Is one who knows of the presence of a doctor infected with a dangerous blood-borne disease in a hospital sinful if they do not report it, fearing the transmission of the disease, or does the matter not concern them because the information reached them through a third party?

The ruling for a doctor who is ill is the same as the ruling for a patient concerning the disclosure of secrets. The general principle is to safeguard their secret and conceal it, unless there is a right of another party involved, or it is to prevent injustice or harm, or if it relates to a public interest for society. Among the situations where it is permissible to disclose a patient's secret are: if the disclosure is intended to report a contagious disease, in which case the disclosure is restricted to the authorities designated by the competent health agencies.

If specialists determine that the illness prevents the individual from practicing medicine entirely, or in specific specializations, and this doctor's specialization is among them, then whoever knows of their condition must inform the relevant authorities, to avert harm and prevent corruption.