Diversitat genètica de Trypanosoma cruzi a Espanya

Abstract

Chagas disease or American Trypanosomiasis, endemic in Latin America, is a zoonosis caused

by the hematic and flagellated protozoan Trypanosoma cruzi, affecting between six and seven

million people worldwide. The main transmission mechanism in Latin America is vector

transmission by insects of the subfamily Triatominae. In non-endemic countries, where the vector

is absent, as in the case of Spain, transmission routes are mainly based on blood transfusions,

organ transplants and the congenital route from mother to child during pregnancy or childbirth.

As a result of globalisation, there has been an increase in migration from Latin America to Europe,

particularly in Spain, which has led to an increase in the number of cases of Chagas disease.

Trypanosoma cruzi has a high intraspecific genetic diversity, which is classified into so-called

discrete typing units (DTUs): TcI-TcVI and TcBat (isolated from bats). DTUs have different

geographical distributions in endemic countries and circulate in three interrelated transmission

cycles. Information on the different DTUs present in Spain is very scarce, so the aim of this

Bachelor’s Thesis is to study the genetic diversity of T. cruzi in Spain, the European country with

the highest Chagas burden, and its implications for the implementation of effective public health

measures to control the disease.

A total of five articles were selected by searching bibliography on the Web of Science site using

a combination of keywords, followed by reading the titles and abstracts of the results obtained.

The limited number of studies investigating the genetic diversity of T. cruzi in Spain is confirmed.

A total of 303 patients with Chagas disease were studied in these publications, of whom 80.2%

(243/303) had DTUs characterised. The 87% of the patients included in the study are Bolivian

and were attended in the major Spanish cities, i.e., Barcelona and Madrid. TcV is the most

frequently identified DTU, which is logical as it is the most common strain in Bolivia and

predominates in peripheral blood. This information must be considered when applying

management plans to control the disease in Spain. Further studies are needed to improve the

resolution of methods for characterising T. cruzi DTUs