Contra Costa County health leaders hope to find out later this week whether the Richmond Health Center is the source of a rare bacterial infection.
Janice Stogner-Smith was diagnosed with Legionnaires' disease a few weeks ago. She is a nurse the center.
Legionnaires'is a potentially deadly infection that can cause pneumonia.
Stogner-Smith believes she may have been infected from water dripping from the ceiling.
Health officials say air tests have come back negative and the results of the water quality test should be in by the end of the week.
Legionnaires' disease is named so because in 1976 many delegates attending a convention in Philadelphia held by the American Legion of Pennsylvania came down with a respiratory disease. The bacteria bacteria that was responsible for the disease was isolated and named as Legionella pneumophila.
Each year, between 8,000 and 18,000 people are hospitalized with Legionnaires' disease, according to the Centers for Disease Control.