<\/span><\/h2>\n\n\n\nSARS-CoV-1 are betacoronavirus (order Nidovirales<\/em>)\nthat are enveloped and pleomorphic. Its positive-sense single-stranded genomic\nRNA of 26-32kb is encapsulated by helical nucleocapsid, surrounded by a viral\nenvelope containing envelope (E), spike (S) and transmembrane (M) proteins\n(Perlman and Netland, 2009). Spike proteins interact with\nangiotensin-converting-enzyme-2 (ACE2) receptor, found abundantly on epithelial\ncells of the respiratory tract, for the entry and pathogenesis of SARS-CoV-1\n(Jia et al., 2005).<\/p>\n\n\n\n<\/span>Signs and Symptoms<\/span><\/h2>\n\n\n\nThe incubation period of SARS-CoV-1 ranges from\nthree to eleven days (Matteelli and Saleri, 2008). The severity of SARS vary\nwidely among patients. Infected patients generally present with a prodrome of\nnon-specific symptoms such as myalgia, lethargy, malaise and headache, then\nhigh fever and mild respiratory symptoms such as dry cough and dyspnoea (Hsu et\nal., 2003). Gastrointestinal symptoms such as diarrhoea, nausea and vomiting\nmay manifest (Hui, Wong and Wang, 2003). <\/p>\n\n\n\n
In the second week after the onset of initial\nsymptoms, symptoms progress to atypical viral pneumonia, and subsequently to\nsecondary typical bacterial pneumonia. Other disease complications that may\ndevelop during the progression of the disease include acute respiratory\nfailure, acute respiratory distress syndrome (ARDS), sepsis, acute kidney\ninjury and refractory hypoxemia (Hui, Wong and Wang, 2003). Laboratory testing\nrevealed leukopenia, lymphopenia, thrombocytopenia, hypokalemia, hyponatremia,\nelevated creatinine kinase, alanine transaminases and lactate dehydrogenase\nlevels in the serum (Hsu et al., 2003).<\/p>\n\n\n\n
<\/span>Treatment<\/span><\/h2>\n\n\n\nSix out of many tested treatments for SARS were\nshown to have some effect when administered in combination: <\/p>\n\n\n\n
- Antiviral agents such as Ribavirin<\/strong><\/strong><\/li><\/ol>\n\n\n\n
Ribavirin, an\nantiviral agent that prevents viral replication, is a nucleoside analogue that\nwas administered intravenously at 8mg\/kg, thrice a day for 5 days and orally at\n1200mg, thrice a day for the next 5-9 days. However, ribavirin produces adverse\nside-effects such as haemolytic anaemia, hypomagnesaemia and hypocalcaemia.\nFurthermore, its efficacy as a treatment for SARS was controversial (Tai, D.,\n2007). <\/p>\n\n\n\n
- Protease inhibitors such as Kaletra<\/strong><\/strong><\/li><\/ul>\n\n\n\n
Kaletra (400mg\nritonavir and 100mg lopinavir) contains protease inhibitors which inhibits\nvirion assembly (a process of assembly for viruses), preventing the SARS virus\nfrom propagating. When used together with ribavirin for 14 days, it had shown\nimpressive results. Its adverse effects include severe pancreatitis and liver\ndysfunction (Tai, D., 2007). <\/p>\n\n\n\n
- Broad spectrum antivirals such as Interferons<\/strong><\/strong><\/li><\/ul>\n\n\n\n
Interferons (IFN),\nwhich are also produced naturally in the body, are potent broad spectrum\nantivirals. A combination of IFN-\u03b1\n(3 million units\/day) and high corticosteroid dosage (160-1000mg\/day) for 5-14\ndays in the early phase had shown more promising results than ribavirin (Tai,\nD., 2007). <\/p>\n\n\n\n
- Corticosteroids such as Methylprednisolone<\/strong><\/strong><\/li><\/ul>\n\n\n\n
Corticosteroids\nameliorate immune-mediated lung damage caused by cytokine dysregulation.\nCurrent recommendations utilises moderate to high dosage of methylprednisolone\n(250-500mg\/day) for 3-6 days in severely ill patients (Tai, D., 2007). <\/p>\n\n\n\n
Other treatments include immunoglobulins and\nconvalescent-phase plasma (Tai, D., 2007). These treatments are mostly\nsymptomatic, due to the lack of specific effective antiviral therapy. 90% of\nthe patients recover without the administration of antivirals or\ncorticosteroids. Only in critically ill patients were these therapies\nadministered (Tai, D., 2007).<\/p>\n\n\n\n
Prevention<\/p>\n\n\n\n
Prevention measures are similar to that of\nMERS-CoV and COVID-19:<\/p>\n\n\n\n
- Contact tracing<\/li>
- Social distancing<\/li>
- Practising hand and face\nhygiene<\/li>
- Wearing face masks<\/li>
- Quarantine<\/li><\/ul>\n\n\n\n
These measures have to be strictly abided,\notherwise outbreaks are greatly prolonged, causing disproportionately large\nnumbers of infections (3Blue1Brown, 2020).<\/p>\n\n\n\n
References<\/p>\n\n\n\n
- Gu, J. and Korteweg, C., 2007.\nPathology and Pathogenesis of Severe Acute Respiratory Syndrome. The American\nJournal of Pathology, 170(4), pp.1136-1147.<\/li>
- Hsu, L., Lee, C., Green, J.,\nAng, B., Paton, N., Lee, L., Villacian, J., Lim, P., Earnest, A. and Leo, Y.,\n2003. Severe Acute Respiratory Syndrome (SARS) in Singapore: Clinical Features\nof Index Patient and Initial Contacts. Emerging Infectious Diseases<\/em>,\n9(6), pp.713-717.<\/li>
- Hui, D., Wong, P. and Wang, C.,\n2003. SARS: clinical features and diagnosis. Respirology<\/em>, 8(s1),\npp.S20-S24.<\/li>
- Jia, H., Look, D., Shi, L.,\nHickey, M., Pewe, L., Netland, J., Farzan, M., Wohlford-Lenane, C., Perlman, S.\nand McCray, P., 2005. ACE2 Receptor Expression and Severe Acute Respiratory\nSyndrome Coronavirus Infection Depend on Differentiation of Human Airway\nEpithelia. Journal of Virology, 79(23), pp.14614-14621.<\/li>
- Matteelli, A. and Saleri, N.,\n2008. Respiratory Diseases. Travel Medicine, pp.566-567.<\/li>
- Perlman, S. and Netland, J.,\n2009. Coronaviruses post-SARS: update on replication and pathogenesis. Nature\nReviews Microbiology, 7(6), pp.439-450.<\/li>
- 3Blue1Brown, 2020. Simulating\nan epidemic. [online video] Available at:\n<https:\/\/www.youtube.com\/watch?v=gxAaO2rsdIs>. [Accessed 7 April 2020]<\/li>
- Tai, D., 2007. Pharmacologic\nTreatment of SARS: Current Knowledge and Recommendations. Annals Academy of Medicine\nSingapore, [online] 36(6), pp.438-443. Available at:\n<http:\/\/www.annals.edu.sg\/pdf\/36VolNo6Jun2007\/V36N6p438.pdf> [Accessed 7\nApril 2020].<\/li>
- WHO, 2003. Consensus Document\nOn The Epidemiology Of Severe Acute Respiratory Syndrome (SARS). [online] Available\nat: <https:\/\/www.who.int\/csr\/sars\/en\/WHOconsensus.pdf> [Accessed 7 April\n2020].<\/li><\/ol>\n\n\n\n
This article is contributed by Goh Jun Hong from MDIS School of Life Sciences<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Severe Acute Respiratory Syndrome (SARS) is a viral respiratory disease caused by SARS-CoV-1. First reports of the SARS outbreak began at Foshan in the Guangdong province of southern China in November 2002. The last confirmed case was reported in May 2004. The total number of cases tallied up to 8098 with 774 deaths and a 9.6% fatality rate (Gu and Korteweg, 2007). The disease had affected 29 different countries (Matteelli and Saleri, 2008). Table of Contents TransmissionStructureSigns and SymptomsTreatment Transmission SARS-CoV-1 originated from horseshoe bats in Yunnan province of China, through the intermediate palm civet hosts, and cross-infected humans. SARS-CoV-1 […]<\/p>\n","protected":false},"author":283,"featured_media":2478,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[13],"tags":[],"_links":{"self":[{"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/posts\/2477"}],"collection":[{"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/users\/283"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/comments?post=2477"}],"version-history":[{"count":2,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/posts\/2477\/revisions"}],"predecessor-version":[{"id":4443,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/posts\/2477\/revisions\/4443"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/media\/2478"}],"wp:attachment":[{"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/media?parent=2477"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/categories?post=2477"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mdis.edu.sg\/blog\/wp-json\/wp\/v2\/tags?post=2477"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}