First-wave COVID-19 transmissibility and severity in China

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First-wave COVID-19 transmissibility and severity in China

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.To get more China news about shanghai coronavirus cases, you can visit shine news official website.

We estimated the instantaneous reproduction number (Rt) 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 Rt 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 Rt >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 Rt and cCFR is needed to inform strategies against a potential second wave to achieve an optimal balance between health and economic protection.
Since the third week of January, 2020, massive public health interventions have been implemented across China to contain the spread of coronavirus disease 2019 (COVID-19; figure 1). Wuhan, the epicentre of the outbreak, has been locked down since Jan 23, with 16 of its neighbouring cities in Hubei province included behind the cordon sanitaire shortly thereafter. The national Spring Festival holiday was extended by 8 days to Feb 7, and most schools have remained closed to date. As the Spring Festival holiday ended, stringent social distancing measures and mobility restrictions were coordinated and implemented by the central and local governments in many Chinese megacities (ie, the largest and wealthiest; figure 1), including Beijing (north of Wuhan), Guangzhou and Shenzhen (south), Shanghai and Hangzhou (east), and Chengdu (west). For example, only residents were allowed to enter residential communities, face mask-wearing was made compulsory, and non-essential community services were shut down. Although the aggressive countermeasures appear to have reduced the number of reported cases, the absence of herd immunity against COVID-19 suggests that counts could easily resurge when these interventions are relaxed, as business, factory operations, and schools resume.