Legionella pneumophila tekitatud raske pneumoonia (tõeline legionelloos), an acute, sometimes fatal, bacterial disease caused by infection with Legionella pneumophila, not spread by person-to-person contact, that is characterized by pneumonia, high fever, gastrointestinal pain, headache, and sometimes involvement of the kidneys, liver or nervous system, a serious, sometimes fatal, infection, caused by the bacterium Legionella pneumophila, which has symptoms similar to those of pneumonia: believed to be spread by inhalation of contaminated water vapour from showers and air-conditioning plants