This is only a rough draft of what I had started on.
And you shall know the truth, and the truth shall make you free. (John 8:32)
Why warn at all?
The first issue of concern here is the possibility of a preventable medical error occurring, namely that a patient could have a diagnosed disease and not be aware of it.
The central ethical question in this case pertains to the duty to warn. The attending presumably agrees that the patient has a right to know about her diagnosis, but also believes that because (a) the patient probably already knows of the diagnosis, and (b) there is no established relationship with the patient, that there is no duty to warn.
I disagree with this reasoning because I see little harm in telling the patient that she may have syphilis, whereas I can see great potential harm in not telling her.
I believe there is a duty to warn irrespective of whose patient Mrs Scott is. If the patient already knows she has syphilis, I doubt she will be upset at having someone go to the trouble of contacting her to make sure she knows. In fact, I think it more likely that she will be appreciative, knowing that someone was paying such attention to her health, an action based on the ethical principle of beneficence. However, if she does not know of her syphilis, withholding that information could delay potentially beneficial treatment until someone else makes the diagnosis. This is essentially contradictory to the ethical principal of non-maleficence (do no harm) because withholding the diagnosis could do harm if it delays treatment.
In regard to whether a duty to warn actually exists in this case, I think it does. According to Opinion 8.12, "Patient Information" of the AMA's Code of...