Trypanosoma cruzi infection in the human population of the Bolivian Chaco. Four serosurveys over a 26-year period (1987-2013)

Introduction: Chagas disease (CD) remains a public health concern in several Latin American countries. At global level, Bolivia has the highest CD burden and the Chaco region, in the southeast of the country, is the most affected area. We report the results of four serosurveys for Trypanosoma cruzi antibodies, carried out approximately ten years apart from each other, during the lapse 1987-2013, in different localities of the Bolivian Chaco. Methodology: Four cross-sectional surveys were conducted in various localities, mostly rural, of the Bolivian Chaco, during the period 1987-2013. Results: Although a reliable analysis of CD epidemiological trend is challenging, a partial reduction of anti-T. cruzi seroprevalence over the past four decades in the Bolivian Chaco may be assumed. In particular, in 1987 the exposure to T. cruzi in rural setting was universal since the first years of life, while it resulted gradually lower and age-dependent thereafter. Moreover, T. cruzi seroprevalence among women of reproductive age (15-45 years) has been persistently high in rural areas. Conclusions: T. cruzi transmission is still active and CD remains a concern throughout the Bolivian Chaco. More efforts are needed in order to achieve a sustainable interruption of vector-borne CD transmission in this area.