An 82-year-old Italian woman died after she contracted Legionnaires’ disease, from the water in her dentist’s office in February 2011, according to a case report published in The Lancet.

Tests on the water showed  Legionella bacteria in the dentist’s water line. Water lines carry water from the main water supply to certain devices used during patient care and a recent survey has found dental water lines to be another major source of contamination with Legionella bacteria.