PDF(Pubmed)
Abstract：
BACKGROUND: Exposure risk was shown to have affected individual susceptibility and the epidemic spread of COVID-19. The dynamics of risk by and across exposure settings alongside the variations following the implementation of social distancing interventions are understudied.
OBJECTIVE: This study aims to examine the population\'s trajectory of exposure risk in different settings and its association with SARS-CoV-2 infection across 3 consecutive Omicron epidemic waves in Hong Kong.
METHODS: From March to June 2022, invitation letters were posted to 41,132 randomly selected residential addresses for the recruitment of households into a prospective population cohort. Through web-based monthly surveys coupled with email reminders, a representative from each enrolled household self-reported incidents of SARS-CoV-2 infections, COVID-19 vaccination uptake, their activity pattern in the workplace, and daily and social settings in the preceding month. As a proxy of their exposure risk, the reported activity trend in each setting was differentiated into trajectories based on latent class growth analyses. The associations of different trajectories of SARS-CoV-2 infection overall and by Omicron wave (wave 1: February-April; wave 2: May-September; wave 3: October-December) in 2022 were evaluated by using Cox proportional hazards models and Kaplan-Meier analysis.
RESULTS: In total, 33,501 monthly responses in the observation period of February-December 2022 were collected from 5321 individuals, with 41.7% (2221/5321) being male and a median age of 46 (IQR 34-57) years. Against an expanding COVID-19 vaccination coverage from 81.9% to 95.9% for 2 doses and 20% to 77.7% for 3 doses, the cumulative incidence of SARS-CoV-2 infection escalated from <0.2% to 25.3%, 32.4%, and 43.8% by the end of waves 1, 2, and 3, respectively. Throughout February-December 2022, 52.2% (647/1240) of participants had worked regularly on-site, 28.7% (356/1240) worked remotely, and 19.1% (237/1240) showed an assorted pattern. For daily and social settings, 4 and 5 trajectories were identified, respectively, with 11.5% (142/1240) and 14.6% (181/1240) of the participants gauged to have a high exposure risk. Compared to remote working, working regularly on-site (adjusted hazard ratio [aHR] 1.47, 95% CI 1.19-1.80) and living in a larger household (aHR 1.12, 95% CI 1.06-1.18) were associated with a higher risk of SARS-CoV-2 infection in wave 1. Those from the highest daily exposure risk trajectory (aHR 1.46, 95% CI 1.07-2.00) and the second highest social exposure risk trajectory (aHR 1.52, 95% CI 1.18-1.97) were also at an increased risk of infection in waves 2 and 3, respectively, relative to the lowest risk trajectory.
CONCLUSIONS: In an infection-naive population, SARS-CoV-2 transmission was predominantly initiated at the workplace, accelerated in the household, and perpetuated in the daily and social environments, as stringent restrictions were scaled down. These patterns highlight the phasic shift of exposure settings, which is important for informing the effective calibration of targeted social distancing measures as an alternative to lockdown.
OBJECTIVE: This study aims to examine the population\'s trajectory of exposure risk in different settings and its association with SARS-CoV-2 infection across 3 consecutive Omicron epidemic waves in Hong Kong.
METHODS: From March to June 2022, invitation letters were posted to 41,132 randomly selected residential addresses for the recruitment of households into a prospective population cohort. Through web-based monthly surveys coupled with email reminders, a representative from each enrolled household self-reported incidents of SARS-CoV-2 infections, COVID-19 vaccination uptake, their activity pattern in the workplace, and daily and social settings in the preceding month. As a proxy of their exposure risk, the reported activity trend in each setting was differentiated into trajectories based on latent class growth analyses. The associations of different trajectories of SARS-CoV-2 infection overall and by Omicron wave (wave 1: February-April; wave 2: May-September; wave 3: October-December) in 2022 were evaluated by using Cox proportional hazards models and Kaplan-Meier analysis.
RESULTS: In total, 33,501 monthly responses in the observation period of February-December 2022 were collected from 5321 individuals, with 41.7% (2221/5321) being male and a median age of 46 (IQR 34-57) years. Against an expanding COVID-19 vaccination coverage from 81.9% to 95.9% for 2 doses and 20% to 77.7% for 3 doses, the cumulative incidence of SARS-CoV-2 infection escalated from <0.2% to 25.3%, 32.4%, and 43.8% by the end of waves 1, 2, and 3, respectively. Throughout February-December 2022, 52.2% (647/1240) of participants had worked regularly on-site, 28.7% (356/1240) worked remotely, and 19.1% (237/1240) showed an assorted pattern. For daily and social settings, 4 and 5 trajectories were identified, respectively, with 11.5% (142/1240) and 14.6% (181/1240) of the participants gauged to have a high exposure risk. Compared to remote working, working regularly on-site (adjusted hazard ratio [aHR] 1.47, 95% CI 1.19-1.80) and living in a larger household (aHR 1.12, 95% CI 1.06-1.18) were associated with a higher risk of SARS-CoV-2 infection in wave 1. Those from the highest daily exposure risk trajectory (aHR 1.46, 95% CI 1.07-2.00) and the second highest social exposure risk trajectory (aHR 1.52, 95% CI 1.18-1.97) were also at an increased risk of infection in waves 2 and 3, respectively, relative to the lowest risk trajectory.
CONCLUSIONS: In an infection-naive population, SARS-CoV-2 transmission was predominantly initiated at the workplace, accelerated in the household, and perpetuated in the daily and social environments, as stringent restrictions were scaled down. These patterns highlight the phasic shift of exposure settings, which is important for informing the effective calibration of targeted social distancing measures as an alternative to lockdown.
摘要：
背景：暴露风险已被证明影响了个体易感性和COVID-19的流行传播。对暴露环境和暴露环境之间的风险动态以及实施社会距离干预措施后的变化进行了研究。
目的：本研究旨在研究在香港连续3次Omicron流行波中，人群在不同环境下的暴露风险轨迹及其与SARS-CoV-2感染的关系。
方法：从2022年3月至6月，向41,132个随机选择的居住地址发出邀请函，以招募家庭进入预期人口队列。通过基于Web的每月调查以及电子邮件提醒，每个登记家庭的代表自我报告了SARS-CoV-2感染事件，COVID-19疫苗接种，他们在工作场所的活动模式，以及上个月的日常和社交环境。作为他们暴露风险的代表，根据潜在类别增长分析,将每个环境中报告的活动趋势区分为轨迹.通过使用Cox比例风险模型和Kaplan-Meier分析，评估了2022年SARS-CoV-2感染总体和Omicron波（第1波：2月至4月；第2波：5月至9月；第3波：10月至12月）的不同轨迹之间的关联。
结果：总计，在2022年2月至12月的观察期内，收集了5321名个人的33,501份月度回复，其中41.7%(2221/5321)为男性，中位年龄为46(IQR34-57)岁。COVID-19疫苗接种覆盖率从2剂的81.9%扩大到95.9%，3剂的20%扩大到77.7%，SARS-CoV-2感染的累积发病率从<0.2％上升到25.3％，32.4%,到第1、2和3波结束时，分别为43.8%。在2022年2月至12月期间，52.2%(647/1240)的参与者定期在现场工作，28.7%(356/1240)远程工作，19.1%(237/1240)显示出不同的模式。对于日常和社交环境，确定了4个和5个轨迹，分别,11.5%(142/1240)和14.6%(181/1240)的参与者被认为具有高暴露风险。与远程工作相比，定期在现场工作(调整后的风险比[aHR]1.47,95%CI1.19-1.80)和生活在较大家庭(aHR1.12,95%CI1.06-1.18)与第1波中SARS-CoV-2感染的风险较高相关.来自最高每日暴露风险轨迹(aHR1.46,95%CI1.07-2.00)和第二高社会暴露风险轨迹(aHR1.52,95%CI1.18-1.97)的人在第2波和第3波的感染风险也增加，相对于最低风险轨迹。
结论：在未感染的人群中，SARS-CoV-2传播主要在工作场所开始，在家庭中加速，并在日常和社会环境中永存，随着严格的限制被缩小。这些模式突出了曝光设置的相位偏移，这对于告知有效校准有针对性的社会距离措施作为封锁的替代措施非常重要。
目的：本研究旨在研究在香港连续3次Omicron流行波中，人群在不同环境下的暴露风险轨迹及其与SARS-CoV-2感染的关系。
方法：从2022年3月至6月，向41,132个随机选择的居住地址发出邀请函，以招募家庭进入预期人口队列。通过基于Web的每月调查以及电子邮件提醒，每个登记家庭的代表自我报告了SARS-CoV-2感染事件，COVID-19疫苗接种，他们在工作场所的活动模式，以及上个月的日常和社交环境。作为他们暴露风险的代表，根据潜在类别增长分析,将每个环境中报告的活动趋势区分为轨迹.通过使用Cox比例风险模型和Kaplan-Meier分析，评估了2022年SARS-CoV-2感染总体和Omicron波（第1波：2月至4月；第2波：5月至9月；第3波：10月至12月）的不同轨迹之间的关联。
结果：总计，在2022年2月至12月的观察期内，收集了5321名个人的33,501份月度回复，其中41.7%(2221/5321)为男性，中位年龄为46(IQR34-57)岁。COVID-19疫苗接种覆盖率从2剂的81.9%扩大到95.9%，3剂的20%扩大到77.7%，SARS-CoV-2感染的累积发病率从<0.2％上升到25.3％，32.4%,到第1、2和3波结束时，分别为43.8%。在2022年2月至12月期间，52.2%(647/1240)的参与者定期在现场工作，28.7%(356/1240)远程工作，19.1%(237/1240)显示出不同的模式。对于日常和社交环境，确定了4个和5个轨迹，分别,11.5%(142/1240)和14.6%(181/1240)的参与者被认为具有高暴露风险。与远程工作相比，定期在现场工作(调整后的风险比[aHR]1.47,95%CI1.19-1.80)和生活在较大家庭(aHR1.12,95%CI1.06-1.18)与第1波中SARS-CoV-2感染的风险较高相关.来自最高每日暴露风险轨迹(aHR1.46,95%CI1.07-2.00)和第二高社会暴露风险轨迹(aHR1.52,95%CI1.18-1.97)的人在第2波和第3波的感染风险也增加，相对于最低风险轨迹。
结论：在未感染的人群中，SARS-CoV-2传播主要在工作场所开始，在家庭中加速，并在日常和社会环境中永存，随着严格的限制被缩小。这些模式突出了曝光设置的相位偏移，这对于告知有效校准有针对性的社会距离措施作为封锁的替代措施非常重要。
