Hard-To-Detect Bacteria Blamed For 12 Deaths

A stubborn type of bacteria that can escape detection despite rigorous screening of the blood supply has killed at least 12 people through tainted transfusions since 1985, the government said Thursday.

The bacteria, yersinia enterocolitica, thrive when stored in lab refrigerators, the Centers for Disease Control and Prevention said.

“You may have a case where the tests weren’t able to detect but a small amount of it, not enough to make a person sick,” said Dr. Matt Kuehnert, a CDC epidemiologist. “As it sits in the refrigerator, it can actually grow.”

Yersinia is found in unpasteurized cheese or undercooked meat. People who receive transfusions tainted with it can suffer fever, chills and breathing trouble and eventually die.

It has sickened at least 21 people since 1985, the CDC said.

Before 1985, there were no cases of illness reported from the bacteria. Health officials don’t understand why the bug has managed to become a menace since then.

Kuehnert speculated that the bacterium may have become stronger. Usually, it attacks the digestive system, causing stomach cramps. But it can also invade the bloodstream.

Blood donors are screened rigorously, and their blood is tested several times for viruses and bacteria. But tiny, overlooked amounts of yersinia can grow in storage.

The CDC said it suspects the bacteria have caused more than the 21 reported cases. It plans to start studying the problem nationally this summer before recommending any changes in the way blood is tested and stored.