FDA issues warning over false results of virus test
WASHINGTON — A widely used coronavirus test is under scrutiny this week after federal health officials warned that it could deliver inaccurate results if laboratory technicians don’t follow the latest updates from the manufacturer.
The Food and Drug Administration’s warning over Thermo Fisher Scientific’s TaqPath test underscores the complexity of COVID-19 tests and how easily they can be skewed by faulty processing and equipment.
The FDA action follows a report last month by Connecticut public health officials that the test resulted in at least 90 people receiving false positive results for the coronavirus.
Thermo Fisher’s test is one of the standard tools used to screen for COVID-19, run on large, automated machines found in many U.S. hospitals and laboratories. The FDA flagged two separate issues that could potentially result in false results: the chemical mixing process and computer software that runs on the company’s machine. Thermo Fisher has provided new instructions for mixing. And a software update fixes the second problem, the FDA said.
Thermo Fisher said its data shows the issues are rare and most users get accurate results by following company directions.
No test is 100% accurate and all medical tests are expected to deliver a certain small portion of false results.
Less is known about the accuracy of COVID-19 tests because of how quickly they were rushed through the regulatory process.
Thermo Fisher’s test was among the first granted emergency use by the FDA in midMarch. Like other companies, it got the OK based on laboratory experiments. However, experts have warned that these laboratory measures are very different from large patient studies that assess real-world performance.