Trypanosoma (Duttonella) vivax and Typanosomosis in Latin America: Secadera/Huequera/Cacho Hueco

Abstract

The disease caused by T. vivax is commonly called Nagana in Africa and “secadera/cachera/cacho hueco/huequera” in parts of South America. This chapter will focus on the disease and its causative agent, reviewing new diagnostic methods, economic impact, chemotherapy, phylogenetic analysis of T. vivax isolates from Africa and South America, epidemiological studies in Latin America, and the analysis of recent genomic and transcriptomic data. T. vivax has a significant economic impact on livestock production in sub-Saharan Africa, where it is transmitted by the tsetse fly, and elsewhere in the African continent and in Central and South America, where it is transmitted mechanically. T. vivax is enzootic in most Latin American countries, and recurrent epizootic outbreaks causing significant morbidity and mortality have been reported over the past decades. Several significant landmarks in T. vivax research have been achieved in the last 2 years, including the publication of high-quality draft genome sequences and partial RNA-seq data for the Y486 strain, as well as the complete transcriptome of the LIEM-176 strain. Comparative analysis of the T. vivax, T. brucei, and T. congolense genomes revealed important differences in the surface proteins responsible for host immune response evasion in these species, and data from the T. vivax LIEM-76 transcriptome support the participation of other surface proteins, in addition to the VSG, in immune evasion. Proteins of the trans-sialidase family have been identified as important virulence factors that catalyze the desialylation of the host red blood cell, which in turn triggers the erythrophagocytosis that results in anemia. These findings will provide novel tools to tackle the challenge of controlling animal trypanosomosis caused by T. vivax in the developing world.