Discussion
In the battle against COVID-19, China has rolled out perhaps the most ambitious, agile and aggressive disease containment effort in history (World Health Organization. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19). 2020). The rapid spread and the course of this rapidly escalating and deadly epidemic has been changed under the China’s powerful and scientific Joint Prevention and Control Mechanism. The effective control of COVID-19 in China provides at least two prevention and control modes for similar highly contagious diseases, one being the control mode in Wuhan, the epicenter of the outbreak, and the other being the early control mode in regions outside Hubei Province in China.
Consistent with our knowledge about other coronaviruses, SARS-CoV-2 is mainly transmitted via respiratory droplets and contact. In China, interpersonal transmission of COVID-19 occurs mainly in families (Chen et al., 2020; Li et al., 2020; Yu et al., 2020), and the relative high basic reproductive number R0 (J. T. Wu et al., 2020; Li et al., 2020; Y. Yang et al., 2020; Yu et al., 2020) may account for the nationwide outbreak. All populations are susceptible to SARS-CoV-2, including children and infants, and elderly men with underlying diseases are prone to develop severe cases (Chen et al., 2020; D. Wang et al., 2020; Huang et al., 2020; Liang et al., 2020; Xu X , Wu X, Jiang X, 2020; Z. Wu and McGoogan, 2020). Despite implementing comprehensive controls in a shorter period of time, the number of confirmed cases of COVID-19 still far exceeds SARS (8,422 cases), suggesting that SARS-CoV-2 may be more contagious than SARS-CoV. Although the case fatality rate (CFR) is much lower than SARS (9%) and MERS (36%) (Su et al., 2016), COVID-19 results in a higher overall death toll due to the large number of cases. It is worth noting that it is widely reported that asymptomatic infected people are also contagious (Bai et al., 2020; Lirong Zou et al., 2020; Pan et al., 2020; Rothe et al., 2020; Sebastian Hoehl et al., 2020; Shi et al., 2020; Yu et al., 2020), which is different from SARS-CoV (Zeng et al., 2009), greatly enhancing the difficulty of outbreak control (Fraser et al., 2004; Peak et al., 2017).
The exponential growth of patients nearly crashed down the health care system of Wuhan, even Hubei Province. In order to alleviate the shortage of medical resources in Hubei, as of February 25, 380 medical teams comprising of more than 42,000 health workers from all over China have been providing their help in Wuhan. In addition to increasing isolation wards in existing hospitals and transforming general hospital into infectious disease hospital, Wuhan established the Leishenshan Hospital and Huoshenshan Hospital as designated hospitals of COVID-19. A dozen mobile cabin hospitals were also built overnight to treat mild patients. Meanwhile, apart from lockdown of city and traffic quarantine, Wuhan government has also worked tremendously on household-to-household daily temperature checks of all of its residents and strictly controlled communities. As promising antiviral drugs, Remdesivir and chloroquine prove to effectively inhibit SARS-CoV-2 in vitro (M. Wang et al., 2020), several randomized controlled trials are already underway (https://clinicaltrials.gov/ct2/show/NCT04252664?term=remdesivir&draw=2&rank=2. https://clinicaltrials.gov/ct2/show/NCT04257656?term=remdesivir&draw=2&rank=1. https://clinicaltrials.gov/ct2/show/NCT04280705?cond=Adaptive+COVID-19+Treatment+Trial&draw=2&rank=1.), and the successful use of Remdesivir in relieving clinical symptoms in the United States also provides a clinical reference (Holshue et al., 2020). In addition, Chinese herbal medicine has been proven to greatly relieve patients’ condition. The combination of treatment and public health intervention has shown results in recent days. According to the prediction model of Nanshan Zhong ’s team (Z. Yang et al., 2020), lifting the Hubei quarantine (such as cancelling lockdown of Wuhan and surrounding cities, returning to normal Spring Festival travel rush) would result in a second epidemic peak in Hubei Province in mid-March and extend the epidemic to late April. But in fact, the number of newly confirmed case in Wuhan has changed from several thousand to 0 on March 18, indicating that the outbreak in Wuhan has been well controlled. Wuhan’s experience in control and treatment provides a good reference for other countries/regions with COVID-19 outbreak.
Outside Hubei, China has employed another model of prevention and control, because, unlike Hubei, the other provinces are at the early stage of outbreak. Despite sending medical staff and personal protective equipment to Hubei, many provinces were actually confronted with tough situation. The official classification of COVID-19 as a Category B infectious disease with the prevention and control methods of Category A, has marked the transition from local-level to central level of disease prevention and control. By January 29, all provinces in Mainland China have launched first-level response to a major public health emergency. The aim of all enforced public health interventions was to isolate, diagnosis, and treat people coming back from Hubei Province as early, quarantine those having contacts with confirmed case, and reduce the possibility of secondary transmission in other provinces. Take Guangdong and Zhejiang Province for example, as popular destinations for migrant workers, the two provinces effectively prevent the spread of COVID-19 by continuous early detection and early isolation of Hubei-related residents. Nationally, the number of newly confirmed cases outside Hubei increased rapidly from January 20 to February 2, reached a peak on February 3. Since then, it has maintained a steady downward trend, with only an exception peak on February 20.
Although China has made great achievements in this anti-virus combat, the epidemic is still surging worldwide and involving more and more countries (https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200319-sitrep-59-covid-19.pdf?sfvrsn=c3dcdef9_2.). WHO has raised COVID-19 global risk to very high on March 13. And dramatically, the number of confirmed cases worldwide took over three months to reach the first 100,000 confirmed cases, and only 12 days to reach the next 100,000, even grow exponentially around the world in recent days. In the absence of a specific antiviral drug or vaccine, other countries could follow China’s example to prevent a global outbreak. At the same time, China should stay alert. The focus should be shifted from preventing the spread of domestic epidemics to the importation of international cases. Only when the government pays enough attention together with global effort can epidemic prevention work be better carried out. What’s more, Tie Song, deputy director of the Guangdong Provincial CDC, said 14% of discharged patients in Guangdong returned positive nucleic acid results (http://www.scio.gov.cn/xwfbh/gssxwfbh/xwfbh/guangdong/Document/1674339/1674339.htm.). JAMA also reported that the pharyngeal swab nucleic acid results of 4 medical staff who have been cured turned out to be re-positive (Lan et al., 2020). Some experts believe that the virus in the patient has always been positive, the difference is whether it was successfully detected. Therefore, it is of high priority of other countries to confirm the proportion of discharged patients with positive nucleic acid results and whether they are contagious. Whether it is necessary to use more sensitive nucleic acid kits, increase the location of samples, adopt more strict discharge standards or post-discharge isolation measures, all are the focus of our future work.
In conclusion, China has made a great achievement in control the spread of COVID-19 through the enforced nationwide intervention even suspension of normal social and economic operations and sacrifice by China and its people in both human and material terms. However, there are still many challenges and a lot of work need to do to curb the new disease since outbreak occurred internationally now, such as explore the source of infection, transmissibility, pathogenesis and virulence of the virus, risk factors for infection and disease progression, surveillance, diagnostics, the effective drugs and vaccine development. China has shared successful model of joint prevention and management experience against COVID-19 with international community. In face this previous unknown disease, all countries need to unite, learn from the excellent prevention and control model, adopt the method suitable for their own countries and regions, to control the new pneumonia.