**2. SARS-CoV**

#### **2.1 Etiology, epidemiology, and clinical presentation**

Severe acute respiratory virus (SARS) is a deadly pulmonary infection caused by the SARS coronavirus (SARS-CoV), first reported in Guangdong Province, China, in November 2002 [7]. The emergence of SARS-CoV signaled the first time the public, as well as numerous scientists, observed this cluster of viruses, and its potential to cause severe infections and death in humans [8]. By July 3, 2003, SARS global infections were 8439 cases of which 812 were fatal [9]. This prompted a full-bodied international response estimated at roughly 40 billion dollars which aided in containing the outbreak [10]. By the close 2004 there were no new reported cases [9, 10]. Genetic classification indicates that the introduction into the human population took place from civets or other mammals found in live-animal markets of China [9]. Furthermore, it is prevailingly considered that SARS-CoV originated in a colony of horseshoe bats in southern China, with civets acting as the intermediate amplifying and transmitting host to humans [11].

### **3. SARS-CoV infection in humans**

**SARS-CoV** is an airborne virus transmissible between humans through small respiratory droplets, in a similar manner to influenza [6]. SARS-CoV can also be spread indirectly via surfaces that have been touched by someone who is infected with the virus, and by close interactions with infected individuals acting as socalled "super spreaders" [6]. The incubation period of SARS-CoV is generally 2–7 days, but infected persons may present symptoms as long as 10 days after infection [6]. Several epidemiological studies conducted during the outbreak identified numerous deaths occurring disproportionately among the elderly, and individuals who were immunosuppressed. At the onset of SARS-CoV illness, patients present with flu-like symptoms typically non-specific, with mild respiratory symptoms identified as most common in some cases, while other symptoms included rash, malaise, fever, and myalgia [12, 13]. Approximately 70% of the SARS-CoV patients experience shortness of breath and lingering or persistent fever, while clinical improvements were observed in 30% patients after the first week [14]. Intensive care treatments such mechanical ventilation was required by about 20 to 30% of SARS-CoV patients [14, 15]. Individuals 12 years of age and younger displayed limited severe disease manifestations [6, 13, 16]. Prognostic studies indicate greater risk of severe outcomes associated with increased age, high pulse, and lactate dehydrogenase (LDH) levels [7, 17, 18].

*Severe Acute Respiratory Syndromes and Coronaviruses (SARS-CoV, MERS-CoV… DOI: http://dx.doi.org/10.5772/intechopen.97564*
