Abstract: The 2019-nCoV outbreak has raised concern of global spread. While person-to-person transmission within the Wuhan district has led to a large outbreak, the transmission potential outside of the region remains unclear. Here we present a simple approach for determining whether the upper limit of the confidence interval for the reproduction number exceeds one for transmission in the United States, which would allow endemic transmission. As of February 7, 2020, the number of cases in the United states support subcritical transmission, rather than ongoing transmission. However, this conclusion can change if pre-symptomatic cases resulting from human-to-human transmission have not yet been identified.
### Competing Interest Statement
The authors have declared no competing interest.
### Funding Statement
None of the authors received payment or services from a third party for any aspect of the submitted work. The authors are supported by grants by the NIH and Gates Foundation, but no additional funding was received for this work.
### Author Declarations
All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.
All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.
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).
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.
The data for this study is available for the public (see references). The methodology has been previously published (see references).
Blumberg Seth, Lietman Thomas M, Porco Travis C. (2020). Assessing the plausibility of subcritical transmission of 2019-nCoV in the United States. Cold Spring Harbor Laboratory Press