SARS
Severe acute respiratory syndrome (SARS) is a human viral respiratory disease caused by a coronavirus, called SARS-associated coronavirus (SARS-CoV). SARS was first reported in Southern China in November 2002 and was transported to other Asian regions and the world over the next few months. There has been no contestable statistics on the 2002-2003 pandemic outbreak, and on July 13, 2003, the last probable documented cases were a total of 8,096 with 774 deaths. [1] Albeit the mortality rate is not low, the overall morbidity statistics with zoonotic origin theorization did not catch the attentions SARS-CoV viruses deserve until SARS-CoV-2 hit in 2019, with COVID-19 the 3rd leading cause of death the following year in 2020. [2] [3]
Epidemiology
Symptoms
In general, SARS begins with a high fever with a temperature greater than 38.0°C (100.4°F). Other symptoms may include headache, an overall feeling of discomfort, body aches, and mild respiratory symptoms at the outset. About 10 to 20 percent of patients have diarrhea. After 2 to 7 days, SARS patients may develop a dry cough. Most patients develop pneumonia.
Transmission
The main way that SARS seems to spread is by close person-to-person contact. In the context of SARS, close contact means having cared for or lived with someone with SARS or having direct contact with respiratory secretions or body fluids of a patient with SARS. Examples of close contact include kissing or hugging, sharing eating or drinking utensils, talking to someone within 3 feet, and touching someone directly. Close contact does not include activities like walking by a person or briefly sitting across a waiting room or office. The virus that causes SARS is thought to be transmitted most readily by respiratory droplets (droplet spread) produced when an infected person coughs or sneezes. Droplet spread can happen when droplets from the cough or sneeze of an infected person are propelled a short distance (generally up to 3 feet) through the air and deposited on the mucous membranes of the mouth, nose, or eyes of persons who are nearby. The virus also can spread when a person touches a surface or object contaminated with infectious droplets and then touches his or her mouth, nose, or eye(s). In addition, it is possible that the SARS virus might spread more broadly through the air (airborne spread).
Virology
In 2004, Xue Wu Zhang and Yee Leng Yap noticed the structural similarities between SARS-CoV's Spike (S) 2 protein and Human Immunodeficiency Virus Type 1 (HIV-1) gp41 protein. It is still believed that the S1 and S2 proteins are the common structural features in coronavirus. [4]
References
- ↑ Cherry, J. D. (2004). The chronology of the 2002–2003 SARS mini pandemic. Paediatr. Respir. Rev., 5(4): 262–269. DOI: 10.1016/j.prrv.2004.07.009, PMID: 15531249, PMCID: PMC7106085
- ↑ Sheahan, T., Rockx, B., Donaldson, E., et al. (2008). Mechanisms of Zoonotic Severe Acute Respiratory Syndrome Coronavirus Host Range Expansion in Human Airway Epithelium. J. Virol., 82(5): 2274–2285. DOI: 10.1128/JVI.02041-07, PMID: 18094188, PMCID: PMC2258931
- ↑ National Center for Health Statistics (2022). 2020 Final Death Statistics: COVID-19 as an Underlying Cause of Death vs. Contributing Cause. Centers for Disease Control and Prevention.
- ↑ Zhang, X. W. & Yap, Y. L. (2004). Structural similarity between HIV-1 gp41 and SARS-CoV S2 proteins suggests an analogous membrane fusion mechanism. Journal of Molecular Structure: THEOCHEM, 677(1): 73-76. DOI: 10.1016/j.theochem.2004.02.018, PMID: 32287546, PMCID: PMC7141560