WASHINGTON — Hundreds of people were wrongly told they were clear of the Zika virus, after D.C.’s Public Health Laboratory made a math mistake and other errors.
Retests at other labs of the first 62 of the samples have found two pregnant women initially told they did not have any sign of the virus in fact were positive for Zika or a related virus.
The D.C. Department of Forensic Sciences acknowledged Thursday that all 409 of the samples from July 14, 2016, to Dec. 14, 2016 needed to be retested by other labs. People who had samples sent to the lab by their health care providers in that period should learn the results of retesting through their doctors, department Director Dr. Jenifer Smith said.
“We don’t want to have to extrapolate, we are assuming that there may be some [positive results] in there, and we are also hopeful that the majority of those will continue to be retesting as … negative,” Smith said.
Dr. Anthony Tran said he identified the problems in December shortly after he took over at the lab. He called one issue a technical formulation error, and another issue a calculation error.
Tran said the issue has been corrected, but the lab has not resumed doing its own Zika testing yet.
It is not the first issue for the Department of Forensic Sciences. Analysts at a separate lab at the agency that analyzes DNA samples was found to be incompetent in 2015, just before Smith took over the department.