Monitoring Social Distancing and SARS-CoV-2 Transmission in Brazil Using Cell Phone Mobility Data (preprint)

BACKGROUND: In the absence of vaccines and effective pharmacological interventions to reduce with the COVID-19 transmission, social distancing measures have been implemented to mitigate the impact on healthcare systems and secure time to prepare the public health response. METHODS: We assessed the relationship between mobility data collected by mobile phone and time-dependent reproduction number R(t) using severe acute respiratory illness cases reported by 102 Brazilian cities with COVID-19 confirmed cases until April 15, grouped by demographic density (low, intermediate and high). FINDINGS: The mean social distancing index from February 1 to April 15 was 43.6% (27.2% to 63.7%), and no significant difference observed comparing the groups of demographic density (p-value = 0.809). The social distancing index measure obtained from mobility data was able to predict future values of R(t) in all groups of demographic density. Furthermore, using SARI cases, cross-correlation analyses showed that isolation was highly correlated with R(t) (ccfINTERPRETATION: The early implementation of social distancing measures greatly reduced the COVID-19 spread. A major advantage to our approach is that the social distancing index data is available on a daily basis, in contrast with R(t) measurement, which is subject to significant delays. This index metric can be monitored in real time to assess adherence to social distancing measures and help guide, with real time data, the public health policy decision making process.FUNDING: FADQ and JC were granted a fellowship for research productivity from the Brazilian National Council for Scientific and Technological Development – CNPq, process/contract identification: 312656/2019-0 and 310551/2018-8, respectively.DECLARATION OF INTERESTS: Authors declare no competing interests.ETHICS APPROVAL STATEMENT: This study followed Brazilian and International legislation for conducting human research. This research project was approved by the National Research Ethics Committee (Comissão Nacional de Ética em Pesquisa, CONEP) in Brazil, Register number (CAAE): 11946619.5.0000.5421.

Monitoring social distancing and SARS-CoV-2 transmission in Brazil using cell phone mobility data (preprint)

Social distancing measures have emerged as the predominant intervention for containing the spread of COVID-19, but evaluating adherence and effectiveness remains a challenge. We assessed the relationship between aggregated mobility data collected from mobile phone users and the time-dependent reproduction number R(t), using severe acute respiratory illness (SARI) cases reported by Sao Paulo and Rio de Janeiro. We found that the proportion of individuals staying home all day (isolation index) had a strong inverse correlation with R(t) (rho

The impact of early social distancing at COVID-19 Outbreak in the largest Metropolitan Area of Brazil. (preprint)

We evaluated the impact of early social distancing on the COVID-19 transmission in the Sao Paulo metropolitan area. Using an age-stratified SEIR model, we determined the time-dependent reproductive number, and forecasted the ICU beds necessary to tackle this epidemic. Within 60 days, these measures might prevent 89,133 deaths.