Method of transmission of legionella includes all, except:

Ans. (a) i.e. Patients suffering from legionella to contacts Human to human transmission does not occur in legionella Mode of Infection of Legionella: Source: Natural habitat for L. pneumophila are aquatic bodies including lakes and streams. However their number is very low in aquatic bodies When the contaminated water from these aquatic bodies is stored in human constructed water reservoirs (water cooler), legionella grow and proliferate. Warm temperature and sediment enhances the proliferation L. pneumophila can form microcolonies within biofilms in water coolers, its eradication requires disinfectants that can penetrate the biofilm Ameboe, alga, ciliated protozoans are symbiotic to L. pneumophila and promotes the growth Mode of transmission: Aspiration: Predominant mode. Aspiration can occur either from oropharyngeal colonization, or through contaminated water Aerosolization: Air conditioners, whirlpools, nebulizers aerosolize the legionella which then gets inhaled. Direct instillation into the lungs: Either through contaminated instruments (endotracheal tube) or through res-piratory tract manipulation which mobilizes the oropharyngeal colonies to respiratory tract.