Breathing on a camera lens for cleaning is the next worst thing to do. If you do not clean off well enough after that, fungi will grow. Do not do that again. In our production line (for medical use), what seems harmless like finger prints and vapor from our mouth can cause great harm very soon.
the conditions in my room is also right (1 degree hotter than any other rooms in the house) but only both my kit lens got fungus while my 4 year old superzoom compact fz5 (lens diameter should be the same size as yours) never kena any even after being in the rain and to japan in winter.
sold off cheaply to a friend due to a white particle in the lens...no idea to as how it even get there in the first place.
i suppose having a cleaning session once a week helps to reduce the risk of fungus in compact, or else just buy a dry cabinet and throw anything with lens into the cabinet.
having fungus growing on a compact, usually means that the compact has been left untouched for quite a period of time.
Maybe I am in too much micro lab to let you know that everything can be a source for fungi. Worst of all you may not even be able to see with your naked eyes. If you have a chance, look at the culture in the labs and you know what I mean. Good Luck if you think fungi do not grow on compact.