Two samples arrived last Thursday at the Idaho Bureau of Laboratories. Health care providers in two different parts of the state had taken their patients to test for suspected monkeypox infections.
The lab processed the monkeypox tests and sent the results.
Four days later, the state lab received a request from the Centers for Disease Control and Prevention. The CDC had received samples from the same patients, to confirm the results from the state lab — but those samples and the test results did not match.
It turned out that the Idaho State lab had inadvertently swapped the two patients’ samples. It wasn’t just a paperwork error, though. This caused a person who did not have monkeypox to test positive and – of greater public health concern – a person who had monkeypox to test negative.
The Idaho Department of Health and Wellness announced the lab’s error, and its subsequent investigation into the error, in a news release Tuesday.
Christopher Ball, director of the Idaho Office of Laboratories, told the Capital Sun Tuesday afternoon what was wrong and what the lab was doing to prevent future errors.
The lab is one of the largest and most capable of running complex tests in Idaho. It was the starting point for much of the pandemic’s COVID-19 testing progress. It also has a high containment area, where scientists can safely test for things like monkeypox without contaminating the rest of the lab.
There is one important rule for the Containment Zone: Items that go in don’t go out. So when the lab received a potentially infectious sample, an employee would bring the sample to the containment area and leave the paperwork at the lab, so it wouldn’t have to be destroyed.
Each sample comes with two labels that identify the patient. A label remains with the paperwork; we go with the specimen.
Prior to the current monkeypox outbreak, the lab rarely needed to test more than one patient sample per day in the containment zone, Ball said, so there were few situations where tags could get mixed up between two samples. .
But on Thursday, the lab received two samples, and that’s exactly what happened.
“We all felt pretty stupid once we saw the error in our ways,” Ball said. “How my staff handled it, as soon as they were alerted to a problem (by the CDC on Monday) they notified me immediately.”
The lab corrected the test results and sent them immediately, he said. Yet a patient with monkeypox may have spent four days believing they did not have an infectious disease.
Ball said staff quickly came up with a simple solution to avoid a problem of this magnitude in the future: make an extra copy of documents that can be discarded, so they can go to the containment area next to the specimen. of testing.
“Errors, unfortunately, are part of the laboratory job”, Ball told the Idaho statesman in an interview about the error. “The way they are treated is commensurate with the staff we have here.”
What about previous samples? Has this happened before, and did the CDC or state lab just not catch the error?
Ball said it was part of the investigation.
“Because we receive so few samples in our high-containment lab,” there weren’t many tests where confounding was even possible, he said, but a review of those tests did not. found “no evidence to suggest” this has ever happened before.