NEW YORK – Public health and commercial laboratories are bringing molecular and serology testing online to help manage the ongoing measles outbreaks in Texas and New Mexico.

纽约——公共卫生和商业实验室正在上线分子和血清学检测，以帮助应对德克萨斯州和新墨西哥州持续的麻疹疫情。

While public health labs have sufficient capacity to handle the current case numbers, declining childhood vaccination rates could lead to larger outbreaks and increased demand for testing in coming years, suggested one clinical lab executive.

一位临床实验室主管表示，虽然公共卫生实验室有足够能力应对当前的病例数量，但儿童疫苗接种率的下降可能导致未来几年更大的疫情爆发，并增加对检测的需求。

According to the US Centers for Disease Control and Prevention (CDC), as of March 13, 301 measles cases had been confirmed across 15 states. The bulk of those cases have occurred in Texas, which as of March 18 had confirmed 279 infections, most of those in Gaines County, which sits at the state's western border.

根据美国疾病控制与预防中心 (CDC) 的数据，截至 3 月 13 日，全美 15 个州共确诊麻疹病例 301 例。其中大多数病例发生在德克萨斯州，截至 3 月 18 日，该州已确认 279 例感染病例，而这些病例大多集中在位于该州西部边界的盖恩斯县。

New Mexico has experienced a smaller outbreak, with 38 measles cases confirmed as of March 18..

新墨西哥州的疫情较小，截至 3 月 18 日，已确认 38 例麻疹病例。

During a recent media call hosted by the College of American Pathologists, Ben Bradley, medical director of virology at ARUP, said these numbers were likely undercounts.

在最近由美国病理学家学会主办的媒体电话会议上，ARUP 的病毒学医疗主任本·布拉德利表示，这些数字很可能被低估了。

'Knowing the true impact of these highly transmissible viral events is challenging,' he said. 'The numbers we are putting out right now are the confirmed cases that we have been able to document, but we know that the spread is probably greater than that, that this is an underestimation.'

“了解这些高传染性病毒事件的真实影响具有挑战性，”他说。“我们目前发布的数字是我们能够记录的确诊病例，但我们知道传播可能比这更广泛，这是一个低估。”

Because measles is a relatively rare disease in the US, most testing capacity is in public health labs, said Kelly Wroblewski, director, infectious disease, at the Association of Public Health Laboratories.  'There's not enough volume to really justify maintaining capacity in [commercial] laboratories.'.

凯利·罗布列夫斯基是公共卫生实验室协会传染病部门的主任，她说：“由于麻疹在美国是一种相对罕见的疾病，所以大多数检测能力都在公共卫生实验室。没有足够的样本量来证明在[商业]实验室维持这种检测能力是合理的。”

Several tests are being used to manage the outbreaks, Wroblewski said. PCR testing is most commonly used and is the most helpful for making a diagnosis. In the case of measles, testing may also include a second PCR assay called the measles vaccine assay, which allows clinicians to distinguish between viral genetic material present due to an infection from genetic material present due to recent vaccination.

沃罗布列夫斯基说，正在使用若干测试来控制这些疫情。最常用的是PCR测试，也是对诊断最有帮助的。在麻疹的情况下，测试还可能包括第二种称为麻疹疫苗测定的PCR测定，这使得临床医生能够区分因感染而存在的病毒遗传物质和因近期接种疫苗而存在的遗传物质。

The test, which is used as a reflex test following a positive result, distinguishes between the measles strain used in vaccines and the wildtype strain, and 'is important during an outbreak when an active vaccination campaign is happening,' Wroblewski said..

Wroblewski 表示，该测试作为一种在阳性结果后的反射测试，能够区分疫苗中使用的麻疹毒株和野生毒株，“在爆发期间进行积极的疫苗接种活动时非常重要”。

Genotyping is also commonly done to establish the genotype of the virus in infected individuals. Wroblewski said that thus far all the Texas and New Mexico infections have been caused by the D8 genotype, which has been involved in a number of recent outbreaks globally.

基因分型也常用于确定感染者体内病毒的基因型。沃罗布勒夫斯基表示，到目前为止，德克萨斯州和新墨西哥州的感染都是由D8基因型引起的，这种基因型在全球范围内与多次近期爆发有关。

Serology testing is also available, though Wroblewski said it has limited utility in highly vaccinated populations. It can be useful for testing individuals who have been exposed but are outside the window in which a PCR test would pick up the virus, she said, noting that IgM antibodies to the virus, which indicate a recent infection, typically linger a bit longer in the body than does the virus's genetic material..

血清学检测也是一种选择，尽管沃罗布列夫斯基表示它在高接种率人群中用途有限。她指出，这种检测对于那些已经暴露但不在PCR检测能够发现病毒的时间窗口内的人是有用的，她还提到，表示近期感染的IgM抗体会在体内存留较长时间，相比病毒的遗传物质而言。

There are no US Food and Drug Administration-cleared

没有美国食品药品监督管理局批准的

in vitro

体外

diagnostics for measles. In Texas, the Department of State Health Services (DSHS) laboratory in Austin offers molecular testing for the virus as does the state's Laboratory Response Network's Lubbock facility, said DSHS spokesperson Lara Anton. She said the state's El Paso and North Texas LRN laboratories are also planning to bring molecular testing for measles online soon..

德克萨斯州的诊断服务。德克萨斯州卫生服务部（DSHS）位于奥斯汀的实验室提供针对麻疹病毒的分子检测，该州实验室响应网络的拉伯克设施也同样提供此项服务，DSHS发言人拉拉·安东表示。她还说，该州的埃尔帕索和北德克萨斯LRN实验室也计划很快上线麻疹分子检测服务。

In New Mexico, all measles testing is being done through the state Department of Health's Scientific Laboratory, which, New Mexico DOH spokesperson David Morgan said, is, to his knowledge, the only lab in the state that does molecular testing for the virus. He said the state's current testing needs are well covered by the lab's existing capacity and that it provides results within 24 hours..

在新墨西哥州，所有麻疹检测都通过该州卫生部的科学实验室进行。新墨西哥州卫生部发言人戴维·摩根表示，据他所知，这是该州唯一一家进行病毒分子检测的实验室。他说，目前该州的检测需求完全能够被实验室现有的能力覆盖，并且能够在24小时内提供结果。

While public health labs have largely handled measles testing thus far, commercial labs including Quest Diagnostics and Laboratory Corporation of America offer serology and PCR testing for the virus, and others are adding molecular measles tests to their menus. Denton, Texas-based infectious disease testing firm HealthTrackRx is launching a PCR test for the virus this month.

公共卫实验室迄今为止主要负责了麻疹检测，而包括Quest Diagnostics和Laboratory Corporation of America在内的商业实验室则提供针对该病毒的血清学和PCR检测，其他一些实验室也在增加分子麻疹检测项目。总部位于德克萨斯州登顿的传染病检测公司HealthTrackRx将在本月推出针对该病毒的PCR检测。

Jay Reddy, the company's CSO, said it is not developing the test in response to the current outbreak so much as to prepare for the possibility of larger and more frequent measles outbreaks in the future..

该公司首席科学官杰伊·雷迪表示，公司开发这项测试不是为了应对当前的疫情，而是为了防范未来麻疹更大规模、更频繁爆发的可能性。

Reddy said that for the last several years HealthTrackRx has received requests from physician customers for molecular testing for measles. This, combined with declining measles vaccination rates, led the company to develop a test.

雷迪表示，在过去几年里，HealthTrackRx 收到了来自医生客户的麻疹分子检测请求。再加上麻疹疫苗接种率的下降，这使得该公司开发了一项测试。

'It's kind of a protective measure,' he said. 'If you continue to have an outbreak of 150 to 250 people in a region of Texas or New Mexico, that's not that big a deal. But if you get to the point where you are reaching thousands [of cases] … that testing line might be of value then.'

“这有点像是一种保护措施，”他说。“如果你继续在德克萨斯州或新墨西哥州的一个地区爆发150到250人的疫情，那并不是什么大问题。但如果你达到数千例的时候……那么那条测试线可能就有价值了。”

Reddy said that, in particular, physicians the company works with appear interested in testing to prevent spread within their own offices in the event of a large outbreak.

雷迪说，特别是公司合作的医生们似乎有兴趣进行检测，以防止在大规模爆发时病毒在他们自己的办公室内传播。

According to the CDC, over the last four years, the percentage of US kindergartners vaccinated against measles has fallen from 95.2 percent during the 2019-2020 school year to 92.7 percent during the 2023-2024 school year.

根据疾控中心的数据，过去四年中，美国幼儿园儿童接种麻疹疫苗的比例从2019-2020学年的95.2%下降到2023-2024学年的92.7%。

'When you look at the overall landscape, you say, this could be a [situation] where a larger outbreak could occur, and at that point you would need a public-private kind of relationship to support higher volume testing,' Reddy said.

雷迪说：“当你审视整个局势时，你会说，这可能会导致更大规模的爆发，到那时，你就需要一种公私合作关系来支持更大批量的检测。”

He said HealthTrackRx will be able to run around 1,000 samples per day at launch of the test with the ability to expand from there if needed. He added that while the company expects most testing to continue to go through public health labs, it does have a large number of clients in the affected regions and has received requests for testing from some of those clients..

他说，HealthTrackRx在测试启动时每天能够处理大约1000个样本，并且如果需要的话，还可以在此基础上进行扩展。他补充道，虽然该公司预计大多数测试仍会继续通过公共卫生实验室进行，但它在受影响地区确实有大量的客户，并且已经收到其中一些客户的测试请求。

Reddy said that HealthTrackRx developed its test with guidance from CDC, which provided advice on items including where to source material for validating the assay.

雷迪表示，HealthTrackRx 在 CDC 的指导下开发了其测试，CDC 就从哪里获取材料以验证检测方法等问题提供了建议。

ARUP's Bradley said his lab offers serology testing and is also developing a molecular measles test that it plans to launch in mid-April.

ARUP的布拉德利说，他的实验室提供血清学测试，同时还在开发一种分子麻疹测试，计划于四月中旬推出。

As laboratory-developed tests, measles molecular assays are subject to the FDA rule on LDTs, including new reporting requirements set to go into effect in May. Tests that were on the market prior to release of the rule in April 2024 may be exempt from later stages of the rule's implementation, including premarket review requirements.

作为实验室开发的测试，麻疹分子检测受FDA关于LDTs规则的约束，包括将于五月生效的新报告要求。在2024年4月发布规则之前已在市场上的测试可能不受该规则实施后期阶段（包括上市前审查要求）的限制。

The newly developed tests from the Texas LRN labs and HealthTrackRx and ARUP, on the other hand, may be subject to these requirements..

另一方面，德克萨斯州LRN实验室、HealthTrackRx和ARUP新开发的测试可能会受到这些要求的影响。

FDA has issued draft guidance detailing how it may offer enforcement discretion of LDTs both in cases where it has implemented Emergency Use Authorization authority and in situations where it has not but in which testing may nonetheless be needed to respond to a health emergency. The agency has not finalized this guidance, however, and, in any case, it is unclear if it would apply to current or future measles testing needs..

FDA发布了详细说明其可能对LDT实施执法自由裁量权的指南草案，无论是在实施紧急使用授权的情况下，还是在未实施但应对健康紧急情况仍需进行检测的情况下。然而，该机构尚未最终确定这一指南，并且无论如何，目前尚不清楚它是否适用于当前或未来的麻疹检测需求。