Hello doctor, i'm a kidney transplant recipient, father donor. 1 year completed. I've a general question. Does body react or catches infection on the very first encounter of a bacteria/virus etc (food infection) or is it a slow process. Reason why I would like to understand is, i've had meals outside couple of times last month and I wonder how to know for sure that the food I had was good (safe for me) and what precautions should I take whenever I have no option but to eat outside? Thanks.