI: 1.08–1.37) were significantly associated with an increased VBG failure incidence. Time from injury to surgery (IRR 1.09, CI: 1.06–1.12) and height-to-length (H/L) ratio (IRR 53.98, CI: 1.16–2,504.24) were significantly associated with an increased NVBG failure incidence, though H/L ratio demonstrated a wide CI. Decreased proximal fragment contrast uptake on MRI was a statistically significant predictor of increased failure incidence for both VBG (IRR 2.03 CI: 1.13–3.66) and NVBG (IRR 1.39, CI: 1.16–1.66). Punctate bleeding or radiographic AVN, scapholunate angle, radiolunate angle, and prior failed surgery were not associated with failure incidence for either bone graft type (p > 0.05). Conclusion Humpback deformity and/or DISI and increasing lateral intrascaphoid angle may be predictors of VBG failure. Time from injury to surgery may be a predictor of NVBG failure. AVN as defined by decreased contrast uptake on MRI may be a marker of increased failure risk for both bone graft types.

The Prevalence of Angiostrongylus Cantonensis in Rodent Hosts in China and Several Asian Countries: A Systematic Review and Meta-Analysis

Background: Angiostrogylus cantonensis (A.cantonensis) is a zoonotic parasitic nematode, with a worldwide distribution, causing eosinophilic meningitis or meningoencephalitis in humans. Although the biology of A.cantonensis is relatively well known, little is understood about the transmission level in different zoogeographical regions, especially in Asia. Here, to evaluate the prevalence of A.cantonensis in rodent hosts in China and several Asian countries, we conducted a systematic review registered with PROSPERO (CRD42020161665). Methods: Records were selected systematically from 7 databases (Medline via to Pubmed, Web of science, Scopus, Google Scholar, CNKI, Wangfang, CBM ). Forest plots and random-effects model were used to display pooled estimates. The Freeman-Tukey double arcsine transformation of R software was used to conduct meta-analysis and statistical significance was set at 0.05.Results: A total of 67 studies met the inclusion criteria and were included in the systematic review and meta-analysis. The pooled prevalence estimates of A.cantonensis infection in rodents was 0.1003 (95%CI: 0.0765, 0.1268). There was significant heterogeneity in reported outcomes (p<0.0001). So we considered that there was no publication bias in the included studies.Conclusion: The A.cantonensis infection rate among rodent hosts was still high in Asia, particularly in China, especially in Rattus norvegicus, and thus comprehensive measures should be taken for rodent hosts control to avoid an angiostrongyliasis outbreak. Due to the wide distribution and movement of rodent hosts, people in all regions of China, even in other Asia area live at risk of an infection. Hence, the development of more reliable diagnostic tests will be key for an effective identification of cases as well as improved patient care. Consequently, further studies are required to updated strategies for controlling A.cantonensis infection among human population.

Prevalence of uterine rupture among women with one prior low transverse cesarean and women with unscarred uterus undergoing labor induction with PGE2: A systematic review and meta-analysis

Background As uterine rupture may affect as many as 11/1000 women with 1 prior cesarean birth and 5/10.000 women with unscarred uterus undergoing labor induction, we intended to estimate the prevalence of such rare outcome when PGE2 is used for cervical ripening and labor induction. Methods We searched MEDLINE, ClinicalTrials.gov and the Cochrane library up to September 1st 2020. Retrospective and prospective cohort studies, as well as randomized controlled trials (RCTs) on singleton viable pregnancies receiving PGE2 for cervical ripening and labor induction were reviewed. Prevalence of uterine rupture was meta-analyzed with Freeman-Tukey double arcsine transformation among women with 1 prior low transverse cesarean section and women with unscarred uterus. Results We reviewed 956 full text articles to include 69 studies. The pooled prevalence rate of uterine rupture is estimated to range between 2 and 9 out of 1000 women with 1 prior low transverse cesarean (5/1000; 95%CI 2-9/1000, 122/9000). The prevalence of uterine rupture among women with unscarred uterus is extremely low, reaching at most 0.7/100.000 (<1/100.000.000; 95%CI <1/100.000.000–0.7/100.000, 8/17.684). Conclusions Uterine rupture is a rare event during cervical ripening and labor induction with PGE2.

Safety and Efficacy of Leadless Pacemakers: A Systematic Review and Meta‐Analysis

Background Leadless pacemaker is a novel technology, and evidence supporting its use is uncertain. We performed a systematic review and meta‐analysis to examine the safety and efficacy of leadless pacemakers implanted in the right ventricle. Methods and Results We searched PubMed and Embase for studies published before June 6, 2020. The primary safety outcome was major complications, whereas the primary efficacy end point was acceptable pacing capture threshold (≤2 V). Pooled estimates were calculated using the Freedman‐Tukey double arcsine transformation. Of 1281 records screened, we identified 36 observational studies of Nanostim and Micra leadless pacemakers, with most (69.4%) reporting outcomes for the Micra. For Micra, the pooled incidence of complications at 90 days (n=1608) was 0.46% (95% CI, 0.08%–1.05%) and at 1 year (n=3194) was 1.77% (95% CI, 0.76%–3.07%). In 5 studies with up to 1‐year follow‐up, Micra was associated with 51% lower odds of complications compared with transvenous pacemakers (3.30% versus 7.43%; odds ratio [OR], 0.49; 95% CI, 0.34–0.70). At 1 year, 98.96% (95% CI, 97.26%–99.94%) of 1376 patients implanted with Micra had good pacing capture thresholds. For Nanostim, the reported complication incidence ranged from 6.06% to 23.54% at 90 days and 5.33% to 6.67% at 1 year, with 90% to 100% having good pacing capture thresholds at 1 year (pooled result not estimated because of the low number of studies). Conclusions Most studies report outcomes for the Micra, which is associated with a low risk of complications and good electrical performance up to 1‐year after implantation. Further data from randomized controlled trials are needed to support the widespread adoption of these devices in clinical practice.

Cure Rates of Control Interventions in Randomized Trials for Onychomycosis Treatments: A Systematic Review and Meta-Analysis

&lt;p&gt;Background: The efficacy of antifungals for onychomycosis has been determined in randomized controlled trials (RCTs); interestingly their control arms have demonstrated some therapeutic effects. These controls constitute either placebos (inert pills) or vehicles (all but the antifungal component of the creams). The objective of this research was to determine (i) whether RCT controls exhibited statistically-relevant efficacy rates (i.e. beyond the "placebo effect"), (ii) whether oral and topical controls differed in their efficacies, and (iii) if the efficacy rates of the controls correlated with those of the active comparator associated with that control.&lt;/p&gt; &lt;p&gt;Methods: RCTs of oral and topical monotherapies for dermatophyte toenail onychomycosis were identified through a systematic literature search. For our meta-analyses of cure rates the double arcsine transformation was used. The N-1 chi squared test was used to determine whether the cure rates significantly differed between topical and oral controls. Correlation was investigated using Kendall rank correlation tests.&lt;/p&gt; &lt;p&gt;Results: The pooled mycological, complete, and clinical cure rates of all control interventions (n = 19 trials) were 9%, 1%, and 6%, respectively. The pooled efficacy rates for oral and topical controls were: mycological cure rate, 7% and 12% (p=0.0016); complete cure rate, 1% for both; and clinical cure rate, 4% and 8%, respectively (p=0.0033). For oral RCTs, the respective cure rates of the active therapies were not correlated with controls. However, for topical RCTs, as the mycological and clinical cure rates of the active therapy increased, so did those of the topical vehicle associated with the active therapy in question, and vice versa.&lt;/p&gt; &lt;p&gt;Conclusions: The topical vehicle cure rates were often higher than the oral placebo cure rates, likely due to the presence of non-antifungal chemicals (e.g. moisturizers, urea) with antifungal and debriding properties, which are not present in oral controls.&lt;/p&gt;

High SVR12 With 8-Week Course of Direct-Acting Antivirals in Adolescents and Children With Chronic Hepatitis C: A Comprehensive Analysis

Direct-acting antiviral (DAA) treatment for 8 weeks has a sustained virological response rate in adults with chronic hepatitis C. We have conducted a systematic review and meta-analysis to compare the efficacy and safety of the 8-week vs. 12/24-week DAA treatment in adolescents and children with CHC. The PubMed, Web of Science, and Cochrane databases were searched for the relevant articles from January 1, 2017 to August 28, 2020 and further screened for literature reviews on April 1, 2021. Pool proportions with 95% CIs for SVR12 were summarized with fixed/random effects models using Freeman–Tukey double arcsine transformation. Subgroup analysis was used to explore the source of heterogeneity. Thirty-six relevant publications were identified. For adolescents aged 12–17 years old, the pooled SVR12 and AE rate were 99.4% (95% CI: 98.7–99.9) and 34.7% (95% CI: 31.9–37.6). No one discontinued treatment due to drug intolerance. In addition, the SVR12 adolescents treated for 12 and 8/24 weeks were 99.3% (95% CI: 98.4–99.9) and 100%, respectively. The pooled SVR12 rate, AEs, and SAEs for children younger than 12 years were 98.9% (95% CI: 97.3–99.8), 51.6% (95% CI: 47.0–56.2), and 1.1% (95% CI: 0.4–2.5), respectively. The most common AE was fatigue (28.4%). The SVR12 was 98.8% (95% CI: 97.1–99.8) and 100% for the pediatric patients treated for 12 weeks and 8/24 weeks, respectively. Taken together, DAAs are generally effective against CHC and well-tolerated by the adolescents and children. A treatment duration of 8 weeks is equally effective and safe as 12/24 weeks in this demographic group.

19 Colectomy Rate for Moderate to Severe Ulcerative Colitis with Biologics

Introduction Biologics are recommended by both the ACG and ECCO community for the treatment of ulcerative colitis. Yet, current literature has yet to estimate the rate of colectomies after biologic therapy, and thus a pooled meta-analysis was conducted the rate of colectomies in 1month, 6 months, 1 year, 2years and five years after biologics. Method Medline and Embase were searched for articles examining biologics use in moderate to severe UC or acute severe UC (ASUC) from inception to 21st May 2020. Analysis of proportions were undertaken after a freeman-tukey double arcsine transformation. Results The pooled overall colectomy rates of ASUC and moderate to severe UC were 9% (CI: 4% - 14%) at one month, 18% (CI: 13% - 25%) at six months, 21% (CI:16% - 27%) at one year, 29% (CI:24% - 34%) at two years and 38% (CI:30% - 45%) at five years. Additionally, colectomy rates were consistently lower comparing between articles before and after 2010. At one-year, overall colectomy rate following infliximab use was at 25%, golimumab at 15%, vedolizumab at 14%, and adalimumab at 3%. Conclusions Colectomy rates in the era of biologics ranged from 8% to 38% and lower post-2010 showing significant improvement in management and supporting the utility of biologics in Ulcerative colitis management.