You can have raw chicken in restaurants in Japan - it's delicious. Depending on where you live there may be better or worse food safety standards, but there is nothing poisonous about raw chicken itself.
By the way, sushi is a dish with vinegary rice. The raw-meat dish is Sashimi http://en.wikipedia.org/wiki/Sashimi. A picture of chicken sashimi:
You will note that in this photo the chicken is actually not raw but quite rare. The exterior of the chicken flesh is actually seared and cooked through several millimeters.
