California and Washington in May asked the U.S. Centers for Disease Control and Prevention (CDC) to validate a new way to test for measles — but after waiting two months, the CDC rejected the request, citing “other competing priorities,” according to a letter from the West Coast Health Alliance to CDC Director Erica Schwartz.
The letter, signed by health officials in California, Hawaii, Oregon and Washington, asks Schwartz to reconsider and validate a rapid, high-volume measles test in anticipation of major outbreaks. The alliance also asked the CDC to create protocols for testing other high-priority pathogens to prepare for future outbreaks.
The CDC is “ensuring that state and local health departments have the support they need to strengthen measles detection and outbreak response,” said Emily Hilliard, a spokesperson for the U.S. Department of Health and Human Services (HHS). The agency was “prioritizing emerging technologies” to respond to the measles outbreak, Hilliard said.
The spokesperson did not respond to questions about whether the CDC was considering validating a test or a high-throughput measles test.
Such a test would “significantly enhance” labs’ ability to respond quickly to outbreaks, health officials said — helping prepare for known pathogens like Ebola or hantavirus as well as emerging threats.
Currently, laboratories must rely on lower-volume measles tests, such as individual polymerase chain reaction (PCR) tests.
During the Covid pandemic, most public health laboratories purchased equipment in large quantities, such as the Hologic Panther Fusion, a disease diagnostic PCR platform capable of processing up to 500 tests in eight hours. This way, laboratories could process large batches of Covid tests very quickly.
But there is no high-throughput test to diagnose measles that has been validated by the CDC.
Texas state labs developed such a test during the measles outbreak in West Texas last year, but they have neither distributed nor published the protocol. ARUP Laboratories, a national, academic, nonprofit reference laboratory, published its test for measles in the Journal of Clinical Microbiology in December. The CDC could validate this or another protocol so that other public health laboratories can perform diagnostic testing.
High-throughput testing can process large numbers of samples at once, but automated instruments can also be faster and simpler than manual testing. “One of the big advantages they offer is essentially greater flexibility,” said Benjamin Bradley, assistant professor of pathology at the University of Utah and medical director of virology at ARUP.
This is particularly important in the case of a rapidly evolving epidemic. “With a measles outbreak, time is really of the essence,” Bradley said. One measles patient can infect 12 to 18 other unvaccinated people, and the virus can linger in the air for two hours. “You can quickly see how exponential this becomes, from a handful of cases to an entire community of cases,” he said.
Faster testing can help curb such an outbreak, helping identify and isolate positive patients as quickly as possible and leading to faster contact tracing. It also means that authorities can quickly offer vaccines to anyone who has been exposed and is not already vaccinated. If vaccines are taken within 72 hours of exposure, they can prevent infection.
There is no commercially available test for measles; current tests are developed by laboratories. Validation and publication of the process of creating these tests is crucial so that laboratories can create and perform them.
“That basically requires doing science,” Bradley said. This means planning, performing and documenting experiments, then verifying that the test is reliable. “A lot of this work is very cumbersome for the labs to put together. So having groups that can share their protocols, that helps the labs,” Bradley said.
The CDC reportedly completed studies on the Texas and ARUP Labs tests, “but these were not complete validations or a complete comparison,” West Coast officials said in the letter.
The alliance asked Schwartz to develop a test, or test, for measles diagnostic testing on the Panther Fusion and to publish that protocol so that any laboratory could perform the tests. Having tests ready to go is a critical part of preparedness, the letter states: “If a significant outbreak were to occur in our region, without broadband capacity it would be more difficult to scale up diagnostic testing appropriately, harming patient care and public health investigations. »
Gn Health
