In the wake of a lead contamination crisis affecting cities across the country, the US Food and Drug Administration (FDA) on Wednesday warned that a commonly used line of lead testing systems may provide falsely low results under certain circumstances.
If your child is age 6 or younger and has been tested for lead by having blood drawn from his arm, you may need to get him retested.
Still, Shuren said the FDA 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".
"For this reason, because every child's health is important, the CDC recommends that those at greatest risk be retested", said Patrick Breysse, Ph.D., director of the CDC's National Center for Environmental Health.
"The FDA is concerned that Magellan lead tests that use blood drawn from a vein may provide results that are lower than the actual level of lead in the blood".
On November 4, 2016, Magellan notified its customers of a similar problem when processing venous blood samples taken with their LeadCare II testing systems, and by November 11 they notified customers by bulletin that the rubber caps of some of the blood collection tubes may introduce a substance into the blood sample when used with the LeadCare II systems.
A CDC representative said that due to their ongoing involvement with Flint, Mich. - where lead testing is of considerable importance - they estimated that less than 1% of children under 6 years who were re-tested in 2016 were at risk for having blood lead levels underestimated.
Federal officials are warning that some blood tests may have "significantly" underestimated lead levels, and they are urging the retesting of some children, as well as pregnant and breast-feeding women. It can cause serious long-term health problems. The FDA noted that it hadn't found any evidence of problems with the capillary blood samples.
The tests in question were manufactured by Magellan Diagnostics, a testing company based in MA.
It is unclear why Magellan lead tests perform differently with venous blood than with capillary blood from a finger or heel stick, FDA said.
But he said while the FDA and CDC are in the "early stages" of their investigation, they did not want to delay issuing this warning to the public. In addition, other types of lead testing methods are not believed to be affected. But if those levels are elevated, a follow up test is done with blood drawn from the arm. Higher lead levels can cause damage to the kidneys and nervous system, while very high levels can be fatal, the Mayo Clinic states.
Since previous year, Reuters has identified more than 3,300 USA neighborhood areas with documented childhood lead poisoning rates double those found in Flint, Michigan.