Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing

Abstract

The newly emergent human virus SARS-CoV-2 is resulting in high fatality rates and incapacitated health systems. Preventing further transmission is a priority. We analysed key parameters of epidemic spread to estimate the contribution of different transmission routes and determine requirements for case isolation and contact-tracing needed to stop the epidemic. We conclude that viral spread is too fast to be contained by manual contact tracing, but could be controlled if this process was faster, more efficient and happened at scale. A contact-tracing App which builds a memory of proximity contacts and immediately notifies contacts of positive cases can achieve epidemic control if used by enough people. By targeting recommendations to only those at risk, epidemics could be contained without need for mass quarantines ('lock-downs') that are harmful to society. We discuss the ethical requirements for an intervention of this kind.

State-specific Projection of COVID-19 Infection in the United States and Evaluation of Three Major Control Measures

“…On the other hand, we need to impose strong transmission-reduction intervention and increased testing capacity and report rate to contain the spread of virus. The result is in agreement with previous findings (9,12,14,23,36,40), suggesting that the effect of travel ban at a later stage of the outbreak is rather modest. This is also in line with the fact that the outbreaks still occurred in Europe even upon the strong travel ban on the earlier epicenter of Wuhan and its surrounding cities in China.…”

“…So far, since there is no treatment or vaccine for SARS-COV-2 available, these actions have been taken largely based on classic epidemic controls. Works on evaluating similar measures in other countries, especially China, started to emerge (14,24). For example, the effect of travel restriction on delaying the virus spread in China has been reported (9,36).…”

“…Modeling and analyzing the spread of COVID-19, and assessing the effect of various policies could be instrumental to national and international agencies for health response planning (9,14,21,28,36,38). We show that the effect of interstate travel reduction is at most modest in the United States when the outbreak has already widespread in all states.…”

Exit strategies: optimising feasible surveillance for detection, elimination and ongoing prevention of COVID-19 community transmission

“…Although investigation of downstream contacts is part of most surveillance strategies, follow up of upstream contacts is not uniformly undertaken, but is a feature of those settings implementing successful control1,30,31 Investigation of contacts can be supported through training and integration of community volunteer networks into existing surveillance and contact tracing teams. Software may assist considerably in these efforts, 18 and, linked to penalties for those found not to be with their phone during random spot checks by authorities, is again an important part of follow up in those settings with effective control.32…”

How did SARS-CoV-19 spread in India from Italy, Iran and China? Genetic surveillance of early cases and virus demography

“…The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), emerged at Wuhan city of China in the early December of 2019 [1], resulted out high fatality and incapacitated health systems by causing respiratory illness in human [2]. The virus spread rapidly after the outbreak and took a heavy toll on human life, by causing 187 705 deaths over 213 Countries, areas or territories till dated 25th April 2020 [3].…”