Public Health Emergencies

As I write this chapter, the entire world is reeling from the COVID-19 pandemic, one of the worst disease outbreaks in modern history. COVID-19 is a respiratory infection caused by the novel coronavirus SARS-CoV-2 (see Fig. 9.1). The pandemic is thought to have started in December 2019 in the wet markets of Wuhan, China, when a virus that normally resides in horseshoe bats acquired the mutations that allowed it to infect people. The mutations were for genes that code for the protein spike on the receptor binding domain of the virus. The protein spike enables the virus to bind to human lung epithelial cells (Andersen et al. 2020; Zhou et al. 2020). There has been speculation that SARS-CoV-2 is a genetically engineered virus that escaped from the Wuhan Institute of Virology, a BSL-IV laboratory in Wuhan, China, where researchers had been working with coronaviruses. However, researchers from the lab have denied this claim and there is no direct evidence to support it (Bryner 2020). Most scientists believe the virus mutated naturally but some dispute this claim and argue that a laboratory accident is a plausible scenario that cannot be ruled out (Andersen et al. 2020; Latham and Wilson 2020). The virus, which is transmissible by respiratory water droplets, quickly spread from China to Europe, the US, and other parts of the world. As of January 14, 2021, there were 92.6 million confirmed COVID-19 cases and nearly 2 million deaths, for a case fatality rate of 2.1%.