During the course of our work a number of bioethical questions have arisen It has been recognized that hepatitis B may be transmitted by means other than transfusion, i.e. by contact, fecal-oral spread, insects, etc. The current estimate is more than 1 million carriers in the USA and 375 million carriers world wide. This has led to a situation which may be unique in medicine. Although some carriers may be able to transmit hepatitis by means other than blood transfusion, this is probably not true for many (or most) carriers. It is now known that HBV can be transmitted sexually, from mothers to children by the use of "dirty needles", and by other means. The bioethical problems that are raised from the studies of hepatitis carriers can be viewed as a conflict between public health interests and individual liberty. When the risk to the public is clear, and the restrictions on personal liberties are small, there is little problem in arriving at appropriate regulations. For example, the transfusion of blood containing hepatitis B antigen is a disadvantage to the patient recipient and it has been stopped. The denial of the right to donate blood is not a great infringement of personal activity and the individuals concerned and society have agreed to accept this moderate restriction. The problems raised by person-to-person transmission are more difficult.

The AIDS epidemic started after the publication of this paper. The ethical problems associated with the carrier state have been a major concern to public health authorities, the HIV carriers, and others.