Kurian Anika K, Schmidt Susanne, Goros Martin, Gelfond Jonathan A, Agha Golareh, Wealther Ryan, DelBello Robert G, Tami Claudina, Taylor Barbara S
San Antonio Metropolitan Health District, San Antonio, TX.
Department of Population Health Sciences, UT Health San Antonio, San Antonio, TX.
Tex Public Health J. 2022 Summer;74(3):34-39.
Asymptomatic and pre-symptomatic infections may play a significant role in the spread of COVID-19 but determining prevalence of these infections in the general population is labor intensive.
This approach describes an innovative surveillance strategy using teams of medical students and emergency medical technicians (EMTs). Medical students represent a highly trained but underutilized workforce in the pandemic response.
A household-level sampling frame generated a population-weighted representative sample of households in San Antonio, Texas. Households were included if an English or Spanish-speaking adult (≥18yo) answered the door and was willing to participate; excluded if household members had past or present COVID-19 symptoms or close contact with confirmed COVID-19 infection. Interdisciplinary teams of medical or medical/public health dual degree students paired with EMTs conducted a survey and instructed participants on how to self-administer nasal swabs among 502 community members without symptoms of COVID-19 from June 1-6, 2020, weeks prior to a community case surge.
Of 502 participants, median age was 52 years and average household size was 3.1. Only 40% reported no medical risk factors for COVID-19 complications. Hypertension (23.6%) and diabetes (13.4%) were the most common pre-existing medical conditions; 29% of respondents reporting feeling at risk for SARS-CoV-2 during daily outside-of-the-home activities. All 502 SARS-CoV-2 PCR tests were negative, suggesting a prevalence range of 0%-1.2%.
It is unlikely that pre-symptomatic and asymptomatic COVID-19 infections in households without existing COVID-19 infections played a major role in the propagation of the epidemic at this point in time. While community-wide testing of individuals without symptoms of COVID-19 may be low yield in the context of low prevalence of symptomatic cases of COVID-19, medical students provided valuable support for community-based surveillance at a time when public health infrastructure was severely taxed.
无症状和症状前感染可能在新冠病毒病（COVID-19）传播中发挥重要作用，但确定普通人群中这些感染的流行率需要耗费大量人力。
本方法描述了一种利用医学生和急救医疗技术人员（EMT）团队的创新监测策略。医学生是大流行应对中一支训练有素但未得到充分利用的劳动力队伍。
一个家庭层面的抽样框架生成了得克萨斯州圣安东尼奥市家庭的人口加权代表性样本。如果说英语或西班牙语的成年人（≥18岁）应门并愿意参与，则该家庭被纳入；如果家庭成员有过去或现在的COVID-19症状或与确诊的COVID-19感染者有密切接触，则该家庭被排除。2020年6月1日至6日，在社区病例激增前几周，由医学或医学/公共卫生双学位学生与急救医疗技术人员组成的跨学科团队对502名无COVID-19症状的社区成员进行了调查，并指导参与者如何自行采集鼻拭子。
502名参与者的中位年龄为52岁，平均家庭规模为3.1。只有40%的人报告没有COVID-19并发症的医学风险因素。高血压（23.6%）和糖尿病（13.4%）是最常见的既往疾病；29%的受访者表示在日常户外活动中感觉有感染严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的风险。所有502份SARS-CoV-2聚合酶链反应（PCR）检测均为阴性，表明流行率范围为0%-1.2%。
在此时，没有现有COVID-19感染的家庭中，症状前和无症状的COVID-19感染不太可能在疫情传播中起主要作用。虽然在COVID-19症状性病例患病率较低的情况下，对无COVID-19症状的个体进行全社区检测可能收益较低，但在公共卫生基础设施承受巨大压力之时，医学生为基于社区的监测提供了宝贵支持。
