KENTON, DEL. – Following a Listeria monocytogenes outbreak that led to one death, the U.S. Food and Drug Administration on March 11 suspended the food facility registration of Roos Foods, Inc., a maker of cheese and dairy products.

An investigation of the facility by the F.D.A. and the Centers for Disease Control and Prevention found unsanitary conditions that included: a roof leaking water onto cheese processing equipment and storage tanks; standing water on the floor throughout the cheese curd processing room near cheese vats in the storage rooms; rust appearing on  metal roof, ceiling and supports; food residues found on equipment after cleaning; openings to milk storage tanks and transfer piping not capped to prevent contaminants; and floors, wall and equipment deteriorated and in bad repair, including processing equipment and storage vats with rust holes and floors with rough concrete deterioration.

Additionally, the F.D.A. collected environmental samples from different areas of the facility and found 12 swabs testing positive for Listeria monocytogenes, 11 of which were linked to the same outbreak strain that sickened eight in Maryland and California.

The inspection was conducted from Feb. 18 to March 4. The state of Delaware’s Division of Public Health issued a cease-and-desist production and distribution order to the firm on Feb. 28.

The F.D.A. said it will reinstate Roos’ facility registration when it determines the food manufactured, processed, packed or held at the facility no longer has reasonable probability of causing adverse health consequences or death.

Roos Foods issued voluntary recalls on Feb. 23, Feb. 25 and March 1 of Hispanic cheeses and sour creams that were distributed through retail stores in Delaware, Maryland, New Jersey, New York, Virginia and the District of Columbia.

Eight illnesses, including one death, have been reported in California and Maryland. The illnesses were diagnosed between Aug. 1 and Nov. 27, 2013.