I dont know if I had any of these specific salmonella, but I do now recall, I've have had too many cases of food poisoning over the years while at curtain colleges, restaurants/fast food venues or abroad. I didn't realise the significance of it until now a weakened digestive tract or stomach = a weakened immune system and weakened body in general. I think it will also be the case for most as this article suggests that most people don't need hospitalisation or waste doctors time with it, they just take days off work and/or sweat out a fever or sickness with all the symptoms at home. Once they feel better they may carry on as normal although milder symptoms may last for a long time causing loss of appetite, tiredness, bad stomach, aching joints etc and without prior knowledge many people may just ignore this as i did myself, causing other problems later down the line. 

So I guess my main point is lots of people may of had this or similar food poisoning but were never diagnosed or even told a doctor so they wouldn't know either way!