Health department tests confirmed the bacteria that cause Legionnaires’ disease showed up in three cases at a nursing home in Philadelphia, health officials told the Associated Press.

A 92-year-old who died in April after developing pneumonia was infected with the Legionella bacteria, said Mike Baysinger, head of the county health department’s communicable disease division. She was a resident at the Madlyn and Leonard Abramson Center for Jewish Life.

A 101-year-old man who developed a high fever also tested positive for the Legionella bacteria, but developed recovered in a few days. A center employee also was infected and became ill but recovered, health officials said.

The Centers for Disease Control and Prevention estimate that anywhere from 8,000 to 18,000 people contract Legionnaires’ disease in the United States each year, but many develop no symptoms or mild symptoms and most go unreported.