Thank you sir,you mean the canker sore cannot be the route of infection? even with blood?
HIV is not transmitted in that fashion.
Thank you sir,but I remembered a passer-by did cough when I passed him,
If,I mean If he coughed up blood on my food,and I eat my food immediately,is it risky?I just worry about the canker sore in my mouth,is that can be a route of infection?
NO NO NO.Saliva is NOT infectious even with blood present and this is irrational thinking anyway.No one spat in your food.