The general ethical guidelines which apply to health care workers are drawn up by the appropriate regulatory bodies for each clinical discipline. In general they place an ethical and professional obligation on each health care worker not to engage in any behaviour which would put patients at risk. In the case of clinical staff who are, or who have reason to believe that they may be HIV positive, there is an ethical obligation on them to seek appropriate professional advice and adhere to any advice given by their doctor as to the nature and extent of any clinical work they may undertake, i.e. not to undertake exposure prone procedures which might pose a risk of infecting a patient.