tetano
Editor, Senior Moderator
Lancet. 2020 Apr 8. pii: S0140-6736(20)30746-7. doi: 10.1016/S0140-6736(20)30746-7. [Epub ahead of print]
First-wave COVID-19 transmissibility and severity in China outside Hubei after control measures, and second-wave scenario planning: a modelling impact assessment.
Leung K[SUP]1[/SUP], Wu JT[SUP]2[/SUP], Liu D[SUP]1[/SUP], Leung GM[SUP]1[/SUP].
Author information
Abstract
BACKGROUND:
As of March 18, 2020, 13 415 confirmed cases and 120 deaths related to coronavirus disease 2019 (COVID-19) in mainland China, outside Hubei province-the epicentre of the outbreak-had been reported. Since late January, massive public health interventions have been implemented nationwide to contain the outbreak. We provide an impact assessment of the transmissibility and severity of COVID-19 during the first wave in mainland Chinese locations outside Hubei.
METHODS:
We estimated the instantaneous reproduction number (R[SUB]t[/SUB]) of COVID-19 in Beijing, Shanghai, Shenzhen, Wenzhou, and the ten Chinese provinces that had the highest number of confirmed COVID-19 cases; and the confirmed case-fatality risk (cCFR) in Beijing, Shanghai, Shenzhen, and Wenzhou, and all 31 Chinese provinces. We used a susceptible-infectious-recovered model to show the potential effects of relaxing containment measures after the first wave of infection, in anticipation of a possible second wave.
FINDINGS:
In all selected cities and provinces, the R[SUB]t[/SUB] decreased substantially since Jan 23, when control measures were implemented, and have since remained below 1. The cCFR outside Hubei was 0?98% (95% CI 0?82-1?16), which was almost five times lower than that in Hubei (5?91%, 5?73-6?09). Relaxing the interventions (resulting in R[SUB]t[/SUB] >1) when the epidemic size was still small would increase the cumulative case count exponentially as a function of relaxation duration, even if aggressive interventions could subsequently push disease prevalence back to the baseline level.
INTERPRETATION:
The first wave of COVID-19 outside of Hubei has abated because of aggressive non-pharmaceutical interventions. However, given the substantial risk of viral reintroduction, particularly from overseas importation, close monitoring of R[SUB]t[/SUB] and cCFR is needed to inform strategies against a potential second wave to achieve an optimal balance between health and economic protection.
FUNDING:
Health and Medical Research Fund, Hong Kong, China.
Copyright ? 2020 Elsevier Ltd. All rights reserved.
PMID:32277878DOI:10.1016/S0140-6736(20)30746-7
First-wave COVID-19 transmissibility and severity in China outside Hubei after control measures, and second-wave scenario planning: a modelling impact assessment.
Leung K[SUP]1[/SUP], Wu JT[SUP]2[/SUP], Liu D[SUP]1[/SUP], Leung GM[SUP]1[/SUP].
Author information
Abstract
BACKGROUND:
As of March 18, 2020, 13 415 confirmed cases and 120 deaths related to coronavirus disease 2019 (COVID-19) in mainland China, outside Hubei province-the epicentre of the outbreak-had been reported. Since late January, massive public health interventions have been implemented nationwide to contain the outbreak. We provide an impact assessment of the transmissibility and severity of COVID-19 during the first wave in mainland Chinese locations outside Hubei.
METHODS:
We estimated the instantaneous reproduction number (R[SUB]t[/SUB]) of COVID-19 in Beijing, Shanghai, Shenzhen, Wenzhou, and the ten Chinese provinces that had the highest number of confirmed COVID-19 cases; and the confirmed case-fatality risk (cCFR) in Beijing, Shanghai, Shenzhen, and Wenzhou, and all 31 Chinese provinces. We used a susceptible-infectious-recovered model to show the potential effects of relaxing containment measures after the first wave of infection, in anticipation of a possible second wave.
FINDINGS:
In all selected cities and provinces, the R[SUB]t[/SUB] decreased substantially since Jan 23, when control measures were implemented, and have since remained below 1. The cCFR outside Hubei was 0?98% (95% CI 0?82-1?16), which was almost five times lower than that in Hubei (5?91%, 5?73-6?09). Relaxing the interventions (resulting in R[SUB]t[/SUB] >1) when the epidemic size was still small would increase the cumulative case count exponentially as a function of relaxation duration, even if aggressive interventions could subsequently push disease prevalence back to the baseline level.
INTERPRETATION:
The first wave of COVID-19 outside of Hubei has abated because of aggressive non-pharmaceutical interventions. However, given the substantial risk of viral reintroduction, particularly from overseas importation, close monitoring of R[SUB]t[/SUB] and cCFR is needed to inform strategies against a potential second wave to achieve an optimal balance between health and economic protection.
FUNDING:
Health and Medical Research Fund, Hong Kong, China.
Copyright ? 2020 Elsevier Ltd. All rights reserved.
PMID:32277878DOI:10.1016/S0140-6736(20)30746-7