Background:Similar to outbreaks of many other infectious diseases,success in controlling the novel 2019 coronavirus infection requires a timely and accurate monitoring of the epidemic,particularly during its early per...Background:Similar to outbreaks of many other infectious diseases,success in controlling the novel 2019 coronavirus infection requires a timely and accurate monitoring of the epidemic,particularly during its early period with rather limited data while the need for information increases explosively.Methods:In this study,we used a second derivative model to characterize the coronavirus epidemic in China with cumulatively diagnosed cases during the first 2 months.The analysis was further enhanced by an exponential model with a close-population assumption.This model was built with the data and used to assess the detection rate during the study period,considering the differences between the true infections,detectable and detected cases.Results:Results from the second derivative modeling suggest the coronavirus epidemic as nonlinear and chaotic in nature.Although it emerged gradually,the epidemic was highly responsive to massive interventions initiated on January 21,2020,as indicated by results from both second derivative and exponential modeling analyses.The epidemic started to decelerate immediately after the massive actions.The results derived from our analysis signaled the decline of the epidemic 14 days before it eventually occurred on February 4,2020.Study findings further signaled an accelerated decline in the epidemic starting in 14 days on February 18,2020.Conclusions:The coronavirus epidemic appeared to be nonlinear and chaotic,and was responsive to effective interventions.The methods used in this study can be applied in surveillance to inform and encourage the general public,public health professionals,clinicians and decision-makers to take coordinative and collaborative efforts to control the epidemic.展开更多
Background:The novel coronavirus disease(COVID-19)was first reported in Wuhan,China.The mass population mobility in China during the Spring Festival has been considered a driver to the transmission of COVID-19,but it ...Background:The novel coronavirus disease(COVID-19)was first reported in Wuhan,China.The mass population mobility in China during the Spring Festival has been considered a driver to the transmission of COVID-19,but it still needs more empirical discussion.Methods:Based on the panel data from Hubei,China between January 6th and February 6th,2020,a random effects model was used to estimate the impact of population mobility on the transmission of COVID-19.Stata version 12.0 was used,and p<0.05 was considered statistically significant.Results:The COVID-19 was more likely to be confirmed within 11-12 days after people moved from Wuhan to 16 other prefecture-level cities in Hubei Province,which suggests a period of 11-12 days from contact to being confirmed.The daily confirmed cases and daily increment in incidence in 16 prefecture-level cities show obvious declines 9-12 days post adaptation of city lockdown at the local level.Conclusion:Population mobility is found to be a driver to the rapid transmission of COVID-19,and the lockdown intervention in local prefecture-level cities of Hubei Province has been an effective strategy to block the COVID-19 epidemic.展开更多
文摘Background:Similar to outbreaks of many other infectious diseases,success in controlling the novel 2019 coronavirus infection requires a timely and accurate monitoring of the epidemic,particularly during its early period with rather limited data while the need for information increases explosively.Methods:In this study,we used a second derivative model to characterize the coronavirus epidemic in China with cumulatively diagnosed cases during the first 2 months.The analysis was further enhanced by an exponential model with a close-population assumption.This model was built with the data and used to assess the detection rate during the study period,considering the differences between the true infections,detectable and detected cases.Results:Results from the second derivative modeling suggest the coronavirus epidemic as nonlinear and chaotic in nature.Although it emerged gradually,the epidemic was highly responsive to massive interventions initiated on January 21,2020,as indicated by results from both second derivative and exponential modeling analyses.The epidemic started to decelerate immediately after the massive actions.The results derived from our analysis signaled the decline of the epidemic 14 days before it eventually occurred on February 4,2020.Study findings further signaled an accelerated decline in the epidemic starting in 14 days on February 18,2020.Conclusions:The coronavirus epidemic appeared to be nonlinear and chaotic,and was responsive to effective interventions.The methods used in this study can be applied in surveillance to inform and encourage the general public,public health professionals,clinicians and decision-makers to take coordinative and collaborative efforts to control the epidemic.
文摘Background:The novel coronavirus disease(COVID-19)was first reported in Wuhan,China.The mass population mobility in China during the Spring Festival has been considered a driver to the transmission of COVID-19,but it still needs more empirical discussion.Methods:Based on the panel data from Hubei,China between January 6th and February 6th,2020,a random effects model was used to estimate the impact of population mobility on the transmission of COVID-19.Stata version 12.0 was used,and p<0.05 was considered statistically significant.Results:The COVID-19 was more likely to be confirmed within 11-12 days after people moved from Wuhan to 16 other prefecture-level cities in Hubei Province,which suggests a period of 11-12 days from contact to being confirmed.The daily confirmed cases and daily increment in incidence in 16 prefecture-level cities show obvious declines 9-12 days post adaptation of city lockdown at the local level.Conclusion:Population mobility is found to be a driver to the rapid transmission of COVID-19,and the lockdown intervention in local prefecture-level cities of Hubei Province has been an effective strategy to block the COVID-19 epidemic.
