Actually, duck is as susceptible to bacteria as any other poultry, particularly listeria and salmonella. Check this article:
Food Poisoning Bacteria Prefer Duck To Beef On Meat Factory Surfaces
recommends cooking duck to an internal temperature of 70 degrees Centigrade (158 Fahrenheit):
"Should duck be cooked to an internal temperature less than 70°C as per the requirements for poultry? It is common practice to have duck pink and bloody in the middle - but is it associated with salmonella?
The practice of serving duck pink in the middle is traditional practice in restaurants, and yes there is a potential risk of salmonella. It is suggested that if the duck is not pierced by a knife or similar object then bacteria have not been introduced to the duck breast. This is similar to rare or blue steaks. However, to be safe, cook your ducks thoroughly
I wouldn't worry too much about it, especially if the duck if purchased from a reliable source and seems to be in good shape, but OTOH I wouldn't serve rare duck to kids, old folks, or anyone with compromised health.