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

Abstract

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 Mexicos 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.

Comparing the evolutionary dynamics of predominant SARS-CoV-2 virus lineages co-circulating in Mexico

“…Our results further revealed several clades belonging to different virus lineages distributed within the south region of the country, suggesting that this area has played a key role in the spread of SARS-CoV-2. Of notice, such pattern is comparable to what has been observed for arboviral epidemics in Mexico ( Gutierrez et al, 2023 ; Thézé et al, 2018 ). Despite differences in the transmission mechanism between SARS-CoV-2 and arboviruses, we speculate that common epidemiological patterns may have emerged in Mexico due to the dependence of vector populations on human behavior and mobility patterns ( Gutierrez et al, 2023 ; Thézé et al, 2018 ).…”

“…Of notice, such pattern is comparable to what has been observed for arboviral epidemics in Mexico ( Gutierrez et al, 2023 ; Thézé et al, 2018 ). Despite differences in the transmission mechanism between SARS-CoV-2 and arboviruses, we speculate that common epidemiological patterns may have emerged in Mexico due to the dependence of vector populations on human behavior and mobility patterns ( Gutierrez et al, 2023 ; Thézé et al, 2018 ). Virus transmission rates may also vary within specific regions due to population density coupled with social factors (for example, unregulated migration across borders).…”

A Highly Sensitive Molecular Technique for RNA Virus Detection

“…One report shows thirteen introductions for the virus into Mexico, with half of them leading to persistent transmission. However, CHIKV only evidenced a single transmission event from the Asian lineage, which was then followed by the virus's spread across the Central Caribbean and South, Central, and North America [49].…”