Methods for the surveillance of endemic treponematoses and sero-immunological investigations of "disappearing" disease.

Although the treatment of whole communities with long-acting penicillin for the control of endemic treponematoses of childhood during the past twenty years has led to a remarkable initial regression of disease, early clinical yaws has not yet been eliminated in large endemic areas and the elimination of early childhood syphilis has been observed in favourable environmental conditions in a single instance only. In most areas, transmission of infection continues at varying levels and recrudescence or periodic focal outbreaks continue to occur.Mass penicillin campaigns have been undertaken in 46 countries and up to the end of 1970 some 160 million people had been examined and some 50 million clinical cases, latent cases, and contacts had been treated. In the past few years, sero-epidemiological studies of the changing pattern of disease and infection have become possible and methods for long-term surveillance of endemic treponematoses have been developed. The application of these methods to the study of "disappearing" disease is described, particularly with regard to yaws but also to childhood syphilis and pinta.