简介:AbstractAlthough significant achievements have shown that the coronavirus disease 2019 (COVID-19) resurgence in Beijing, China, was initiated by contaminated frozen products and transported via cold chain transportation, international travelers with asymptomatic symptoms or false-negative nucleic acid may have another possible transmission mode that spread the virus to Beijing. One of the key differences between these two assumptions was whether the virus actively replicated since, so far, no reports showed viruses could stop evolution in alive hosts. We studied severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequences in this outbreak by a modified leaf-dating method with the Bayes factor. The numbers of single nucleotide variants (SNVs) found in SARS-CoV-2 sequences were significantly lower than those called from B.1.1 records collected at the matching time worldwide (P = 0.047). In addition, results of the leaf-dating method showed ages of viruses sampled from this outbreak were earlier than their recorded dates of collection (Bayes factors > 10), while control sequences (selected randomly with ten replicates) showed no differences in their collection dates (Bayes factors < 10). Our results which indicated that the re-emergence of SARS-CoV-2 in Beijing in June 2020 was caused by a virus that exhibited a lack of evolutionary changes compared to viruses collected at the corresponding time, provided evolutionary evidence to the contaminated imported frozen food should be responsible for the reappearance of COVID-19 cases in Beijing. The method developed here might also be helpful to provide the very first clues for potential sources of COVID-19 cases in the future.
简介:AbstractMany factors have been identified as having the ability to affect the sensitivity of rapid antigen detection (RAD) tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to identify the impact of sample processing on the sensitivity of the RAD tests. We explored the effect of different inactivation methods, viral transport media (VTM) solutions, and sample preservation on the sensitivity of four RAD kits based on two SARS-CoV-2 strains. Compared with non-inactivation, heat inactivation significantly impacted the sensitivity of most RAD kits; however, β-propiolactone inactivation only had a minor effect. Some of the VTM solutions (VTM2, MANTACC) had a significant influence on the sensitivity of the RAD kits, especially for low viral-loads samples. The detection value of RAD kits was slightly decreased, while most of them were still in the detection range with the extension of preservation time and the increase of freeze-thaw cycles. Our results showed that selecting the appropriate inactivation methods and VTM solutions is necessary during reagent development, performance evaluation, and clinical application.
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简介:摘要:出现在中国武汉市的新型严重急性呼吸系统综合症冠状病毒(SARS-CoV-2)已在世界范围内传播,严重影响了人类健康和生产生活。室内“超级传播者”等传播感染事件的出现,让新型冠状病毒感染主要归咎于飞沫传播的观点受到了质疑。研究发现,气溶胶才是大多数呼吸道疾病最有可能的主要传播途径,然而对于新型冠状病毒通过气溶胶传播机制的认识仍然不足。为此,本文经文献复习,就病毒的传播方式的历史演进进行综述,评述了病毒气溶胶的产生及特点以及冠状病毒在室内外环境气溶胶中的赋存特征及生存能力,探讨了对未来疫情防控发展战略的展望,为 COVID-19防控策略提供依据。
简介:摘要紧急医学救援是国家公共卫生体系和社会安全保障体系不可缺少的组成部分,既是践行人民至上、生命至上理念的直接体现,也是衡量政府应急管理水平和能力的重要指标。突发事件造成的伤害主要是“伤”和“病”。新型冠状病毒肺炎(COVID-19)疫情的发生,使我国以“病”为主要特征的紧急医学救援体系建设取得了巨大进步,为高水平建立以“伤”为特征的紧急医学救援体系提供了宝贵经验。笔者回顾我国紧急医学救援体系发展历程,系统总结COVID-19疫情防控经验,就如何高水平建设以“伤”为主要特征的紧急医学救援体系进行分析,为建强新时代我国紧急医学救援体系、更好地服务于中华民族复兴宏伟蓝图发挥积极作用。
简介:2007年岁末至2008年年初,一场罕见的低温雨雪冰冻天气突袭中国南方十余省区的广袤大地。一时间引起交通、电力、能源、食品的全线告急。后经中央协调,胡锦涛总书记和温家宝总理的亲切关怀和亲临一线指挥,以及全国人民和海外同胞的大力支持,迅速化解了危机,缓解了灾情,取得了抗灾救灾的重大胜利。但是,灾害过后,检视灾情由发生到救助的全过程,也留给我们诸多的反思与警示。为此,中共桂林市委党校经济管理学教研室、科研处、教务处联合组织部分教研人员就抗灾救灾的经济学、公共管理学、生态学、社会学等领域的启示意义作了相应的探讨。现将研讨时的部分发言节录于后,以求正于方家学者。
简介:【摘要】目的:探讨抗击新型冠状病毒肺炎一线护理人员职业心理情况以及应对策略。方法: 2020年 2月 -2020年 3月期间,以我院 73名抗击新冠状肺炎一线的护理人员为研究对象。抗疫前后分别为抗疫前组和抗疫后组;抗疫结束后,实施心理干预则为心理干预组。发放 SCL-90症状自评量表对抗议前后进行调查问卷。结果:与抗疫前相比,抗议后护理人员 SCL-90量表中躯体化、强迫、抑郁、焦虑以及总分均较高,差异均有显著性差异( P< 0.01);经过综合性心理干预后, 73名一线护理人员 SCL-90量表的强迫、抑郁、焦虑等项目分值均明显下降,差异具有比较显著性差异( P< 0.01)。结论:对抗击新型冠状病毒肺炎一线护理人员采取有效的心理护理与疏导措施,能够改善一线护理人员的职业心理健康状况。