The tremendous success which has been achieved in the control of virus diseases such as smallpox, poliomyelitis, measles, and rubella by the use of vaccines has blinded many people to the importance of traditional public health approaches. Experience in many industrialized countries has shown that hepatitis A can be controlled and eliminated when economic conditions and living conditions are favorable. Good personal hygiene has been shown to reduce the risk of transmission of enteric infections and is particularly important in attempts to reduce transmission of hepatitis A. Passive immunization is usually recommended in the face of common-source, water- or food-borne epidemics; however, by the time the source of infection has been identified, it is usually too late for human normal immunoglobulin to be effective. Prevention of water-borne infections is largely an exercise in engineering; the same practices which have virtually eliminated water-borne bacterial infections have proved effective in limiting the spread of enterically transmitted viral infections.