Duty to care: ethical analysis of the physician's response to an influenza pandemic.

Many fear that the world may be on the brink of an influenza pandemic. One significant ethical issue which could occur in a pandemic is the lack of clarity regarding the duty of physicians to care for patients despite personal risk. This duty is examined through statements made by professional societies, as well as from a legal, moral, and historical perspective. Options to clarfiy this issue are also examined.