Some blood tests used to check for lead poisoning in children and women since 2014 may have wrongly indicated that children were safe from lead exposure, federal health officials warned Wednesday. Children under 6 and pregnant and nursing women may need to be retested.
The concern is that the original tests may have underestimated blood lead levels, providing false reassurance to parents. Infants and young children are especially vulnerable to the effects of lead poisoning, which can cause cognitive deficits and affect almost every system in the body.
The tests under scrutiny are made by Magellan Diagnostics, which discovered as far back as 2014 that its tests could yield inaccurate results when used on blood drawn from a vein, Food and Drug Administration officials said in a news conference.
For young children, many doctors use less invasive finger sticks or heel sticks to draw samples of capillary blood for testing, and F.D.A. officials said there is no evidence at this point that the finger- and heel-pricking methods have provided inaccurate results.
They emphasized that they have just started their investigation.
“The F.D.A. is deeply concerned by this situation and is warning laboratories and health care professionals that they should not use any Magellan Diagnostics lead tests with blood drawn from a vein,” said Dr. Jeffrey Shuren, director of the F.D.A.’s Center for Devices and Radiological Health. “The agency is aggressively investigating this complicated issue to determine the cause of the inaccurate results.”
Magellan, which calls itself “the most trusted name in lead testing,” did not return calls for comment.
F.D.A. officials did not provide estimates of how many people may have been at risk for a faulty test. Although Magellan is the only test approved for immediate lead testing in a doctor’s office or clinic, it’s not clear how many tests were given by drawing blood from a vein or by a pin prick.