Chagas disease control-surveillance in the Americas: the multinational initiatives and the practical impossibility of interrupting vector-borne Trypanosoma cruzi transmission

Abstract

Chagas disease (CD) still imposes a heavy burden on most Latin American countries. Vector-borne and mother-to-child transmission cause several thousand new infections per year, and at least 5 million people carry Trypanosoma cruzi . Access to diagnosis and medical care, however, is far from universal. Starting in the 1990s, CD-endemic countries and the Pan American Health Organization-World Health Organization (PAHO-WHO) launched a series of multinational initiatives for CD control-surveillance. An overview of the initiatives’ aims, achievements, and challenges reveals some key common themes that we discuss here in the context of the WHO 2030 goals for CD. Transmission of T. cruzi via blood transfusion and organ transplantation is effectively under control. T. cruzi , however, is a zoonotic pathogen with 100+ vector species widely spread across the Americas; interrupting vector-borne transmission seems therefore unfeasible. Stronger surveillance systems are, and will continue to be, needed to monitor and control CD. Prevention of vertical transmission demands boosting current efforts to screen pregnant and childbearing-aged women. Finally, integral patient care is a critical unmet need in most countries. The decades-long experience of the initiatives, in sum, hints at the practical impossibility of interrupting vector-borne T. cruzi transmission in the Americas. The concept of disease control seems to provide a more realistic description of what can in effect be achieved by 2030.

Interrogating the transmission dynamics of Trypanosoma cruzi (Trypanosomatida, Trypanosomatidae) by Triatoma venosa (Hemiptera: Reduviidae) after the elimination of vector transmission by Rhodnius prolixus in Boyacá eastern Colombia

“…However, T. venosa prevalence infection is lower than reported by other species of greater epidemiological relevance as R. prolixus (55.84) and T. dimidiata in Colombia (40% -70.31%) (Hernandez et al, 2016;Cantillo-Barraza et al, 2020a;Velazquez-Ortiz et al, 2022). On the other hand, similar prevalence values have been reported by other secondary species with an active role in the transmission cycle of T. cruzi following the primary vectors elimination, such as T. brasiliensis (2.8 -15.8%), T. pseudomaculata (0 -12.8%), T. sordida (0 -3.75%) and P. megistus (0 -11.6%) (Lima et al, 2012;Monteiro et al, 2013;Rojas de Arias et al, 2021).…”

“…These results, together with other studies conducted in the area by our working group since 2017 where infestation and colonization indices were lower, demonstrate that the reinfestation and colonization processes carried out by T. venosa are sustained and increasing . Similar eco-epidemiological situations regarding the increase in entomological indices have been described for T. dimidiata the major intradomiciliary vector of T. cruzi in Colombia Velaśquez-Ortiz et al, 2022), as well as, for T. brasiliensis, T. pseudomaculata, T. sordida and P. megistus in Southern Cone countries (Rojas de Arias et al, 2021).…”

“…Therefore, some international initiatives have been implemented INCOSUR (Initiative of the Southern Cone Countries), IPCAM (The Initiative of the Central American Countries and Mexico) and IPA (Initiative of the Andean Countries). Hence, contributing to the interruption of the transmission of T. cruzi in Latin America ( Rojas de Arias et al., 2021 ).…”

Simultaneous external and internal marking of Triatoma sordida nymphs: trace element efficacy and microgeographic dispersal in a peridomestic Brazilian Cerrado rural household

“…Chagas disease is still a major public health concern in Latin America [ 1 , 2 ]. Caused by the flagellate Trypanosoma cruzi and transmitted to humans by blood-feeding insects of the Triatominae subfamily [ 3 ], the most common way to acquire the infection is through contact of the contaminated feces of the insect vector with the host’s mucous membranes [ 4 , 5 ].…”

Subregional initiatives for Chagas disease. A path of technical cooperation, opened by the countries, as an approach to a neglected disease

“…These considerations are made in the sense of contributing to suggest and / or clarify some aspects that are relevant to such an important public health issue in the Region of the Americas, which have been requested by the Fundação Oswaldo Cruz- FIOCRUZ Publication Secretariat. First, we must congratulate the authors for the power of synthesis, which allows us to have an overview of these regional initiatives in the article: “Surveillance and control of Chagas disease in the Americas: regional initiatives and the practical impossibility of interrupting the Trypanosoma cruzi transmission vector”.…”