Factors associated with a SARS-CoV-2 recurrence after hospital discharge among patients with COVID-19: systematic review and meta-analysis

Background: The proportion of recurrences after discharge among patients with coronavirus disease 2019 (COVID-19) was reported to be between 9.1% and 31.0%. Little is known about this issue, however, so we performed a meta-analysis to summarize the demographical, clinical, and laboratorial characteristics of non-recurrence and recurrence groups. Methods: Comprehensive searches were conducted using eight electronic databases. Data regarding the demographic, clinical, and laboratorial characteristics of both recurrence and non-recurrence groups were extracted, and quantitative and qualitative analyses were conducted. Results: Ten studies involving 2071 COVID-19 cases were included in this analysis. The proportion of recurrence cases involving patients with COVID-19 was 17.65% (between 12.38% and 25.16%) while older patients were more likely to experience recurrence (weighted mean difference (WMD)=1.67, range between 0.08 and 3.26). The time from discharge to recurrence was 13.38 d (between 12.08 and 14.69 d). Patients were categorized as having moderate severity (odds ratio (OR)=2.69, range between 1.30 and 5.58), while those with clinical symptoms including cough (OR=5.52, range between 3.18 and 9.60), sputum production (OR=5.10, range between 2.60 and 9.97), headache (OR=3.57, range between 1.36 and 9.35), and dizziness (OR=3.17, range between 1.12 and 8.96) were more likely to be associated with recurrence. Patients presenting with bilateral pulmonary infiltration and decreased leucocyte, platelet, and CD4⁺ T counts were at risk of COVID-19 recurrence (OR=1.71, range between 1.07 and 2.75; WMD=−1.06, range between −1.55 and −0.57, WMD=−40.39, range between −80.20 and −0.48, and WMD=−55.26, range between −105.92 and −4.60, respectively). Conclusions: The main factors associated with the recurrence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after hospital discharge were older age, moderate severity, bilateral pulmonary infiltration, laboratory findings including decreased leucocytes, platelets, and CD4⁺ T counts, and clinical symptoms including cough, sputum production, headache, and dizziness. These factors can be considered warning indicators for the recurrence of SARS-CoV-2 and might help the development of specific management strategies.     

运动与病毒性感染疾病的关系

一次力竭性运动或持续超大强度训练均可增加机体上呼吸道感染和其他病毒性感染的易感性,但不影响机体对细菌性感染的抵抗力。大强度训练对T细胞-白细胞介素-NK细胞系统具有抑制效应,且效应可持续1周以上。相反,适度训练则能增强免疫功能。鉴于急性病毒感染对运动能力和精神面貌的负性影响,加之伴随病毒性心肌炎而偶发的急性死亡事件,所以应尽量降低运动员病毒性感染的发生率。坚持预防注射程序、减少感染暴露、避免超大强度训练、保证合理饮食、减轻心理和环境压力等,都是可采用的措施。     

《国家学生体质健康标准》中大学生心血管机能评价指标有效性的实验研究

为了分析<国家学生体质健康标准>中心台阶试验作为有氧耐力素质指标的有效性,对358名普通大学生进行体质健康测试和最大吸氧量测试.研究结果表明:大学生最大吸氧量与台阶试验测试值和台阶试验得分无显著线性相关(r=0.015,P>0.05),<国家学生体质健康标准>中台阶试验不能作为评价大学生心血管功能和机体有氧工作能力的有效指标;男、女大学生台阶指数分别为46.53和47.30,男女生的台阶指数之间存在显著差异(P<0.05);男女大学生平均最大吸氧量分别为50.85 ml/kg.min和35.03 ml/kg.min,男女大学生最大吸氧量差异显著(P<0.01);大学生最大吸氧量与其肺活量指数之间呈一定的相关关系.     

关于缺氧训练的再认识

缺氧训练目前被广泛采用,本文目的在于阐明与缺氧训练有关的术语及其基本原理,探讨缺氧训练在生理上所产生的适应性变化,是否对提高成绩有效。在竞技训练中对缺氧训练的理解,进行再认识,对今后的运动训练将起到一定的借鉴作用。     

少年中长跑运动员最佳呼吸效率点及对应参数的研究

以连续递增负荷的踏车运动,测定了34名少年中长跑运动员在不同工作负荷时的通气量、吸氧量、心率、最大吸氧量、呼吸当量曲线,确定了最佳呼吸效率点及生理参数,从理论上探讨了最佳呼吸效率点在运动训练中的作用,为少年中长跑运动员的训练工作提供科学依据。     

显示运动专项营养配比的呼吸商

本文通过对近期国内外文献的查阅,综述了可根据不同项目、不同负荷时间和强度确定运动员能量代谢时营养配比的呼吸商。     

跆拳道有氧训练对儿童有氧适能影响的研究*

探索跆拳道有氧训练方式对男女童有氧适能的影响.将10-13岁男、女童各60名随机分为2组:分为实验组和对照组,每组男、女童各30名,实验组进行以中低等强度有氧训练为主的运动素质与跆拳道专项技能相结合的训练,进行为20周,每周2次,每次60min,对照组在试验期间不参加任何系统体育活动,实验前后测试男女童肺活量指标及台阶指数.研究显示运动素质训练与跆拳道专项技能学习相结合的有氧训练能够大幅度提高男、女童的肺活量及台阶指数,性别之间并无显著差异,这种训练方式对增强呼吸及心血管系统机能具有更明显的效果.其训练为提高儿童的有氧适能,促进儿童身体健康发展提供有效方法与手段.     

不同体力活动水平50-59岁女性递增负荷运动中呼吸机能比较研究

目的:探讨不同体力活动对呼吸机能的影响,为确定能有效提高呼吸机能水平的体力活动量提供参考依据.方法:以50名不同体力活动水平50-59岁女性为研究对象,根据国际体力活动问卷将其分为低、中、高体力活动组,并进行逐级递增负荷运动,记录各级负荷的摄氧量(VO2)、二氧化碳输出量(VCO2)、潮气量(VT)、通气量(VE)及呼吸商(RQ).结果:安静状态高体力活动组和低体力活动组摄氧量、二氧化碳输出量、潮气量、通气量和呼吸商均存在显著性差异;递增负荷运动过程中,高体力活动组和低体力活动组呼吸机能各指标也存在显著性差异;低体力活动组与中等体力活动组呼吸机能各指标不存在显著性差异.结论:不同体力活动对呼吸机能有影响且体力活动量必须≥3 000 MET-minutes/week才能有效提高和维持呼吸机能水平.     

College Students’ Perspectives in Sexually Transmitted Infections (STIs) in Malaysia,Singapore, England,and the US: Formative Evaluation Insights and Implications

The purpose of this study was to elicit college students’ knowledge and perceptions about sexually transmitted infections (STIs), attitudes and practices regarding condom use, and information about what educational and prevention materials that they think would be most effective for their peers. As part of a larger study, data was collected using focus groups and questionnaires. While American and Malaysian college students in the US participated in the focus groups, the open-ended questionnaire was emailed to college students recruited in Malaysia, Singapore, and England. Participatory communication was used as the theoretical framework to generate information and message concepts necessary for the design of effective health education and promotion materials. This study revealed that college students, regardless of nationality, should be informed and educated of the STIs problem on a gradual basis through various means and communication channels.     

人体呼出气溶胶在封闭环境中的分布特性

研究了1.0～10.0μm的呼吸道颗粒物在混合送风、置换送风和地板送风的办公室环境中的浓度空间分布和瞬态演变规律.仿真结果表明：小于10.0μm的飞沫在混合送风的房间内几乎是均匀分布的.然而,在置换送风和地板送风中,垂直温度梯度使得小于10.0μm的飞沫在人体呼吸区高度聚集,导致一个较高的浓度水平,因此室内人员被感染的概率比较高.由咳嗽或者打喷嚏产生的飞沫在置换和地板送风中的稀释（浓度衰减）比在混合送风中慢,这是因为置换和地板送风中人体呼吸区的风速比较小,飞沫在此聚集,不易被气流携带排出室内空间.