Epidemic Models of Contact Tracing: Systematic Review of Transmission Studies of Severe Acute Respiratory Syndrome and Middle East Respiratory Syndrome

“The current systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis: The PRISMA statement [14].”

“For example, SARS transmission in high-rise buildings among residents of Amoy Gardens suggested possible airborne transmission [46,47] and government officials were prone to political pressures regarding quarantine.”

“Quarantine and Isolation Efficiency Contact tracing is shown to be an essential and successful public health tool in reducing the transmission risk of new emerging infectious diseases such as SARS among Hong Kong population [10].”

“[19] defined a distribution characterizing an individual person who had not been isolated by the time since infection to reflect isolation delay.”

“In the 2003 SARS outbreak, it was observed that the time between symptoms onset and hospitalization was 3–5 days, with longer times earlier in the epidemic [27].”

“The majority of SARS cases occurred amonghealthcareworkers;while substantial number of MERS cases were patients [3], with most MERS severe cases and mortality being individuals with comorbidities [6].”

“The majority of SARS cases occurred amonghealthcareworkers;while substantial number of MERS cases were patients [3], with most MERS severe cases and mortality being individuals with comorbidities [6].”

“These choices are especially relevant to models of contact tracing, as was evident in the early 2000s when two apparently similar models [39,40] came to very different conclusions about likely efficacy of contact tracing because of their different implicit assumptions about the variance of the latent period distributi…”

“Contact tracing and follow-up control measures such as quarantine and isolation were crucially important during the SARS outbreak in 2003 [10], the Ebola outbreak in Africa in 2014 [11], as well as its part in the eradication of smallpox [12].”

“Previous work [35 – 37] suggested the importance of realistic distribution of these quantities facilitated more understanding in the epidemic size, the disease progression and how their distributions be adjusted in response to different intervention strategies [38].”

“These choices are especially relevant to models of contact tracing, as was evident in the early 2000s when two apparently similar models [39,40] came to very different conclusions about likely efficacy of contact tracing because of their different implicit assumptions about the variance of the latent period distributi…”

“In our two studyCo-Vs, SARS had a slightly shorter incubation period than latent period [15,17].”

“In our two studyCo-Vs, SARS had a slightly shorter incubation period than latent period [15,17].”

“As of 18 August 2018, there has been no confirmed case caused by asymptomatic transmission for MERS, with one possible case of asymptomatic transmission occurred during the 2012 outbreak [26].”

“Lloyd-Smith assumed gamma distribution [16,17,19,20].”

“Contact tracing, the identification and follow-up of individuals who have had contacts with infectious individuals, is a critical process to ensure the best possible chance of control and the longest possible time to local take-off [9].”

“[19] addressed this issue by pointing out this misassumption as a limitation of their model, and suggested that models incorporate this feature or alternative mechanisms [9,43] with heterogeneity transmission would give a more unbiased efficacy estimate of contact tracing.”

“It was particularly useful during ongoing outbreaks, and was used for evaluating public health policies for disease containment in the SARS outbreak [10], predicting transmission progression, testing efficacy and evaluating effectiveness of contact tracing during the Ebola outbreak in 2013 [31,32].”

“Contact tracing and follow-up control measures such as quarantine and isolation were crucially important during the SARS outbreak in 2003 [10], the Ebola outbreak in Africa in 2014 [11], as well as its part in the eradication of smallpox [12].”

“Diseases caused by them were deadly, with a mortality rate of 29.8% for MERS [7] and 7% for SARS [8].”

“Becker et al. [21], Chen et al. [18] and Klinkenberg et al. [17] did not model possible transmission that might occur while being isolated, assuming isolation to be 100% effective to stop disease transmission.”

“assumed that symptom onsets occurred prior to infection, and used incubation period from previous literatures as latent period [21].”

“Geographic disparity of Ro estimate for SARS in 2003 due to different disease and community dependent transmission rate [45] highlighted the need for different levels of contact tracing approach during the epidemics.”

“Previous study found that social contact patterns was heterogeneous [41,42], and social contact pattern within age groups was a signi fi cant factor of age-speci fi c infection rates [42].”

“[34] suggested that models with gamma distributed infectious period were best fit to the data compared with those assuming constant transmission probability or proportional relation with viral load.”

“Previous study found that social contact patterns was heterogeneous [41,42], and social contact pattern within age groups was a signi fi cant factor of age-speci fi c infection rates [42].”

“However, some studies proposed to adopt gamma distribution instead to better describe the disease stages of SARS [27,33].”

“However, the follow-upquarantine and isolation did not necessarily stop all transmission, as illustrated in nosocomial outbreaks of SARS [28] andMERS [29].”

“For some novel pathogens such as pandemic influenza, cutting-edge technologymay shorten the time needed for vaccine development after initial isolation, bridging shorter gaps between epidemic emergence and vaccine availability [13].”

“Six studies simulated community setting in the models [15–17,19–21]; three studies simulated hospital setting in their models [16,18,20].”

“Previous work [35–37] suggested the importance of realistic distribution of these quantities facilitated more understanding in the epidemic size, the disease progression and how their distributions be adjusted in response to different intervention strategies [38].”

“These outbreaks have resulted in more than 8000 and 2200 confirmed SARS and MERS cases, respectively [8].”

“7 8 Here we leverage detailed social network data from the UK to model both transmission and the act of tracing, and identify the implications of early contact tracing for containment of a novel pathogen, using parameters for the novel coronavirus (COVID-19).”

“It is necessary to estimate the R0 of COVID-19 to determine the severity and size of the pandemic, as well as to design appropriate interventions and responses to protect the population and to control the spread of the disease [35].”

“…for disease outbreak detection such as tuberculosis [17], Ebola outbreak in 2014 [18], severe acute respiratory syndrome (SARS) outbreak in 2003 [19], Middle East respiratory syndrome (MERS) outbreak in 2012 in the Middle East Saudi Arabian Peninsula region and MERS outbreak in 2015 in South…”