The endemic treponematoses: not yet eradicated.

The endemic treponematoses which comprise yaws, endemic syphilis (bejel) and pinta constitute a group of potentially disabling and disfiguring infections which primarily afflict children in tropical and subtropical areas. Foci where these diseases are now endemic have a patchy distribution and are typically confined to underprivileged communities living in remote rural areas, with little or no access to health services and removed from the mainstream of socioeconomic development. A drastic decline in the prevalence of these infections was brought about by the implementation of mass treatment campaigns with penicillin under the technical guidance of WHO and with material support from UNICEF in the 1950s and 1960s. These worldwide campaigns against the endemic treponematoses halted disease transmission in many areas and held the promise of complete eradication if intensive surveillance could be continued for some time with the increasing involvement of the basic health services. National campaigns were so successful that relatively low priority was given to the preparation of the rural health services for this new task. The failure of many countries to integrate active control measures into the functions of the rural health services led to the gradual build-up and extension of treponemal reservoirs and the resurgence of foci of increased disease transmission particularly in communities where standards of hygiene and health care had remained low. In a number of former endemic foci only low-level transmission persisted; in a few areas disease prevalence increased dramatically to reach pre-campaign levels. The lack of technical and financial resources limited the success of renewed national control activities in the most affected areas. Today, with waning interest in these diseases confined to remote, and thus silent, population groups, and a decreasing ability of health staff to identify cases, data collected by countries need to be supplemented by information from other sources in order to arrive at a more valid assessment of the situation concerning the endemic treponematoses. Central and West Africa are most severely affected by the resurgence of the endemic treponematoses. In recent years a number of countries (e.g. Ghana, Côte d'Ivoire and Mali) have launched renewed control efforts, often combining yaws or endemic syphilis control with other public health programmes. In Central Africa itinerant pygmy groups are still highly affected by yaws and are an important source of infection for the sedentary population with which they come into contact. In Chad, Sudan and Ethiopia, there is some evidence of persistent foci of endemic treponematoses; the epidemiological situation in Southern Africa is not well established.(ABSTRACT TRUNCATED AT 400 WORDS)