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The endemic, or nonvenereal, treponematoses are bacterial infections caused by close relatives of Treponema pallidum subspecies pallidum, the etiologic agent of venereal syphilis (Chap. 169). Yaws, pinta, and endemic syphilis are traditionally distinguished from venereal syphilis by mode of transmission, age of acquisition, geographic distribution, and clinical features. These infections are limited to rural areas of developing nations and are seen in developed countries only among recent immigrants from endemic regions. Our “knowledge” about the endemic treponematoses is based on observations by health care workers who have visited endemic areas; virtually no well-designed studies of the natural history, diagnosis, or treatment of these infections have been conducted. The treponemal infections are compared and contrasted in Table 170-1.

Table 170-1 Comparison of the Treponemes and Associated Diseases


The endemic treponematoses are chronic diseases transmitted by direct contact during childhood and, like syphilis, can cause severe late manifestations years after initial infection. In a World Health Organization (WHO)–sponsored mass eradication campaign from 1952 to 1969, more than 160 million people in Africa, Asia, and South America were examined for treponemal infections, and more than 50 million cases, contacts, and latent infections were treated. This campaign reduced the prevalence of active yaws from >20% to <1% in many areas. In recent decades, lack of focused surveillance and diversion of resources have resulted in documented resurgence of these infections in some regions. The estimated geographic distribution of the endemic treponematoses in the 1990s is shown in Fig. 170-1. The most recent WHO estimate (1997) suggested that there are 460,000 new cases per year and a prevalence of 2.5 million infected persons; during the subsequent decade, an increased incidence was documented in some countries. Areas of resurgent yaws morbidity include West Africa (Ivory Coast, Ghana, Togo, Benin), the Central African Republic, Nigeria, and rural Democratic Republic of Congo. The prevalence of endemic syphilis is estimated to be >10% in some regions of Ghana, Mali, Niger, Burkina Faso, and Senegal. In Asia and the Pacific Islands, reports suggest active outbreaks of yaws in Indonesia, Papua New Guinea, East Timor, Vanuatu, Laos, and Kampuchea. India actively renewed its focus on yaws eradication in 1996 ...

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