3.7. Prevention, Diagnosis, and Treatment

3.7.1. Prevention
As the number of COVID-19 patients in China has been growing rapidly, preventing the spread of SARS-CoV-2 is the most important and urgent task [57]. It was shown that human-to-human transmission of SARS-CoV-2 has spread via droplets or close contacts [58,59], but aerosol and fecal-oral transmission still need further study [60,61]. To reduce virus transmission, early detection and isolation are essential. In addition, close monitoring in crowded places is also important [62]. The possible pathogens of SARS and COVID-19 are both derived from wild animals [63]. Therefore, hunting, selling, and eating wild animals not only seriously damage the ecosystem, but also lead to the spread of epidemic diseases [64]. Thus, banning all wildlife trade is an effective measure to prevent viral prevalence. Wearing level-D protective clothing can protect medical staff from infection of respiratory viruses [65]. A vaccine against SARS-CoV has not been described in any published articles [66]. However, on Jan. 26th, 2020, the China CDC started to develop a new vaccine for SARS-CoV-2. The virus has been successfully isolated and seed strains have been screened [67].

3.7.2. Diagnosis
The early symptoms of SARS and COVID-19 are very similar to winter influenza, and the most important way to distinguish flu and pneumonia is to take throat swabs for viral testing [68]. Current diagnostic tests for coronavirus include RT-PCR, real-time reverse transcription PCR (rRT-PCR), reverse transcription loop-mediated isothermal amplification, as well as real-time RT-LAMP [69,70,71,72]. National Medical Products Administration has approved seven new nucleic acid test reagents for coronavirus, which were developed based on fluorescence PCR by Feb. 1st, 2020 [73]. Suspected infections can be detected accurately and quickly for timely isolation and treatment to avoid infecting others by using these test reagents.

3.7.3. Treatment
Both SARS-CoV and SARS-CoV-2 are CoVs; hence, the treatment strategies of SARS could be relevant for COVID-19 [74]. In 2003, SARS was mainly treated by isolation of the patients, hormones treatment, antiviral and symptomatic treatments, and many drugs such as glucocorticoid [29] and interferon [75]. Now, isolation, antiviral, and symptomatic treatments are still mainly adopted for COVID-19 treatment. As effective drugs for SARS, hormones and interferons can also be used to treat COVID-19 [74]. Lopinavir is one kind of protease inhibitor used to treat HIV infection, with ritonavir as a booster. Lopinavir and/or ritonavir has anti coronavirus activity in vitro. Hong Kong scholars found that, compared with ribavirin alone, patients treated with lopinavir/ritonavir and ribavirin had lower risk of acute respiratory distress syndrome (ARDS) or death caused by SARS-CoV [76,77]. Lopinavir/ritonavir has also been clinically tested in treatment of COVID-19, and showed wonderfully effective treatment for some patients, but the general clinical effect has not been determined [78].
More effective treatments are still under continuing exploration: On Jan. 25th, 2020, a joint research team from the Shanghai Institute of Materia Medica, Chinese Academy of Sciences, and Shanghai Tech University screened and identified 30 potential drugs that are reported to be effective against SARS-CoV-2 [79]. A high-resolution crystal structure of SARS-CoV-2 coronavirus 3CL hydrolase (Mpro) was announced after the outbreak of COVID-19 in the world [80], and human coronaviruses (HCoVs) have been treated as severe pathogens in respiratory tract infections. Nelfinavir was predicted to be a potential inhibitor of SARS-CoV-2 main protease [81]. The first patient in the US had been trial-treated with intravenous remdesivir (a novel nucleotide analogue prodrug in development) due to a severe infection [82,83]. No adverse reactions were observed during the administration, and the patient’s condition was effectively improved [84]. Clinical trials of remdesivir for treatment of COVID-19 just started on Feb. 5th and 12th, 2020 in Wuhan and Beijing, respectively, and the experimental results remain unclear [85,86].