135 Syphilis, Nonvenereal
Nonvenereal syphilis has apparently occurred in many forms and places, and one interpretation of this phenomenon is that venereal syphilis can revert to nonvenereal transmission.
Others see it as a discrete disease with its own etiologic epidemiology. The most common and enduring form of the disease is called bejel; it occurs in the arid regions of North Africa, the Middle East, and the eastern Mediterranean, and seems to have antedated venereal syphilis as a disease entity by a considerable period of time. It is one of the endemic treponematoses caused by spirochetes, bacteria belonging to the genus Treponema. Other diseases in this group are yaws and pinta. Like yaws, bejel is essentially a disease of children, although those who escape the illness as children are likely to acquire it as adults, often from their own children. Its specific cause seems to be Treponema pallidum, the same agent as that of syphilis, although it may be a treponema intermediary between T. pallidum and Treponema pertenue, the agent of yaws. Although treponemal disease has been transferred experimentally to animals, humans appear to be the only natural reservoir.Etiology, Epidemiology, and Clinical Manifestations
Because the treponemas that cause yaws, nonvenereal syphilis, pinta (an American disease), and syphilis are morphologically and serologically indistinguishable, it is believed that at least the Old World diseases may represent an evolutionary continuum running from south to north. Yaws, thought to be the oldest, spreads by skin-to-skin contact and flourishes in the hot and moist regions of Africa south of the Sahara where individuals have historically worn little clothing. Syphilis, by contrast, seems to be the newest of the treponematoses. Venereal transmission allows it to spread among peoples of colder climates whose clothing would frustrate skin-to-skin transmission.
Bejel or nonvenereal syphilis seems to be intermediate between the two both bacteriologically and geographically. It has been conceived of as yaws modified by a desert environment, and as juvenile, nonvenereal syphilis. It is not transmitted congenitally. The disease spreads from child to child in dry, mostly rural areas where a lack of cleanliness facilitates transmission. The spirochetes of nonvenereal syphilis, like those of yaws and syphilis, perish in the presence of atmospheric oxygen, soaps, detergents, and antiseptics, and are very sensitive to drying. T. pallidum is able to penetrate mucous membranes, but intact skin presents it with a formidable barrier. The primary lesion is often in the region of the mouth, probably the result of sharing drinking vessels or eating utensils or by direct mouth-to- mouth contact. It can also spread from direct nonsex- ual contact, and flies, lice, and fleas may also have a role in transmission.
The stages of the disease - primary, secondary, and late or tertiary — are not so pronounced as are those of syphilis. In the case of bejel, the primary lesion is soon followed by the appearance of moist papules in skin folds and by drier lesions on the trunk and extremities. Late lesions, when they occur, can be ugly. Huge ulcers may form, and ulceration of the palatal and nasal bones can cause them to erode. Other possible physical symptoms are changes in pigment distribution and in the deformity of other bones, especially long bones such as the tibia.
Immunology and Pathology
Although pinta has been given experimentally to syphilitics, a high degree of cross-immunity between T. pallidum and T. pertenue seems to exist. Thus, one who has suffered nonvenereal syphilis is not only safe from another attack but is also at least partially protected against syphilis and yaws.
The pathogenic mechanisms in this and other treponemal infections are not yet fully understood. The pathogens do not kill cells, and they produce no known toxic substances.
Thus it would seem that much of the pathology stems from the immune response of the host. Nonvenereal syphilis or bejel is similar to yaws in some respects, among them, juvenile acquisition, an absence of chancres, and congenital transmission. Moreover, both diseases rarely involve the cardiovascular and the central nervous systems. Yet nonvenereal syphilis resembles syphilis in its affinity for the mucous membranes, and in many of its pathological aspects. And, like syphilis, it occurs outside of the tropics. Finally, the usual serologic tests for syphilis are positive in nonvenereal syphilis.History and Geography
The story of bejel is intimately bound up with the work of Ellis Herndon Hudson, a physician and medical historian. He first described the disease in 1928, after observing it among the Bedouin Arabs. In 1937 he summarized all available information on this form of nonvenereal syphilis and stated that the Arab word bejel had been introduced into the literature to distinguish this nonvenereal and endemic form of syphilis from the venereal variety.
In 1946 he emphasized the intermediary nature of bejel between yaws and syphilis and presented a Unitarian concept of treponematosis, which stressed the evolutionary relationship among yaws, endemic syphilis, pinta, and venereal syphilis, and held that they were all varieties of a single disease caused by one parasite, T. pallidum.
Not all agree. Some, for example, argue that the various treponemal infections are due to changes in the treponemal strains themselves - to mutations. Others feel that the treponemal infections are essentially different diseases, caused by different parasites, whereas E. I. Grin has advanced the argument that venereal syphilis has reached villages (in the Sudan at least) from towns, only to become endemic (i.e., nonvenereal) in a rural environment.
There is, however, general agreement that nonvenereal syphilis is a very old disease. Hudson argues that it flourished in the villages that first appeared during the early Neolithic period and that it was the “venereal leprosy” of the Middle Ages, the “sibbens” of Scotland, the “button-scurvy” of Ireland, the radesyge of the Scandinavian countries, and the skerljeυo of the Balkans.
Apparently, it never took root in the Americas.Because endemic syphilis fades in the face of the cleanliness associated with civilization, and because of the high efficacy of penicillin as a cure, the disease has withdrawn from most of Europe. But the bejel of the Middle East has its counterparts in the njoυera of Rhodesia, the dichuchwa that plagues the Bushmen, and the irkintia of the Australian aborigines.
Kenneth F. Kiple
Bibliography
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