U.S. health leaders are warning parents not to use three popular powdered infant formulas manufactured at an Abbott plant in Sturgis, Michigan, that investigators recently linked to bacterial contamination.

The FDA is investigating four reports of infants who were hospitalized after consuming the formula, including one who died.

The agency said one of the cases involved salmonella and three involved a rare, but dangerous, germ that can cause blood infections and other serious complications.

The recall affects certain lots of Similac, Alimentum and EleCare with expiration dates of April 1, 2022, or later.

FDA staff are now inspecting Abbott’s plant in Sturgis, where environmental samples tested positive for the bacteria.

Inspectors have also uncovered potential manufacturing problems, and past records showing the destruction of formula due to bacterial contamination.