Genotypic characterization of a Plasmodium falciparum outbreak in Urbina, north coast of Ecuador (2023 –2024): diversity and population structure

Malaria is an important problem for public health and is one of the leading causes of morbidity and mortality worldwide. In Ecuador, malaria is endemic to the north coastal areas and the Amazon region, particularly in border areas where transmission rates are higher than in the rest of the territory. Ecuador has been in elimination phase of malaria since 2012; however, despite notable progress, it continues to face substantial challenges in achieving its elimination goal. Between November 2023 and March 2024, an outbreak of Plasmodium falciparum occurred in Urbina parish (north coast of Ecuador). This study analyzed the origin, distribution, and genotypic polymorphisms of P. falciparum in infections circulating between 2021 and 2024. The population structure and genetic diversity of the outbreak isolates (2023– 2024), and other isolates collected in northwestern Ecuador between 2021 and 2024, were characterized, using microsatellites and multiplex amplicon sequencing. The results show important changes in the population structure of P. falciparum in Ecuador over the years, characterized by increased clonality, high genetic differentiation, and low genetic flow. Three genetic groups circulate in the northern coast of Ecuador, some similar to previously described lineages in the region. A new predominantly clonal outbreak was observed in Urbina parish between 2023 and 2024, unrelated to previously characterized parasites in Ecuador. Identity by descent analysis confirmed that this outbreak (Urbina; 2023 – 2024) is unrelated to previously characterized lineages, while other samples collected in 2021 and 2022 were closely related to lineages previously identified in Ecuador (2013 – 2016 and 2019 – 2020) and Colombia (2008 – 2009). These results show the continuous circulation of specific groups with strong genetic connections in the region, suggesting the persistence of some lineages over time, as well as the introduction of a new group from Colombia. Population genetics studies allow the determination of the origin or introduction, transmission patterns, and genotypic polymorphisms of circulating lineages. Consequently, the results of this study underline the importance of molecular surveillance, border control, and cooperation between neighboring countries to achieve malaria elimination.

• 主要作者: Zapata Berrones, Karina Elizabeth (author)
• 格式: masterThesis
• 出版: 2025
• 主題: AMPLseq; Malaria; Plasmodium falciparum; Malaria falciparum; Genética de población; Microsatélites (Genética); Epidemias
• 在線閱讀: https://repositorio.puce.edu.ec/handle/123456789/45741