Originally Posted by
travellingwineO
Eating under-cooked chicken is only dangerous if that chicken is infected with or colonized by Salmonella (or other bacteria. Salmonella is the most common and most notorious one). Salmonella is nearly endemic among chickens in the US. In many other parts of the world, salmonella in poultry is much less of a problem. Chicken that is not contaminated with Salmonella is perfectly safe to eat raw.
There are other bacteria in chicken that will also cause food poisoning, besides salmonella where campylobacter is the main one. In Sweden there is little to no salmonella in chicken, but they still urge you to prepare it well.
It should be noted, however, that salmonella and campylobacter are closely related and the infected chicken is safe to eat undercooked or raw if it has been slaughtered in a way that prevents the campylobacter to spread from the intestines.