Selective primary health care: strategies for control of disease in the developing world. XX. Typhoid fever.

The incidence of typhoid fever remains unacceptably high in developing countries. Because Salmonella typhi is disseminated by carriers, there is an urgent need to increase the rate of detection of carriers and to decrease the risk they pose to their communities. In urban areas where sewage disposal is lacking or inadequate, public water supplies are contaminated and typhoid fever is common. The contamination of food by carriers is the second commonest route of infection. Water purification processes lead to a rapid decline in the incidence of the disease; thus, many developing countries hope to develop pure water supplies for all citizens by the end of this century. Until this important public health goal is achieved, the use of vaccine, especially in children, could cause a significant decrease in the incidence of typhoid fever. A new oral attenuated vaccine promises to be effective and safe.