Hui David S, Zumla Alimuddin, Tang Julian W
Department of Medicine & Therapeutics & Stanley Ho Center for Emerging Infectious Diseases.
The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
Curr Opin Pulm Med. 2021 May 1;27(3):146-154. doi: 10.1097/MCP.0000000000000774.
Severe acute respiratory syndrome-coronaviruses-2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), emerged as a new zoonotic pathogen of humans at the end of 2019 and rapidly developed into a global pandemic. Over 106 million COVID-19 cases including 2.3 million deaths have been reported to the WHO as of February 9, 2021. This review examines the epidemiology, transmission, clinical features, and phylogenetics of three lethal zoonotic coronavirus infections of humans: SARS-CoV-1, SARS-CoV-2, and The Middle East respiratory syndrome coronavirus (MERS-COV).
Bats appear to be the common natural source of SARS-like CoV including SARS-CoV-1 but their role in SARS-CoV-2 and MERS-CoV remains unclear. Civet cats and dromedary camels are the intermediary animal sources for SARS-CoV-1 and MERS-CoV infection, respectively whereas that of SARS-CoV-2 remains unclear. SARS-CoV-2 viral loads peak early on days 2-4 of symptom onset and thus high transmission occurs in the community, and asymptomatic and presymptomatic transmission occurs commonly. Nosocomial outbreaks are hallmarks of SARS-CoV-1 and MERS-CoV infections whereas these are less common in COVID-19. Several COVID-19 vaccines are now available.
Of the three lethal zoonotic coronavirus infections of humans, SARS-CoV-2 has caused a devastating global pandemic with over a million deaths. The emergence of genetic variants, such as D614G, N501Y (variants 1 and 2), has led to an increase in transmissibility and raises concern about the possibility of re-infection and impaired vaccine response. Continued global surveillance is essential for both SARS-CoV-2 and MERS-CoV, to monitor changing epidemiology due to viral variants.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）是2019冠状病毒病（COVID-19）的病原体，于2019年末作为一种新的人类人畜共患病原体出现，并迅速发展成为全球大流行。截至2021年2月9日，世界卫生组织已收到超过1.06亿例COVID-19病例报告，其中包括230万例死亡病例。本综述研究了三种导致人类致命的人畜共患冠状病毒感染的流行病学、传播、临床特征和系统发育学：SARS-CoV-1、SARS-CoV-2和中东呼吸综合征冠状病毒（MERS-CoV）。
蝙蝠似乎是包括SARS-CoV-1在内的类SARS-CoV的常见天然宿主，但其在SARS-CoV-2和MERS-CoV中的作用仍不清楚。果子狸和单峰骆驼分别是SARS-CoV-1和MERS-CoV感染的中间动物宿主，而SARS-CoV-2的中间动物宿主尚不清楚。SARS-CoV-2病毒载量在症状出现后的第2-4天早期达到峰值，因此在社区中传播率很高，无症状和症状前传播也很常见。医院内暴发是SARS-CoV-1和MERS-CoV感染的特征，而在COVID-19中则较少见。目前已有几种COVID-19疫苗可供使用。
在三种导致人类致命的人畜共患冠状病毒感染中，SARS-CoV-2已造成一场毁灭性的全球大流行，死亡人数超过100万。D614G、N501Y（变体1和2）等基因变体的出现导致了传播性增加，并引发了对再次感染可能性和疫苗反应受损的担忧。对SARS-CoV-2和MERS-CoV持续进行全球监测至关重要，以监测由于病毒变体导致的流行病学变化。
