三种新冠家庭自检试剂大评测

admin · 发表于 2021-5-22 23:34:40

麻省理工科技评论 2021-05-11 安东尼奥·雷加拉多生物科技

Over-the-counter home tests for covid-19 are finally here. MIT Technology Review obtained kits sold by three companies and tried them out.

在柜台上就可以买到的新冠肺炎家庭测试终于上市了。《麻省理工科技评论》买了来自三家公司的测试组合装，并进行了试用。

After buying tests from CVS and online, I tested myself several times and ended up learning an important lesson: while some people worry that home tests could miss covid cases, the bigger problem may be just the opposite. These tests have “false positive” rates of around 2%, which means that if you keep using them, you’ll eventually test positive, even though you don't have covid-19.

从CVS和网上购买了这些测试套装以后，我对自己进行了多次新冠检测，并最终学到了重要的一课：虽然有些人担心家庭测试可能会测不出来阳性，但更大的问题却恰恰相反。这些测试的“假阳性”概率大约为2％，这意味着，如果你持续使用它们，即使你没有患病，最终测试结果也可能为阳性。

That happened to me. I tested negative several times, but the fourth time the result came up “POSITIVE FOR COVID-19.” I knew that was probably wrong—I’m a dedicated quarantiner who rarely goes anywhere. But I was sufficiently alarmed to follow the directions and scurry to a hospital for a gold-standard laboratory test, wasting my time and that of the friendly nurse who swabbed deep into my nasal cavity. That result was negative.

这恰恰就发生在我身上。我测试出了几次阴性，但第四次的结果却是“ 新冠病毒阳性”。我知道这可能是错误的--我已经自行隔离很久了，在此期间基本没去过任何地方。但是我非常小心，赶紧去了医院做了标准的实验室测试，这浪费了我的时间，也浪费了友善的护士捅我鼻孔的时间；结果是阴性的。

Some experts have argued that cheap, fast tests could be used to screen the whole population every week. But what I learned is that this type of mass screening could be as much of a public nuisance as pandemic-buster. In fact, if you tested everyone in the US tomorrow with over-the-counter tests, the large majority of positive results—maybe nine out of 10—would be false alarms.

一些专家认为，我们每周可以使用便宜且快速的测试筛查所有人口。但根据我的了解，这种大规模筛查可能像此次疫情大爆发一样，是对一种公众的滋扰。说实话，如果你明天对所有在美国的人进行了这种家庭测试，那么大多数检测出来的阳性结果（可能十分之九）将是错误的。

After trying them, I do think there is an important role for consumer tests. Overall, I found they’re easy to use, cheaper than existing mail-in tests, and more convenient than waiting at a testing site. If you have symptoms, or fear you’ve been exposed, having a test handy could help. As a screening tool for schools or businesses, they could also work, so long as there’s a backup plan to confirm positives.

在试用了它们之后，我的确认为消费者测试是有一定意义的。总的来说，我发现它们易于使用，比现有的邮寄测试便宜，并且比在测试站等待方便得多。如果你有症状，或者担心自己已经接触过这种病毒，那么顺手就能进行测试可能会有所帮助。作为学校或企业的检测工具，只要有备用方案来进行阳性确认的话，它们也能行。

Accuracy issues
The issue with home tests is accuracy, which is between 85% and 95% for detecting covid. That is, they catch about nine of every 10 infections, a metric called the test’s “sensitivity.” Some people have said that any missed cases are a worry, since a person with a false negative could go out and infect someone else. But if the alternative is no test at all, then none of those infections would be caught.

准确性问题

家庭测试的一个问题是准确性，对于新冠检测，这些准确性通常在85％到95％之间。也就是说，它们在每10例感染中能检测出9例，该项指标被称为测试的“敏感性”。有人说，任何被遗漏的病例都是令人担心的，因为假阴性的人可能会外出，进而感染他人。但是，如果完全不进行任何测试，那么这些感染都不会被发现。

The tricky part of unrestricted testing, I learned, comes instead from the concept of “specificity,” or the rate at which a test correctly identifies negatives. For the home tests I tried, that figure is about 98%, with a corresponding 2% rate of false positives. What I didn’t realize—and what your everyday CVS shopper won’t either—is that there are two ways that less-than-perfect specificity can get amplified into a bigger problem.

据我理解，这种无限制测试的棘手部分来自“特别性”的概念，即这些测试能够正确测出阴性的比率。对于我试用的这些家庭测试，该比率约为98％，意味着相应的误报率为2％。我没有意识到的是，同时作为日常CVS购物者也不会意识到的是，有两种办法可以将不够完美的特别性放大为一个更严重的问题。

The first way is through repeat testing, the kind I did. By the time my review of the home tests was complete, I’d tested five times in two days, accumulating 1 in 10 odds of being told I had covid when I didn’t (a 2% chance of a false positive each time, multiplied by five tests). The second source of trouble I didn’t anticipate is what is known as “pretest probability.” As I said, I don’t socialize, so my probability of actually having covid in first place was very low, maybe even zero. What this meant is that my chance of a correct positive when I took the test was also essentially zero, while my false positive chance remained 2% like everyone else’s. The way I was using the test, any positive result was nearly certain to be wrong.

第一个办法是像我这样反反复复地进行测试。在我对家庭测试的调查完成之时，我已经在两天里进行了五次测试，相当于每10次里面我就会被误诊一次（每次有2％的假阳性率，再乘上5次测试）。我没想到的第二个麻烦是所谓的“预测概率”。正如我前面说的，我并不参加社交活动，因此我真正被感染的可能性非常低，甚至可能为零。这意味着我参加自己测试的时候被正确检测出阳性的几率也基本上是零，而我的错误阳性概率却与其他人一样，依然是2％。根据我使用进行测试的方法来看，几乎可以肯定的是，任何的阳性结果都是虚假的。

Now consider this same phenomenon—a higher chance of false positives than of real ones—applying to a large group, or even a whole country. In the US, covid rates are falling. This lower background rate means if home tests were used by everyone in the country tomorrow, there could be five to 15 wrong positives for every right one.

现在考虑将这种相同的现象（误阳的几率高于真实的阳性）应用到一个大的群体，甚至整个国家上。在美国，确诊率正在下降。在这个背景下，这较低的确诊率意味着，如果明天对在美的每个人都进行家庭测试，每个真正的阳性病例可能都会伴随着5到15个误诊的阳性病例。

As a result, I don’t think home tests are as useful as some have hoped. If used at scale to screen for covid, they could send millions of anxious people in search of lab tests and medical care they don’t need.

作为结论，我认为家庭测试没有一些人所希望的那么有用。如果用于大规模新冠筛查，那么将会多出数百万焦虑的人寻找他们本来并不需要的实验室测试和医疗护理。

Still relevant?
As the covid-19 pandemic spread around the globe last year, economists and scientists called for massive expansion of testing and contact tracing in the US, to find and isolate infected people. But the number of daily tests in the US has never much exceeded 2 million, according to the Covid Tracking Project, and most of those were done in labs or on special instruments.

还有用吗？

随着去年新冠疫情在全球蔓延，经济学家和科学家呼吁在美国进行大规模扩展测试和接触者追踪，以发现和隔离感染者。但是，根据Covid Tracking Project的数据，在美国，每天测试的数量从未超过200万，而且大多数测试是在实验室或专用仪器上进行的。

Home tests will now be manufactured in the tens of millions, say their makers, but some experts aren’t sure how much they will matter at this point. “The real value of these tests was six months ago,” says Amitabh Chandra, a professor at Harvard University’s Kennedy School. “I think that the move to over-the-counter is great, but it has limited value in a world where vaccines become more widely available.” Vaccination credentials could be more important for travel and dining than test results are.

根据制造商的说法，现在将会有数以千万计的家庭测试投入量产，但是一些专家不确定它们在此刻会有多少用处。哈佛大学肯尼迪学校的教授阿米塔布·钱德拉说：“这些测试的真正价值应该是在半年前。我认为这种不用处方就能买到测试的做法很棒，但现在由于疫苗越来越普及，这种测试方法的价值就很有限了。” 疫苗接种证明对于旅行和聚餐而言可能比家庭测试的结果更为重要。

Companies selling the tests say they are still a relevant strategy for getting back to normal, especially given that kids aren’t getting vaccinated yet. For employers who want to keep an office or factory open, they say, self-directed consumer tests might be a good option. A spokesperson for Abbott told me that they might also help people “start thinking about coordinating more covid-conscious bridal showers, baby showers, or birthday parties.”

销售家庭测试的公司则表示，它们（这些测试）仍然是恢复正常生活的一种相关策略，尤其是考虑到孩子们都还未接种疫苗。他们说，对于想要保持办公室或工厂开放的雇主来说，消费者的这种自行测试可能是一个不错的选择。Abbott公司的一位发言人告诉我，它们还可能会帮助人们“开始考虑计划举办更多的新娘送礼会，婴儿送礼会或生日聚会。

The UK government started giving away covid antigen tests for free, by mail and on street corners, on April 9, saying it wants people “to get in the habit” of testing themselves twice a week as social distancing restrictions are eased. Along with vaccines, free tests are part of that nation’s plan to quash the virus. Later, though, a leaked government memo said health officials were privately worried about a tsunami of false positives.

英国政府于4月9日开始提供免费的邮寄和街边新冠抗体测试，称其希望人们对于一周进行两次自我测试这一做法“养成习惯”，因为社交距离限制正在逐步得到缓解。除疫苗外，免费进行新冠病毒抗体测试也是英国消除病毒计划的一部分。不过后来，有一份被泄漏的政府备忘录说，健康部的官员们私下里还是很担心假阳性测试结果的泛滥。

In the US, there’s no still no national campaign around home tests or subsidy for them, and as an out-of-pocket expense, they are still too expensive for most people to use with any frequency. That may be for the best, given my experience.

在美国，还没有针对家庭测试或补贴的全国性政策，而且作为自付费用，对于大多数人而言，它们仍然太贵了，所以人们并不是想做就能做。根据我的经验，这可能是件好事。

Types of tests
The three tests we tried included two antigen tests, BinaxNow from Abbott Laboratories and a kit from Ellume, as well as one molecular test, called Lucira. In general, molecular tests, which detect the genes of the coronavirus, are more reliable than antigen tests, which sense the presence of the virus’s outer shell.

测试的类型
我们试用的三个测试包括两个抗原测试，即Abbott Laboratories的BinaxNow和Ellume的试剂盒，以及一个名为Lucira的分子测试。通常，检测新冠病毒基因的分子检测比检测病毒外壳的抗原检测更为可靠。

Everything you need is in one box, except in the case of the Ellume test, which must be paired with an app. Overall, the Lucira test had the best combination of advertised accuracy and simplicity, but it was also the most expensive at $55.

测试需要的所有东西都在一个盒子里，Ellume测试除外：该测试必须与一个手机app配对。总体而言，Lucira测试有着最准确和最便于使用的最佳组合，但它也是最昂贵的，一盒价格为55美元。

We didn’t try Quidel QuickVue, another antigen test, or a molecular test from Cue Health. Those tests, while authorized for home use, are not being sold directly to the public yet.

我没有试过另一种叫Quidel QuickVue的抗原测试，或名为Cue Health的分子测试。这些测试虽然已授权可以家用，但还没有上市进行公共销售。

After trying all the tests, I am not planning to invest in using them regularly. I work from home and don’t socialize, so I don’t really need to. Instead, I plan to keep at least one test in my cupboard so that if I do feel sick, or lose my sense of smell, I will be able to quickly find out whether it’s covid-19. The ability to test at home might become more important next winter when cold and flu season returns.

在试过了所有测试之后，我并不打算投资定期使用它们。我在家工作并且不怎么参加社交活动，所以我真的不太需要这些。不过，我计划在我的橱柜中至少囤好一盒测试，以便如果我感到恶心或失去嗅觉的时候可以迅速测出我是否得了新冠。在明年冬天感冒和流感季节来临时，在家进行测试的能力可能就显得尤为重要。

BinaxNow by AbbottTime required: about 20 minutes
Price: $23.99 for twoAvailability: At some CVS stores starting in April. Abbott says it is making tens of millions of BinaxNow tests per month.Accuracy: 84.6% for detecting covid-19 infections, 98.5% for correctly identifying covid-19 negativesAbbott的BinaxNow
所需时间：约20分钟
价格：$23.99 (两个)
购买方式：4月开始在某些CVS商店中上市。Abbott表示，他们每月要进行数以千万计的BinaxNow测试。
准确度：84.6％（用于检测新冠病毒感染），98.5％（用于正确识别新冠阴性）

This is the at-home version of the fast, 15-minute test the White House was using last year to screen staff and visitors. It’s an antigen test, meaning that it examines a sample from a nasal swab to detect a protein in the shell of the virus. It went on sale in the US last week, and I was able to buy a two-test kit at CVS for $23.99 plus tax.

这是白宫去年使用的15分钟快速测试的在家版本，该测试被用于检查工作人员和访客是否感染。这是一项抗原测试，这意味着它会检查鼻拭子中的样本以检测病毒外壳中的蛋白质。它于上周在美国上市销售，在CVS能以23.99美元（加税）的价格购买一盒两件套测试套装。

The technology used is called a “lateral flow immunoassay.” In simple terms, that means it works like a pregnancy test. It’s basically a paper card with a test strip. As the sample flows through it, it hits antibodies that stick to the virus protein and then to a colored marker. If the virus is present, a pink bar appears on the strip.

这种测试所使用的技术称为“侧向免疫测定”。简单来说，它就像验孕棒一样。它张是带有测试条的纸卡。当样品流过它时，它会粘附在病毒蛋白的抗体上，然后再粘附在有色标记上。如果存在病毒，该条上就会出现一个粉红色的条。

I found the test fairly easy to perform. You use an eye dropper to dispense six drops of chemical into a small hole in the card; then you insert a swab after you’ve run it around in both nostrils. Rotate the swab counterclockwise, fold the card to bring the test strip in contact with the swab, and that’s it. Fifteen minutes later, a positive result will show up as a faint pink line.

我发现这个测试相当容易执行：使用滴管将六滴试剂滴进卡上的一个小孔中；用拭子在两个鼻孔中进行采样后将它们塞进孔中；逆时针旋转拭子；折叠卡片使测试条与拭子接触，然后等着就行了。15分钟后，阳性结果将由淡淡的粉红色线条显示。

The drawback of the test is that there’s room for two different kinds of user error. It’s hard to see the drops come out of the dropper, and using too few could cause a false negative. So could swabbing your nose incorrectly. Unlike the other tests, this one can’t tell if you’ve made a mistake.

该测试的缺点是有可能会出现两种不同类型的用户使用错误。我们很难看到滴管是从滴管中流出的，或者使用过少的试剂可能会导致假阴性。在鼻孔中采样时也有可能操作失误。与其他测试不同，这项测试无法判断使用者是否犯了错误。

And besides the prospect of user error, the test itself has issues with accuracy. BinaxNow is the cheapest test out there, but it’s also the most likely to be wrong, missing about one in seven real infections. Abbott cautions that results “should be treated as presumptive” and “do not rule out SARS-Cov-2.”

除了可能出现用户错误外，测试本身还存在准确性方面的问题。BinaxNow是目前最便宜的测试，但也是最有可能出错的检查，它会漏掉了大约七分之一的实际感染病例。Abbott警告说，结果“应被视为推定”，并且“不排除严重急性呼吸系统综合症冠状病毒2（SARS-Cov-2）”。

But a buyer won’t find the accuracy rate without digging into the fine print. The company also buries a crucial requirement imposed by regulators: to compensate for the lower accuracy, you are supposed to use both tests in the kit, at least 36 hours apart. I doubt a casual buyer will realize that. The two-test requirement is barely mentioned in the instructions.

然而，如果不细细研究盒子上的小字，消费者是找不到准确率的。该公司还设法满足了监管机构的一项关键要求：为了补偿较低的精度，人们应该在第一次测试至少36小时后使用盒子里的第二个测试。我并不认为一个通常的买家会注意到这一点。说明书中几乎没有提到两次测试的要求。

Lucira Check-It
Time required: about 40 minutes
Price: $55Availability: Can be purchased online at lucirahealth.comAccuracy: 94% for positives, 98% for negativesLucira的Check-It套装
所需时间：大约40分钟
价格：$55
购买方式：可以在lucirahealth.com上在线购买
准确度：阳性为94％，阴性为98％

Of all the kits I used, Lucira was far and away my favorite. This is a laboratory-type test, with techniques similar to those used by professional labs, and you feel a little bit like a scientist using it.

在我试用过的所有套装里，Lucira无疑是我的最爱。这是一种实验室类型的测试，其技术与专业实验室使用的技术类似，在用的时候你会感觉自己像个科学家。

Since it’s not in stores yet, the Lucira test needs to be ordered online, and I would suggest doing so well before you need it. The first test I purchased took five days to arrive, leaving me anxious about its whereabouts. The company says you can track its packages, but I wasn’t able to access any tracking data until after my kit arrived. I ordered a second test, this time paying $20 for express shipping, and I still couldn’t find the tracking information.

由于这种测试还未在商店里上架，我们只能通过在线订购Lucira测试。因此我建议人们应该提前就买好它以备不时之需。我购买的第一个测试包五天才送达，让我不禁担心它是不是被弄丢了。该公司表示人们可以跟踪其包裹行程，但是一直到我的套装到货后，我才能看到包裹跟踪信息。我在网上下单了第二次测试，这次我支付了20美元的快递费，但我仍然找不到跟踪信息。

At $55, this is the most expensive test we reviewed, so it’s not something you’ll use too often. Still, it’s about half the cost of the mail-away swab tests from companies like Vault Health—previously my go-to option for avoiding hospitals and crowded testing facilities, as when I needed to test my kid last July so she could go to sleep-away camp. Those mail-in tests give an answer within 48 hours. With Lucira, you’ll get your answer in under an hour.

这是我测评过的最昂贵的测试，价格为55美元，所以人们并不会常常用到它。不过，这仍是Vault Health等公司进行的邮寄测试费用的一半：邮寄测试以前是我避免医院和拥挤的实验室所采用的首选方法，例如去年7月我需要对孩子进行测试以便她可以去外面郊游。这些邮寄测试会在48小时内给出结果。而使用Lucira，你将在一个小时内得到测试结果。

The test kit includes a swab, a tube of purple chemicals, and a small battery-operated base station. It works with a technology called LAMP, a molecular method that makes copies of a coronavirus gene until the amount is large enough to detect. That means it’s nearly equivalent to PCR, the gold-standard test used by labs. Unlike PCR, a test using LAMP doesn’t need rapid heating and cooling, so it can be run at home.

这组测试套装包括一个棉签，一管紫色化学试剂和一个小型电池供电的底座。它使用一种称为LAMP的技术进行工作，LAMP是一种分子测验方法，可以复制冠状病毒基因，直到其量达到能被检测出来为止。这意味着它几乎等同于PCR--实验室里使用的黄金测试。与PCR不同的是，使用LAMP进行的测试不需要快速加热和冷却，因此我们完全可以在家中进行。

After swabbing your nose, you stir the swab in the tube and then then click it into place in the base station. After half an hour, one of two LED lights turns on, saying either “Positive” or “Negative.” I found the Lucira test’s readout the easiest to understand.

在鼻腔取样后，把棉签放入试管中，然后将其插入底座的适当位置里。半小时后，两个LED灯之一将会亮起，表示“阳性”或“阴性”。我发现Lucira测试的读数是最易于理解的。

Ellume Home Covid Test
Time required: about 45 minutes
Price: $38.99Availability: Available online at CVS.com The company says it is shipping 100,000 tests a day to the US from Australia and will be manufacturing 500,000 tests a day in the US by the end of the year.Accuracy: 95% for positives, 97% for negativesEllume家庭新冠病毒测试
所需时间：大约45分钟
价格：38.99美元
购买方式：可在CVS.com上在线购买。该公司表示，他们现在每天从澳大利亚向美国运送100,000个测试，到年底将在美国每天制造500,000个测试。
准确度：阳性95％，阴性97％

Home tests still aren’t easy to find, and I couldn't find a pharmacy that stocked Ellume, a test marketed by an Australian company of the same name. But the company had previously sent me a sample kit, which I used in this review. As of this week, the Ellume test can also be purchased through the website of CVS.

现在仍然很难找到家庭测试，而且我找不到一家药店有Ellume的库存，这是一款由同名澳大利亚公司销售的家庭测试。该公司以前曾向我发送了一个样本套装，我在这次评测中用了这一套。从本周起，人们也可以通过CVS网站购买Ellume测试组合。

Of all the tests I tried, Ellume’s had the most components—five, versus three for the others. That tally included an app that you have to download onto your phone. Including resetting your Apple ID if you forget it, as I always do, and answering the app’s questions, including your name, address, and phone number, plus a break to get a cup of coffee, this test took longer to carry out. Budget an hour if you decide to read the app’s privacy policy and terms and conditions.

在我尝试过的所有测试中，Ellume的组件最多—它有五个配件，而其他测试只有三个。这些配件里包含一个必须下载到手机上的应用程序，包括重设苹果ID（如果你像我一样忘了你的苹果账户的话），并回答该app的问题，包括您的姓名，地址和电话号码。再加上休息一下喝杯咖啡的时间，这项测试花费的时间十分长。如果你决定阅读这款应用程序的隐私权政策以及条款和条件，请再留出一个小时。

Like the Abbott test, Ellume’s is an antigen test. But it is a more sophisticated one, with embedded optics and electronics that read a fluorescent result. In addition to looking for the virus, it also detects a common human protein, so if you didn’t swab you nose correctly, the test will know.

像Abbott测试一样，Ellume测试也是一种抗原测试。但该测试使用了一种更为复杂的技术，它具有嵌入式光学和电子设备，可以读取荧光结果。除了寻找病毒外，它还能检测人类的一种常见蛋白质，因此，如果你在鼻腔取样的方式有误，这个测试就会知道（并提醒你）。

Thanks to these bells and whistles, and a special swab, Ellume has a higher accuracy rate for spotting covid than other antigen tests, missing only one in 20 infections, according to the company. The drawback is that it is 50% more likely than other tests to falsely inform you that you are positive for covid-19 when you are not. Indeed, my false positive result occurred while using this test.

多亏了这些钟声，口哨声，以及特殊的拭子，Ellume能够比其他抗原检测方法更准确地发现新冠病毒抗体，只有20分之一的感染会被遗漏。缺点是，这项测试出现假阳性的可能性比其他测试高出50％。是的，我的假阳性结果就是在使用此测试时发生的。

Because it uses a phone app, you’ll need an internet connection to use Ellume, which involves communication between your phone and the kit via Bluetooth. An advantage of the app is that it provides good directions and an electronic receipt for your test—the kind you can show to a school or employer. The others I tried didn’t have a paper trail, so there’s no proof you took the test. But that receipt comes with a privacy cost. Of the three tests I tried, Ellume’s was the only one that isn’t entirely private. The app warns that it will share “certain information with public health authorities.” That information turns out to include your birthday, your zip code, and your test result. The company says the data helps health agencies track the pandemic and report infection levels.

由于它使用手机app，所以您需要互联网连接才能使用Ellume，并且通过蓝牙将手机和组件之间连接起来。该应用程序的一个优势在于，它可以为您的考试提供良好的指导和电子结果单，你可以向学校或雇主展示这种收据。我试用过的其他测试都没有书面记录，因此没有证据证明你进行过检测。但是那张结果单会带来隐私隐患。在我尝试的三项测试中，Ellume是唯一不完全私有的一项。它的应用程序警告说，它将与公共卫生当局共享“某些特定信息”。该信息包括你的生日，邮政编码和测试结果。该公司表示，这些数据可帮助卫生机构追踪疫情并报告感染水平。