Severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1; or Severe acute respiratory syndrome coronavirus, SARS-CoV) is a

strain Strain may refer to: Science and technology * Strain (biology), variants of plants, viruses or bacteria; or an inbred animal used for experimental purposes * Strain (chemistry), a chemical stress of a molecule * Strain (injury), an injury to a mu ...

coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the com ...

that causes

severe acute respiratory syndrome Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), the first identified strain of the SARS coronavirus species, ''seve ...

(SARS), the

respiratory illness Respiratory diseases, or lung diseases, are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, bron ...

responsible for the

2002–2004 SARS outbreak The 2002–2004 outbreak of SARS, caused by severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), infected over 8,000 people from 29 countries and territories, and resulted in at least 774 deaths worldwide. The outbreak wa ...

. It is an enveloped,

positive-sense In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context ...

single-stranded When referring to DNA transcription, the coding strand (or informational strand) is the DNA strand whose base sequence is identical to the base sequence of the RNA transcript produced (although with thymine replaced by uracil). It is this stra ...

RNA virus An RNA virus is a virusother than a retrovirusthat has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA ( ssRNA) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses ...

that infects the

epithelial cells Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercell ...

within the lungs. The virus enters the host cell by binding to

angiotensin-converting enzyme 2 Angiotensin-converting enzyme 2 (ACE2) is an enzyme that can be found either attached to the membrane of cells (mACE2) in the intestines, kidney, testis, gallbladder, and heart or in a soluble form (sACE2). Both membrane bound and soluble ACE2 a ...

. It infects

humans Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

bats Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bi ...

, and palm civets. On April 16, 2003, following the outbreak of SARS in

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

and secondary cases elsewhere in the world, the

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...

(WHO) issued a press release stating that the

identified by a number of laboratories was the official cause of SARS. The

Centers for Disease Control and Prevention The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...

(CDC) in the United States and the

National Microbiology Laboratory The National Microbiology Laboratory (NML) is part of the Public Health Agency of Canada (PHAC), the agency of the Government of Canada that is responsible for public health, health emergency preparedness and response, and infectious and chronic ...

(NML) in Canada identified the SARS-CoV-1

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...

in April 2003. Scientists at

Erasmus University Erasmus University Rotterdam (abbreviated as ''EUR'', nl, Erasmus Universiteit Rotterdam ) is a public research university located in Rotterdam, Netherlands. The university is named after Desiderius Erasmus Roterodamus, a 15th-century humanist ...

Rotterdam Rotterdam ( , , , lit. ''The Dam on the River Rotte'') is the second largest city and municipality in the Netherlands. It is in the province of South Holland, part of the North Sea mouth of the Rhine–Meuse–Scheldt delta, via the ''"N ...

, the Netherlands, demonstrated that the SARS coronavirus fulfilled

Koch's postulates Koch's postulates ( )"Koch"
''

macaques infected with the virus developed the same symptoms as human SARS patients. A virus very similar to SARS was discovered in late 2019. This virus, named

severe acute respiratory syndrome coronavirus 2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a No ...

(SARS-CoV-2), is the causative

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December ...

, the propagation of which started the

COVID-19 pandemic The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identif ...

SARS

Severe acute respiratory syndrome Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), the first identified strain of the SARS coronavirus species, ''seve ...

(SARS) is the disease caused by SARS-CoV-1. It causes an often severe illness and is marked initially by systemic symptoms of

muscle pain Myalgia (also called muscle pain and muscle ache in layman's terms) is the medical term for muscle pain. Myalgia is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another like ...

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

, and

fever Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...

, followed in 2–14 days by the onset of respiratory symptoms, mainly cough,

dyspnea Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathing, breathe well enough. The American Thoracic Society defines it as "a subjective experience of brea ...

, and

pneumonia Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...

. Another common finding in SARS patients is a decrease in the number of lymphocytes circulating in the blood. In the SARS outbreak of 2003, about 9% of patients with confirmed SARS-CoV-1 infection died. The mortality rate was much higher for those over 60 years old, with mortality rates approaching 50% for this subset of patients.

Origin and evolutionary history

In March 2003, WHO established a global network of leading laboratories to collaborate in the identification of the causative agent of SARS. Early on, labs in the network narrowed the search to members of the paramyxovirus and coronavirus families. Early findings shared by the labs pointed to coronaviruses with increasing consistency. On 21 March, scientists from the

University of Hong Kong The University of Hong Kong (HKU) (Chinese: 香港大學) is a public research university in Hong Kong. Founded in 1887 as the Hong Kong College of Medicine for Chinese, it is the oldest tertiary institution in Hong Kong. HKU was also the fi ...

announced the isolation of a new virus that was strongly suspected to be the causative agent of SARS. Epidemiological evidence suggested a

zoonotic A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human. ...

origin of the virus: more than 33% of the first detected cases of SARS in Guangdong corresponded to animal or food handlers. Seroprevalence studies reinforced this zoonotic link (a high proportion of asymptomatic animal handlers at markets in Guangdong Province had antibodies against SARS-CoV). On April 12, 2003, scientists working at the Michael Smith Genome Sciences Centre in

Vancouver Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the ...

finished mapping the

genetic sequence A nucleic acid sequence is a succession of bases signified by a series of a set of five different letters that indicate the order of nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. By convention, sequences are usua ...

of a coronavirus believed to be linked to SARS. The team was led by

Marco Marra Marco A. Marra is a Distinguished Scientist and Director of Canada's Michael Smith Genome Sciences Centre at the BC Cancer Research Institute and Professor of Medical Genetics at the University of British Columbia (UBC). He also serves as UBC Can ...

and Caroline Astell and worked in collaboration with the

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

Centre for Disease Control and the

Winnipeg Winnipeg () is the capital and largest city of the province of Manitoba in Canada. It is centred on the confluence of the Red and Assiniboine rivers, near the longitudinal centre of North America. , Winnipeg had a city population of 749,6 ...

Manitoba Manitoba ( ) is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population o ...

, using samples from infected patients in

Toronto Toronto ( ; or ) is the capital city of the Canadian province of Ontario. With a recorded population of 2,794,356 in 2021, it is the most populous city in Canada and the fourth most populous city in North America. The city is the ancho ...

. The map, hailed by the WHO as an important step forward in fighting SARS, is shared with scientists worldwide via the GSC website (see below).

Donald Low Donald Low (May 2, 1945 - September 18, 2013) was a Canadian microbiologist noted for his role in battling the SARS outbreak of 2003. He was microbiologist-in-chief at Mount Sinai Hospital, Toronto, from 1985 to 2013. Low graduated from medical s ...

of Mount Sinai Hospital in Toronto described the discovery as having been made with "unprecedented speed". The sequence of the SARS coronavirus has since been confirmed by other independent groups. Molecular epidemiological research demonstrated the virus isolated in 2002–2003 in south China and the virus isolated in the same area in late 2003 and early 2004 are different, indicating separate species-crossing events. The phylogeny of the outbreak strains shows that the southwestern provinces including Yunnan, Guizhou and Guangxi compare to the human SARS-CoV-1 better than those of the other provinces, but the viruses' evolution is a product of the host interaction and particularity. In late May 2003, studies from samples of wild animals sold as food in the local market in

Guangdong Guangdong (, ), alternatively romanized as Canton or Kwangtung, is a coastal province in South China on the north shore of the South China Sea. The capital of the province is Guangzhou. With a population of 126.01 million (as of 2020) ...

, China, found a strain of SARS coronavirus could be isolated from

masked palm civet The masked palm civet (''Paguma larvata''), also called the gem-faced civet, is a palm civet species native to the Indian subcontinent and Southeast Asia. It has been listed as least concern on the IUCN Red List since 2008 as it occurs in many p ...

s (''Paguma'' sp.), but the animals did not always show clinical signs. The preliminary conclusion was the SARS virus crossed the

xenographic Xenotransplantation (''xenos-'' from the Greek meaning "foreign" or strange), or heterologous transplant, is the transplantation of living cells, tissues or organs from one species to another. Such cells, tissues or organs are called xenograft ...

barrier from palm civet to humans, and more than 10,000 masked palm civets were killed in Guangdong Province. The virus was also later found in

raccoon dog The common raccoon dog (''Nyctereutes procyonoides''), also called the Chinese or Asian raccoon dog, is a small, heavy-set, fox-like canid native to East Asia. Named for its raccoon-like face markings, it is most closely related to foxes. Common ...

s (''Nyctereuteus'' sp.),

ferret badger Ferret-badgers are the six species of the genus ''Melogale'', which is the only genus of the monotypic mustelid subfamily Helictidinae. * Bornean ferret-badger (''Melogale everetti'') * Chinese ferret-badger (''Melogale moschata'') *Formosan fer ...

s (''Melogale'' spp.), and domestic cats. In 2005, two studies identified a number of SARS-like coronaviruses in Chinese

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most ...

s. Although the bat SARS virus did not replicate in cell culture, in 2008, American researchers altered the genetic structure of bat SARS virus with the human receptor binding domain both in the bat virus and in the mice which demonstrated how

zoonosis A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human. ...

might occur in evolution. Phylogenetic analysis of these viruses indicated a high probability that SARS coronavirus originated in bats and spread to humans either directly or through animals held in Chinese markets. The bats did not show any visible signs of disease, but are the likely natural reservoirs of SARS-like coronaviruses.

Intermediate host

In 2004, scientists from the

Chinese Center for Disease Control and Prevention The Chinese Center for Disease Control and Prevention (CCDC; ) is an institution directly under the National Health Commission, based in Changping District, Beijing, China. Established in 1983, it works to protect public health and safety ...

of the

and the

Guangzhou Guangzhou (, ; ; or ; ), also known as Canton () and alternatively romanized as Kwongchow or Kwangchow, is the capital and largest city of Guangdong province in southern China. Located on the Pearl River about north-northwest of Hong Kon ...

Center for Disease Control and Prevention established a genetic link between the SARS coronavirus appearing in civets and humans, confirming claims that the virus had jumped across species.

Phylogenetic

Bats are likely to be the natural reservoir, that is, the host that harbored the pathogen but that does not show ill effects and serves as a source of infection. No direct progenitor of SARS-CoV was found in bat populations, but WIV16 was found in a cave in

Xiyang Yi Ethnic Township Xiyang Yi Ethnic Township (Yi script:?, ) is an ethnic township in Jinning District, Yunnan. Demographics and Languages Among its 10,155 residents, 78% (7,921) are ethnic minorities in China, chiefly Yi people (Lolo) and Hani people, as of 2006. ...

, Yunnan, China between 2013 and 2016, and has a 96% genetically similar virus strain. The hypothesis that SARS-CoV-1 emerged through recombinations of bat SARSr-CoVs in the Yunnan cave of WIV16 or in other yet-to-be-identified bat caves is considered highly likely.

Virology

SARS-CoV-1 follows the replication strategy typical of the

subfamily. The primary human receptor of the virus is

(ACE2) and hemaglutinin (HE), first identified in 2003. Human SARS-CoV-1 appears to have had a complex history of recombination between ancestral

es that were hosted in several different animal groups.Zhang XW, Yap YL, Danchin A. Testing the hypothesis of a recombinant origin of the SARS-associated coronavirus. Arch Virol. 2005 Jan;150(1):1–20. Epub 2004 Oct 11. In order for recombination to happen at least two SARS-CoV-1

s must be present in the same host cell. Recombination may occur during genome replication when the

RNA polymerase In molecular biology, RNA polymerase (abbreviated RNAP or RNApol), or more specifically DNA-directed/dependent RNA polymerase (DdRP), is an enzyme that synthesizes RNA from a DNA template. Using the enzyme helicase, RNAP locally opens the ...

switches from one template to another (copy choice recombination). SARS-CoV-1 is one of seven known coronaviruses to infect humans. The other six are: * Human coronavirus 229E (HCoV-229E) * Human coronavirus NL63 (HCoV-NL63) * Human coronavirus OC43 (HCoV-OC43) * Human coronavirus HKU1 (HCoV-HKU1) * Middle East respiratory syndrome–related coronavirus (MERS-CoV) * Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Biosafety

The SARS outbreak raised biosafety concerns among the biotechnology community and, specifically, the question of risk assessment regarding the contained use of SARS-CoV for laboratory work. Since this event, China has been making efforts to regulate safely the activities conducted in high-level biosafety laboratories, enacting some laws and decrees in this regard.

References

Citations

Sources

* * * * * * *

External links

WHO press release identifying and naming the SARS virus

The SARS virus genetic map

''Science'' special on the SARS virus
(free content: no registration required) *
U.S. Centers for Disease Control and Prevention (CDC) SARS home

World Health Organization on alert
{{DEFAULTSORT:Severe acute respiratory syndrome coronavirus SARS-related coronavirus Infraspecific virus taxa Chiroptera-borne diseases Severe acute respiratory syndrome