Coronavirus Epidemiology

Outbreaks of coronavirus types of relatively high mortality are shown below.

Outbreak Virus type Deaths
2003 severe acute respiratory syndrome outbreak SARS-CoV 774
2012 Middle East respiratory syndrome coronavirus outbreak MERS-CoV Over 400
2015 Middle East respiratory syndrome outbreak in South Korea MERS-CoV 36
2018 Middle East respiratory syndrome outbreak MERS-CoV 41
2019–20 coronavirus outbreak SARS-CoV-2 At least 443,000

Coronavirus disease 2019 (COVID-19)
The 2019–20 coronavirus outbreak is an ongoing global outbreak of coronavirus disease 2019 and a Public Health Emergency of International Concern. It is caused by the SARS-CoV-2 coronavirus, first identified in Wuhan, Hubei, China. As of 17 June 2020, more than 8,142,000 cases have been confirmed. Almost all countries in the world have been affected, with major outbreaks in Central China, South Korea, Italy, Iran and the US. More than 443,000 people have died, with over 4,600 in mainland China and over 34,000 in Italy. In the US more than 2,137,000 people are infected with over 116,000 deaths.

Overall mortality and morbidity rates due to infection are not well established; while the case fatality rate (CFR) changes over time in the current outbreak, the proportion of infections that progress to diagnosable disease remains unclear. However, preliminary research has yielded case fatality rate numbers between 2% and 3%; in January 2020 the WHO suggested that the case fatality rate was approximately 3%, and 2% in February 2020 in Hubei.

COVID-19 World Maps & visuals

COVID-19 Local US Maps & visuals

Geographic distribution of COVID-19 cases worldwide, as of 19 May 2020
Figure 1. Geographic distribution of COVID-19 cases worldwide, as of 19 May 2020 (source ECDC).

Middle East respiratory syndrome (MERS)
In September 2012, a new type of coronavirus was identified, initially called Novel Coronavirus 2012, and now officially named Middle East respiratory syndrome coronavirus (MERS-CoV). Two confirmed cases involved people who seemed to have caught the disease from their late father, who became ill after a visit to Qatar and Saudi Arabia. Despite this, it appears that the virus had trouble spreading from human to human, as most individuals who are infected do not transmit the virus. By 30 October 2013, there were 124 cases and 52 deaths in Saudi Arabia. In May 2015, an outbreak of MERS-CoV occurred in the Republic of Korea, when a man who had traveled to the Middle East, visited 4 hospitals in the Seoul area to treat his illness. This caused one of the largest outbreaks of MERS-CoV outside the Middle East. As of December 2019, 2,468 cases of MERS-CoV infection had been confirmed by laboratory tests, 851 of which were fatal, a mortality rate of approximately 34.5%.

MERS-CoV map of the 2012 outbreak
Figure 2. MERS-CoV map of the 2012 outbreak.

Total cases of MERS-CoV outbreak worldwide
Figure 3. Total cases of MERS-CoV outbreak worldwide (source: WHO)

Severe acute respiratory syndrome (SARS)
The outbreak of severe acute respiratory syndrome (SARS) was first reported in Asia in February 2003. The virus spread to more than two dozen countries in North America, South America, Europe, and Asia before the SARS global outbreak of 2003 was contained. The WHO stating that a novel coronavirus identified by a number of laboratories was the causative agent for SARS. The virus was officially named the SARS coronavirus (SARS-CoV). Over 8,000 people were infected, about 10% of whom died. Since 2004, there have not been any known cases of SARS reported anywhere in the world. A few cases have been reported as a result of laboratory accidents or, possibly, through animal-to-human transmission (Guangdong, China).

Figure 4. SARS epidemic of 2003 (source: Encyclopaedia Britannica)