{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2025,12,20]],"date-time":"2025-12-20T12:28:48Z","timestamp":1766233728788,"version":"3.48.0"},"posted":{"date-parts":[[2025,12,18]]},"group-title":"Epidemiology","reference-count":48,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2025,12,18]],"date-time":"2025-12-18T00:00:00Z","timestamp":1766016000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2025,12,18]]},"abstract":"<jats:p>During an outbreak, infectious disease can spread among populations through host movement, potentially fueling local outbreaks with their own epidemiological dynamics. However, it is difficult to know how often infections between populations are transmitted by diseased travelers infecting healthy residents when abroad, rather than by diseased residents infecting healthy travelers, who later return home with the new pathogen. In this paper, we introduce a phylogeographic model where pathogens spread through visitor dynamics, whereby hosts \u201cvisit\u201d other populations for short trips before returning home. To do so, we used the stationary properties of an epidemiological compartment model with visitor dynamics to construct an approximation that is statistically accurate and computationally tractable for phylogenetic modeling. We applied our model to empirical infection data and travel statistics from the European SARS-CoV-2 pandemic. Inference under our model suggests that, in the early stages of the outbreak, SARS CoV-2 was more often \u201cpulled\u201d into new countries by returning travelers than \u201cpushed\u201d into new countries by visitors from the source country. Estimates of host movement\u2013related parameter values under our visitor model suggest that competing migration models, with trips of indefinite length, may underestimate the magnitude of outbreaks caused by visitors. This study emphasizes the importance of carefully incorporating host movement dynamics into such models.<\/jats:p>\n                <jats:sec>\n                  <jats:title>Significance Statement<\/jats:title>\n                  <jats:p>Viral infections can spread among distinct locations by human travel. Being able to identify the source of a local outbreak \u2013 whether triggered by infected visitors or individuals returning home \u2013 is crucial. Here, we designed a phylogenetic model for modeling infectious disease transmission in spatially structured populations, explicitly accounting for realistic host movement. By accounting for \u201cshort trips\u201d, our model can help inform travelrelated strategies for containing outbreaks.<\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2025.12.16.25342415","type":"posted-content","created":{"date-parts":[[2025,12,18]],"date-time":"2025-12-18T21:15:20Z","timestamp":1766092520000},"source":"Crossref","is-referenced-by-count":0,"title":["Inferring epidemiological parameters under an infectious phylogeography model with visitor dynamics"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2527-4361","authenticated-orcid":false,"given":"Albert C.","family":"Soewongsono","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ammon","family":"Thompson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8672-6966","authenticated-orcid":false,"given":"Michael J.","family":"Landis","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"54368","reference":[{"issue":"1","key":"2025122004250571000_2025.12.16.25342415v1.1","doi-asserted-by":"crossref","first-page":"3319","DOI":"10.1038\/s41467-022-30642-8","article-title":"Disease-economy trade-offs under alternative epidemic control strategies","volume":"13","year":"2022","journal-title":"Nature communications"},{"key":"2025122004250571000_2025.12.16.25342415v1.2","doi-asserted-by":"publisher","DOI":"10.1038\/nature22040"},{"key":"2025122004250571000_2025.12.16.25342415v1.3","doi-asserted-by":"crossref","first-page":"e249","DOI":"10.1017\/S0950268820002423","article-title":"A predictive model for covid-19 spread\u2013with application to eight US states and how to end the pandemic","volume":"148","year":"2020","journal-title":"Epidemiology & Infection"},{"issue":"1","key":"2025122004250571000_2025.12.16.25342415v1.4","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1038\/s42005-021-00570-y","article-title":"Optimal, near-optimal, and robust epidemic control","volume":"4","year":"2021","journal-title":"Communications Physics"},{"key":"2025122004250571000_2025.12.16.25342415v1.5","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-021-04069-y"},{"key":"2025122004250571000_2025.12.16.25342415v1.6","doi-asserted-by":"publisher","DOI":"10.1007\/BF00178324"},{"key":"2025122004250571000_2025.12.16.25342415v1.7","doi-asserted-by":"publisher","DOI":"10.1137\/s0036144500371907"},{"issue":"772","key":"2025122004250571000_2025.12.16.25342415v1.8","doi-asserted-by":"crossref","first-page":"700","DOI":"10.1098\/rspa.1927.0118","article-title":"A contribution to the mathematical theory of epidemics","volume":"115","year":"1927","journal-title":"Proceedings of the royal society of london. Series A, Containing papers of a mathematical and physical character"},{"key":"2025122004250571000_2025.12.16.25342415v1.9","doi-asserted-by":"publisher","DOI":"10.1093\/molbev\/msx176"},{"issue":"12","key":"2025122004250571000_2025.12.16.25342415v1.10","doi-asserted-by":"crossref","first-page":"1829","DOI":"10.1038\/s41591-020-1104-0","article-title":"Crowding and the shape of COVID-19 epidemics","volume":"26","year":"2020","journal-title":"Nature medicine"},{"key":"2025122004250571000_2025.12.16.25342415v1.11","doi-asserted-by":"publisher","DOI":"10.1006\/tpbi.1994.1032"},{"key":"2025122004250571000_2025.12.16.25342415v1.12","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0501226102"},{"key":"2025122004250571000_2025.12.16.25342415v1.13","doi-asserted-by":"publisher","DOI":"10.1016\/j.jtbi.2009.02.016"},{"key":"2025122004250571000_2025.12.16.25342415v1.14","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2007488118"},{"issue":"2","key":"2025122004250571000_2025.12.16.25342415v1.15","doi-asserted-by":"crossref","first-page":"veab052","DOI":"10.1093\/ve\/veab052","article-title":"Phylodynamics reveals the role of human travel and contact tracing in controlling the first wave of COVID-19 in four island nations","volume":"7","year":"2021","journal-title":"Virus evolution"},{"key":"2025122004250571000_2025.12.16.25342415v1.16","doi-asserted-by":"publisher","DOI":"10.1126\/science.1090727"},{"key":"2025122004250571000_2025.12.16.25342415v1.17","doi-asserted-by":"publisher","DOI":"10.1098\/rstb.1995.0088"},{"issue":"33","key":"2025122004250571000_2025.12.16.25342415v1.18","doi-asserted-by":"crossref","first-page":"eadk7623","DOI":"10.1126\/sciadv.adk7623","article-title":"Early detection of highly transmissible viral variants using phylogenomics","volume":"10","year":"2024","journal-title":"Science Advances"},{"issue":"3","key":"2025122004250571000_2025.12.16.25342415v1.19","doi-asserted-by":"crossref","first-page":"e1002947","DOI":"10.1371\/journal.pcbi.1002947","article-title":"Viral phylodynamics","volume":"9","year":"2013","journal-title":"PLoS computational biology"},{"key":"2025122004250571000_2025.12.16.25342415v1.20","doi-asserted-by":"crossref","first-page":"e1000520","DOI":"10.1371\/journal.pcbi.1000520","article-title":"Bayesian phylogeography finds its roots","volume":"5","year":"2009","journal-title":"PLoS Computational Biology"},{"key":"2025122004250571000_2025.12.16.25342415v1.21","doi-asserted-by":"publisher","DOI":"10.1093\/ve\/vez030"},{"key":"2025122004250571000_2025.12.16.25342415v1.22","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2012008118"},{"issue":"1","key":"2025122004250571000_2025.12.16.25342415v1.23","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1093\/emph\/eoz001","article-title":"The origins of the great pandemic","volume":"2019","year":"2019","journal-title":"Evolution, Medicine, and Public Health"},{"key":"2025122004250571000_2025.12.16.25342415v1.24","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pbio.3002914"},{"key":"2025122004250571000_2025.12.16.25342415v1.25","doi-asserted-by":"crossref","unstructured":"J\u00e9r\u00e9mie Scire , Jo\u00eblle Barido-Sottani , Denise K\u00fchnert , Timothy G Vaughan , and Tanja Stadler . Improved multi-type birth-death phylodynamic inference in BEAST 2. BioRxiv, pages 2020\u201301, 2020.","DOI":"10.1101\/2020.01.06.895532"},{"key":"2025122004250571000_2025.12.16.25342415v1.26","doi-asserted-by":"publisher","DOI":"10.1093\/molbev\/msz106"},{"key":"2025122004250571000_2025.12.16.25342415v1.27","doi-asserted-by":"publisher","DOI":"10.1093\/molbev\/msw064"},{"key":"2025122004250571000_2025.12.16.25342415v1.28","doi-asserted-by":"publisher","DOI":"10.3201\/eid2605.200146"},{"issue":"7812","key":"2025122004250571000_2025.12.16.25342415v1.29","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1038\/s41586-020-2284-y","article-title":"Population flow drives spatio-temporal distribution of COVID-19 in China","volume":"582","year":"2020","journal-title":"Nature"},{"key":"2025122004250571000_2025.12.16.25342415v1.30","doi-asserted-by":"publisher","DOI":"10.1007\/s11434-011-4598-5"},{"issue":"1","key":"2025122004250571000_2025.12.16.25342415v1.31","doi-asserted-by":"crossref","first-page":"4605","DOI":"10.1038\/s41467-025-59757-4","article-title":"Competition between transmission lineages mediated by human mobility shapes seasonal influenza epidemics in the US","volume":"16","year":"2025","journal-title":"Nature Communications"},{"issue":"1","key":"2025122004250571000_2025.12.16.25342415v1.32","doi-asserted-by":"crossref","first-page":"5110","DOI":"10.1038\/s41467-020-18877-9","article-title":"Accommodating individual travel history and unsampled diversity in bayesian phylogeographic inference of SARS-CoV-2","volume":"11","year":"2020","journal-title":"Nature communications"},{"key":"2025122004250571000_2025.12.16.25342415v1.33","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0906910106"},{"key":"2025122004250571000_2025.12.16.25342415v1.34","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2213913120"},{"key":"2025122004250571000_2025.12.16.25342415v1.35","doi-asserted-by":"publisher","DOI":"10.1093\/molbev\/mst057"},{"key":"2025122004250571000_2025.12.16.25342415v1.36","doi-asserted-by":"publisher","DOI":"10.1093\/sysbio\/syw021"},{"key":"2025122004250571000_2025.12.16.25342415v1.37","unstructured":"Mike R. May and Xavier Meyer . TensorPhylo (unreleased), 2020. Accessed: 2020-10-27."},{"issue":"8","key":"2025122004250571000_2025.12.16.25342415v1.38","doi-asserted-by":"crossref","first-page":"e1005421","DOI":"10.1371\/journal.pgen.1005421","article-title":"New routes to phylogeography: a Bayesian structured coalescent approximation","volume":"11","year":"2015","journal-title":"PLoS genetics"},{"key":"2025122004250571000_2025.12.16.25342415v1.39","doi-asserted-by":"publisher","DOI":"10.1093\/sysbio\/syw054"},{"key":"2025122004250571000_2025.12.16.25342415v1.40","doi-asserted-by":"publisher","DOI":"10.1093\/sysbio\/syu015"},{"key":"2025122004250571000_2025.12.16.25342415v1.41","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1109314108"},{"key":"2025122004250571000_2025.12.16.25342415v1.42","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2021.03.052"},{"key":"2025122004250571000_2025.12.16.25342415v1.43","doi-asserted-by":"publisher","DOI":"10.1016\/j.jtbi.2013.08.032"},{"key":"2025122004250571000_2025.12.16.25342415v1.44","doi-asserted-by":"publisher","DOI":"10.1001\/jama.1996.03530280057037"},{"key":"2025122004250571000_2025.12.16.25342415v1.45","doi-asserted-by":"publisher","DOI":"10.2307\/1936609"},{"key":"2025122004250571000_2025.12.16.25342415v1.46","doi-asserted-by":"publisher","DOI":"10.2307\/1941192"},{"issue":"10","key":"2025122004250571000_2025.12.16.25342415v1.47","doi-asserted-by":"crossref","first-page":"e76863","DOI":"10.1371\/journal.pone.0076863","article-title":"Interactions between social structure, demography, and transmission determine disease persistence in primates","volume":"8","year":"2013","journal-title":"PLoS One"},{"key":"2025122004250571000_2025.12.16.25342415v1.48","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1613616114"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2025.12.16.25342415","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,20]],"date-time":"2025-12-20T12:25:15Z","timestamp":1766233515000},"score":1,"resource":{"primary":{"URL":"http:\/\/medrxiv.org\/lookup\/doi\/10.64898\/2025.12.16.25342415"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,18]]},"references-count":48,"URL":"https:\/\/doi.org\/10.64898\/2025.12.16.25342415","relation":{},"subject":[],"published":{"date-parts":[[2025,12,18]]},"subtype":"preprint"}}