ON THE ORIGIN OF THE HUMAN TREPONEMATOSES (PINTA, YAWS, ENDEMIC SYPHILIS AND VENEREAL SYPHILIS)

A close relationship between the four human treponematoses is suggested by their clinical and epidemiological characteristics and by such limited knowledge of the treponemes as there is at present. No treponeme of this group (except for that of the rabbit) is known other than in man, but the human treponemes probably arose long ago from an animal infection. The long period of infectiousness of pinta suggests that it may have been the earliest human treponematosis. It may have been spread throughout the world by about 15 000 B.C., being subsequently isolated in the Americas when the Bering Strait was flooded. About 10 000 B.C. in the Afro-Asian land mass environmental conditions might have favoured treponeme mutants leading to yaws; from these, about 7000 B.C., endemic syphilis perhaps developed, to give rise to venereal syphilis about 3000 B.C. in south-west Asia as big cities developed there. Towards the end of the fifteenth century A.D. a further mutation may have resulted in a more severe venereal syphilis in Europe which, with European exploration and geographical expansion, was subsequently carried throughout the then treponemally uncommitted world. These suggestions find some tentative support in climatic changes which might have influenced the selection of those treponemes which still survive in humid or arid climates. Venereal transmission would presumably remove the treponeme from the direct influence of climate. The author makes a plea for further investigation of many aspects of this subject while this is still possible.

Endemic treponematoses in the Sudan. A report on a survey

It has been recognized for many years that Africa contains a very large reservoir of endemic treponematoses, and all information on the foci of infection contributes to the goal of elimination of these diseases as public health problems.In 1959 the author undertook, at the request of the Sudanese Government, a number of pilot surveys in areas where the endemic treponematoses were thought to be prevalent. From the information acquired in these surveys and from official data it is clear that yaws and endemic syphilis are a major problem of public health in the Sudan. It is estimated that some 5 million people in six provinces are at risk, and that about 20% of the population in an area of 1 543 000 km(2) suffer from one or the other of the two diseases in the active clinical stage.In some localities yaws was found to be prevalent, and in some endemic syphilis. In others, the two infections were seen to co-exist; and it is suggested that, since little is known of the extent to which one infection confers protection against the other, the situation in the Sudan provides a perhaps unique opportunity for scientific studies of the interrelationship of these two diseases and their possible relationship with venereal syphilis.Another interesting finding, worthy of further investigation, was that mucous lesions occurred only in areas where syphilis was present and not where yaws alone was prevalent.