Other Major Trypanosomiasis

Abstract

In this chapter we will address Trypanosoma species of medical (Trypanosoma rangeli) or veterinary (T. vivax, T. evansi, T. equiperdum, T. congolense, and T. simiae) importance. Trypanosoma rangeli is a nonpathogenic trypanosome of the Latin American continent, which infects several mammalian species, including humans, and is transmitted through the bite of triatomine bugs (Chap. 18 has more details on the biology of triatomine bugs) mainly those belonging to the genus Rhodnius. Along with the controversial taxonomic position and the unknown life cycle in the vertebrate host, the sharing of antigenic determinants with T. cruzi (Chagas disease) and their sympatric distribution in an extensive geographical area are of major importance for diagnosis and epidemiology. Trypanosoma equiperdum may cause “dourine,” a sexually transmitted trypanosomiasis of equids. Trypanosoma evansi is the etiological agent of “Surra,” a disease of veterinary importance of horses, camels, and several livestock species worldwide, causing significant morbidity and mortality. The parasite is transmitted noncyclically by hematophagous flies in Africa, Asia, and South America and also by the common American vampire bat, Desmodus rotundus. Trypanosoma vivax is also transmitted mechanically to a variety of wild and domestic ungulate species in both American and African continents; in the last it is more commonly vectored by the tsetse flies, having a major impact on livestock production. Two other tsetse-transmitted trypanosomes are Trypanosoma congolense, the agent of “Nagana,” and Trypanosoma simiae, the agent of acute swine trypanosomiasis. In this chapter we address historical aspects of these parasites and their biology, focusing on the diseases and their relevance to humans and livestock.