Angel Ramos-Ligonio

By Aracely López-Monteon, Eric Dumonteil and Angel Ramos-Ligonio

Chagas disease, or American trypanosomiasis, is a parasitic disease of the Americas. In nature, Trypanosoma cruzi is transmitted through various species of triatomine bugs. However, non-vectorial transmission can also occur, such as transmission through blood products or by transplanting infected organs, by vertical transmission, and lately by oral route. Currently, Chagas disease affects approximately 6–7 million people worldwide, and the process of urbanization in Latin America and migratory movements from endemic countries have led to Chagas disease being diagnosed in areas where the infection is not endemic. There are several methods for diagnosing Chagas disease. Some of these are mostly used for research purposes, while others are used in routine diagnostic laboratories. According to the World Health Organization (WHO), chronic Chagas disease diagnosis is based on two serological techniques. To establish a definitive diagnosis, the results must be concordant. In the case of discordances, the WHO proposes repeating serology in a new sample, and if results remain inconclusive, a confirmatory test should be performed. This chapter shows aspects of the diagnosis of Chagas disease, which varies in its sensitivity and specificity, and its use depends on the geographical location, the available resources, and the purpose of the diagnosis.

Part of the book: Current Topics in Neglected Tropical Diseases

By Anette Hernández-Andrade, Joel Moo-Millan, Nohemi Cigarroa-Toledo, Angel Ramos-Ligonio, Claudia Herrera, Bruno Bucheton, Jean-Mathieu Bart, Vincent Jamonneau, Anne-Laure Bañuls, Christophe Paupy, David Roiz, Denis Sereno, Carlos N. Ibarra-Cerdeña, Carlos Machaín-Williams, Julián García-Rejón, Sébastien Gourbière, Christian Barnabé, Jenny Telleria, Bruno Oury, Frédérique Brenière, Frédéric Simard, Miguel Rosado, Philippe Solano, Eric Dumonteil and Etienne Waleckx

The implementation of sustainable control strategies aimed at disrupting the transmission of vector-borne pathogens requires a comprehensive knowledge of the vector ecology in the different eco-epidemiological contexts, as well as the local pathogen transmission cycles and their dynamics. However, even when focusing only on one specific vector-borne disease, achieving this knowledge is highly challenging, as the pathogen may exhibit a high genetic diversity and multiple vector species or subspecies and host species may be involved. In addition, the development of the pathogen and the vectorial capacity of the vectors may be affected by their midgut and/or salivary gland microbiome. The recent advent of Next-Generation Sequencing (NGS) technologies has brought powerful tools that can allow for the simultaneous identification of all these essential components, although their potential is only just starting to be realized. We present a metabarcoding approach that can facilitate the description of comprehensive host-pathogen networks, integrate important microbiome and coinfection data, identify at-risk situations, and disentangle the transmission cycles of vector-borne pathogens. This powerful approach should be generalized to unravel the transmission cycles of any pathogen and their dynamics, which in turn will help the design and implementation of sustainable, effective, and locally adapted control strategies.

Part of the book: Vector-Borne Diseases

By María de la Soldedad Lagunes-Castro, Aracely López-Monteon, Daniel Guzmán-Gómez and Angel Ramos-Ligonio

Neglected tropical diseases such as Chagas disease, dengue, Zika, chikungunya, and malaria cause millions of deaths each year and they are caused by a variety of pathogens whose diagnosis is very limited or subject to conventional testing, making a treatment less accessible, accurate and timely diagnosis for choosing their treatments. Traditional methods for pathogen detection have not been able to meet the growing need for diagnosis and control. The incorporation of new technologies such as next-generation sequencing (NGS) and digital PCR (dPCR) represent a better diagnostic possibility due to their ability to absolutely quantify pathogens with high selectivity and precision. Our planet is currently experiencing environmental changes of an unprecedented magnitude and rate, including climate change, globalized pollution, biodiversity loss, and land use changes, so neglected diseases require a comprehensive understanding of the ecology of vectors in the different eco-epidemiological contexts, as well as of the transmission cycles of pathogens and their transmission dynamics. In this sense, NGS and dPCR open a new panorama for a better understanding of these diseases with the aim of proposing new programs for their care.

Part of the book: New Advances in Neglected Tropical Diseases