Can Legionnaires’ be ingested and give symptoms of nausea and vomiting and migrate to the lungs via the digestive route?
Your scenario above is not quite correct, but close. Click on About the Disease and there is some discussion on Aspiration. Nausea, vomiting, diarrhea can occur. The Legionella bacterium, enters the lung not through the digestive tract, but is aspirated through the windpipe (trachea).