What is the difference between SARS AND MERS?
Answers
Answer:
Explanation: Abstract
Within two decades, there have emerged three highly pathogenic and deadly human coronaviruses, namely SARS-CoV, MERS-CoV and SARS-CoV-2. The economic burden and health threats caused by these coronaviruses are extremely dreadful and getting more serious as the increasing number of global infections and attributed deaths of SARS-CoV-2 and MERS-CoV. Unfortunately, specific medical countermeasures for these hCoVs remain absent. Moreover, the fast spread of misinformation about the ongoing SARS-CoV-2 pandemic uniquely places the virus alongside an annoying infodemic and causes unnecessary worldwide panic. SARS-CoV-2 shares many similarities with SARS-CoV and MERS-CoV, certainly, obvious differences exist as well. Lessons learnt from SARS-CoV and MERS-CoV, timely updated information of SARS-CoV-2 and MERS-CoV, and summarized specific knowledge of these hCoVs are extremely invaluable for effectively and efficiently contain the outbreak of SARS-CoV-2 and MERS-CoV. By gaining a deeper understanding of hCoVs and the illnesses caused by them, we can bridge knowledge gaps, provide cultural weapons for fighting and controling the spread of MERS-CoV and SARS-CoV-2, and prepare effective and robust defense lines against hCoVs that may emerge or reemerge in the future. To this end, the state-of-the-art knowledge and comparing the biological features of these lethal hCoVs and the clinical characteristics of illnesses caused by them are systematically summarized in the review.
Background
Coronaviruses (CoVs) refer to a family of enveloped, positive-sense, single-stranded, and highly diverse RNA viruses [1]. There are four genera (alpha, beta, gamma, and delta), among which α-coronavirus and β-coronavirus attract more attention because of their ability to cross animal-human barriers and emerge to become major human pathogens [2]. So far, there are seven documented human coronaviruses (hCoVs), including the beta-genera CoVs, namely Severe Acute Respiratory Syndrome (SARS)-CoV (SARS-CoV), Middle East Respiratory Syndrome (MERS)-CoV (MERS-CoV), SARS-CoV hCoV-HKU1, and hCoV-OC43 and the α-genera CoVs, which are hCoV-NL63 and hCoV-229E, respectively [1, 3].
Although hCoV-HKU1, hCoV-OC43, hCoV-NL63 and hCoV-229E mainly cause asymptomatic or mild respiratory and gastrointestinal infections, they have been circulating in humans since they were recognized, and accounting for approximately 5–30% of common colds. Nonetheless, we have not treated hCoVs seriously until we witnessed the global epidemic caused by SARS-CoV and realized how devastating outcomes it brought to us [1]. To date, there have been three documented highly pathogenic and lethal hCoVs, namely SARS-CoV, MERS-CoV and SARS-CoV-2, because of their dreadful impacts on humans [4]. Unlike other hCoVs, SARS-CoV, MERS-CoV, and SARS-CoV-2 are prone to infect the lower respiratory tract, resulting in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), septic shock and multi-organ failure, with high case fatality ratio (CFR) [5]. As shown in Table 1, SARS-CoV first emerged in Foshan, China in November 2002 [16], and was subsequently transported to Hong Kong in February 2003, from where it spread globally [10]. The epidemic was finally contained in July 2003 as the transmission chain of SARS-CoV in Taiwan was interrupted [10, 17]. There were four instances of SARS reemergence that occurred chronologically in Singapore, Taipei, Guangdong and Beijing afterwards [10, 18]. No more infected human cases have been reported since May 2004. However, another deathful hCoV emerges only a decade later. MERS-CoV first occurred in April 2012 in Jordan [19] and has been causing persistent endemics in countries within and sporadically spreading to countries outside the Middle East regions [13]. The most recent laboratory-confirmed patients were reported by Riyadh on 28 March 2020 [20]. SARS-CoV-2 has emerged while humans continue to be threatened by MERS-CoV [21]. SARS-CoV-2 first occurred in Wuhan, China in December 2019 and it swiftly spread across China and has been aggressively infecting people globally. It was documented as a public health emergency of international concern and a pandemic on 30 January and 11 March 2020, respectively, making SARS-CoV-2 the first hCoV to cause a pandemic [6, 7]. Uniquely, the recent ongoing pandemic is accompanied by an infodemic, which has caused additional worldwide panic [22]
thanks.
Taxonomically, SARS-CoV-2 is a strain of severe acute respiratory syndrome-related coronavirus (SARSr-CoV). It is believed to have zoonotic origins and has close genetic similarity to bat coronaviruses, suggesting it emerged from a bat-borne virus.Six species of human coronaviruses are known, with one species subdivided into two different strains, making seven strains of human coronaviruses altogether.Coronaviruses are large group of viruses that cause illness in humans and animals. Rarely, animal coronaviruses can evolve and infect people and then spread between people such as has been seen with MERS and SARS.
Although most human coronavirus infections are mild, the epidemics of the severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), have caused more than 10,000 cumulative cases in the past two decades, with mortality rates of 10% for SARS-CoV.