Understanding the drivers of transmission of SARS-CoV-2.
Understanding the drivers of transmission of SARS-CoV-2.
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DOI：
10.1016/s1473-3099(21)00005-0
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发表时间：
2021-05
期刊：
影响因子：
--
通讯作者：
André E
中科院分区：
文献类型：
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作者：
Cornelissen L;André E
尽管最近开发出了针对严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 的有效疫苗，但非药物干预措施在一段时间内仍将是对抗 COVID-19 的基石。此类干预措施是有效的，但具有重大的社会和经济影响，因此应尽可能有选择性地使用。接触 COVID-19 患者后进行隔离就是这样一种措施。据报道，所谓的高风险接触者中的二次攻击率差异很大，从低于 1% 到 54·9%。 1 在《柳叶刀传染病》中，为了更好地了解这些差异，Michael Marks 及其同事探索了与 SARS-CoV-2 继续传播相关的因素。 2 作者使用了巴塞罗那一项随机对照试验的数据，该试验评估了羟氯喹作为暴露后预防的用途。 3 除了人口统计和流行病学变量（年龄、性别、症状、接触类型等）外，数据集还包含通过定量 PCR 评估的指示病例和检测呈阳性的接触者的病毒载量信息。利用来自 282 名指示病例和 753 名接触者的数据，作者评估了病毒载量与病例特征（年龄、性别、报告症状出现的天数、是否发烧、咳嗽、呼吸困难、鼻炎和嗅觉丧失）之间的关系，以及传播风险与指示病例和接触者特征之间的关联。Marks 及其同事发现，指示病例的病毒载量与进一步传播的风险密切相关（每增加 log10 调整比值比）。病毒载量 1· 3，95% CI 1· 1–1· 6)，家庭接触者 (2· 7、1· 4–5· 06) 的这种风险高于其他类型的接触者（医护人员、疗养院工作人员或疗养院居民）。此外，他们发现接触者年龄的影响虽小但很重要，年龄较大的人更容易被感染。由于指示病例和接触者的人口主要由 27-57 岁的成年人组成，因此更重要的年龄影响（例如儿童的影响）可能难以识别。尽管口罩的有效性已得到证实，但 4、5
Despite the recent development of effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), non-pharmaceutical interventions will remain the cornerstone in the battle against COVID-19 for some time. Such interventions are effective but have major societal and economic impacts and should therefore be used as selectively as possible. Quarantine after exposure to a patient with COVID-19 is such a measure. Reported secondary-attack rates among so-called high-risk contacts have varied widely from lower than 1% to 54· 9%. 1 In the Lancet Infectious Diseases, to better understand these differences, Michael Marks and colleagues explored factors related to onwards transmission of SARS-CoV-2. 2 The authors used data from a randomised controlled trial in Barcelona that assessed the use of hydroxychloroquine as postexposure prophylaxis. 3 In addition to demographic and epidemiological variables (age, sex, symptoms, type of exposure, and so on) the dataset contained information on viral load as assessed by quantitative PCR for both the index case and the contacts with a positive test. With these data from 282 index cases and 753 contacts, the authors assessed the relationship of viral load and characteristics of cases (age, sex, number of days from reported symptom onset, and presence or absence of fever, cough, dyspnoea, rhinitis, and anosmia) and associations between risk of transmission and characteristics of the index case and contacts.Marks and colleagues found that the viral load of the index case was strongly associated with the risk of onward transmission (adjusted odds ratio per log10 increase in viral load 1· 3, 95% CI 1· 1–1· 6) and that this risk was higher for household contacts (2· 7, 1· 4–5· 06) than for other types of contact (health-care worker, nursing home worker, or nursing home resident). Additionally, they found a small, but significant, effect for age of the contact person, with older individuals being more at risk of becoming infected. Because the included population of both index cases and contacts consisted mainly of adults aged 27–57 years, more important age effects, such as those for children, might have been difficult to identify. Although the effectiveness of masks is well established, 4, 5 in the