Any physician who diagnoses a contagious disease has a duty to counsel the patient about the communicability of the disease and to ensure that any other persons at risk are warned. This duty has been clear and explicit in the laws of this country since the nineteenth century. This duty can be discharged directly, by warning the exposed individuals, or indirectly, by reporting the disease to public health officials or by counseling the patient to warn persons at risk. The proper method of discharging this duty to warn is shaped by the applicable reporting and privacy laws. The patient’s privacy is best protected by indirect warnings through the health department. This route may be ineffective, however, in jurisdictions where the health department declines to warn persons who are exposed to communicable diseases such as HIV. For example, a physician who treated a married man with syphilis would have to report the disease to the local health department, which would contact the man’s wife. They would interview her to determine if there were other contacts who might require treatment. The physician would have discharged his or her duty to warn the wife and to report the disease. The health department also protects the patient’s confidence. A disease investigator does not tell a contact to a communicable disease carrier who the carrier is— simply that there has been a contact.

In this case, if the wife has not had sexual relations with anyone except her husband, she will know who her contact was. It is important to keep in mind that the resulting family problems are not the fault of the reporting physician if the health department does the warning. Conversely, if a physician attempts to warn a person at risk and does so negligently, the physician may be liable for the ensuing marital disharmony.

In the classic Molien case, the physician negligently diagnosed syphilis in a married woman. The physician then told the woman to tell her husband that he might be infected and to come in for testing. The consequences of this negligent diagnosis and counseling were suspicion, disharmony, and divorce. The court found that the physician was responsible for this result and had to pay damages to the husband for negligent infliction of mental distress. [ Molien v. Kaiser Found. Hosp., 616 P.2d 813 (Cal. 1980).] Had the physician reported the disease to the health department and relied on it to investigate the case and to warn the husband, the potential liability for marital distress would have been reduced or eliminated.

This case is especially interesting because the strategy of counseling patients to warn their own contacts is often recommended for HIV-infected persons. Under this court’s analysis, instructing an infected plaintiff to warn others and ask them to come in for testing can leave the physician liable for any negligently inflicted mental distress suffered by the patient’s contacts.

Such potential liability, coupled with the greater expertise of the health department disease investigators, means that physicians should rely on the health department to warn persons at risk. Some health departments, however, still refuse to trace and warn the contacts of HIV carriers. In such jurisdictions, physicians are in a difficult bind: they have a duty to warn but may be liable for consequences of negligent warnings, delivered by either the patient or the physician. If they warn without the patient’s consent, they also may be liable for violating the patient’s privacy. If the state law permits the physician to warn third persons without the patient’s permission, the physician must be careful not to disclose the disease carrier’s identity, even if the contact clearly knows the identity and asks the physician to confirm it. Laws allowing the physician to warn still leave the physician liable for the consequences of a negligent warning.

The problem of warning third parties is exacerbated if a contact is a patient of the physician, commonly the case for family physicians. Physicians who treat families can obviate the confidentiality problem by asking patients to authorize sharing necessary medical information with other family members. This should be done on the first patient visit to prevent the violation of state laws requiring the physician to protect each individual patient’s confidential information. If the patient refuses, the physician must be careful not to violate his or her confidences. Even if the patient agrees, which she did in the Molien case, this is no protection against negligently inflicted harm.