Transmission Dynamics and Control Methodology of COVID-19: a Modeling Study

Abstract

The coronavirus disease 2019 has grown up to be a pandemic within a short span of time. To investigate transmission dynamics and then determine control methodology, we took epidemic in Wuhan as a study case. Unfortunately, to our best knowledge, the existing models are based on the common assumption that the total population follows a homogeneous spatial distribution, which is not the case for the prevalence occurred both in the community and in hospital due to the difference in the contact rate. To solve this problem, we propose a novel epidemic model called SEIR-HC, which is a novel epidemic model with two different social circles. Using the model alongside the exclusive optimization algorithm, the spread process of COVID-19 epidemic in Wuhan city is reproduced and then the propagation characteristics and unknown data are estimated. Furthermore, the control measures implemented in Wuhan are assessed and the control methodology of COVID-19 is discussed to provide guidance for limiting the epidemic spread.

Inferred duration of infectious period of SARS-CoV-2: rapid scoping review and analysis of available evidence for asymptomatic and symptomatic COVID-19 cases

“…This suggests that the average infectious period, assuming a symptomatic infectious period of 7 days was approximately 9.3 days (95% CI 7.8-10 days, where CI is only reported for the presymptomatic period). He et al 29 estimated that the proportion of all transmission that was presymptomatic was 44% (95% CI 25% to 37 used a mean prior of 10 days, with the model estimated mean duration being 12.5 days (variance 10; Weibull distribution). Piccolomiini and Zama 38 used a fixed estimate of 20-day infectious period to model the Italian epidemic.…”

“…These values may represent an overestimation of the infectious period; one study suggested that there was on average 2.5 days between end of infectiousness and 'removal' (recovery or death). 37 Cheng et al 33 provided evidence of transmissibility, based on attack rate from primary to secondary cases, at around symptom onset. The authors estimate cumulative infectiousness from onset, which suggests that 67% of total infectiousness potential occurs by the first day postonset.…”

Inferred duration of infectious period of SARS-CoV-2: rapid scoping review and analysis of available evidence for asymptomatic and symptomatic COVID-19 cases

“…Studies that collated such information suggest mean durations of 18.07 days (95%ci: 15.14 -20.99), but with time to discharge being 4.96 days shorter (95%CI: 2.15-7.76) on average than time to death. These values may represent an over estimation of the infectiousperiod; one study suggested that there was on average 2.5 days between end of infectiousness and 'removal' (recovery or death) [37].…”

Modeling the Novel Coronavirus (SARS-CoV-2) Outbreak in Sicily, Italy

“…To estimate the unknown parameters, we employed a Sequential Quadratic Programming (SQP) algorithm for large-scale constrained optimization, which solved a sequence of optimization subproblems to minimize the objective function (6) satisfying all the constraints [ 9 ]. This algorithm has already been used for modeling purposes in the context of SARS-CoV-2 epidemic [ 10 ]. The model is based on 10 predefined parameters (i.e., N , S , E , I com , I hos , I icu , R , D , σ , and γ ) and 9 parameters to be estimated (i.e., β com , β hos , β icu , υ com , υ hos , υ icu , μ com , μ hos , and μ icu ).…”