Convergent trends and spatiotemporal patterns of arboviruses in Mexico and Central America

Background Arboviruses cause both seasonal epidemics (e.g. dengue viruses, DENV) and emerging outbreaks (e.g. chikungunya and Zika viruses, CHIKV and ZIKV) with a significant impact on global health. These viruses share mosquito vector species, often infecting the same host population within overlapping geographic regions. Thus, comparative analyses of their evolutionary and epidemiological dynamics across spatial and temporal scales could reveal convergent transmission trends. Methodology/Principal Findings Focusing on Mexico as a case study, we generated CHIKV, DENV-1 and DENV-2 genomes from an epidemiological surveillance-derived historical sample collection, and analysed them together with longitudinally-collected genome and epidemiological data from the Americas. Arboviruses endemically circulating within the country were found to be introduced multiple times from lineages predominantly sampled from the Caribbean and Central America. For CHIKV, at least thirteen introductions were inferred over a year, with six of these leading to persistent transmission chains. For both DENV-1 and DENV-2, at least seven introductions were inferred over a decade. Conclusions/Significance Our results suggest that CHIKV, DENV-1 and DENV-2 in Mexico share similar evolutionary and epidemiological trajectories. The southwest region of the country was determined to be the most likely location for viral introductions from abroad, with a subsequent spread into the Pacific coast towards the north of Mexico. The virus diffusion patterns observed across the country are likely driven by multiple factors, including mobility linked to human migration from Central towards North America. Considering Mexico‘s economic role and geographic positioning displaying a high human mobility across borders, our results prompt the need to better understand the role of anthropogenic factors in the transmission dynamics of arboviruses, particularly linked to land-based human migration. AUTHOR SUMMARY Mexico is endemic to several mosquito-borne viruses relevant to global health, and ranks within the top five countries in the Americas that report the highest case numbers. Our study provides a general overview of arbovirus introduction, spread and establishment patterns in North and Central America, and should be of interest to both local health and global authorities. Moreover, it sets to explore the paradigm of convergence at different scales in independent virus populations, represented by comparable epidemiological and evolutionary trends in arboviruses sharing ecological niches. Our results represent important advances in the study of mosquito-borne viruses listed as a threat to global health, specifically applied to key countries within the developing world ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research was funded by United Kingdom Research & Innovation office and the Department of Health and Social Care using UK Aid funding, managed by the BBSRC/EPSRC/NIHR 971557 (to A.R.S). The views expressed in this publication are those of the author(s) and not necessarily those of the Department of Health and Social Care. The project was further funded by the John Fell OUP Research Fund Award 0008724 (Project ATD00390 to MEZ and MUGK). SCH is supported by a Wellcome Trust Sir Henry Wellcome Postdoctoral Fellowship (220414/Z/20/Z). OGP and MUGK acknowledges support of the Oxford Martin School. MUGK and JT acknowledge support from the European Union Horizon 2020 project MOOD (#874850). MEZ is supported by Leverhulme Trust ECR Fellowship (ECF-2019-542). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: ETHICS STATEMENT We declare that under the authority of the ethics committee 'Comite de etica e investigacion del ICSa UAEH' (Instituto de Ciencias de la Salud/Universidad Autonoma del Estado de Hidalgo, Mexico), our study has been granted ethical approval registered under the following number: ICSa 57/2023 (signed by the president Dra. Itzia Maria Cazares Palacios on March 6th 2023). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Virus sequences generated in this study are provided as alignments in Supplementary Data 1 (CHIKV), 2 (DENV-1) and 3 (DENV-2). GenBank Accession numbers for the publicly available sequences used in this study are listed in the Supplementary Data 4.