In D.C., Zika Testing of Pregnant Women Was Mishandled for Months
When Anthony Tran took over the District’s public health lab late last year, he had a feeling something was wrong with its testing for the Zika virus. He had just come from the public health lab in New York City, where technicians had been finding markers for Zika in the blood of arriving travelers almost every day. In the smaller, but still international, city of Washington, the same test was negative — every time.
Soon, U.S. health officials joined in Tran’s concern: Samples supplied by the federal government of the frightening, mosquito-borne virus that were tested in the lab as a control were appearing as if they contained no virus.
“I knew then that something was tremendously wrong,” Tran said late last week in an interview. He halted testing, and with help from analysts at the Centers for Disease Control and Prevention, traced the problem to a mistake that any high school chemistry student could understand.
There were two types of solution the District could have purchased to conduct a phase of the test. One bottle came marked with a “D,” for diluted, and the other with a “U”, for undiluted. D.C. lab workers had purchased the diluted version, Tran said, and then mistakenly watered it down as if it was the more concentrated one, weakening the ability to detect for Zika.
For a public health lab to commit such an error once would be an embarrassment in the high-stakes testing of Zika, which has potentially devastating consequences for pregnant women, scientists and federal health officials say. That the District lab — which is also a first line of defense in screening bioterrorism threats — repeated the mistake daily, and without anyone catching it for more than six months, amounts to a more systemic and worrisome failure, experts said.
Interviews and public documents show that the debacle unfolded over a period of months last year in which the District lab was in a state of turmoil — understaffed, lacking permanent leadership, spread thin on competing projects, and relying on new employees to test for the emerging public health threat in Zika.
“A relatively inexperienced staff and a lack of leadership — that’s a bad combination,” said Kelly Wroblewski, director of infectious diseases for the Association of Public Health Laboratories, which works to safeguard the integrity of public health labs nationwide. “The positive here is that the lab does have new leadership and he caught the error quickly, even though the situation is already really, very unfortunate.”
Since D.C. officials announced the error on Feb. 9, public health officials in a network of nearly 50 labs studying Zika have questioned how it could have gone so wrong. It was the only jurisdiction in the country to have mishandled the testing.
In the District, the mishap has shaken public confidence in Zika testing and, attorneys say, could result in millions of dollars in legal claims. And all of that may pale in comparison to the effects that the botched tests may have on a handful of D.C. families.
At least nine pregnant women in the nation’s capital were caught in the faulty testing between July and December of last year, D.C. officials said Thursday. The women were told they did not have Zika when in fact new testing by a CDC lab in Colorado shows that the women did have antibodies that could signal the presence of the virus. Follow-up tests on eight have been inconclusive and one has been confirmed as having a Zika infection.