Evolutionary ecology of Chagas disease; what do we know and what do we need?

• Published in: Evolutionary applications Vol. 11; no. 4; pp. 470 - 487
• Main Authors: Flores‐Ferrer, Alheli, Marcou, Olivier, Waleckx, Etienne, Dumonteil, Eric, Gourbière, Sébastien
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01-04-2018; Blackwell; John Wiley and Sons Inc; Wiley
• Subjects: adaptive dynamics; Chagas disease; Disease control; Disease transmission; domiciliation; Ecology; Emerging diseases; Evolution; generalist parasite; Human health and pathology; Infectious diseases; insecticide resistance; Insecticides; Life Sciences; local adaptation; Microbiology and Parasitology; microevolution; multihost virulence evolution; Parasitology; Pesticide resistance; Protozoa; Public health; Review and Syntheses; Spraying; Trypanosomatidae; Virulence; Argentina; Europe; Brazil; Bolivia; Australia; Peru; Latin America; Chaco region; Trypanosomatidae; local adaptation; microevolution; adaptive dynamics; domiciliation; generalist parasite; insecticide resistance; multihost virulence evolution
• ISSN: 1752-4571; 1752-4563; 1752-4571
• DOI: 10.1111/eva.12582

The aetiological agent of Chagas disease, Trypanosoma cruzi, is a key human pathogen afflicting most populations of Latin America. This vectorborne parasite is transmitted by haematophageous triatomines, whose control by large‐scale insecticide spraying has been the main strategy to limit the impact of the disease for over 25 years. While those international initiatives have been successful in highly endemic areas, this systematic approach is now challenged by the emergence of insecticide resistance and by its low efficacy in controlling species that are only partially adapted to human habitat. In this contribution, we review evidences that Chagas disease control shall now be entering a second stage that will rely on a better understanding of triatomines adaptive potential, which requires promoting microevolutionary studies and –omic approaches. Concomitantly, we show that our knowledge of the determinants of the evolution of T. cruzi high diversity and low virulence remains too limiting to design evolution‐proof strategies, while such attributes may be part of the future of Chagas disease control after the 2020 WHO's target of regional elimination of intradomiciliary transmission has been reached. We should then aim at developing a theory of T. cruzi virulence evolution that we anticipate to provide an interesting enrichment of the general theory according to the specificities of transmission of this very generalist stercorarian trypanosome. We stress that many ecological data required to better understand selective pressures acting on vector and parasite populations are already available as they have been meticulously accumulated in the last century of field research. Although more specific information will surely be needed, an effective research strategy would be to integrate data into the conceptual and theoretical framework of evolutionary ecology and life‐history evolution that provide the quantitative backgrounds necessary to understand and possibly anticipate adaptive responses to public health interventions.