生物与医学2020medrxiv.org
波士顿无家可归者收容所中的 Covid-19：对普遍检测的启示
Covid-19 at a homeless shelter in Boston: Implications for universal testing
入门 · 约 30 分钟读完前置知识：流行病学基础概念、PCR 检测原理
导读
这篇预印本研究波士顿一家大型无家可归者收容所的新冠疫情：对两天内住在该收容所的 408 人进行症状评估和 PCR 检测，发现 147 人（36%）阳性，且咳嗽、发热、呼吸困难等症状在阳性者中很少见，大多数人无症状。研究提示无症状感染比例可能很高，支持对聚集性居住场所进行普遍检测。
HN 关注点：疫情早期 HN 读者高度关注无症状传播和真实感染率——如果大量感染者无症状，实际感染规模和群体免疫进度可能远超官方确诊数字。
HN 评论精选
这几条评论里：支持 1 质疑 1 补充 2
支持多数阳性者无症状，提示实际感染规模远大于确诊数，需更多无症状研究来指导重启经济。
咳嗽（7.5%）、呼吸困难（1.4%）和发热（0.7%）在新冠阳性者中都不常见。更重要的结论是大多数阳性者无症状，这再次佐证实际感染人数可能比确诊数高出几个数量级。要想尽快重启经济，我们需要更多针对无症状病例的研究——想象一下如果 10% 以上的人口已经感染并免疫，我们离群体免疫就比目前认为的近得多。
jcp2fa查看英文原文
> Cough (7.5%), shortness of breath (1.4%), and fever (0.7%) were all uncommon among COVID-positive individuals It seems the more important point here is that the majority of the COVID-positive individuals were asymptomatic, putting another datapoint towards the conclusion that there are orders of magnitude more people that have this disease than have tested positive. We need more studies to gather data on these asymptomatic cases if we want to reopen the economy soon. Imagine if 10+% of the population already had COVID and where immune, we'd be much closer to heard immunity than we currently think.
质疑质疑标题以偏概全：单一收容所的样本不能代表波士顿全体无家可归者。
标题应该说'受检测的无家可归者中 36% 阳性'。论文只检测了波士顿一家收容所的住客，这家收容所未必能代表波士顿所有收容所，更不能推广到不住在收容所的无家可归者群体。样本不足以支撑这样的普遍化结论。
zadkey查看英文原文
(Regarding the Headline) Surely you mean 35% of homeless who were tested. We can't say for certain that the sample is an exact representation of the general population of the homeless in Boston. "Upon observing a cluster of COVID-19 cases from a single large homeless shelter in Boston, Boston Health Care for the Homeless Program conducted symptom assessments and polymerase chain reaction (PCR) testing for SARS-CoV-2 among all guests residing at the shelter over a 2-day period. Of 408 participants, 147 (36.0%) were PCR-positive for SARS-CoV-2" The key thing here is they tested people from one single homeless shelter. Is this one homeless shelter in Boston representative of all homeless shelters in Boston? There is not enough info in this article to make that assumption. Nor is it enough information to make generalizations about the populations of the homeless who do not live in shelters.
补充补充数据：纽约孕妇 15% 阳性，佐证感染已广泛传播。
另外，纽约市有 15% 的孕妇检测出携带病毒。这说明病毒的实际传播范围可能已经比人们认为的广泛得多。
rb808查看英文原文
Also 15% of pregnant Moms in NYC had the virus. This could already be much more widely spread that people think. https://www.nbcnewyork.com/news/local/nyc-hospital-finds-high-covid-19-infection-rate-but-few-symptoms-in-pregnant-women/2372863/
补充指出大众普遍混淆 SARS-CoV-2 病毒与 COVID-19 疾病两个概念。
关于标题里的'Covid+'：大多数人（甚至新闻媒体）并不区分 SARS-CoV-2（病毒）和 COVID-19（疾病）。这个区分正在被放弃吗？我不是要吹毛求疵，只是好奇大众的实际用法。
kens查看英文原文
Regarding the title "Covid+", it seems that most people (even on the news) don't care about the difference between SARS-CoV-2 (the virus) and COVID-19 (the disease). Is this distinction being abandoned? (I'm not trying to be pedantic here; I'm just curious about the common usage.)
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