Projecting international mpox spread in Asia: ongoing global health risk

The global mpox outbreak affected many Asian countries in 2023, following a sustained local transmission in Japan. Given the large population sizes and limited vaccine rollout in Asia, the potential risk of global mpox reemergence arising from Asia is of concern. Using a mathematical model incorporating heterogeneous sexual networks among MSM, calibrated to incidence data in Japan, we projected the patterns of international mpox spread across 42 Asian countries. Our simulations highlight countries at a high risk of mpox introductions, many of which were low- and middle-income countries (LMICs) in South-eastern Asia. Our analysis also suggests a shifting focus of importation risk from Eastern Asia to South-eastern Asia, and subsequently to Central, Southern and Western Asia, which roughly coincided with the observed spread patterns in 2023. Global cooperation and support are warranted, especially for LMICs with an elevated risk of mpox introduction, to minimise the risk of continued circulation in Asia and beyond. ### Competing Interest Statement FM received research funding from AdvanSentinel Inc. ### Funding Statement This study is funded by Japan Science and Technology Agency (JST; grant number JPMJPR22R3, to AE) and Japan Agency for Medical Research and Development (JP223fa627004). TRA is supported by the Rotary Foundation (GG2350294) and the Nagasaki University World-leading Innovative & Smart Education (WISE) Program of the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). S-mJ is supported by the Centers for Disease Control and Prevention Safety and Healthcare Epidemiology Prevention Research Development Programme (200-2016-91781). AT is funded by a predoctoral fellowship from the Rotary Foundation (GG2238676). FM is supported by the Japan Society for the Promotion of Science (JSPS) Grants-in-Aid KAKENHI (JP20J00793) and JST (JPMJPR23RA), and the MEXT to a project on Joint Usage/Research Center Leading Academia in Marine and Environment Pollution Research (LaMer). AE is supported by JSPS Overseas Research Fellowships, JSPS Grants-in-Aid KAKENHI (JP22K17329) and National University of Singapore Start-Up Grant. ### 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: For the NInJaS data, the Regional Ethics Committee at the University of Tokyo, Japan approved the study (ref: 2019305NI-(2)). All other data are publicly available. - Mpox incidence in Japan: https://github.com/akira-endo/mpoxlinelist_JPN and https://www.niid.go.jp/niid/ja/monkeypox-m/2596-cepr/12570-mpox-ra-0321.html - Mpox incidence in the world: https://ourworldindata.org/ - International flight volume data: https://www.e-unwto.org/subscribe - 1st reporting dates of mpox in each country and the source country of the importation are collected from publicly available data, which is listed in Table S2 in the Supplementary material. 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, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All the data used in this study is publicly available, except for the NInJaS study under an ethics-associated restriction on data sharing.