https://wwwnc.cdc.gov/eid/page/about Emerging Infectious Diseases is an open access journal in the public domain. All content is freely available without charge to the user or his/her institution. In accordance with the Budapest Open Access Initiative definition of Open Access, users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. Because the journal is in the public domain, its usage policy also conforms to conditions set for by Creative Commons. https://creativecommons.org/licenses/by/4.0/