@article {Felizola Diniz-Filho2020.07.28.20163493, author = {Felizola Diniz-Filho, Jos{\'e} Alexandre and Jardim, Lucas and Toscano, Cristiana M. and Rangel, Thiago Fernando}, title = {The effective reproductive number (Rt) of COVID-19 and its relationship with social distancing}, elocation-id = {2020.07.28.20163493}, year = {2020}, doi = {10.1101/2020.07.28.20163493}, publisher = {Cold Spring Harbor Laboratory Press}, abstract = {The expansion of the new coronavirus disease (COVID-19) triggered a renewed interest in epidemiological models and on how parameters can be estimated from observed data. Here we investigated the relationship between average number of transmissions though time, the reproductive number Rt, and social distancing index as reported by mobile phone data service inloco, for Goi{\'a}s State, Brazil, between March and June 2020. We calculated Rt values using EpiEstim package in R-plataform for confirmed cases incidence curve. We found a correlation equal to -0.72 between Rt values and isolation index at a time lag of 8 days. As the Rt values were paired with center of the moving window of 7 days, the delay matches the mean incubation period of the virus. Our findings reinforce that isolation index can be an effective surrogate for modeling and epidemiological analyses and, more importantly, helpful for anticipating the need for early interventions, a critical issue in public health.Competing Interest StatementThe authors have declared no competing interest.Funding StatementAuthors thank National Council for Scientific and Technological Development (CNPq) for productivity fellowships and grants. Our work on simulation and population modeling has been continuously supported by National Institute of Science and Technology (INCT) in Ecology, Evolution and Biodiversity Conservation (J. A. F. D.-F. and T.F.R), supported by CNPq and FAPEG. CMT is a researcher of the Institutes for Health Technology Assessment (IATS), also supported as a INCT by CNPq.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as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).YesI 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.Yes.}, URL = {https://www.medrxiv.org/content/early/2020/07/29/2020.07.28.20163493}, eprint = {https://www.medrxiv.org/content/early/2020/07/29/2020.07.28.20163493.full.pdf}, journal = {medRxiv} }